Nuova ricerca

Daniela PREVEDELLI

Professore Ordinario presso: Dipartimento di Scienze della Vita sede ex-Biologia


Home | Curriculum(pdf) | Didattica |


Pubblicazioni

2020 - A Chemical and Ecological Approach Sheds Light on the Urticating System of Marine Fireworms [Abstract in Atti di Convegno]
RIGHI, SARA; SAVIOLI, MARTINA; FORTI, Luca; PREVEDELLI, Daniela; SIMONINI, Roberto
abstract

Marine fireworms (Annelida, Amphinomidae) hold stinging dorsal bristles (chaetae) that cause injuries to divers and bathers. Hermodice carunculata is the most notorious species and it has recently attracted interest as a potentially invasive fireworm with few predators and uncharacterized defensive capacities. To date, the only acute inflammation inducer isolated from an amphinomid is “complanine”, a trimethylammonium compound. The main goal of this study was to promote an ecological understanding of H. carunculata defences through a multidisciplinary approach. The occurrence of complanine within tissues and its mode of delivery were assessed combining chromatographic steps and high resolution LC-MS/MS. The exact mass and retention time of complanine were detected in the extracts of the main ectodermal (dorsal body wall, gills, dorsal chaetae, ventral chaetae) and endodermal (gut, pharynx) tissues of H. carunculata. The role of complanine in trophic interactions was assessed offering the ectodermal tissues towards a predator (the fish Chromis viridis) and two relevant prey species (the anemones Anemonia viridis and Aiptasia diaphana). Only the dorsal chaetae were effective against predators and prey: they strongly deterred fishes and induced paralysis in the anemone tentacles. Dorsal chaetae treated with organic solvents lost their deterrence against fish predators and an inner hollow cavity suitable to vehicle toxins could be viewed by ESEM. These findings support a synergy between the mechanical injury of dorsal chaetae penetration and the release of complanine. This unique feature could support the success of fireworms in marine benthic environments and significantly improves knowledge on the chemical ecology of amphinomids.


2019 - Ecotoxicity of hallachrome, an unusual 1-2 anthraquinone excreted by the infaunal polychaete Halla parthenopeia: evidence for a chemical defence? [Articolo su rivista]
Simonini, R; Iori, D; Forti, L; Righi, S; Prevedelli, D
abstract

Polychaetes play a prominent role in marine systems, but little is known about their secondary metabolites compared with other benthic taxa. In the present study, we investigated the toxicity of hallachrome, an unusual 1-2 anthraquinone identified from the skin of some polychaetes, including the Mediterranean infaunal species Halla parthenopeia. Under stress conditions, this worm releases a harmful purple mucus, whose noxious compounds were still unknown. We hypothesized that hallachrome also occurs in the purple mucus, giving rise to its color and toxicity. Soon after the production of the purple exudate, H. parthenopeia also secretes a harmless, transparent mucus, which pushes away the toxic one, suggesting protective functions for the worm itself. LC-MS and H-1-NMR analyses confirmed the presence of the pigment hallachrome in the purple mucus. The average concentration of the pigment in the purple mucus was about 310 mg L-1. Ecotoxicological bioassays on representative species of bacteria, protozoans, rotifers, crustaceans (Artemia franciscana) and polychaetes (Dinophilus gyrociliatus) revealed its severe toxic effects: LC50/EC(50)values ranged from 0.11-5.67 mg L-1. Hallachrome showed higher toxicity for A. franciscana than other naturally occurring anthraquinones. Tests on encapsulated embryos of D. gyrociliatus evidenced the ability of a mucus layer to limit hallachrome diffusion, confirming the protective role of the transparent mucus. Given the information available on polychaetes anti-predator strategies, hallachrome cannot be considered a consumer deterrent. However its toxicity and wide range of activity suggest chemical defensive functions against potential competitors, parasites and/or pathogens.


2019 - Esemplari mediterranei del verme di fuoco Hermodice carunculata (Annelida) catalogati nelle raccolte zoologiche di musei europei [Articolo su rivista]
Simonini, Roberto; Prevedelli, Daniela; Righi, Sara
abstract

L’espansione delle popolazioni del verme di fuoco Hermodice carunculata (Annelida: Amphinomidae) potrebbe influenzare gli ecosistemi costieri a fondo roccioso, ma le conoscenze attuali sulla distribuzione di questa specie in Mediterraneo sono scarse. In questo lavoro sono stati censiti gli esemplari di H. carunculata raccolti nel Mar Mediterraneo presenti nei cataloghi di musei italiani e esteri, con l’obiettivo di ottenere una prima ricostruzione dell’areale storico della specie. I campioni più antichi risalgono al XIX secolo e sono depositati presso i musei di Storia Naturale di Berlino, Parigi e Vienna. Questi esemplari erano originari di Sicilia, Grecia e Vicino Oriente, tutte zone che anche oggi ospitano dense popolazioni di vermi di fuoco. I campioni conservati presso il Museo della Stazione Zoologica “Anton Dohrn”, raccolti a cavallo del XX secolo nel Golfo di Napoli, permettono di fissare il limite settentrionale delle specie nel Mare Tirreno. Le informazioni dedotte dalle collezioni museali, insieme a ricerche bibliografiche, questionari, monitoraggi e analisi molecolari permetteranno di studiare la biogeografia di H. carunculata e di evidenziare o prevedere potenziali spostamenti verso i poli in risposta al riscaldamento del Mediterraneo.


2019 - Morphometric and molecular characterization of an expanding Ionian population of the fireworm Hermodice carunculata (Annelida) [Articolo su rivista]
Righi, S.; Maletti, I.; Maltagliati, F.; Castelli, A.; Barbieri, M.; Fai, S.; Prevedelli, D.; Simonini, R.
abstract

The amphinomid fireworm Hermodice carunculata is a potentially invasive species reported throughout the subtropical Atlantic Ocean and the Mediterranean Sea, which is known as a generalist predator and opportunistic feeder. The ongoing climate changes and seawater warming may favour fireworm poleward range expansions and density increases. Our results provide the first investigation into a population which has purportedly been spreading widely in the Salento Peninsula (Apulia, Italy). The specimens were analysed using allometric variables and molecular markers. The best morphometric parameters to estimate individual size were determined as key information for future studies on fireworm population dynamics. To phylogeographically characterize the Apulian population, sequences of the mitochondrial COI and 16S rDNA regions were obtained from a pool of individuals and treated together with those of Atlantic specimens retrieved from GenBank. The estimates of genetic variability for Apulian population were consistent with those recently reported in the literature. Inferences on demographic history analysis confirmed a recent expansion event in Apulia, as has been recounted by fishermen and scuba divers during recent years. Overall, these results constitute a crucial step in the characterization of present-day H. carunculata populations, and provide greater insight into fireworm population ecology.


2018 - Caratteri morfometrici di una popolazione ionica del verme di fuoco Hermodice carunculata (Annelida, Amphinomidae) [Articolo su rivista]
Righi, S.; Maletti, I.; Simonini, R.; Fai, S.; Tessari, V.; Prevedelli, D.
abstract

We measured different allometric traits (body length, weight, number of segments and width) of bearded fireworms (Hermodice carunculata) from Porto Cesareo (LE). Correlation and regression analyses suggested the existence of significant and statistically positive relationships among traits. A few studies have dealt with Mediterranean fireworm biology and these results are important contributions to investigate fireworm population dynamic.


2018 - Evaluation of different procedures for fertilization and larvae production in Hediste diversicolor (O.F. Müller, 1776) (Nereididae, Polychaeta) [Articolo su rivista]
Nesto, Nicoletta; Simonini, Roberto; Prevedelli, Daniela; Da Ros, Luisa
abstract

Different experimental trials were performed to clarify some aspects of the biology of the polychaete Hediste diversicolor (O.F. Müller, 1776) as a further step towards the development of appropriate breeding protocols for indoor farming systems. In particular, the trials were addressed to evaluate the effectiveness of two fertilization conditions (in vitro and "natural-like"); induce gamete spawning by exposing mature individuals to thermal shock or to tissue homogenates; estimate the density effects on larval growth and survival; and evaluate the most suitable parameters to be used as proxy for biomass assessment. The highest percentages of fertilized eggs and larvae were obtained by the in vitro fertilization condition. Mature organisms were induced to spawn by exposure to thermal shock although the spawned eggs revealed low rates of fertilization and hatching. The treatment with male tissue homogenates induced females to successful spawning, and the resulting eggs showed high fertilization and hatching rates. The density of larvae in the rearing phase had no effect on growth or on survival rates of juveniles. Finally, allometric evaluations showed that fresh weight and L3 length are the most reliable parameters to be used as proxy for biomass assessment of this species.


2018 - Laboratory observations on predator–prey interactions between the bearded fireworm (Hermodice carunculata) and Mediterranean benthic invertebrates [Articolo su rivista]
Simonini, Roberto; Maletti, Isabella; Righi, Sara; Fai, Sergio; Prevedelli, Daniela
abstract

The bearded fireworm (Hermodice carunculata) is an amphinomid polychaete with a circumtropical Atlantic-Mediterranean distribution. In the Mediterranean Sea, very little information is available on its feeding habits and ecological functions. Here, its increasing abundance and the ability to actively prey on a keystone sea urchin species suggest potential repercussions for the structure and functioning of benthic communities. We performed laboratory feeding experiments to investigate interactions between Mediterranean H. carunculata and 12 species of sessile or sedentary invertebrates. H. carunculata preyed efficiently on 9 of the species offered. In particular, active predation of a polychaete upon nudibranchs, colonial ascidians and chitons was reported for the first time. Fireworms’ predatory ability may be due to a combination of several ‘weapons’ (large size, motility, stinging chaetae and eversible, sucking pharynx) which seems to be unique among marine worms, and could enable H. carunculata to persist also after radical changes in prey community composition and withstand selective pressures associated with ongoing environmental changes.


2017 - Bearded versus thorny: The fireworm Hermodice carunculata preys on the sea urchin Paracentrotus lividus [Articolo su rivista]
Simonini, Roberto; Righi, Sara; Maletti, Isabella; Fai, Sergio; Prevedelli, Daniela
abstract

The bearded fireworm, Hermodice carunculata (Polychaeta: Amphinomidae) has rapidly increased in abundance in Mediterranean infralittoral rocky habitats. We have recently observed the bearded fireworm preying on the sea urchin Paracentrotus lividus, which is a major determinant of algal community structure in this system. To document the full sequence of behaviors in an attack, we observed interactions between H. carunculata and P. lividus under controlled conditions in the lab. Upon a fortuitous contact, a fireworm rapidly initiated an attack on the urchin, everting its pharynx over it and starting to suck and ingest the spines. The attack forced the detachment of the urchin from the substrate and the exposure of its oral side. Then, the fireworm moved toward the urchin mouth, placed its buccal mass over the Aristotle's lantern (the large powerful urchin “jaw”), removed it with a suction generated by the pharyngeal musculature and entered the test. When an increase in P. lividus mortality caused by predation occurs, a top–down control of communities may take place, triggering different habitat formation (algal forest vs. barren). Further research on the effects of the predation of the bearded fireworm on urchin populations is required to assess their potential repercussions for the structure and functioning of Mediterranean rocky reef ecosystem.


2017 - PREDAZIONE ATTIVA DI HERMODICE CARUNCULATA (ANNELIDA) SU PARACENTROTUS LIVIDUS (ECHINOIDEA) [Articolo su rivista]
Righi, Sara; Fai, S.; Maletti, I.; Simonini, R.; Prevedelli, D.
abstract

Fieldwork and laboratory observations evidenced the ability of the polychaete Hermodice carunculata to actively prey on the sea urchin Paracentrotus lividus, turning it upside down and penetrating inside the test through ingestion of the Aristotle’s lantern. A relationship between sea urchins size and frequency of predation events seems to occur. Further researches should be necessary to determine potential effects of H. carunculata on sea urchin at the level of population


2017 - Predazione di Hermodice carunculata (Annelida: Amphinomidae) su esacoralli (Anthozoa) [Articolo su rivista]
Maletti, I.; Simonini, R.; Righi, S.; Fai, S.; Prevedelli, D.
abstract

The ability of the polychaete Hermodice carunculata to prey on some species of hexacorals was assessed through laboratory feeding experiments. Soft corals and sea anemones were almost completely consumed, while the carbonatic skeleton of hard corals seems to discourage polychaetes from consumption. The results highlighted the capacity of Mediterranean H. carunculata to prey on a wide range of anthozoans.


2017 - Valutazione delle capacità deterrenti delle chete di Hermodice carunculata (Annelida: Amphinomidae) [Articolo su rivista]
Simonini, R.; Fai, S.; Prevedelli, D.; Maggggioni, F.
abstract

The deterrence of the bristles (washed or not with organic solvents) of the polychaete Hermodice carunculata was assessed through palatability tests with the fish Chromis viridis as consumer. Artificial baits containing the unwashed notochaete were always rejected by C. viridis. The treatment with organic solvents reduced the deterrence of the notochaete. These results suggested the involvement of secondary metabolites in the defences of Hermodice carunculata.


2016 - Checklist of benthic macroinvertebrates of the Lago Pratignano (northern Apennines, Italy): an extremely rich ecosystem [Articolo su rivista]
Ansaloni, Ivano; Prevedelli, Daniela; Ruocco, Matteo; Simonini, Roberto
abstract

A checklist of the macroinvertebrates fauna of the Lago Pratignano is presented here. The Lago Pratignano is a small, natural water body of the high (1,307 m above sea level) Northern Apennines, Italy. It represents an important site for the conservation of endangered flora and amphibians, and its importance for the conservation of the macroinvertebrate fauna is highlighted. The 82 taxa recorded make it an extremely rich habitat. The most represented group was Diptera, with 31 taxa, followed by Coleoptera, with nine, and Oligochaeta and Arachnida, each with eight taxa. Other groups are present in lower numbers. Despite the scant attention to theP study of the macroinvertebrates of small lentic habitats in the Northern Apennines, their importance for the conservation of the invertebrate fauna and the high contribution they give to the biodiversity is highlighted here.


