DIET COMPOSITION OF THE BATHYAL CRABS CHACEON MEDITERRANEE MANNING & HOLTHUIS AND GERYON LONGIPEI A. MILNE-EDWARDS (DECAPODA, GERYONIDAE) COLLECTED AT DIFFERENT DEPTHS IN THE EASTERN MEDITERRANEAN

摘要

A large number of specimens of Geryon longipes and Chaceon mediterraneus were collected by a series of baited traps deployed at 11 stations in the Cretan sea and the Levantine basin, covering a depth range of 1511 to 3080 m. The two crab species werenot trapped together in any of the traps, however. Stomach content analysis of both species revealed a rather wide variety of prey categories (excluding the bait), such as Ascidiacea, Alcyonaria, Decapoda, Mysidacea, Amphipoda, and Polychaeta. C. mediterraneus showed a highly diversified diet with Crustacea, Alcyonaria, and Ascidiacea being the most dominant prey categories. The diet variability of G. longipes is less than that of C. mediterraneus, but Alcyonaria and Ascidiacea appeared again to be thetwo most abundant prey categories. However, the diet compositions of these two species appear to be different, with only few prey categories in common. The vacuity coefficient value was lower in C. mediterraneus than in G. longipes, which seems to have alower feeding activity. Both species seem to exploit a variety of food resources. This makes living possible in the bathyal zone of the oligotrophic eastern Mediterranean.