Neoleptastacus secundus Krishnaswamy, 1957

Sak, Serdar, Karaytuğ, Süphan & Huys, Rony, 2024, Review of Neoleptastacus Nicholls, 1945 (Harpacticoida, Arenopontiidae), including an updated key to species and proposal of Phreatipontia gen. nov., Zootaxa 5525 (1), pp. 1-66 : 43-44

Neoleptastacus secundus Krishnaswamy, 1957

Arenopontia secunda ( Krishnaswamy, 1957) Lang (1965: 418 , 419)

Arenopontia (Neoleptastacus) secunda ( Krishnaswamy, 1957) : Wells (1967: 324)

Original description. Krishnaswamy (1957): 96–98; Text-Fig. 21.

Type locality. India, Tamil Nadu, Chennai District, Chennai (= Madras); sandy beach [cf. Krishnaswamy (1957: 144–151) for sand texture characteristics].

Body length. 410 μm (♀), 323 μm (♂).

Remarks. Krishnaswamy’s (1957) vague description has made most authors assume (e.g. Lang 1965; Bodiou & Colomines 1986; Karanovic 2000) that the P3 enp-2 carries two setae but this remains to be confirmed since the P3 was not illustrated in the original description. The author only stated that it “… resembled the second one, but the inner seta on the first endopod joint is absent”. As pointed out above, the presence of paired anal processes indicates that N. secundus belongs in the acanthus -group and most likely in the gussoae -subgroup. The species shows a remarkable similarity with N. longiremis in the length and shape of the P5 (spinous process longest in ♀ in N. secundus , but longest in ♂ in N. longiremis ) and the elongate caudal rami. Itô (1968) pointed out several deficiencies in Krishnaswamy’s (1957) description (P4 endopod refers to exopod; inner seta on P2 enp-1 should insert on enp-2; description of mouthparts unreliable) and recommended a critical re-examination of the type material. Given the inadequate original description N. secundus is here placed as a species inquirenda in the gussoae -subgroup. Krishnaswamy (1957) provides zonation and vertical distribution data.

Neoleptastacus secundus has not been recorded again since it its original description, however, it is conceivable that some of the records of N. indicus refer to this species [e.g. Mantha et al. (2012) who reported it from Chennai, the type region of N. secundus ] or that the latter is indeed conspecific with N. secundus . Evidence in support of such conspecificity is provided by Rao’s (1967: fig. 3-28, 29 but not fig. 1-11, 12) illustrations of the P 5 in both sexes of N. indica which shows a similarly long apical spinous process.