2016 - Palatabilità di diverse parti del corpo di Hermodice carunculata (Pallas, 1766) (Annelida: Amphinomidae) [Articolo su rivista]
Simonini, Roberto; Fai, S.; Righi, S.; Prevedelli, Daniela
abstract

The palatability of different parts of the polychaete Hermodice carunculata was assessed using the fish Chromis viridis as consumer. The feeding responses of C. viridis were highly reproducible. Pieces of the body wall, branchiae, and parapodia from which bristles were removed were promptly consumed. Conversely, whole notopodia with bristles strongly deterred the consumer feeding.


2016 - Predation on Anemonia viridis (Actiniaria) by Hermodice carunculata (Annelida: Amphinomidae): preliminary data [Articolo su rivista]
Prevedelli, Daniela; Fai, S.; Righi, S.; Simonini, Roberto
abstract

The ability of the polychaete, Hermodice carunculata, to prey on a sea anemone, Anemonia viridis, was investigated under controlled aquarium conditions. Upon contacting, the polychaete everted its pharynx over part of the anemone and sucked its tissues. All the attacked anemones were fully consumed. H. carunculata did not seem affected by the anemones nematocysts. Further researches are needed to assess the effects of H. carunculata on sessile and sedentary species of the Mediterranean habitat.


2016 - Status quo of knowledges on Italian high altitude lacustrine macroinvertebrates [Abstract in Atti di Convegno]
Ruocco, Matteo; Ansaloni, Ivano; Prevedelli, Daniela; Zaupa, Silvia; Boggero, Angela
abstract

High altitude lakes and their fauna are one of the most threatened and less investigated ecosystems in Italy. Alpine lakes are highly influenced by climate harshness and by air pollution, and because of their small dimensions are extremely vulnerable to global climate warming. Italy, in addition to the Alps, hosts another mountain range: the Apennines, reaching in some cases comparable altitudes, and therefore subject to the same risks. Moreover, the gentler slope of the Apennines makes them extremely vulnerable even to direct human impacts. In the present work, for the first time, high altitude lakes belonging to the Alps and to the Apennines are compared to highlight which meteo-climatic or chemical characteristics could be considered key drivers for their macroinvertebrate structure. The study area was explicitly focused on natural lakes placed above 1300 m of altitude and above the 44° parallel, thus in the alpine area and subject to a continental climate. 25 lakes were chosen (19 in the central-western Alps and 6 in the Modenese Apennines) with surface areas lower than 1 km2 and with maximum depths lower than 15 m. Physico-chemical parameters and macroinvertebrates were studied and compared. Samples were taken through the use of a hand-net (250 μm mesh size) along the littorals on different substrates following standardised methodologies during the richer-fauna season to allow an easier identification of species. Parallel to that, water samples were collected and analysed. Species richness and the Taxonomic Distinctness Indices were applied to underline the different complexity of the community structure of the two areas. Results showed different macroinvertebrates communities with peculiar characteristics and highlighted a more structured and diverse composition on the Apennines. Predictive models on the future climate scenarios show how the peninsular portion of Italy will be even more affected by the increase in temperatures than the Alpine area. Thus, this work could be highly informative, mainly for central Italy, where proximity to towns encourage tourists to reach these type of lakes, even if placed in protected areas or parks. Therefore, protection and management plans, and conservation efforts of high altitudes cannot overlooked a thorough understanding of the biological diversity of these environments, which still appears fragmented and limited to some sector of the Alps. Furthermore, the fundamental role of high altitude lakes as water resource needs a specific management regime, as they are not included under the monitoring programs of the Water Framework Directive legislation.


2016 - Which future for Italian high altitude lakes? [Abstract in Atti di Convegno]
Ruocco, Matteo; Ansaloni, Ivano; Prevedelli, Daniela; Zaupa, Silvia; Boggero, Angela
abstract

Abstract: High altitude lakes and their fauna are one of the most threatened and less investigated ecosystems in Italy. Alpine lakes are highly influenced by climate harshness and by air pollution, and because of their small dimensions are extremely vulnerable to global climate warming. Italy, in addition to the Alps, hosts another mountain range: the Apennines, reaching in some cases comparable altitudes, and therefore subject to the same risks. Moreover, the gentler slope of the Apennines makes them extremely vulnerable even to direct human impacts. In the present work, for the first time, high altitude lakes belonging to the Alps and to the Apennines are compared to highlight which meteo-climatic or chemical characteristics could be considered key drivers for their macrinvertebrate structure. The study area was explicitly focused on natural lakes placed above 1300 m of altitude and above the 44° parallel, thus in the alpine area and subject to a continental climate. 25 lakes were chosen (19 in the central-western Alps and 6 in the Modenese Apennines) with surface areas lower than 1 km2 and with maximum depths lower than 15 m. Physico-chemical parameters and macroinvertebrates were studied and compared. Samples were taken through the use of an hand-net (250 μm mesh size) along the littorals on different substrates following standardised methodologies during the richerfauna season to allow an easier identification of species. Parallel to that, water samples were collected and analysed. Species richness and the Taxonomic Distinctness Indices were applied to underline the different complexity of the community structure of the two areas. Results showed different macroinvertebrates communities with peculiar characteristics and highlighted a more structured and diverse composition on the Apennines. Predictive models on the future climate scenarios show how the peninsular portion of Italy will be even more affected by the increase in temperatures than the Alpine area. Thus, this work could be highly informative, mainly for central Italy, where proximity to towns encourage tourists to reach these type of lakes, even if placed in protected areas or parks. Therefore, protection and management plans, and conservation efforts of high altitudes cannot overlooked a thorough understanding of the biological diversity of these environments, which still appears fragmented and limited to some sector of the Alps. Furthermore, the fundamental role of high altitude lakes as water resource needs a specific management regime, as they are not included under the monitoring programs of the Water Framework Directive legislation.


2015 - Analisi preliminari sulla tossicità di essudati di Arenicola marina (Linnaeus, 1758) (Annelida: Arenicolidae) [Articolo su rivista]
Iori, D.; Mirra, M.; Forti, Luca; Prevedelli, Daniela; Simonini, Roberto
abstract

The effects of the exudate (crude and its organic extracts) obtained by Arenicola marina (Annelida: Arenicolidae) were evaluated through acute toxicity bioassays on the annelid Dinophilus gyrociliatus. Preliminary chemical analyses were also performed. The exudate and its n-buthanol extract were toxic (LC50 24h=12%, c.i.=9.7-14.7% and 31.7 mg l-1, c.i.=27.9-36 mg l-1, respectively). The results support the hypothesis that the exudate could be involved in the chemical defence of A. marina.


2015 - Life history di cinque specie simpatriche del genere Ophryotrocha (Annelida, Dorvilleidae) [Articolo su rivista]
Simonini, Roberto; Grandi, Valentina; MASSAMBA N'SIALA, Gloria; Prevedelli, Daniela
abstract

Marine annelids belonging to the Ophryotrocha genus have proven to be valid models in several fields of biological sciences. Eight species of Ophryotrocha were found along the Italian coast, but their distribution is very different. In the present paper we examined the life history of five sympatric species (O. adherens, O. diadema, O. labronica, O. robusta and O. puerilis) collected from Porto Empedocle (Strait of Sicily) looking for differentiation patterns which can be correlated with species distribution. Life history traits of the F1 generation such as body size and growth, biological cycle and reproductive traits were analysed. Three life history patterns based on the maximum body length, egg size, age at first deposition, reproductive investment (RI) and RI per deposition were identified, but they do not seem related to the distribution of the five species.


2015 - Phylogeography of Ophryotrocha labronica (Polychaeta, Dorvilleidae) along the Italian coasts [Articolo su rivista]
Cossu, Piero; Maltagliati, Ferruccio; Pannacciulli, Federica G.; Simonini, Roberto; MASSAMBA N'SIALA, Gloria; Casu, Marco; Lardicci, Claudio; Prevedelli, Daniela; Alberto Castelli, Alberto
abstract

Species of the genus Ophryotrocha are a well-studied group of organisms but, despite the relatively large body of biological studies, little is known about their intra-specific patterns of genetic diversity. In the present study, we analysed the patterns of genetic variation in samples of Ophryotrocha labronica (Polychaeta, Dorvilleidae) collected along the Italian coasts within three regions with different thermal regimes: the Northern Adriatic Sea (NAS), the Ligurian Sea (LS), and the South/Southeast Sicilian Sea (SS). A partial sequence of the cytochrome c oxidase subunit I (COI) gene was used as a genetic marker. An analysis of molecular variance (AMOVA) showed significant genetic differentiation between the NAS and the other regions. Conversely, little or no genetic structuring was found between the LS and the SS or amongst locations within a given region. A Bayesian phylogenetic tree and a median-joining network provided evidence for the occurrence of two highly divergent genetic lineages characterized by a high average sequence divergence (17.2%, Kimura twoparameter distance). The spatial patterns of genetic variation found in O. labronica may reflect the signature of past expansion events of the two genetic lineages. Although the high sequence divergence suggested that cryptic speciation within O. labronica may have occurred, other traits such as the absence of reproductive isolation, pattern of phenotypic variation and habitat specificity prompted us to regard the two groups as distinct COI lineages of O. labronica.


2014 - Application of the Shore Zone Functionality Index to the Mantua lakes (Italy) and its comparison with two biological quality indices. [Abstract in Atti di Convegno]
Pascarella, L; Galassi, L; Fioravanti, M; Ansaloni, Ivano; Ruocco, Matteo; Simonini, Roberto; Prevedelli, Daniela
abstract

The Shore zone Functionality Index (SFI), proposed by the Italian Institute for Environmental Protection and Research (ISPRA) in 2009, assesses the quality of lake surrounding areas complying with the Water Framework Directive (WFD 2000/60/CE). The method evaluates the functionality of lake surrounding areas providing a useful instrument for land planning and management. In this study, the SFI has been applied to three lakes near the city of Mantua (Lombardia, North Italy) and compared with two other indices: a diatomic eutrophication/pollution index and a biological quality index based on macroinvertebrates. The comparison was carried out in order to verify the connection between the quality of lake surrounding areas and the biological quality of the lake’s water body. The application of the method showed very heterogeneous SFI index values along the shore zone of the three lakes: differences in type and abundance of vegetation and land use have led to judgments of functionality ranging from excellent to extremely poor. No correlations were found between the two indices and the SFI demonstrating that the quality of the shore zone of a lake is not necessary connected with the biological quality of the water body. The SFI index appears very promising to assess functional levels of the surrounding areas of lakes, however the method should be always associated with other indices that evaluate the biological quality of the water body in order to provide a wide knowledge to the land planners and managers.


2014 - Difese chimiche in anellidi marini: valutazione della tossicità dell’hallacromo prodotto da Halla parthenopeia (Polychaeta: Oenonidae) [Abstract in Atti di Convegno]
Simonini, Roberto; Iori, Dario; Forti, Luca; MASSAMBA N'SIALA, Gloria; Prevedelli, Daniela
abstract

Alcuni anellidi marini producono metaboliti secondari per difendersi chimicamente contro predatori, competitori e/o patogeni. L’hallacromo (C16H12O4) è un antrachinone presente nel muco violaceo prodotto dall'anellide marino Halla parthenopeia in risposta a stress. Abbiamo recentemente osservato che l’esposizione al muco violaceo è nociva o letale per organismi-test appartenenti a taxa molto diversi. In questo lavoro la tossicità dell’hallacromo (estratto dal muco, purificato tramite cromatografia e diluito in DMSO dopo caratterizzazione tramite LC-MS e NMR) è stata valutata tramite una batteria di saggi ecotossicologici. L’hallacromo è letale a basse concentrazioni per il polichete Dinophilus gyrociliatus (LC50 96 h= 0.11 mg l-1, NOEC=0.026 mg l-1) e presenta una elevata tossicità anche per gli altri organismi testati (Brachionus plicatilis: LC50 24 h= 0.16 mg l -1; Euplotes crassus: LC50 2h= 0.29 mg l-1; Vibrio fischeri: EC50 30’= 0.77 mg l-1; Artemia francescana: LC50 24h= 5.67-7.05 mg l-1). I risultati suggeriscono che l’hallacromo sia il responsabile dell’attività biologica del muco violaceo di H. parthenopeia. L'elevata tossicità e l'ampia gamma di organismi su cui esercita effetti suggerisce che l’hallacromo rappresenti una difesa chimica verso competitori e parassiti. Di norma gli studi sulle difese chimiche degli invertebrati marini si basano su test di palatabilità, che evidenziano soprattutto le difese antipredatorie. Integrare i test di palatabilità con saggi ecotossicologici potrebbe contribuire al miglioramento delle conoscenze sui differenti tipi di difese chimiche messe in atto dagli invertebrati marini.


2014 - Macroinvertebrates colonization and evolution in the WWF protected area “La Francesa" (Pianura Padana, Italy): a new man-made pond. [Abstract in Atti di Convegno]
Ruocco, Matteo; Sala, Luigi; Simonini, Roberto; Prevedelli, Daniela; Ansaloni, Ivano
abstract

The WWF protected area “La Francesa”, established in 2005 in the province of Modena (Emilia-Romagna, Italy), is one of the few areas of natural interest in the low lands of the province. Originally, it was a land of 23 ha used for agricultural purposes, set aside because of its low productivity. From the beginnings of the ‘90s, it has been managed in order to recover its naturalness with the planting of native species and, at the end of 2005, a new man-made pond of 8 ha was created to increase its natural value and the variety of the ecosystem. The present study shows the result of two monitoring surveys carried out during summer 2006 and 2011 to assess the colonization status, and its variation along time, of the macrozoobenthic community of the pond. Samplings were performed with an Ekman bottom grab sampler and a standardized net in six different stations. Results showed a temporal shift in species composition due to changes in the habitat, specifically the development of hydrophytic vegetation along the shore favoured by the stabilization of the system, and the spread of the exotic plant Ludwigia peploides that covered the wet meadow of the pond.


