ZOOSYSTEMATICS AND EVOLUTION, cilt.99, sa.1, ss.15-27, 2023 (SCI-Expanded)
A new amphipod species belonging to the genus Gammarus is described from the Gökgöl Cave, Zonguldak Province, Türkiye. The newly-identified species is relatively small (13 mm) and is a member of the Gammarus pulex-group by the presence of numerous long setae along the posterior margins of pereopods 3 and 4. The specimens were sampled from a shallow pond located in the dark zone (about 1 km inside the entrance) of the cave. Minute eyes, setose (both peduncle and flagellar segments) second antenna, slightly swollen flagellar segments of the second antenna, setose pereopods 3 and 4 and relatively short endopod/exopod ratio of the third uropod are the character combination of the newly-identified species in addition to lacking body pigmentation. The molecular phylogeny, based on the concatenated dataset (28S+COI, 1495 bp) indicated that the new species was resolved from the other Gammarus species by high bootstrap (NJ: 100, ML: 100). In addition to Gammarus tumaf sp. nov., mtDNA COI and nuclear DNA 28S gene data of Gammarus baysali