Neoleptastacus australis ( Chappuis, 1953 ), 2008

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 : 12

Neoleptastacus australis ( Chappuis, 1953)

Arenopontia australis Chappuis, 1953

Arenopontia (Neoleptastacus) australis Chappuis, 1953 : Wells (1967: 324)

Neoleptastacus australis ( Chappuis, 1953) Sak et al. (2008: 412)

Original description. Chappuis (1953): 148–150; Fig. 2 .

Type locality. Madagascar, Faux Cap (south coast); sandy beach .

Body length. 380 μm (♀).

Remarks. Chappuis (1953) stated that the antennary exopod bears either one or two setae but this must be an error. He also illustrated a short inner spine on P1 exp-2 and P4 enp-1 and a short outer seta on P2 enp-1. In reality these structures are ornamentation elements and their taxonomic value was rightly dismissed by Noodt (1955b). It must also be noted that the entire P4 endopod was accidentally rotated in Chappuis’s mount as indicated by the position of the shorter distal element (being positioned on the inner corner instead of the outer one). His drawing of the female P2 endopod appears to be based on a similar observational error (the correct setation pattern is shown for the male) and the distal portion of the P1 endopod also seems to be rotated, showing the short apical element at the inner instead of the outer corner of enp-2. Although Chappuis (1953) illustrated both rami only for P2, he stated explicitly that the exopods of P2–P4 display the same formula as in Arenopontia subterranea Kunz, 1937 . The inferred absence of the inner seta on P4 exp-3 (formula 0.0.021) is therefore shared only with N. pacificus (a member of the spinicaudatus -group). Neoleptastacus australis is so far the only species displaying the combination of a 2-segmented P2 endopod and a 1-segmented P3 endopod ( Table 2). The species is known from one female and two males collected at the type locality and has not been recorded again since its original description.

Figures

FIGURE 2. Neoleptastacus acanthus (Chappuis, 1954): (A) habitus (♂), dorsal; (B) anal somite and caudal rami (♀), dorsal; (C) anal somite and left caudal ramus (♀), lateral; (D) antenna (♀), medial; (E) antennary endopod (♀), outer. [Lateral spines of antennary endopod indicated by arrows in D–E]