2014 - Oasi WWF La Francesa (Carpi, Modena): quale ruolo per la salvaguardia della biodiversità? [Abstract in Atti di Convegno]
Simonini, Roberto; Ruocco, Matteo; Ansaloni, Ivano; Sala, Luigi; Prevedelli, Daniela
abstract

L’Oasi WWF “La Francesa” si estende su circa 23 ettari nella ZPS “Valle di Gruppo” nella bassa pianura modenese. A partire dal 1993, è stata oggetto di interventi di rinaturalizzazione per creare un’area di interesse naturalistico con habitat adatti ad ospitare specie fortemente penalizzate da un ambiente circostante intensamente antropizzato. Nel 2005, per diversificare ulteriormente gli habitat presenti, e quindi migliorare il loro valore naturalistico, viene creata una zona umida di 8 ettari con differenti livelli di profondità. Vengono qui presentati i dati relativi alle analisi della fauna a macroinvertebrati della zona umida raccolti in due fasi temporali - estate 2006, a lavori appena ultimati, ed estate 2011 - al fine di caratterizzare la comunità pioniera e studiarne l’evoluzione nel tempo. I campionamenti sono stati effettuati in 6 stazioni nel 2006 e replicati solo in 3 nel 2011 a causa della carenza di acqua. I parametri chimico-fisici dell’acqua misurati nei due periodi risultano sostanzialmente invariati, mentre sono state osservate differenze significative nei taxa rilevati. Tali differenze sono probabilmente da imputare alla comparsa della pianta esotica Ludwigia peploides, la cui invasività ha impedito l’insediarsi di altre specie, sia elofite che idrofite, alterando l’evoluzione naturale del bacino idrico. Anche la massiccia presenza di specie animali alloctone osservata nell’area di studio evidenzia come la creazione di nuovi habitat in zone a forte impatto antropico debba essere affiancata da una gestione scientificamente orientata per garantire il riequilibrio ecologico complessivo che costituisce l’obiettivo fondamentale di ogni Oasi situata all’interno di siti della rete ecologica Natura 2000.


2014 - Tossicitá del muco colorato di Halla parthenopeia (Delle Chiaje, 1828) (Annelida, Oenonidae) [Articolo su rivista]
Iori, Dario; Forti, Luca; Prevedelli, Daniela; N’Siala, G. Massamba; Simonini, Roberto
abstract

The toxic effects of the coloured mucus produced under stress conditions by Halla parthenopeia (Polychaeta: Oenonidae) was assessed by means of a battery of ecotoxicological tests that included bacteria, protozoan, rotifers, polychaetes and crustaceans. Coloured mucus was toxic at concentrations ranging from 70.000 to 300 mg l-1 (in terms of LC50 values) depending on the tested species. Results suggest that the coloured mucus should play a role in the chemical defence of H. parthenopeia.


2014 - Toxicity of the purple mucus of the polychaete Halla parthenopeia (Oenonidae) revealed by a battery of ecotoxicological bioassays [Articolo su rivista]
Iori, Dario; Forti, Luca; MASSAMBA N'SIALA, Gloria; Prevedelli, Daniela; Simonini, Roberto
abstract

Mucus secretions play a number of functions related to polychaete physiology and ecology. Under stress conditions, the polychaete Halla parthenopeia (Oenonidae) produces a purple mucus after mechanical stimulation, whose function is still unknown. Here, we assessed the toxicity of this purple mucus by means of both acute toxicity bioassays on the polychaete Dinophilus gyrociliatus and commercial ecotoxicological kits (Microtox®, Rotoxkit® and Artoxkit®). Palatability was also tested with the fish Oryzias melastigma. After emitting purple mucus, H. parthenopeia quickly moves away and starts releasing transparent mucus. Acute toxicity bioassays showed that the mucus was harmless (transparent), or lethal even when diluted about 1000 times (purple). Purple mucus was toxic at different concentrations, the LC50 ranging from 0.7-0.3 g l–1 for D. gyrociliatus to 76 g l–1 for Artemia franciscana (Artoxkit®). Freeze-dried brine shrimp coated with transparent or purple muci were both consumed by O. melastigma. We hypothesized that the purple mucus is involved in the chemical defence of H. parthenopeia against competitors and parasites, and that its colour and toxicity are due to hallachrome, a 1,2-anthraquinone found in the skin of H. parthenopeia.


2014 - Trans-generational plasticity in physiological thermal tolerance is modulated by maternal pre-reproductive environment in the polychaete Ophryotrocha labronica [Articolo su rivista]
MASSAMBA N'SIALA, Gloria; Prevedelli, Daniela; Simonini, Roberto
abstract

Maternal temperature is known to affect many aspects of offspring phenotype, but its effect on offspring physiological thermal tolerance has received less attention, despite the importance of physiological traits in defining organismal ability to cope with temperature changes. To fill this gap, we used the marine polychaete Ophryotrocha labronica to investigate the influence of maternal temperature on offspring upper and lower thermal tolerance limits, and assess whether maternal influence changed according to the stage of offspring pre-zygotic development at which a thermal cue was provided. Measurements were taken on adult offspring acclimated to 18 or 30°C, produced by mothers previously reared at 24°C and then exposed to 18 or 30°C at an early and late stage of oogenesis. When the shift from 24°C was provided early during oogenesis, mothers produced offspring with greater cold and heat tolerance whenever mother–offspring temperatures did not match, with respect to when they matched, suggesting the presence of an anticipatory maternal effect triggered by the thermal variation. Conversely, when the cue was provided later during oogenesis, more tolerant offspring were observed when temperatures persisted across generations. In this case, maternal exposure to 18 or 30°C may have benefited offspring performance, while limitations in the transmission of the thermal cue may account for the lack of correlation between maternal experiences and offspring performance when mother–offspring environments did not match. Our results provided evidence for a trans-generational effect of temperature on physiological performance characterised by a high context dependency, and are discussed in the light of maternal pre-reproductive experiences.


2013 - Plasticità trans-generazionale della tolleranza termica nel polichete Ophryotrocha labronica (Annelida: Dorvilleidae) [Abstract in Rivista]
MASSAMBA N'SIALA, Gloria; Simonini, Roberto; Prevedelli, Daniela
abstract

Il fenotipo e l’ambiente materno sono noti essere importanti fattori in grado di influenzare il fenotipo dei discendenti. Tuttavia, poco si sa del loro ruolo nell’influenzare la tolleranza termica della prole. Abbiamo utilizzato il polichete marino Ophryotrocha labronica (Annelida: Dorvilleidae) per 1) studiare l’effetto che la temperatura ambientale materna ha sulle risposte di tolleranza termica dei discendenti, 2) stabilire se questo effetto è mantenuto anche nella fase adulta dei discendenti, e 3) valutare il ruolo dello stadio di sviluppo pre-zigotico dei discendenti nel definire il risultato dell’effetto materno. Abbiamo misurato i limiti di tolleranza termica superiori e inferiori di individui adulti acclimatati a 18 °C o 30 °C, le cui madri erano state fatte crescere a 24 °C e, al raggiungimento della maturità sessuale, erano state esposte a 18 °C o 30 °C sia ad uno stadio precoce che uno tardivo dell’oogenesi. Quando la temperatura materna e quella della prole differiva e l’esposizione da 24 °C a 18 °C o 30 °C avveniva ad uno stadio precoce dell’oogenesi, venivano prodotti discendenti più resistenti sia al freddo che al caldo, suggerendo l’esistenza di un effetto materno di tipo “anticipatorio” innescato dal segnale termico sperimentato dalle madri. Al contrario, quando le madri sperimentavano la variazione termica in una fase più tardiva dell’oogenesi, la tolleranza termica dei discendenti si riduceva (rispetto a quanto osservato quando temperatura materna e della prole si eguagliavano). L’esistenza di limiti nella trasmissione del segnale materno nel corso dello sviluppo pre-zigotico potrebbe spiegare quest’ultimo risultato. Infine, l’influenza materna è stata mantenuta fino allo stadio adulto dei discendenti. Per la prima volta in una specie marina, abbiamo dimostrato l’esistenza di plasticità trans-generazionale nella tolleranza termica. I nostri risultati sono importanti per migliorare la comprensione delle strategie evolute dalle specie in ambienti termicamente fluttuanti e sono utili nel definire le risposte degli organismi nei confronti dell’inasprimento delle variazioni termiche in conseguenza ai cambiamenti climatici.


2012 - Effects of diet and density on growth, survival and gametogenesis of Hediste diversicolor (O.F. Müller, 1776) (Nereididae, Polychaeta) [Articolo su rivista]
N., Nesto; Simonini, Roberto; Prevedelli, Daniela; L., Da Ros
abstract

The effects of diet and density on growth, survival and gametogenesis of the common ragworm Hediste diversicolor (Nereididae, Polychaeta) were investigated with the aim of contributing to define their optimal ranges in the context of a commercial farming system. Two different experimental trials were set up: in the first one, juveniles of H. diversicolor, obtained from laboratory cultures established with specimens taken from the Venice Lagoon, were fed according to three different food regimes (two based on commercial feeds and one consisting of an homogenate of the brown alga Sargassum muticum); in the second trial the juveniles were maintained at different rearing densities (300, 1000 and 3000 ind. m−2). In both trials, the effects on growth, survival and gametogenesis were evaluated at various time-intervals during the eight-week period of the experiments. Results showed that H. diversicolor might be a promising species to be commercially exploited in an indoor farming system. In particular, high-protein diets permits elevated growth rates, earlier gametogenesis and sexual maturation. Both growth and survival rates were higher at the lowest densities, whereas the processes of gametogenesis and sexual maturation were not influenced by density.


2012 - Life-history and thermal tolerance traits display different thermal plasticities and relationships with temperature in the marine polychaete Ophryotrocha labronica La Greca and Bacci (Dorvilleidae) [Articolo su rivista]
MASSAMBA N'SIALA, Gloria; P., Calosi; D. T., Bilton; Prevedelli, Daniela; Simonini, Roberto
abstract

In order to gain insights into links between fitness and physiological function, the phenotypic plasticity of life-history traits and thermal tolerances has been investigated in a laboratory strain of the polychaete Ophryotrocha labronica acclimated to a broad range of temperatures. Reproductive pairs were kept in isolation for two months at one of six temperatures (10, 15, 20, 25, 30 and 35 °C), and survival and a number of life-history traits recorded. Tolerance to heat and cold was assessed in individuals that survived the acclimation period by measuring upper and lower thermal limits. Life-history and thermal tolerance traits showed different relationships with temperature: generally non-monotonic for life-history and monotonic for thermal limits. The thermal history of the strain used in the study seemed to be partly responsible for this pattern, affecting the thermal responses of most life-history traits, but not those of the upper and lower thermal limits. Survival correlated positively with tolerance to cold but not with heat tolerance. This result supports the idea that tolerance to heat is under stronger selection in O. labronica, resulting in a lower level of plasticity for this trait. Some life-history features positively co-varied with tolerance to heat (e.g. body size), whilst in other cases reproductive traits showed apparent trade-offs with thermal limits. In all cases correlations amongst traits were apparently driven by their relationship with temperature. Even if we found no evolutionary trade-offs among the thermal responses of life-history traits and thermal limits, the strategies evolved by organisms to cope with thermal variability result from the mutual interaction of these traits, which plays a key role in defining organisms' responses to temperature changes and fluctuations.


2012 - Monitoraggio degli effetti dell’estrazione di sabbie sulle comunità macrozoobentoniche di fondali pelitici (area A, Adriatico settentrionale) tramite un disegno beyond-BACI [Articolo su rivista]
Simonini, Roberto; Casa, Silvia Della; MASSAMBA N'SIALA, Gloria; Martino, Maria Pia; Prevedelli, Daniela
abstract

In spring 2007, about 100,000 m3 of sand were dredged from the area A (Northern Adriatic Sea), in which relict sands are covered by a thin layer of fine sediment Taking into account the findings of a previous monitoring plan (2001-2004), the effects of sand extraction on macrozoobenthos were evaluated by means of a beyond-BACI design. The study included three sampling surveys before and three after the dredging. At each survey, seven locations were analyzed, one of which was placed within the dredging area. Data highlighted that the recolonization process at the dredged area started quickly and the complete recovery of the communities required about two years. The design adopted in the present study permitted to distinguish the “natural” from the “sand dredging induced” variability of the benthic communities, giving more robust results respect to those obtained from the 2001-2004 monitoring.


2012 - Ricolonizzazione e recupero delle comunità macrozoobentoniche in seguito all’estrazione di sabbie relitte. [Articolo su rivista]
Simonini, Roberto; Grandi, Valentina; Iotti, Mirko; N'Siala, Gloria Massamba; Prevedelli, Daniela
abstract

The sand-extraction operations may influence the biological characteristics of the impacted sea beds both directly, through removal, smothering and damage caused by the dredge head, and indirectly: surface and bottom plumes, changes in plankton bloom seasons, the release of nutrients and chemicals, as well as sound, can affect both the sea bottom and the water column in the immediate area around the dredging site. In this paper, we analyse the long-term effects of sand extraction on macrozoobenthic communities in an offshore area in the Northern Adriatic Sea, characterised by relict sands formed during the last Adriatic post-glacial transgression. Surveys were carried out before, during and 1, 6, 12, 18, 24 and 30 months after extraction at three impacted and seven reference stations. The operations did not influence the physical characteristics of the sediment, but they caused almost complete defaunation at dredged sites. In particular, the effects of sand extraction on the macrozoobenthic communities were particularly intense, especially during and immediately after the extraction, at stations 3 and 4, and were mainly due to the removal of fauna from the seabed. The recolonisation at the impacted station began early by larval settlement (most polychaetes, molluscs, echinoderms and other sedentary organisms) and adult migration (vagile taxa, such as the dominant crustaceans Apseudes latreillii and Ampelisca diadema). Then, starting from 24 months after dredging, the composition and structure of the macrozoobenthic assemblages become quite similar to that observed prior to sand extraction. The scant difference in the community found before and after 30 months after dredging at impacted stations were due to (1) some rare species exclusive to the first or the last survey; (2) differences in the abundances of common species, characteristic of the relict sands biocoenosis, that can be related to the natural temporal variability of the communities. The species in common between the two surveys constituted about 90% of the whole abundances at both B-Ex. and the A-Ex. 30 impacted stations. Therefore, it could be assumed that the communities of the dredged area returned to the original condition 30 months after sand extraction. This pattern of recolonisation–recovery fits well with the commonly encountered scenario where the substratum merely remains unchanged after marine aggregate extraction.


