Nassellarian polycystine radiolarians observed in sediment traps from the southern Ionian Sea (Eastern Mediterranean)

Based on sediment traps moored in the southern Ionian Sea (Eastern Mediterranean), this paper documents nassellarian radiolarian occurrences (54 species). Several taxa are reported and illustrated for the first time for the Mediterranean Sea (i.e., Trisulcus triacanthus, Tricerapyris damaecornis, Archiperidium longispinum and Artostrobus joergenseni). Emphasis was placed on the documentation of various ontogenetic stages for some of the encountered species. We also provide a review of the biogeographical distribution for all the confidently identified species, in order to shed light on the provenance of radiolarian fauna in the eastern Mediterranean Sea. Interestingly, despite a majority of warm-water radiolarians, we frequently encountered temperate to cold-water radiolarian species, such as Artobotrys borealis, Artostrobus joergenseni and Archiperidium longispinum.