Ostracods (Crustacea) and habitat similarities in the Bolu region (Turkey)

A total of 41 freshwater ostracod species belonging to 21 genera was collected from 144 different aquatic bodies in the Bolu region during the summer of 2006. The genus Schellencandona and 12 species (Candona weltneri, C. sanociensis, C. lactea, Fabaeformiscandona cf. breuili, F. balatonica, F. brevicornis, F. protzi, F. latens, Schellencandona cf. belgica, Pseudocandona cf. semicognita, Potamocypris similis, and P. smaragdina) are new for the Turkish Ostracoda fauna. Additionally, 5 other species (Herpetocypris brevicaudata, Heterocypris salina, H. rotundata, Cyclocypris laevis, Trajancypris serrata) are new for Bolu. UPGMA analyses showed districts of Bolu in 5 clustering groups. The highest habitat similarity (75%) was found between Yeniçağa and Göynük, while the least (20%) was observed between Seben and Merkez districts. Shannon-Weaver diversity suggested the highest evenness for ostracods at Dörtdivan (0.95) and the highest diversity index (H’) at Merkez district (2.63). Mechanisms of species dispersion are numerous, and may account for observed distributional patterns.