2011 - Caratteristiche di due forme di Corbicula sp. presenti in canali della provincia di Modena [Abstract in Atti di Convegno]
Simonini, Roberto; Martino, M. P.; MASSAMBA N'SIALA, Gloria; Prevedelli, Daniela
abstract

Nell’ultimo secolo, il bivalve alloctono invasivo Corbicula sp. si è diffuso in habitat lentici e lotici di tutto il mondo, tra cui quelli dell’Italia settentrio-nale. In questo lavoro sono illustrate le caratteristiche morfologiche e la colorazione di conchiglie di Corbicula raccolte da canali dell’alta e della bassa pianura modenese.Campionamenti sono stati effettuati in più siti lungo canali distanti 50 km (S. Pietro e Torbido [alta pianura]; Quarantoli [bassa pianura]), tramite retino. Dopo vagliatura, gli esemplari di Corbicula sono stati dissezionati; le conchiglie sono state misurate tramite calibro micrometrico e fotogra-fate ottenendo informazioni su lunghezza, larghezza, altezza e colorazio-ne.Le conchiglie degli esemplari di Corbicula raccolti lungo i canali di alta pianura raggiungono al massimo 3 cm, hanno forma ellittica, con esterno giallo-marrone ed interno bianco-giallo. Gli individui prelevati dal canale di bassa pianura sono più grandi (fino a 5 cm) hanno conchiglia roton-da/triangolare, verde-marrone esternamente e bianca-violetta interna-mente.Negli ambienti dolciaquicoli europei sono stati identificati tre morfotipi di Corbicula: R (round), Rlc (R light-coloured) e S (saddle). Gli esemplari rinvenuti nell’area studiata sono riconducili alla forma R (bassa pianura) e Rlc (alta pianura). E’ probabile che i due morfotipi corrispondano a due distinti eventi di introduzione.


2011 - Vantaggi selettivi del gonocorismo e dell’ermafroditismo: confronto tra specie appartenenti al genere Ophryotrocha (Polychaeta) [Abstract in Atti di Convegno]
Martino, M. P.; Prevedelli, Daniela; MASSAMBA N'SIALA, Gloria; Schleicherova, D.; Lorenzi, M. C.; Sella, G.; Simonini, Roberto
abstract

I vantaggi selettivi di ermafroditismo e gonocorismo sono stati affrontati approfonditamente a livello teorico, mentre sono scarse le dimostrazioni sperimentali. Il genere Ophryotrocha, che comprende sia specie gonoco-riche che ermafrodite, rappresenta un valido modello biologico per la ve-rifica sperimentale dei vantaggi e degli svantaggi di questi due tipi di ses-sualità.Coorti di individui appartenenti a specie gonocoriche (O. labronica, O. ro-busta) ed ermafrodite (O. adherens, O. diadema), allevate in laboratorio, sono state esposte a diverse densità (‘alta’ e ‘bassa’) per verificare le se-guenti ipotesi: - il gonocorismo è vantaggioso ad alta densità; - l’ermafroditismo riduce lo svantaggio a bassa densità.Ad alta densità le specie gonocoriche presentano fecondità normalizzata alla taglia maggiore di quelle ermafrodite. Viceversa, a bassa densità, le specie ermafrodite hanno una fecondità normalizzata alla taglia parago-nabile o superiore alle specie gonocoriche. Nelle specie ermafrodite la fe-condità è sempre maggiore a bassa piuttosto che ad alta densità.I risultati supportano quanto previsto dalla teoria dell’allocazione sessua-le. Il gonocorismo è la strategia che permette la maggiore fitness quando la densità di popolazione e le probabilità di accoppiamento sono alte; l’ermafroditismo può diventare vantaggioso in condizioni di bassa densità, quando la probabilità di incontrare il partner è bassa.


2010 - DIVERSITY, HABITAT AFFINITIES AND DIET OF OPHRYOTROCHASPECIES (POLYCHAETA, DORVILLEIDAE) LIVING INMEDITERRANEAN HARBOUR HABITATS [Articolo su rivista]
Simonini, Roberto; Grandi, Valentina; MASSAMBA N'SIALA, Gloria; M. P., Martino; Castelli, Alberto; Prevedelli, Daniela
abstract

Information from 40 harbours was used to investigate the diversity and habitataffinities of Ophryotrocha species living in Central Mediterranean coastal habitats. Three environmentaldescriptors were considered: climate, boat traffic in harbours and fouling assemblagesof port wharfs. Moreover, the diet was studied through the analysis of faecal pellets. Thenumber of Ophryotrocha species did not vary among the climatic sub-areas, while the main,high traffic harbours exhibited a higher number of species with respect to the minor harbours.Ophryotrocha species can colonise all the fouling types considered, but the highest number ofspecies was observed in mixed, heterogeneous assemblages. In most of the places investigated,two or more species co-existed on both harbour and wharf scales. The three most common species,O. labronica, O. puerilis (Mediterranean indigenous) and O. japonica (a non-indigenousspecies), differed in their affinities for climatic areas and harbour typology, but no significantpreferences were observed with respect to the fouling types. The examination of faecal pelletsfrom animals collected in the field suggested that all the species are omnivorous. Ophryotrochaspecies can live in very different types of harbour habitats. However, the ability to successfullycolonise these environments varied strongly among species, perhaps because of their “history”(especially in the case of non-indigenous species), tolerance and habitat preferences/requirements.


2010 - SPAWING INDUCTION, FERTILIZATION AND LARVAL DEVELOPMENT OF HEDISTE DIVERSICOLOR(NEREIDIDAE, POLYCHAETA) UNDER DIFFERENT EXPERIMENTAL CONDITIONS [Relazione in Atti di Convegno]
N., Nesto; A., Libertini; Prevedelli, Daniela; Simonini, Roberto; C., Tola Masala
abstract

A suite of experiments with the polychaete Hediste diversicolor were performed to assess the induction of gamete spawning byendogenous substances, to evaluate the percentage of fertilised and hatching eggs in two different conditions (“natural” and in vitrofertilization), and to measure the density effects on larval growth and survival. The results showed that mature females were induced to spawn by adding mature male tissue homogenate in the medium. The percentages of fertilised and hatching eggs were higher in the in vitro fertilisation and larval/juvenile survival was affected by density.


2009 - Assessing the ecological status of the North-western Adriatic Sea within the European Water Framework Directive: a comparison of Bentix, AMBI and M-AMBI methods [Articolo su rivista]
Simonini, Roberto; Grandi, Valentina; MASSAMBA N'SIALA, Gloria; Iotti, Mirko; G., Montanari; Prevedelli, Daniela
abstract

In this paper we looked for the most suitable method for benthic ecological quality status (EcoQS) assessment of the North-western Adriatic Sea. Taking into account the historical and present information, we inter-compared our expectations in terms of EcoQS, with the Bentix, AMBI and M-AMBI classificationmetrics results, and investigated the sensitivity of these indices to the spatial, seasonal and inter-annual variability of benthic communities. The sampling sites were located at increasing distances with respect to the Po Rivermouth, along an (inverse) gradient of eutrophication. Moreover, a 2-year monthly monitoring plan (October 2004–September 2006) was carried out at the CEBEB site, located in a central position with respect to the investigated area. The results highlighted that the three indices differed in the sensitivity to spatial and temporal variability of the benthic communities. The strong seasonaland inter-annual changes in the benthic communities had a significant effect on the Bentix, whereas no relevant modifications were observed on the EcoQS assignation obtained using the M-AMBI and AMBI methods. The environmentalquality ratios (EQR) values and EcoQS classification obtained by the Bentix and AMBI did not match expectations, as they were not inversely correlated with the site distances with respect to the Po mouth, whereas the M-AMBI clearly discriminated the most and the least eutrophicated sites. It thus appears that the M-AMBI could be considered to be the most valuable method for the ecological-status assessment of the North-western Adriatic Seabenthic ecosystem.


2009 - Distribution of the genus Ophryotrocha (Polychaeta) in Italy: new reports and comments on the biogeography of Mediterranean species. Vie et Milieu, in press [Articolo su rivista]
Simonini, Roberto; MASSAMBA N'SIALA, Gloria; Grandi, Valentina; Prevedelli, Daniela
abstract

A number of intensive surveys were performed from 2002 to 2008 to implement the distribution data of the genus Ophryotrocha in Italian harbour and lagoon environments. The occurrences of O. hartmanni, O. l. labronica, O. macrovifera, O. p. puerilis, O. robusta and O. japonica are confirmed, and the first records of O. adherens in Italy and O. diadema in Europe was documented. The three most common Ophryotrocha were O. l. labronica, O. japonica and O. p. puerilis. The other species are rarer. Data are integrated with literature records, and some hypotheses which were proposed to justify the wide, patchy distribution of most Mediterranean Ophryotrocha were discussed. It was previously suggested that isolated populations could be remnants of a wider continuous distribution, the result of anthropogenic dispersion by means of sea traffic, and/or the by-product of a heterogeneous sampling effort in different biogeographic areas. It appears that the last two hypotheses and the dispersion through waves, currents and/or storms could explain the distribution patterns of certain species. The high incidence of the most common species in the investigated area and the scant information outside the Mediterranean suggests that the distribution of Ophryotrocha species could be wider and more continuous than that recognized today.


2009 - RICOSTRUZIONE TRIDIMENSIONALE DELLA MUSCOLATURADI OPHRYOTROCHA ADHERENS (POLYCHAETA: DORVILLEIDAE) [Articolo su rivista]
Grandi, Valentina; Simonini, Roberto; MASSAMBA N'SIALA, Gloria; Prevedelli, Daniela
abstract

The F-actin muscular subset of Ophryotrocha adherens was labelled with phalloidin and the architecture of the muscular system was three-dimensionally reconstructed by means of Confocal Laser Scanning Microscopy (cLSM). The pattern of musculature resembles that of other dorvilleids and Ophryotrocha species recently described.


2009 - Thermal biology of the interstitial polychaete species Ophryotrocha labronica (Polychaeta, Dorvilleidae) [Abstract in Rivista]
MASSAMBA N'SIALA, Gloria; Prevedelli, Daniela; Grandi, Valentina; Simonini, Roberto; D. T., Bilton; P., Calosi
abstract

The gonochoric polychaete Ophryotrocha labronica is a widespread interstitial species commonly found in the fouling communities of harbour and lagoon environments. A number of manipulative experiments have revealed a strong influence of temperature on the life history and demography of this species. Furthermore, significantly different patterns in life-history and demographic traits have been demonstrated among populations inhabiting regions of the Mediterranean Sea with different climatic profiles. However, limited investigations have been carried out so far on the thermal biology of this species. We have conducted an experimental characterisation of the thermal biology of O. labronica, and described mortality curves of individual male–female pairs kept at one of seven different temperatures, ranging between 5 and 35 °C. For each pair, life-history traits (size at first reproduction, growth and total egg production) were also characterised. In a separate experiment, the upper and lower thermal limits and relative acclimatory ability of individual polychaetes were determined using several sublethal end-points, as well as lethal limits. A series of trials were conducted to test the effect of acclimation temperature, duration of acclimation and temperature change rate during warming/cooling experiments. Results are discussed in the light of O. labronica's ecology and life history.


2008 - Applications of Life Table Response Experiments to the Evaluation of Toxicant Effects at the Population Level with the Polychaete Dinophilus gyrociliatus [Capitolo/Saggio]
Simonini, Roberto; Prevedelli, Daniela; Mauri, Marina
abstract

Heavy metals are among the most widespread pollutants in harbor environments andcoastal habitats subject to anthropogenic impact, and their harmful effects have beendemonstrated on various species of polychaetes, depending on the metal and its rolein physiological processes (Reish and Gerlinger, 1997; Reish, 1998). An evaluation ofthe impact of contaminants at both individual and population levels can be obtainedthrough life table response experiments, a method for estimating the effect of pollutantson biological ' tness (Caswell, 2000). This approach has been recently adopted tostudy the biological effects of pollutants on marine environments utilizing the polychaetesCapitella capitata, Streblospio benedicti, and Dinophilus gyrociliatus as bioindicatorspecies (Levin et a l., 1996; Hansen et a l., 1999; Mauri et al., 2002, 2003).In this chapter, we compare the sensitivity of some population parameters such as thepopulation growth rate, λ, the life expectancy, e0, and the net growth rate, R0, estimatedfor cohorts of D. gyrociliatus exposed to zinc and chromium.


