A revision of the genus Arenopontia Kunz, 1937 (Copepoda, Harpacticoida, Arenopontiidae), including the description of five new species Author Sak, Serdar Department of Biology, Faculty of Science and Literature, Balıkesir University, Balıkesir, Türkiye. Author Karaytuğ, Süphan Department of Biology, Faculty of Science, Mersin University, Mersin, Türkiye. Author Huys, Rony Department of Life Sciences, Natural History Museum, Cromwell Road, London SW 7 5 BD, UK. text Zootaxa 2024 2024-04-04 5433 1 1 50 http://dx.doi.org/10.11646/zootaxa.5433.1.1 journal article 10.11646/zootaxa.5433.1.1 1175-5326 10953646 06E5A735-A276-41D7-A9EE-B09642D953B6 Arenopontia subterranea Kunz, 1937 sensu Apostolov (1973) Marinov’s (1971) publication had apparently remained unnoticed to Apostolov (1973) when he stated that A. pontica may well be a synonym of A. subterranea . Apostolov referred to the variability previously reported for the French Mediterranean ( Chappuis, 1954a ) and Romanian “populations” ( Şerban, 1959 ) of A. subterranea as evidence in support of his claim, however fueled the confusion by stating that the Black Sea specimens (from an unspecified locality in Bulgaria ) represented a new but unnamed subspecies of A. subterranea . Although Apostolov (1973: 104–105 ; Fig. 18 -(1–8)) claimed that his material exhibited considerable variability in the caudal rami, P1 exopod and P5, he did state that it agreed with Şerban’s (1959) observations based on Romanian specimens, confirming the absence of the foliaceous condition of caudal ramus seta VII and the penicillate condition of the inner distal seta on P1 exp-3. It is not clear which variability in caudal ramus and P1 endopod morphology Apostolov referred to. As pointed out by Sak et al. (2008) Apostolov (1973) clearly had two or more co-existing species in his samples and failed to distinguish between them as indicated by his illustrations of the female P5. His Figure 18-5 shows a fifth leg of the subterranea - type which is remarkably similar to that of A. anatolica sp. nov. (compare Fig. 6C ) while Sak et al. (2008) had previously noted that his Figure 18-6 was almost certainly based on the species previously identified by Marinov (1971) as A. stygia Noodt, 1955c (= Psammoleptastacus barani Sak, Huys & Karaytuğ, 2008 ). An alternative interpretation is that the latter is based on A. basibuyuki sp. nov. (compare Fig. 8A ) which is known to be widely distributed along the Turkish Black Sea coast. Since Apostolov (1973 : Fig. 18-1 ) did not provide any information about the ornamentation of P1 enp-1, his material (whichever species he depicted) cannot be assigned to either of the two groups defined here.