Rissooidea Species Distributed along the Turkish Levantine Coast

The present study was performed to determine the taxonomical and ecological features of Rissooidea species distributed along the Turkish Levantine coast. The investigated material was collected within the various research projects conducted in the area between the years 1997 and 2011. As a result of the faunistic analysis of the benthic samples taken from various biotopes at depths between 0 and 1302 m in 85 stations, revealed 44 Rissooidea species and 7066 specimens belonging to 7 families (Rissoidae, Barleeidae, Caecidae, Hydrobiidae, Iravadiidae, Tornidae, and Truncatellidae). Among the identified species, Obtusella macilenta (Monterosato, 1880) and Alvania beanii (Hanley in Thorpe, 1844) are new records for the Levantine coast of Turkey. Most of the Rissooidea species (38 species) were found at depths down to 100 m, however, Alvania beanii, Alvania testae, Setia turriculata, Hyala vitrea, Obtusella macilenta and Benthonella tenella were sampled at depths up to 200 m or more. Among the determined taxa, a small number of species (Rissoa similis, Pusillina radiata and Ecrobia ventrosa) were encountered at rocky and mussel biotopes, while the remaining ones were encountered in soft substrata.