2008 - Effetti dell’estrazione di sabbie e dello sversamento di dragaggi portuali sul macrozoobenthos di fondi molli: due casi di studio in adriatico settentrionale [Articolo su rivista]
Simonini, Roberto; Ansaloni, Ivano; Grandi, Valentina; MASSAMBA N'SIALA, Gloria; Iotti, Mirko; Mauri, Marina; G., Montanari; M., Preti; N., De Nigris; Prevedelli, Daniela
abstract

The main findings of two recent monitoring projects on the effects of dumping of harbour-dredged sediment and sand extraction on the macrozoobenthic communities of the Emilia-Romagna coastal area are discussed. In the first case, no significant effects were observed; in the second case, the recovery of benthic communities after defaunation was achieved 30 months after the operations. Biotic and abiotic environmental characteristics and precautionary measures contributed to reduce the medium-long term effects of dumping of dredged sediments and sand extraction on benthic ecosystems


2008 - Responses of a Northern Adriatic Ampelisca–Corbula community to seasonality and short-term hydrological changes in the Po river [Articolo su rivista]
MASSAMBA N'SIALA, Gloria; Grandi, Valentina; Iotti, Mirko; G., Montanari; Prevedelli, Daniela; Simonini, Roberto
abstract

During the 20th century, increased nutrient inflow has increased the frequency and intensity of eutrophicationevents in the North-western Adriatic Sea. More recently, evidence of a reduction in the Po riverflow and a recovery of the benthic environment were reported. We examined the role played by Po riverregime and seasonality in determining the temporal pattern of macrozoobenthos variation: samples werecollected from a site located 10–12 km off Cesenatico during two years from October 2004 to September2006, when the mean Po discharge remained exceptionally low. 88 taxa were found, and the communitywas dominated by few species: Ampelisca diadema, Lumbrineris latreillii, Corbula gibba, Aricidea claudiae,Levinsenia gracilis and Nucula nucleus account for about 80% of total abundances. The density of these speciesexhibited a marked seasonal variability. Moreover, the total abundance and the density of the sensitivespecies, A. diadema, were negatively affected by several disturbance events (hypoxic conditions,frequent storms and an anomalous winter flood) that occurred between November 2005 and March2006. The reduction of C. gibba and the increase of A. diadema densities observed in the investigated period,and verified recently by other authors could be related to the reduction in river inputs as a consequenceof climatic changes.


2008 - The Musculature of Ophryotrocha labronica (Polychaeta: Dorvilleidae). Journal of Morphology 269 (12): 1489. [Abstract in Rivista]
Grandi, Valentina; Leasi, Francesca; MASSAMBA N'SIALA, Gloria; Prevedelli, Daniela; Simonini, Roberto
abstract

The dorvilleid polychetes belonging to the genus Ophryotrocha are considered model organisms for several types of scientific investigations. Yet, until now, there is no study on the muscular arrangement of these species.The F-actin muscular subset of the species Ophryotrocha labronica was labeled with phalloidin and the architecture of the system was threedimensionally reconstructed by means of confocal laser scanning microscopy (CLSM). The body wall contained transverse and bracing musclesand five longitudinal muscle strands: two dorsolateral, two ventral and one ventromedial. In the prostomium, several muscles were observed: longitudinal, transverse, cross, rostral, and radial muscles. The transverse muscles extended from the dorsal to the ventral sides, where they terminated before reaching the midline. The prostomium was connected with the pharyngeal bulb through two pairs of longitudinal and cross muscular strands.A circumbuccal complex was observed in the ventral side near the mouth. In the parapodia, the muscles were grouped in a parapodial complex composed by several elements: longitudinal, diagonal, oblique, acicular and bristle-sac muscles. The general architecture of the muscular system of O. labronica was very similar to that of Dorvillea kastjani, but differed by the peculiar organization of head musculature and bracing muscles.


2007 - Bioturbation in the Venice Lagoon: Rates and relationship to organisms [Articolo su rivista]
M., Gerino; M., Frignani; C., Mugnai; L. G., Bellucci; Prevedelli, Daniela; A., Valentini; A., Castelli; S., Delmotte; S., Sauvage
abstract

Experiments were carried out during autumn 1998 and spring 1999 at four selected sites in the Venice Lagoon in order to estimate the major bioturbation modes, and for quantitative analysis of the contribution of various taxa to these modes. Fluorescent sediment particles (63–350 μm) were supplied as a tracer pulse input at the sediment surface. Tracer depth profiles obtained after 15 and 20 days were simulated with a diffusion-advection-non-local transport model. This allowed the rates of biodiffusion (Db), bioadvection (W), and RS, a non-local transport coefficient to account for the displacement of sediment by regeneration, to be estimated. A combination of fresh water and marine organisms were responsible for the recorded sediment reworking, which was dominated by both types of non-local transports (conveying and regeneration). Considering all the sampling sites and seasons, Db ranged from 0.87 ± 0.02 to 3.17 ± 0.92 cm2 y−1, W from 0.12 ± 0.09 to 27.41 ± 2.47 cm y−1 and RS from 0.00 ± 0.00 to 5.47 ± 1.09 g cm−2 y−1 (mean ± SE, n = 3). A multiple regression analysis was applied to identify the contribution from individual species to sediment transport types. Biodiffusion resulted from the combined activity of polychaetes such as Spio decoratus and meiobenthic harpacticoïd copepods, while the polychaete Hediste diversicolor was mainly responsible for regeneration. Conveying processes were driven by another polychaete, Capitella capitata. Despite heterogeneity in the benthic community composition, biodiffusion and regeneration rates did not vary significantly between sites or season, with only bioadvection found to be higher in spring than in autumn.


2007 - Comunità macrozoobentonica litorale di tre laghi dell’AppenninoModenese: lago Santo, lago Baccio, lago Pratignano [Relazione in Atti di Convegno]
Ansaloni, Ivano; Iotti, Mirko; Mauri, Marina; Prevedelli, Daniela; Simonini, Roberto
abstract

In questo studio sono state analizzate le comunità litorali a macroinvertebrati di tre laghi ad un diverso stadio di maturitàsituati nel Parco Regionale dell’Alto Appennino Modenese. Il lago Pratignano è poco profondo (2 m) e costituisce una dellepoche torbiere di grandi dimensioni rimaste nell’Appennino Settentrionale; il lago Santo è più profondo (11 m) ed ha scarsavegetazione lungo le rive, mentre il lago Baccio ha profondità intermedia (4 m), abbondante vegetazione riparia ma lospecchio d’acqua è libero. I campionamenti, di tipo qualitativo, sono stati effettuati a cadenza stagionale in tre stazioni perogni lago. In ogni occasione sono stati misurati temperatura, conducibilità, ossigeno disciolto e pH. Complessivamente sonostati rinvenuti 98 taxa, dei quali solo 7 sono comuni, 38 sono esclusivi del lago Pratignano, 12 del lago Baccio e 17 del lagoSanto. Le analisi multivariate sulle matrici di presenza/ assenza, integrate con i dati chimici e fisici e di produttività, hannoevidenziato l’esistenza di un sensibile differenziamento delle comunità. Le differenze maggiori riguardano il lago Pratignanoe potrebbero essere dovute al pH acido ed alla minore concentrazione di ossigeno disciolto, caratteristici di un bacino adavanzato grado di maturità.


2007 - Life cycle of Marphysa sanguinea (Polychaeta: Eunicidae) in the Venice Lagoon (Italy). [Articolo su rivista]
Prevedelli, Daniela; G., MASSAMBA N'SIALA; Ansaloni, Ivano; Simonini, Roberto
abstract

The life cycle of a brackish water population of Marphysa sanguinea(Polychaeta Eunicidae), from the Venice Lagoon (Italy), was investigated fromApril 1993 to August 1994. Marphysa sanguinea is a large-sized gonochoricspecies with annual iteroparous strategy and synchronous spawning at populationlevel. The sex-ratio was close to 1:1. There were no morphological differencesbetween males and females and spawning occurred without epitokalmetamorphosis. The gonadial activity was maximum during summer periodin both sexes. From May to September in the females, the greater number ofimmature oocytes could be observed; starting from November immatureoocytes decreased and progressively those with a wider diameter increased innumber. Spawning took place in April–May and generally not all eggs werespawned, a small proportion being kept as a reserve material for the followinggamete production. The pelagic phase (trochophore and metatrochophore stages)was short (2–3 days). The reduction in the dispersal phase, together withthe development of a strong anterior musculature, brought to an early acquisitionof the benthic habit, which was attained with the construction of themucous tube inside of which the larva lived. The results highlighted that colonizationof brackish environments took place thanks to morphological andphysiological features that allow this species to live in a sediment layer characterizedby the stability of the physical and chemical characteristics of thesubstratum.


2007 - Macrobenthos and environmental characteristics of the Venice lagoon [Articolo su rivista]
Prevedelli, Daniela; L. G., Bellucci; Simonini, Roberto; Ansaloni, Ivano; M., Frignani; A., Castelli; M., Ravaioli
abstract

Composition, structure and distribution of macrozoobenthic communities in four areas of the Venice lagoon were investigated. Polychaetes and Oligochaetes were the most abundant groups, followed by crustaceans, dipterans and bivalve molluscs. Area differences turned out to be very significant with a maximum diversity index in the central-south part of the lagoon, where there is a maximum influence of water exchanged with the sea. However, no significant differences in organism densities were observed, due to the high variability within each area. The species and their zonation were typical of Mediterranean lagoons. The biotic pattern does not seem related to the concentration of heavy metals in sediments, but rather to the different hydrological regime of the areas closer to the sea compared with areas closed to the mainland, where the influence of river outflow is greater


2007 - Recolonization and recovery dynamics of the macrozoobenthos after sand extraction in relict sand bottoms of the Northern Adriatic Sea [Articolo su rivista]
Simonini, Roberto; Ansaloni, Ivano; Bonini, P.; Grandi, Valentina; Graziosi, Francesco; Iotti, Mirko; MASSAMBA N'SIALA, Gloria; Mauri, Marina; Montanari, G.; M., Preti; DE NIGRIS, N.; Prevedelli, Daniela
abstract

The long-term effects of sand extraction on macrozoobenthic communities were investigated in an offshore area in theNorthern Adriatic Sea characterised by relict sands formed during the last Adriatic post-glacial transgression. Surveyswere carried out before, during and 1, 6, 12, 18, 24 and 30 months after extraction at three impacted and seven referencestations. The operations did not influence the physical characteristics of the sediment, but they caused almost completedefaunation at dredged sites. Univariate and multivariate analyses highlighted that the macrozoobenthic communityresponses to the dredging operations were (1) a rapid initial recolonisation phase by the dominant taxa present beforedredging, which took place 6–12 months after sand extraction; (2) a slower recovery phase, that ended 30 months afterthe operations, when the composition and structure of the communities were similar in the dredged and reference areas.This pattern of recolonisation–recovery fits well with the commonly encountered scenario where the substratum merelyremains unchanged after marine aggregate extraction.


2007 - Ruolo dei pattern climatici regionali nel differenziamento dellestorie vitali di Dinophilus gyrociliatus (Polychaeta, Dinophilidae) [Relazione in Atti di Convegno]
MASSAMBA N'SIALA, Gloria; Grandi, Valentina; Graziosi, Francesco; Prevedelli, Daniela; Simonini, Roberto
abstract

I cambiamenti nella distribuzione, abbondanza e le variazioni delle “life history” degli organismi sono tra le più evidenticonseguenze del riscaldamento globale. In questo studio è stato analizzato il ruolo svolto dai pattern climatici regionali neldifferenziamento delle “life history” di metapopolazioni del polichete Dinophilus gyrociliatus. Esemplari di D. gyrociliatussono stati raccolti da ambienti portuali e lagunari di due aree del Mediterraneo con diversi regimi termici: l’AdriaticoSettentrionale (AS), area relativamente fredda, ed il Mar Ligure-Tirreno (MLT), area temperata. Per ogni area sono stateconsiderate tre località. Le caratteristiche delle “life history” delle singole popolazioni sono state analizzate tramite Life TableResponse Experiments. Sono state osservate differenze sia a livello di località, riconducibili all’estrema selettività degliambienti portuali, sia a livello di area. Le popolazioni originarie dell’area temperata adottano strategie più opportuniste diquelle provenienti dall’area più fredda. I ceppi del MLT, infatti, si sviluppano e raggiungono la maturità sessuale in tempi piùridotti, hanno vita breve, depongono uova di dimensioni maggiori e mostrano tassi di crescita più elevati rispetto allepopolazioni dell’AS. Questi risultati suggeriscono che una delle conseguenze del riscaldamento globale per gli organismimarini con scarsa capacità di dispersione potrebbe essere lo spostamento verso strategie di tipo opportunista.


2007 - Simpatria e differenziamento delle life history in due specie ermafrodite di Ophryotrocha (Polychaeta: Dorvilleidae) [Relazione in Atti di Convegno]
Grandi, Valentina; Simonini, Roberto; MASSAMBA N'SIALA, Gloria; Graziosi, Francesco; Prevedelli, Daniela
abstract

Nell’ambito di una campagna di campionamento sono stati rinvenuti numerosi esemplari di diverse specie di Ophryotrocha,tra cui O. adherens e O. diadema, specie ermafrodite simultanee finora mai rinvenute nel Mediterraneo Occidentale. In questostudio sono state analizzate in laboratorio le principali caratteristiche delle life history di popolazioni di O. adherens e O.diadema originarie di Porto Empedocle (Sicilia) tramite Life Table Response Experiments. Queste due specie vivono nellostesso habitat e sono caratterizzate dalla stessa strategia sessuale, ma differiscono per numerosi aspetti delle storie vitali: O. adherens si sviluppa più rapidamente, raggiunge precocemente la maturità sessuale, depone uova più piccole, ha taglia delcorpo minore e durata della vita più breve rispetto ad O. diadema. In accordo con osservazioni effettuate su altri gruppi dispecie simpatriche appartenenti al genere Ophryotrocha, è probabile che il differenziamento delle storie vitali svolga un ruolochiave nella coesistenza di queste specie.


2006 - Gonochorism vs. hermaphroditism: relationship between life history and fitness in three species of Ophryotrocha (Polychaeta : Dorvilleidae) with different forms of sexuality [Articolo su rivista]
Prevedelli, Daniela; MASSAMBA N'SIALA, Gloria; Simonini, Roberto
abstract

The relationships between life history, fitness and sexuality, together with their ecological and evolutionary significance, has been analysed comparing the main life-history traits and demography in three closely related species belonging to the genus Ophryotrocha. The species are: the gonochoristic O. labronica, the simultaneous hermaphrodite O. diadema and the protandrous hermaphrodite O. puerilis. 2. Survivorship and reproductive data were collected weekly and were used to construct life tables and population projection matrices for each species and compare life-history characteristics. Elasticity, life-table response and decomposition analyses were performed to examine the relative contribution of fecundity and survivorship to differences in lambda between species. 3. The gonochoristic and hermaphroditic species differ in all the main life-history parameters and also in demographic characteristics. In particular the value of lambda, used commonly to express fitness, is markedly higher in the gonochoristic species while in terms of fitness simultaneous and sequential hermaphroditism are very similar. In the genus Ophryotrocha gonochorism currently represents the most widespread condition, being characteristic of the majority of the known species in the genus. 4. Given the demographic advantage ensured by gonochorism, it remains be understood why some species have retained simultaneous hermaphroditism and one has evolved a sequential type hermaphroditism; the most probable hypothesis is correlated with the density of the species in natural habitats.


