The benthic Copepoda (Crustacea) of Anaximenes Seamount (eastern Mediterranean Sea)-Community structure and species distribution

During research cruise M71/1 of German FV METEOR in winter 2006, meiofauna sampling was undertaken on the eastern Mediterranean Anaximenes Seamount at six sites (the summit, northern slope, north-western slope, north-western base, north-eastern slope and eastern base). Analysis of the benthic Copepoda (i.e. Harpacticoida and Canuelloida) revealed a highly diverse fauna. This is in contrast to what is generally considered an impoverished bathyal and abyssal fauna in the surrounding eastern Mediterranean Sea: It is regarded as one of the most oligotrophic regions of the world's oceans. This is attested to by comparison of the seamount fauna with that of a remote deep-sea (“Far-field”) site in the Rhodes Basin, which presented a clearly impoverished fauna with respect to abundance, higher-taxon diversity and species diversity. Comparison of sites across the seamount found no overall “seamount community” of benthic Copepoda. Instead, three different assemblages could be detected, with abundance and species diversity comparable to north-eastern Atlantic seamounts and islands. Regarding species composition, however, only four of the recorded species are shared with other Mediterranean and Atlantic elevations. The benthic copepod fauna at Anaximenes Seamount is composed mostly by “typical” deep-sea and eurybathic species, whilst “typical” shallow-water species were absent. Thus, it is concluded that Anaximenes Seamount does not play a role in the dispersal of shallow-water benthic Copepoda. Nonetheless, it appears important for the establishment of abundant and diverse deep-sea communities. Moreover, it constitutes no barrier for the dispersal of deep-sea benthic Copepoda in the Mediterranean.