1,721,111 research outputs found
General characteristic of reproduction and recruitment in Polychaete assemblage in a brackish microhabitat (Island of Elba)
No full textLe peuplement de polychetes d'un petit bassin saumatre de l'ile d'elbe (mer mediterranèe)
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Streptosyllis arenae Webster e Benedict, 1884 (Polychaeta, Syllidae): prima segnalazione nel Mediterraneo
No full textDesdemona ornata Banse, 1957 (Polychaeta, Sabellidae, Fabricinae) new record in the Mediterranean Sea
No full textResponse of coastal dune plants to the combined effects of increased sand accretion and nutrient availability under a changing climate
No full textDetection of stress on macrozoobenthos: evaluation of some methods in a costal mediterranean lagoon
No full textThe effects of taxonomic aggregation, the ABC-technique and meta-analysis approaches were tested along a known stress gradient in the Orbetello lagoon, a Mediterranean coastal brackish basin. Multivariate analyses of taxonomic aggregated data detected differences among the three sampled areas, except biomass phylum data analyses which showed a marked loss of information. ABC curves did not succeed in differentiating stress levels at various sites of the Orbetello lagoon. This was mainly due to species distribution, which did not follow the ABC criteria (a decrease in the body size with increasing stress level) in this lagoon. Phylum-level meta-analysis exhibited some, but not all, results consistent with the ordination models. Hence, new methods to achieve a reliable stress classification appear to be necessary in such habitats
Role of the nutritive value of sediment in regulating population dynamics of the deposit-feeding polychaete Streblospio shrubsolii
No full textThe importance of changes in nutritive value of the sediment in regulating the dynamics of the small deposit-feeding polychaete Streblospio shrubsolii (Buchanam, 1890) was examined. First, fluctuations in the population dynamics of S. shrubsolii and in the nutritive content of the sediment were studied on a seasonal scale. Subsequently, a manipulative field experiment was used to test the hypothesis that, in summer, availability of food regulates aspects of the population dynamics of S. shrubsolii. In summer 1997, sharp increases in protein concentrations and in the number of individuals of S. shrubsolii were found compared to all the other seasons. Densities of S. shrubsolii also showed an increase in the subsequent season. Newly recruited juveniles (19-31 setigers) were abundant in summer and autumn 1997, whereas the number of juveniles (32-42 setigers) increased in autumn 1997. Large numbers of adults were found in summer 1997. Significant negative correlations occurred in summer 1997 between the concentrations of proteins and the total number of individuals, the number of newly recruited juveniles and the density of adults. No differences in densities of juveniles, adults or total number of individuals were found among plots before starting the experiment. After 20 days of experimental enrichment, proteins showed a tendency to increase. After 40 days of enrichment, the total number of individuals was significantly greater in the enriched plots. Large numbers of newly recruited larvae and postlarval adults were found in the enriched plots. The experiment corroborated the model that the growth of population was limited by the availability of food in summer. Thus, in this season, patches of food could have a fundamental role in determining the population dynamics of small deposit-feeders under natural conditions and over short time scales
Preliminary results on recolonization in a small brackish basinof Elba Island (Western Mediterranean)
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