2006 - La meiofauna delle sabbie “relitte” dell’Adriatico Settentrionale soggette ad operazioni di escavo [Articolo su rivista]
G., Ferrari; Ansaloni, Ivano; Mauri, Marina; Pagliai, Anna Maria; Prevedelli, Daniela; Simonini, Roberto; Todaro, Mary Antonio Donatello
abstract

The study falls within a larger research programme aimed at assessing the effect of dredging operations on benthic fauna associated with an off-shore sand bank to be used for beach nourishment. Meiofaunal samples in three replicates were collected in three periods: before, during and one month after the dredging operations, at 10 sites: 3 in the impacted area and 7 in adjacent areas not subject to dredging. A faunistic survey of sediment cores found the meiofaunal benthic community to be composed almost exclusively of epibenthic and infaunal forms. The community was dominated by Nematoda followed by Harpacticoida, with the highest density recorded before the beginning of the operations. The dredging had a strong, adverse effect on the fauna, causing near complete defaunation at the impacted sites. One month after completion of the operation, the fauna of the impoverished sites did not show significant evidence of recovery; a working hypothesis relates the slow recolonisation process to the large extension of the impacted area.


2006 - Sessualità e fitness nel genere Ophryotrocha (Polychaeta): confronto tra specie gonocoriche ed ermafrodite. [Articolo su rivista]
MASSAMBA N'SIALA, Gloria; Prevedelli, Daniela; Simonini, Roberto
abstract

In this study the relationship between life-history, sexuality and fitness of three species of Ophryotrocha (Polychaeta, Dorvilleidae) with three different sexual strategies (gonochorism, simultaneous hermaphroditism and protandrous hermaphroditism) has been analyzed. Survivorship and fecundity data were collected weekly and used to define the relative contribution of these two ecological parameters to differences in the population growth rate. Results indicate that gonochorism is the most advantageous condition for fitness and demographic growth.


2005 - Effects of long-term dumping of harbor-dredged material on macrozoobenthos at four disposal sites along the Emilia-Romagna coast (Northern Adriatic Sea, Italy) [Articolo su rivista]
Simonini, Roberto; Ansaloni, Ivano; F., Cavallini; Graziosi, Francesco; Iotti, Mirko; MASSAMBA N'SIALA, Gloria; Mauri, Marina; G., Montanari; M., Preti; Prevedelli, Daniela
abstract

Sediment from harbors of the Emilia-Romagna (Northern Adriatic Sea) were dredged and dumped in four disposal areas characterized by muddy bottoms. The long-term effects of the dumping on macrozoobenthic communities were investigated before and after 6 month, 8 month, 2 years and 4 years. The disposal of dredged material did not influence the granulometry and %TOC in the sediment, and no alterations in the structure of the macrobenthic communities were observed in the four areas. The lack of impact could be ascribed to the environmental characteristics and precautionary measures taken to minimize the effects of the dumping. It appears that: (1) the communities of the dumping areas are well adapted to unstable environments; (2) the sediments were disposed gradually and homogeneously over relatively large areas; Other factors that help to reduce the impact of sediment disposal are the low concentrations of contaminants in dredged materials and the similarity of sediment in the dredged and disposal areas. Off-shore discharge appears a sustainable strategy for the management of uncontaminated dredged sediments from the Northern Adriatic Sea harbors.


2005 - Recupero delle comunità macrozoobentoniche in seguito all'estrazione di sabbie relitte in un'area al largo delle coste dell'Emilia Romagna. In Ecologia. Atti del XV Congresso Nazionale della Società Italiana di Ecologia [Relazione in Atti di Convegno]
Ansaloni, Ivano; F., Cavallini; Graziosi, Francesco; Iotti, Mirko; MASSAMBA N'SIALA, Gloria; Mauri, Marina; Prevedelli, Daniela; Simonini, Roberto; Montanari, ; M., Preti
abstract

Il 'Programma pluriennale di monitoraggio dell'area a mare da cui sono state prelevate le sabbie per il ripascimento delle spiagge emiliano-romagnole', finanziato dalla regione Emilia-Romagna, ha permesso di valutare l'impatto delle operazioni di dragaggio mediante lo studio delle comunità macrozoobentoniche e di analizzare il processo di recupero dell'area dragata. I campionamenti sono stati effettuati prima (03/01), durante (04/02) e dopo circa 1, 6, 12, 18, 24 e 30 mesi dal dragaggio, in 3 stazioni nella zona di prelievo (impattate) ed in 7 stazioni adiacenti (controlli). Le attività di estrazione hanno determinato la quasi completa defaunazione delle zone soggette al dragaggio, ma non hanno alterato la granulometria e la % di TOC del sedimento. Il processo di ricolonizzazione, relativamente veloce (12-18 mesi dall'intervento), è avvenuto soprattutto tramite l'insediamento di specie tipiche delle sabbie relitte mentre il contributo delle specie oppurtuniste è stato trascurabile. Il recupero della struttura delle comunità, invece, è stato più lento e ha richiesto circa 30 mesi. Il limitato impatto delle operazioni di estrazione sulle caratteristiche fisiche del sedimento e le particolari caratteristiche idrologiche dell'area hanno permesso il rapido e completo recupero della comunità macrozoobentonica della zona soggetta al dragaggio.


2005 - The effects of sand extraction on the macrobenthos of a relict sands area (Northern Adriatic Sea): results 12 months post-extraction. [Articolo su rivista]
Simonini, Roberto; Ansaloni, Ivano; Pagliai, Anna Maria; F., Cavallini; Iotti, Mirko; Mauri, Marina; G., Montanari; M., Preti; A., Rinaldi; Prevedelli, Daniela
abstract

Sands for the nourishment of beaches along the Emilia-Romagna coast (northern Adriatic Sea) were dredged from an offshore area characterised by relict sands formed during the last Adriatic post-glacial transgression. The short-term effects of the sand extraction on macrozoobenthic communities were investigated before, during and 1, 6 and 12 months after dredging at three impacted stations and seven control stations. Sand extraction activities did not significantly influence the granulometry and %TOC in the sediment but caused almost complete defaunation at dredging stations. Yet, just 12 months after the extraction, the recolonisation of communities at the impacted stations was at an advanced stage. Unlike other studies on the effects of extraction of marine sand, no significant settlement of opportunistic species was observed. The limited impact of the sand extraction operation on the physical characteristics of the sediment and hydrological-sedimentary characteristics in the relict sand area should aid its rapid recovery and the restoration of the original community in a short period of time (2-4 years after dredging).


2005 - The seasonal dynamics of six species of Dorvilleidae (Polychaeta) in the harbour of La Spezia (Italy) [Articolo su rivista]
Prevedelli, Daniela; MASSAMBA N'SIALA, Gloria; Simonini, Roberto
abstract

In the harbour of La Spezia (Italy) six polychaete species belonging to the family Dorvilleidae are present. The population dynamics of Dillophilus gyrociliatus, Ophryotrocha hartmanni, O. japonica, O. labrotfica, O. puerilis and Schistotnerin-gos rudolphii has been studied from August 2002 to August 2003. The density of each species was considerably different and during the year there was a species succession that alternated in dominating the community. The role of the life-history characteristics of each species and environmental conditions in determining the Population dynamics arc discussed.


2004 - Organic enrichment and structure of the macrozoobenthic community at three sites in the northern Adriatic Sea [Articolo su rivista]
Simonini, Roberto; Ansaloni, Ivano; Pagliai, Anna Maria; Prevedelli, Daniela
abstract

The structure of the macrozoobenthic community and the vertical distribution of organisms in the sediment were studied in order to assess the effects of river outflows and organic enrichment on the benthic community of the North Adriatic Sea. Sampling was carried out at one offshore sandy station (S3) and at two coastal muddy stations (S1 and S2), near to river Po and Adige deltas. Samples were collected in four surveys covering one year fromApril 1995 to January 1996. In all surveys, the offshore sandy station showed a complex trophic structure, high species richness and diversity, with the occurrence of tubicolous or burrowing polychaetes like Nothria conchylega, Aponuphis bilineata, Maldane sarsi, Nematonereis unicornis and Eunice vittata, which also colonized the deeper sediment layers. On the other hand, the coastal muddy stations both exhibited similar species composition and a great abundance of dominant, opportunistic species such as the bivalve Corbula gibba, typical of unstable sea bottoms with a high rate of sedimentation, and some polychaetes typical of sublittoral muddy bottoms such as Levinsenia gracilis, Aricidea claudiae, Prionospio malmgreni, Sternaspis scutata and P. cirrifera. The high density of a few opportunistic species (mainly surface-deposit feeders) and the scant penetration oforganisms within sediments that characterized the stations S1 and S2 support other evidence of the eutrophication of the coastal areas of the north-western Adriatic Sea. However, the high biomass values, the species richness and diversity observed in S1 and S2 suggest the occurrence of less extreme conditions than at other highly-eutrophicated coastal areas. River outflows, eutrophication and, especially, the increasing frequency of acute dystrophic events may be recognized as the driving forces determining the structure and composition of the macrozoobenthic community at coastal areas of north-western Adriatic Sea.


2003 - Differenze nella life history di tre popolazioni di Ophryotrocha japonica (Polychaeta: Dorvilleidae). [Articolo su rivista]
Prevedelli, Daniela; Simonini, Roberto
abstract

This paper examines the life history and demography of three populations of Ophryotrocha japonica an alien species that for until 2001 had only been reported in harbour environments along the Asian and American coasts of the Pacific. The populations analysed came from the Italian harbors of Leghorn and Ravenna and from the brackish Mar Piccolo of Taranto. The three strains are inter-fertile both with one another and with their Pacific counterparts. Notwithstanding among populations were found morphological, reproductive and demographic differences. In Leghorn and Taranto populations there is a sort of sexual dimorphism based on body size that is not present in the Ravenna strain. The most important differences concern the reproductive characteristics. Indeed, fecundity, eggs size and reproductive investment varies greatly between populations. The differences in the life history determine very important consequences for the demography and fitness of the populations, and may depend on the species’ adaptation to different environment or may be the result of independent introduction from different localities or at different times.


2003 - Effects of temperature on two Mediterranean populations of Dinophilus gyrociliatus (Polychaeta : Dinophilidae) I. Effects on life history and sex ratio [Articolo su rivista]
Simonini, Roberto; Prevedelli, Daniela
abstract

The effects of temperature on the life history characteristics of two populations of the polychaete Dinophilus gyrociliatus, one from Ravenna (northern Adriatic Sea) and the other from Genoa (Ligurian Sea), were investigated. The temperatures tested (6, 12, 18, 24 and 30 degreesC) cover a wider range than those prevailing in the natural environment. In the populations studied there are broad differences in timing of development and reproduction. At 6 degreesC, the adults of both populations survive for a long time but they are unable to reproduce. At 12 degreesC, only the animals from Ravenna manage to reproduce. At the higher temperatures (18, 24 and 30 degreesC), the development of the animals belonging to the Genoa strain is faster than that of the Ravenna strain. The duration of the various phases of the biological cycle is very similar in both populations, but that from Ravenna exhibits greater tolerance of low temperatures, slower development rate and lower development threshold temperature than does the Genoa population. Temperature and geographical origin also have strong effects on reproductive characteristics. The highest fecundity values were observed at 12 degreesC in the Ravenna strain, the lowest at 30 degreesC in both groups. At 18 degreesC, the Genoa population is more fecund than the Ravenna one, while the situation is reversed at 12 degreesC. The smallest ovigerous capsules are produced at 30 degreesC, the biggest at 12 degreesC, and the Genoa females produce larger capsules than do the females from Ravenna, except at 12 degreesC. The size of both male and female eggs varies in relation to temperature, the smallest female eggs generally being laid at the higher temperatures. At all the temperatures tested, the sex ratio of the Ravenna population is higher than that of the Genoa population. In the Ravenna strain, temperature has no effect on the sex ratio, while in the Genoa strain the sex ratio at 24 degreesC is lower than at 18 and 30 degreesC. Comparison of the two populations at the same temperature reveals considerable differences in the characteristics of their respective life histories and sex ratios. It is very likely that the extreme selectivity of the harbor environments has favored the fragmentation of the species into differentiated populations that have adapted to the conditions prevailing in the different localities. (C) 2003 Elsevier Science B.V. All rights reserved.


2003 - Effects of temperature on two Mediterranean populations of Dinophilus gyrociliatus (Polychaeta : Dinophilidae) II. Effects on demographic parameters [Articolo su rivista]
Simonini, Roberto; Prevedelli, Daniela
abstract

The effects of temperature on demographic characteristics of two populations from Ravenna and Genoa of the polychaete Dinophilus gyrociliatus were investigated. Temperature affects age-specific survival and fecundity and all the demographic parameters often to a different degree in the two populations. Individuals from Ravenna survive longer than those from Genoa. The most evident differences in the age-specific fecundity curves of the experimental groups are related to age at maturity and the duration of the reproductive period that are in inverse proportion to temperature. In both populations of D. gyrociliatus, the maximum daily fecundity is observed at intermediate temperatures. In all cases, the Genoa females mature earlier, attain their maximum fecundity more quickly and have a shorter reproductive period than their Ravenna counterparts. Age at maturity, fecundity during the first reproductive events and juvenile survival are by far the most important characteristics in determining the fitness of the two populations at the tested temperatures. Even though the greatest net growth rates and highest expectation of life were recorded at 12 degreesC in the Ravenna population, the delay in the attainment of sexual maturity means that, at this temperature, the population growth rate is lowest. The higher juvenile survivorship and the greater fecundity observed at 24 degreesC is counter-balanced by the early attainment of sexual maturity induced at 30 degreesC. The comparison of the population growth rate calculated in laboratory with field data suggests that temperature is one of the main environmental parameters determining the fitness of D. gyrociliatus. (C) 2003 Elsevier Science B.V. All rights reserved.


