Structure and functions of Polychaetofauna living in Mytilus galloprovincialis assemblages in Thermaikos Gulf (north Aegean Sea)

Abstract

The purpose of this study is to examine the Polychaetes populations of the mussel Mytilus galloprovincialis Lamarck 1819 assemblage in Thessaloniki Bay (Perea, Neoi Epivates, Agia Triada) in space and time. Forty-eight Polychaetes species, which belong to 16 families, were identified among 10 593 individuals. The different distribution in space and time can be attributed to the life cycles of the Polychaetes, and also to the various biotic interactions. In general, the abundance follows the succession of the seasons, with some deviations though. Thus, the samples can be divided into two major groups, the winter and summer samples. The structure of the feeding guilds of the Polycheates population was also investigated and 9 different feeding guilds were identified. The microphagous, sedentary Polychaetes were the dominant guild, whilst the carnivores were the most abundant among the macrophagous. No major differences were observed, as regards the composition of the feeding guilds. The study of the structure of the polychaetofauna showed similar diversity with that of other Mediterranean regions. This fact implies that the polychaetofauna of the M. galloprovincialis assemblages in the Mediterranean Sea has a stable structure and shows a certain resemblance. Furthermore, the polychaetofauna includes species known as capable of living in polluted water as well as others that are more sensitive in such conditions. Therefore, the biomonitoring of the examined regions proves to be essential for obtaining valuable information about the state of their waters. © 2000 Ifremer/CNRS/IRD/Éditions scientifiques et médicales Elsevier SAS Polychaeta / infralittoral / hard substratum / trophic relations / Aegean Sea