Psammoleptastacus, PENNAK, 1942 A

Sak, Serdar, Huys, Rony & Karaytuğ, Süphan, 2008, Disentangling the subgeneric division of Arenopontia Kunz, 1937: resurrection of Psammoleptastacus Pennak, 1942, re-examination of Neoleptastacus spinicaudatus Nicholls, 1945, and proposal of two new genera and a new generic classification (Copepoda, Harpacticoida, Arenopontiidae), Zoological Journal of the Linnean Society 152, pp. 409-458 : 422-423

GENUS PSAMMOLEPTASTACUS PENNAK, 1942A

Pennak (1942a) proposed this genus for a new species, P. arenaridus , collected from two sandy beaches near Woods Hole, and placed it without any further comment in the Canthocamptidae . He remarked on the superficial resemblance with other interstitial genera ( Leptastacus , Paraleptastacus , and Arenopontia ), but considered the differences in the antenna, maxillipeds, P5, and caudal rami sufficient for generic distinction. Pennak’s (1942a) paper remained largely unnoticed until Noodt (1955b) synonymized Psammoleptastacus with Arenopontia , a course of action that was endorsed by Lang (1965) but was overlooked by Krishnaswamy (1957), who added a second species, Psammoleptastacus orientalis Krishnaswamy, 1957 from the Madras coast. As noted by Wells (1967), Lang’s (1965) statement that P. orientalis belongs to Arenocaris (Leptastacidae) is obviously a slip of the pen.

Noodt (1955b) considered A. stygia to be most closely related to A. arenarida , recognizing some subtle differences in the caudal rami and P2–P4, whereas Lindgren (1976) suggested A. stygia is potentially ‘... an intraspecific variation of A. arenarida ’. The genus Psammoleptastacus is reinstated herein for the latter two species and a new species, P. barani sp. nov., from the Turkish Black Sea coast, which had previously been misidentified as A. stygia by Marinov (1971). Arenopontia subterranea Kunz, 1937 sensu Rao & Ganapati (1969) is regarded as a species inquirenda in Psammoleptastacus , and P. orientalis is transferred to Onychopontia gen. nov. Psammoleptastacus differs from Arenopontia and other arenopontiid genera in the small size of the P1 endopod, which is shorter than the exopod. It is most closely related to Onychopontia , with which it shares the sexual dimorphism on the P3 endopod (apomorphic) and the presence of two geniculate setae on P1 enp-2.

Diagnosis: Arenopontiidae . Urosomites: without conspicuous surface ornamentation. Anal somite: without paired dorsolateral spinous processes. Anal operculum: not modified. Hyaline frills of abdominal somites with rectangular digitate lappets. Caudal ramus: with dorsolateral spur near medial margin. P1 exopod: three-segmented; exp-1 with outer spine; exp-3 with two spines and two geniculate setae. P1 endopod: not prehensile, shorter than exopod; enp-2 with two geniculate setae. P2–P3 endopods: twosegmented. P3 endopod: with outer distal element defined at base. P4 endopod: with well-developed outer distal element. Armature formula as follows:

Exopod Endopod P2 0.0.021 0.120

P3 0.0.021 0.020

P4 0.0.021 0.020

P3 endopod male: sexually dimorphic, twosegmented; enp-1 unarmed; enp-2 minute, with strong spinule on outer margin, curved spine distally (sometimes fused at base), and fine seta on inner margin. P5: with outer basal seta and four discrete elements; innermost one distinctly smaller in male. P 6 male: with two setae.

Type species: Psammoleptastacus arenaridus Pennak, 1942a (by monotypy).

Other species: Arenopontia stygia Noodt, 1955b = P. stygius ( Noodt, 1955b) comb. nov.; P. barani sp. nov.

Species inquirenda: Arenopontia subterranea Kunz, 1937 sensu Rao & Ganapati (1969)