2003 - Effetti dell'estrazione di sabbie marine sulla comunità macrozoobentonica delle sabbie relitte dell'Adriatico settentrionale [Relazione in Atti di Convegno]
Ansaloni, Ivano; Baraldi, Elena; Mauri, Marina; G., Montanari; Pagliai, Anna Maria; M., Preti; Prevedelli, Daniela; A., Rinaldi; Simonini, Roberto; Todaro, Mary Antonio Donatello
abstract

Il “Programma pluriennale di monitoraggio dell’area a mare da cui sono state prelevate le sabbieper il ripascimento delle spiagge emiliano-romagnole”, finanziato dalla regione Emilia-Romagna, ha previstolo studio delle comunità macrozoobentoniche per valutare l’impatto delle operazioni di dragaggio ed ilprocesso di ripopolamento. I campionamenti sono stati effettuati prima (03/01), durante (04/02) e dopo circa1, 6 e 12 mesi dal dragaggio, in 3 stazioni nella zona di prelievo (impattate) ed in 7 stazioni adiacenti(controlli). Le granulometrie delle stazioni impattate erano simili a quelle osservate nelle stazioni di controlloe non hanno presentato variazioni significative nel corso dei lavori. Durante le cinque campagne sono statirinvenuti 16510 individui, appartenenti a 148 unità sistematiche. La maggior parte delle specie rinvenute ècaratteristica di fondi misti sabbiosi e fangosi. Gli anellidi costituivano il phylum maggiormenterappresentato, seguito da molluschi e artropodi. Le stazioni impattate hanno subito una defaunazione quasicompleta, ma dopo 12 mesi dal dragaggio la comunità macrozoobentonica mostra significativi segnali direcupero e ricolonizzazione. Le aree di controllo non sembrano aver risentito delle operazioni di dragaggio.A differenza di altri interventi analoghi, non si è registrato l’insediamento di specie opportuniste nellestazioni impattate. Inoltre, confrontando i dati faunistici relativi alle diverse campagne, sono state osservatesignificative variazioni nei popolamenti, legate ai cicli biologici delle diverse specie ed alla elevatastagionalità dell’Adriatico settentrionale.


2003 - Effetto della temperatura sul ciclo biologico e la riproduzione di due popolazioni di Dinophilus gyrociliatus (Polychaeta: Dinophilidae). [Articolo su rivista]
Simonini, Roberto; Prevedelli, Daniela
abstract

The effects of temperature on life history characteristics of two populations from Ravenna and Genoa of the polychaete Dinophilus gyrociliatus were investigated. The tested temperatures (6, 12, 18, 24 and 30°C) are upper and lower the range of temperature in the natural environment. In the studied populations there are broad differences in timing of development and reproduction. The duration of the various phases of the biological cycle is very similar in both populations, but the Adriatic strain exhibits greater tolerance of low temperatures, slower development rate and lower development threshold temperature in respect of the Genoa population. Temperature and geographical origin have also strong effects on reproductive characteristics. The size of both male and female eggs varies in relation to temperature, the smallest female eggs generally being laid at the higher temperatures. Comparison of the two populations at the same temperature reveals considerable differences in the characteristics of the life history between the two populations. It is very likely that the extreme selectivity of the harbour environments has favoured the fragmentation of the species into genetically differentiated populations that have adapted to the conditions prevailing in the different localities.


2003 - Karyotype and sex determination in Dinophilus gyrociliatus (Polychaeta: Dinophilidae) [Articolo su rivista]
Simonini, Roberto; Molinari, Federica; Ansaloni, Ivano; Pagliai, Anna Maria; Prevedelli, Daniela
abstract

The study of the male and female karyotypes ofthe polychaete Dinophilus gyrociliatus was performedwith the aim of ascertaining the diploid number ofchromosomes and confirming the existence of karyologicaldifferences between the two sexes. Our resultsevidenced that the female karyotype of D. gyrociliatusconsists of 2n=24 chromosomes, while the male karyotypehas 2n=23 chromosomes. X chromosomes aresubtelocentric and much bigger than the autosomes. Thesize of the D. gyrociliatus chromosomes, which in thefemale embryos vary in length from little more than2.8 lm to less than 0.7 lm, are relatively small bycomparison with those of other polychaetes. The existenceof maternal and environmental factors able toinfluence the sex ratio of D. gyrociliatus and chromosomaldifferences between the sexes confirms that: (1) sexdetermination is chromosomal and syngamic of the XX–X0 type and (2) control of the sex ratio is progamic anddepends on genetic and environmental factors.


2003 - Life cycles in brackish habitats: adaptive strategies of some polychaetes from the Venice lagoon [Articolo su rivista]
Prevedelli, Daniela; Simonini, Roberto
abstract

The life cycle of five species of polychaetes living in the Venice lagoon is analysed with the aim of finding out if some traits can be interpreted as an adaptation to brackish environments. The studied species are characterized by different sizes and reproductive strategies. Marphysa sanguinea is a large-sized, annual iteroparous species belonging to the Eunicidae family that reproduces without epitokal modification. Perinereis cultrifera and P. rullieri are large-sized semelparous species belonging to the Nereididae family: the first reproduce with epitokal metamorphosis, the second do not. Ophryotrocha labronica and Dinophilus gyrociliatus are small iteroparous species with semi-continuous reproduction belonging to the Dorvilleidae and Dinophilidae families, respectively. All the species are gonochoric. The larger species often have a sex ratio close to 1:1, while in the smaller ones the sex ratio is biased toward the female sex (2:1 in O. labronica and 3:1 in D. gyrociliatus). Moreover, D. gyrociliatus exhibits strong sexual dimorphism: the males are dwarf and short living. All the large-sized species have external fertilization, while the small-sized O. labronica and D. gyrociliatus exhibit external fertilization with pseudo-copulation and internal fertilization, respectively, that ensure a high reproductive success. All the species produce lecitotrophic eggs, protect young stages from at least some environmental stresses and reduce larval dispersion. The role of the suppression of epitoky and protection structure for developing eggs in limiting the dispersal phase is discussed. All species, independent of reproductive strategies, are characterized by high fecundity and reproductive effort. In the small-sized species, the marked bias of the sex ratio in favour of the female sex and, in D. gyrociliatus, the reduction in the size of the male eggs, are significant factors in the increasing rate of the populations, enabling them to tolerate sharp variation in density due to environmental unpredictability. (C) 2003 Editions scientifiques et medicales Elsevier SAS and Ifremer/CNRS/IRD. All rights reserved.


2003 - Life history and demography of three populations of Ophryotrocha japonica (Polychaeta : Dorvilleidae) [Articolo su rivista]
Simonini, Roberto; Prevedelli, Daniela
abstract

This paper examines the life history and demography of 3 populations of the polychaete Ophryotrocha japonica, an alien species that until 2001 had only been reported in harbour environments along the Asian and American coasts of the Pacific. The populations analysed came from the Italian harbours of Leghorn and Ravenna, and from the brackish Mar Piccolo of Taranto. The 3 strains are inter-fertile, both with one another and with their Pacific counterparts, but were nevertheless found to have morphological, reproductive and demographic differences. In the Leghorn and Taranto populations there is a sort of sexual dimorphism based on body size that is not present in the Ravenna strain, while the most important differences concern their reproductive characteristics, with great variations being observed in their respective fecundity, egg size and reproductive investment. The differences in life history have very important consequences for the demography and fitness of each population. In particular, morphometric, reproductive and demographic characteristics set the Leghorn population apart from the other 2; it reaches sexual maturity more rapidly, lives longer, is decidedly larger and its population growth rate lambda is 2.26 wk(-1). The Ravenna and Taranto populations appear to be more alike; their eggs are the same size, they are equally fecund, make a similar reproductive investment and have lambda-values of 1.82 and 1.83 wk(-1), respectively. The marked differences observed among the 3 populations may depend on the species' adaptation to different environmental situations, but could also be the result of independent introductions from different localities or at different times.


2002 - I cromosomi di Dinophilus gyrociliatus (Polychaeta; Dinophilidae): il cariotipo femminile. [Articolo su rivista]
Simonini, Roberto; Molinari, Federica; Prevedelli, Daniela
abstract

The sex ratio of Dinophilus gyrociliatus is affected by genetic, environmental and maternal factors,but it was suggested that sex was determined by male heterogamety. In female embrios, a diploid number of 24 chromosomes was determined. Preliminary results on male embryos karyotype evidenced 2n=23 chromosomes, confirming the occurrence of a XX-X0 sex chromosome system.


2002 - Relationship between body size and population growth rate in two opportunistic polychaetes. [Articolo su rivista]
Prevedelli, Daniela; Simonini, Roberto
abstract

The relationship between body size and population growth rate λ has been studied in two species of opportunistic polychaetes, Dinophilus gyrociliatus and Ophryotrocha labronica, which colonize harbour environments. These species exhibit a semi-continuous iteroparous reproductive strategy, are phylogenetically closely-related but differ in body size and in some aspects of their sexuality. Ophryotrocha labronica is about 4 mm in body length, displays only slight sexual dimorphism and its sex ratio is biased towards the female sex in the ratio 2:1. Dinophilus gyrociliatus is about 1 mm in length, the males are extremely small and the sex ratio is strongly biased (3:1) in favour of the females. In spite of the considerable differences in all traits of their life histories and in many demographic parameters, the growth rates of the two populations are very similar. The analyses carried out have shown that the rapid attainment of sexual maturity of D. gyrociliatus gives it an advantage that offsets the greater fecundity of O. labronica. It is very likely that the reproductive peculiarities of D. gyrociliatus help to raise the population growth rates. The ‘saving’ on the male sex achieved both by the shift of the sex ratio in favour of the females and by the reduction in the males' body size would appear to enable D. gyrociliatus to grow at the same rate as O. labronica, a larger and more fecund species.


2001 - Effect of submerged structures on the diversity of macrozoobenthos in the Northern Adriatic Sea. [Relazione in Atti di Convegno]
Crema, Roberto; Prevedelli, Daniela; A., Castelli
abstract

Offshore expoitation of oil and other hydrocarbons requires the installation of platforms or similar structures fixed to the sea bottom. Generally, such structures remain in situ for long time after the end of drilling and pruduction activities. The macrozoobenthic communities of a sea area located in the Northern Adriatic Sea sorrounding one of these platforms were studied on two occasions: the first prior to the installation of the platform (1985), the second 8 years later (1993), after production and other activities had terminated. On both occasions, sampling were performed according to similar sampling grids extended about 3.5. km from the platform site. Comparing the community composition of the two periods, a remarkable decrease of surface deposit-feeders was observed in the second period. Ordering techniques, applied to the entire data set of communities samples of both periods, pointed out not only the expected separation of the sampling points of the two periods but also a different patter of dispersion.


2001 - Effect of temperature on demography of Ophryotrocha labronica (Polychaeta, Dorvilleidae) [Articolo su rivista]
Prevedelli, Daniela; Simonini, Roberto
abstract

A laboratory experiment was performed to evaluate the temperature-induced variation in the life history traits of Ophryotrocha labronica (Polychaeta). In this species age and size at maturity, survival and fecundity are affected by temperature. In particular in O. labronica, low temperatures cause a considerable delay in the attainment of sexual maturity, a reduced number of spawnings and longer intervals between one spawning and the next; fecundity is therefore lower and the animals generally live longer. At high temperatures, the animals mature rapidly, spawn very frequently and at shorter intervals; fecundity is high, even though the animals have a much shorter life span. Temperature determines the age-specific fecundity and survival patterns and hence the demographic characteristics of O. labronica; both the net reproductive rate R-0 and the population growth rate X vary in accordance with the temperature, thus demonstrating the importance of environmental factors in determining not only the reproductive characteristics of the individual animal but also the fitness of the populations as a whole.


2001 - Effects of diet and laboratory rearing on demography of Dinophilus gyrociliatus (Polychaeta : Dinophilidae) [Articolo su rivista]
Prevedelli, Daniela; Simonini, Roberto
abstract

Life table response experiments were performed to evaluate the demographic consequences of: (1) the dietary regimes and (2) the length of laboratory rearing in strains of Dinophilus gyrociliatus, a small infaunal polychaete. The first experiment was performed using animals recently collected from the natural environment and fed either on spinach or on Tetramin (artificial fish food with high caloric content). Starting from this original group, two distinct laboratory strains were established: the first raised only with spinach, the second only with Tetramin. In the first experiment, the group fed on Tetramin exhibited greater population growth rate (lambda), shorter generation time (T) and reduced expectation of life (e(0)) with respect to the animals fed on spinach. The second experiment took place 2 years later to evaluate the difference in life history traits between these two laboratory strains. In the case of the group fed on Tetramin, population parameters exhibited marked variations; in fact, lambda and the net reproductive rate (R-0) were significantly higher and T and e(0) were shorter than the corresponding parameters observed in the first experiment. Conversely, the demographic variations induced by laboratory rearing on a spinach diet were limited to a reduction in the expectation of life. The decomposition analysis showed that the reduction in generation time and the increase in fecundity occurring during the first 4 weeks of life accounted for nearly all the differences in lambda. During the long breeding period at constant temperature, photoperiod and salinity, a continuous selection of the most precocious and fecund individuals may have taken place as a consequence of the abundance of resources and the lack of predation.


