Structure générale des peuplements d’annélides polychètes dans le secteur n-e du golfe de Tunis

Abstract

The purpose of this study is to establish the general structure of the Polychaeta assemblages along the N-E coast of the Tunis gulf. In Total, nine stations were sampled, and the collected specimens were identified, for the majority, to species level. Then, the cluster analysis were carried out using the abundances of the various species at the studied stations, which permits to define three groups of stations with their leaders species. At the same time, principal descriptive synthetic parameters (Specific richness, Abundance, Shannon index and Equitability) were realized for each defined group, and some granulometric analysis were carried out. The results show that the sandy and muddy sediments dominated by Chaetozone setosa are the most diversified, but the least rich (58 species, 808 ind./m super(2)) and the fine sands dominated by Aricidea jeffreysii and Nephtys caeca appear slightly less diversified, but the most rich (45 species, 1833 ind./m super(2)). On the other hand, the muddy sediments dominated by Melinna palmate are the least diversified (19 species, 1240 ind./m super(2)).