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 Chappuis (1954b) Chappuis (1954b) collected Arenopontia specimens in Algeria , Tunisia , the Gulf of Genoa and Catalonia, all of which were attributed to A. subterranea . His brief description ( Chappuis 1954b: 267–268 ; Figs 40–45) provides illustrations of P1, P2–P4 endopods and the P5 of both sexes. The presence of a strong spinule near the outer distal corner as the only spinular ornamentation of P1 enp-1 rules out conspecificity with any of the species listed in Group I ( Table 1 ), including A. subterranea . This is corroborated by the extraordinary length of the segment, being 11 times as long as wide and 2.5 times the length of the exopod. The number of armature elements (four) on the fifth leg relates Chappuis’s (1954b) material to either A. gunduzi sp. nov. or A. nesaie , the latter being closest in terms of enp-1/exp length ratio (2.0). Although there is a general resemblance in P5 morphology (both sexes), other characters such as the longer P2–P3 enp-2 and the unequal terminal elements (outer one half the length of inner one) on P4 enp-2 suggest that Chappuis’s (1954b) specimens are not A. nesaie but possibly belong to another, as yet unidentified, species or an amalgam of species. The presence/absence of the dorsal caudal ramus spur and the condition of the male P6 remain unconfirmed.