2001 - Relationship of non-specific commensalism in the colonization of the deep layers of sediment [Articolo su rivista]
Prevedelli, Daniela; Simonini, Roberto; Ansaloni, Ivano
abstract

The macrofauna of samples collected with a box-corer from northern Adriatic Sea muddy bottoms in five survey campaigns from 1985 to 1993 has been analysed separately in sediment strata of varying depth. Samples were collected before, during and after the dumping of large amounts of inert particulate material that covered the seabed and caused an almost total defaunation. After this disturbance the seabed was recolonized by a new community. This new community differed from the original one mainly on account of the abundance of Mysella bidentata, a small bivalve filter or surface deposit-feeder. In the original community If. bidentata was confined to the more superficial sediment layers (0-5 cm) at low population density. In the new community it was very abundant and evenly distributed even in the deep layers (5-20 cm). Analysis of species association performed on data from each of the 54 corer samples collected in the last sampling period, points to a marked association between M. bidentata and Nephtys incisa in deeper sediment layers. Deep layer colonization by Mysella in association with the burrowing polychaete N. incisa suggests a case of commensalism between these two species.


2001 - Reproduction and larval development of Perinereis rullieri Pilato in the Mediterranean Sea (Polychaeta : Nereididae) [Articolo su rivista]
Prevedelli, Daniela; C., Cassai
abstract

The reproductive biology and larval development of a brackish water population of the nereidid polychaete Perinereis rullieri Pilato was investigated. About 100 specimens were collected monthly over the course of a year from the Venice Lagoon. Observation on gametogenesis indicates that oogenesis takes about 12 months while spermatogenesis is faster and takes about 6 months. The study showed that reproduction occurs once a year with a good synchronization between individuals and that spawning occurs without epitokal metamorphosis. Larval development was studied under laboratory conditions; the stages of trochophora and metatrochophora developed within the periovular jelly matrix and the first free living stage was the 3-setigers nectochaeta. In this species many life history traits can be interpreted as an adaptation to the brackish environments. In particular the adaptive significance of the variable age at maturity and the enclosing of the fertilized eggs in a jelly matrix are discussed.


2000 - Effects of salinity and two food regimes on survival, fecundity and sex ratio in two groups of Dinophilus gyrociliatus (Polychaeta : Dinophilidae) [Articolo su rivista]
Prevedelli, Daniela; Simonini, Roberto
abstract

The effects of salinity on survival, fecundity and sex ratio were studied in Dinophilus gyrociliatus; a small polychaete with a short lifespan, semicontinuous reproduction and progamic sex determination. The experiment was performed on two groups, originally collected as one sample, from the port of Genoa in November 1995. The specimens were separated into two groups, differing only in their diet: the first was fed with frozen spinach and the other with Tetramin Mikromin. The experiment was performed in 1998 after numerous generations had been maintained under laboratory conditions. The maximum expectation of life at birth varied with salinity level, and both groups showed a better tolerance towards a salinity below 35 psu than above 35 psu. The influence of both salinity and diet on fecundity had statistical significance even though the greatest differences were due to diet; animals fed with Tetramin had a two- or even threefold higher fecundity than those fed with spinach. Diet and salinity also had a statistically significant influence on the sex ratio. These results, as well as all the experimental observations carried out up to date, indicate that in D. gyrociliatus the determination of the sex ratio has a strong phenotypic component.


2000 - Effetto della dieta sulle life tables di Dinophilus gyrociliatus (Polychaeta: Dinophilidae) [Articolo su rivista]
Simonini, Roberto; Prevedelli, Daniela
abstract

The diet influences the rate of natural increase in Dinophilus gyrociliatus. two laboratory experiments were performed: the first with animals just collected from the field and the second in 1998 with animals reared in laboratory and fed with spinach or tetramin since 1996. the values of r are 1.21 and 1.50 respectively for spinach and tetramin in 1996; about 50 generations later in 1998 values increase to 1.29 and 2.66 respectively for spinach and tetramin


2000 - Osservazioni su riproduzione e sviluppo larvale di Desdemona ornata (Polychaeta: Sabellidae). [Articolo su rivista]
Sarto, M.; Bacchelli, M.; Prevedelli, Daniela
abstract

Reproductive biology and larval development of the polychaete Desdemona ornata (Banse) (Sabellidae) is described in a population collected in a brackish habitat of the Elba island. D. ornata is a gonochoric species, mature eggs measured 132x66 microns. Embryos and larvae are brooded in the maternal tube. larvae hatched at 3 setigerous segments


2000 - Recovery of the macrozoobenthic community of the Comacchio lagoon system (northern Adriatic Sea) [Articolo su rivista]
Crema, Roberto; Prevedelli, Daniela; Valentini, Andrea; Castelli, Alberto
abstract

From 1976 to 1992 the Comacchio lagoon system (a polyhaline lagoon on the northern Adriatic Sea coast) was exploited for intensive farming of eels and other fish. This activity, and its consequent increased release of organic matter, has led to hypereutrophication of the lagoon, resulting in a bloom of cyanobacteria and all almost total elimination of cukaryotes at both the planktonic and benthic level. After farming stopped, the ecological conditions tended to improve and the macrozoo-benthic community underwent a spectacular recovery The current communities do not differ substantially fi om those present before this ecological catastrophe, with the exception of a low level of internal differentiation not only among different lagoon sites but air, different substrates.


1999 - Fecundity and reproductive effort in Ophryotrocha labronica (Polychaeta : Dorvilleidae) [Articolo su rivista]
Cassai, C; Prevedelli, Daniela
abstract

Reproductive effort in terms of fecundity and energy allocation was studied in Ophryotrocha labronica La Greca and Bacci, 1962 a small, semicontinuous iteroparous species. In O. labronica fecundity is more or less constant throughout life, and the total fecundity of the 64 couples examined in this experiment only declined by 12% from the first to the last spawning. No linear relationship was found between fecundity and body size. The energy content of germinal and somatic tissues was determined by differential scanning calorimeter. The reproductive effort and a reproductive index based on the fifth spawning were evaluated to compare the patterns of energy allocation of a semicontinuous iteroparous species with semelparous and annual iteroparous species. The reproductive index ranged from 0.20 to 0.77, with an average of 0.480. The average reproductive effort was 0.840, ranging from 0.60 to 0.96. These figures highlight the enormous amount of energy that O. labronica allocates to reproductive tissues.


1999 - Survival, fecundity and sex ratio of Dinophilus gyrociliatus (Polychaeta : Dinophilidae) under different dietary conditions [Articolo su rivista]
Prevedelli, Daniela; Zunarelli, Renata
abstract

The influence of different diets (Tetramin dry fish food, frozen spinach, and Dieterba mixed cereals for babies) on survival, fecundity and sex ratio was examined in a population of the polychaete Dinophilus gyrociliatus. Specimens were collected in the harbour of Genoa and were studied under controlled laboratory conditions. In D. tyrociliatus sex determination is progamic; a single ovary produces eggs of two sizes, the small eggs develop into dwarf males and the large ones into females. Sex determination is chromosomal with male heterogamety of the XO/XX type, and therefore a 1:1 population sex ratio is expected. The results of the experiment revealed that diet significantly influenced survival, fecundity and also the sex ratio. With all diets the maximum lifespan was about the same, but after 10 weeks of experiments the percentage of survivors was 9% with Tetramin, 35% with spinach and 39% with cereals. Fecundity was different in relation to diet; females fed with Tetramin produced the maximum number of eggs. The greater and earlier mortality with the Tetramin diet could be related to the greater fecundity seen in this group, in that, the greater amount of energy allocated to the production of gametes may have reduced the percentage of individuals surviving to maximum age. In this species, diet affected not only fecundity but also the sex ratio; the worms fed with cereals showed a clear displacement of sex ratio towards males.


1998 - Effect of diet on reproductive characteristics of Ophryotrocha labronica (Polychaeta: Dorvilleidae) [Articolo su rivista]
Prevedelli, Daniela; Zunarelli, Renata
abstract

Effects of food quality on fecundity (defined as the number of eggs deposited in the entire life of a female), egg size and egg energy content (measured by differential scanning calorimeter were studied in two populations of Ophryotrocha labronica (La Greca and Bacci): one taken from the natural environment immediately prior to the experiment, and the other from the same original environment, but bred for more than 5 years in the laboratory. Results indicated that fecundity is mediated both by food quality and population origin. Specimens fed Tetramin generally spawned more frequently than those receiving the other two diets, while individuals bred in the laboratory since 1990 spawned more frequently than the wild population. Also the number of eggs per spawning and the total fecundity vary with the quality of the diet; Tetramin gives the highest fecundity values. The differences in egg size and energy content seem essentially related to the population origin, in fact, with all diets laboratory specimens produced larger eggs with higher energy contents than wild specimens.


1998 - Reproductive effort, fecundity and energy allocation in Marphysa sanguinea (Polychaeta: Eunicidae). [Articolo su rivista]
Cassai, C.; Prevedelli, Daniela
abstract

Reproductive effort in terms of fecundity and energy allocation was studied in the iteroparous and long lived polychaete Marphysa sanguinea. Both measures show great variability. Fecundity varied from 8500 to 24300 oocytes; no linear relationship was found between oocyte number and jaw length whereas a direct relationship was established between oocyte number and wet body weight. The energy content of germinal and somatic tissues was determined by differential scanning calorimeter (DSC). The reproductive effort for a single reproductive event was calculated according to the formula: RE = E-G/(E-G + E-S) where E-G is the total energy of the germinal tissues and E-S is the total energy of the somatic tissues. The lack of correlation between reproductive effort and size index strongly suggests that reproductive allocation does not increase with age. The reproductive effort ranged from 0.04 to 0.19 with a mean value of 0.120.


1998 - Reproductive effort, fecundity and energy allocation in two species of the genus Perinereis (Polychaeta: Nereididae) [Articolo su rivista]
Cassai, C.; Prevedelli, Daniela
abstract

The reproductive effort in terms of fecundity and energy allocation was studied in two species of semelparous polychaetes belonging to the genus Perinereis, living in the same environment, with different reproductive modalities. There is a great individual variability both in terms of reproductive effort and fecundity. Fecundity varied from 4080 to 15000 oocytes in P. rullieri and from 7000 to 26000 in P. cultrifera; no linear relationship was found between oocyte number and total jaw length utilised as size index. The energy content of germinal and somatic tissues was determined by Differential Scanning Calorimeter (DSC). The reproductive effort was calculated as RE = E-G/(E-G + E-S) where E-G is the total energy in germinal tissues and E-S is the total energy in somatic tissues. Reproductive effort is very high with mean values of 0.62 for P. rullieri and 0.79 for P. cultrifera. The different amounts of energy allocated in germinal tissues can be attributed to the different reproductive modalities-P. rullieri reproduces in the atokous phase whereas P. cultrifera has conserved epitoky in its life-cycle. The lack of correlation between reproductive effort and size index strongly suggests that reproductive allocation does not increase with age. In semelparous species the variability in fecundity and reproductive effort observed cannot be interpreted in terms of a trade-off between fecundity and survival as in iteroparous species. In fact, in semelparous an individual allocates all available resources to reproduction and then dies.


1997 - Survival and growth rate of Perinereis rullieri (Polychaeta, Nereididae) under different salinities and diets [Articolo su rivista]
Prevedelli, Daniela; Zunarelli, Renata
abstract

The effects of salinity and diet on survival and growth rate of the nereidid polychaete Perinereis rullieri have been investigated under controlled laboratory conditions. The experiment began from nec nectochaetes at 5-6 setigerous segments to exclude the high mortality occurring immediately after hatching. The tested salinities were 10 - 20 - 30 and 40 parts per thousand that slightly exceed those recorded in the natural environment during larval emergence. The larvae were fed with Tetramin MicroMin dry fish food and Tetramin MicroMin added with freeze-dried lyophilised Ulva rigida to test the possible antistress effect of vitamins C and E, in which the alga is rich. The experimental results highlight the influence of salinity on survival and growth race of P. rullieri. Enrichment with alga does not significantly affect survivorship and growth rates under all experimental conditions.


1992 - GROWTH-RATES OF PERINEREIS-RULLIERI (POLYCHAETA, NEREIDIDAE) UNDER DIFFERENT CONDITIONS OF TEMPERATURE AND DIET [Articolo su rivista]
Prevedelli, Daniela
abstract

The effects of temperature and diet on growth rates of the nereidid polychaete Perinereis rullieri have been investigated under controlled laboratory conditions from the beginning of larval feeding. Growth rate was evaluated under three diets (filamentous green algae, nauplii of Artemia salina, and Tetramin MikroMin dry fish-food), and three temperatures (15-degrees-C, 21-degrees-C, and 27-degrees-C). Growth rate was influenced both by diet and temperature. Diet appears the main factor strongly modifying the growth pattern.


1991 - INFLUENCE OF TEMPERATURE AND DIET ON SURVIVAL OF PERINEREIS-RULLIERI PILATO (POLYCHAETA, NEREIDIDAE) [Articolo su rivista]
Prevedelli, Daniela
abstract

The effects of temperature and diet on survival of Perinereis rullieri have been investigated under controlled laboratory conditions, from the beginning of larval feeding to adult stage. Survival rate was evaluated under three diets (green algae, nauplii of Artemia salina and Tetramin MikroMin dry fish-food) and three temperatures (15-degrees-C, 21-degrees-C and 27-degrees-C). Survival was influenced both by the composition and size of the food source. Temperature did not significantly affect survival.


1991 - LONG-TERM EUTROPHICATION EFFECTS ON MACROFAUNAL COMMUNITIES IN NORTHERN ADRIATIC SEA [Articolo su rivista]
Crema, Roberto; Castelli, Alberto; Prevedelli, Daniela
abstract

The macrozoobenthic community in the northern Adriatic Sea, south of the Po river, along the Emilia-Romagna region coast, was sampled in 1985. Sampling site was central to a highly eutrophicated area with greatly increased intensity and frequency of dystrophic events over recent decades. The sampled community differs from all those described in the same area in a period (1934-1936) previous to the actual degree of eutrophication. Large abundances of species indicative of unstable bottoms, such as the bivalve Corbula gibba and the polychaete Lumbrineris latreilli were recorded. Moreover, the community structural features indicate a state of immaturity, such as in early successional stage communities. The increased frequency of acute dystrophic events and consequent shortening of the time between successive disturbances is proposed as the cause of biocenosis modification and its current structure and composition.