Arenopontia subterranea Kunz, 1937 sensu Chappuis (1954a)

Sak, Serdar, Karaytuğ, Süphan & Huys, Rony, 2024, A revision of the genus Arenopontia Kunz, 1937 (Copepoda, Harpacticoida, Arenopontiidae), including the description of five new species, Zootaxa 5433 (1), pp. 1-50 : 39

Arenopontia subterranea Kunz, 1937 sensu Chappuis (1954a)

Chappuis (1954a: 43; Fig. III-4, 5) provides illustrations of the endopods of P2 and P4 of specimens collected from a sandy beach in Canet-Plage, Roussillon ( France) which he had identified as A. subterranea . Slight differences were encountered between his Mediterranean specimens and the type material from Kiel Bay, however, as Chappuis (1954a) pointed out himself, some of them could be attributed to deficiencies in Kunz’s (1937) original description. He noted that the penicillate inner seta on P1 exp-3 and the foliaceous seta VII on the caudal ramus were not as distinctly developed as in the German material but that their modification was nevertheless discernible under higher magnification. More importantly, Chappuis (1954a) claimed and illustrated that his specimens carried three apical setae instead of two on P4 enp-2 (formula 0.030) and that the posteriorly directed inner seta on P2 enp-2 was lacking (formula 0.010). This is extremely unlikely since no other arenopontiids carry three setae on the distal endopod segment of P4 [020 as a rule; 010 in Neoleptastacus africanus ( Chappuis & Rouch, 1961) ] and the inner seta is always present on P2 enp-2 with the exception of Onychopontia intermedia ( Rouch, 1962) and O. peteraxi ( Mielke, 1982) . Chappuis (1954a) rightly pointed out that these differences are insufficient to warrant the proposal of a distinct subspecies since it is obvious that all of them are based on observational errors. In the absence of important information on the P1, P5 of both sexes and caudal ramus it is impossible to make any positive statement on the real identity of Chappuis’s (1954a) material other than that it is not conspecific with A. subterranea .

Noodt (1955a, c) confirmed that his A. subterranea material from the French Biscayan coast (♀: 350 μm; ♂: 320 μm) and the Sea of Marmara agreed in all aspects with Kunz’s (1937) original description, except for the dorsal seta VII which is not foliaceous. In two female specimens from France the P1 endopod appeared to be more similar to the slender type illustrated by Chappuis (1954b).