A new freshwater amphipod species, Gammarus obruki sp. nov., from Turkey (Amphipoda: Gammaridae)

A new species of freshwater amphipod, Gammarus obruki sp. nov., collected from İnderesi Cave, Barti{dotless}n Province, Turkey, is described and illustrated. The new species belongs to the Gammarus pulex group. The most discriminant characters of this species are the presence of prolonged extremities, a very long antenna 1 (up to 52 segmented flagellum), densely setose fifth peduncle and flagellar segments of antenna 2, and a fourth peduncle segment that has no long setae. A detailed morphological description and illustrations of the new species are provided and differences from related species are discussed. © TÜBİTAK.