Deep-sea benthic ostracodes from multiple core and epibenthic sledge samples in Icelandic waters

Deep-sea benthic Ostracoda (Crustacea) in Icelandic waters are poorly known. Here we report deep-sea ostracode assemblages from the multiple core (MUC) and the epibenthic sledge (EBS) samples collected from Icelandic waters by the first cruise of the IceAGE (Icelandic Marine Animals: Genetics and Ecology) project. Samples from shelf-edge and lower-bathyal working areas are examined. The results show (1) distinct MUC and EBS faunas due to the large difference in mesh size of MUC and EBS; and (2) distinct shelf-edge and lower-bathyal ostracode faunas. Such remarkable faunal turnover from shelf to bathyal depths is similar to the faunal turnovers reported from depth transects in the adjacent regions of the western North Atlantic Ocean, the Greenland Sea, and the North Sea, but, at the same time, there are certain differences in the faunal composition between the Icelandic waters and these adjacent regions. In addition, we illustrate many Icelandic deep-sea ostracode species with high-resolution scanning electron microscopy and composite all-in-focus stereomicroscopic images for the first time. These results provide important basic information on deep-sea ostracode research and biogeography of this important region connecting North Atlantic proper and Nordic Seas.