Neoleptastacus pseudishikarianus, Sak & Karaytuğ & Huys, 2024

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 : 37

Neoleptastacus pseudishikarianus sp. nov.

https://zoobank.org/ 71936DF5-742B-48DC-8FA7-C1531885AF72

Arenopontia? ishikariana Itô, 1968 sensu Mielke (1987: 336)

Original description. Mielke (1987 —as Arenopontia? ishikariana ): 335–337; Abb. 13B–E, 14.

Type locality. Chile, Antofagasta Region, Antofagasta Province, 25 km north of Antofagasta, La Rinconada (few km north of La Portada); fine grey-brown sandy beach.

Body length. 270–310 μm (♀), 230–300 μm (♂).

Etymology. The specific epithet refers to the close similarity with N. ishikarianus .

Remarks. Mielke (1987) provided a partial description of a Neoleptastacus species from northern Chile but expressed reservations about its identity within the spinicaudatus -group. Rather than considering them as a new species he tentatively assigned his specimens to N. ishikarianus . The South American material differs from the latter in the following characteristics: (1) anal operculum with middorsal rounded projection (vs absent), (2) lappets of abdominal hyaline frills non-digitate and with rounded distal margins (vs digitate with straight margins), (3) P1 rami approximately equal in length (vs endopod distinctly longer than exopod), and (4) P5 with shorter, straight and more robust inner spinous projection (vs longer, slightly curved and slender) and size of marginal spines larger [longest (= outer) spine in ♀ about half the length of spinous process vs about one-quarter]. Mielke (1987) also pointed out that caudal ramus seta III is distinctly longer than in the Japanese specimens but it is unclear if this seta was presented in a foreshortened view in Itô’s (1968: Fig. 4-3 ) illustration. Similarly, Mielke also commented on setal length differences on the P4 endopod but no such discrepancies could be discerned when comparing both descriptions. Based on the differences outlined above, Arenopontia? ishikariana Itô, 1968 sensu Mielke (1987) is attributed discrete specific rank as N. pseudishikarianus sp. nov.

The female specimen illustrated by Mielke (1987: Abb. 13B–E; 14 A, B) and most likely deposited in the Zoologisches Institut und Museum der Universität Göttingen is here designated as the holotype of N.pseudishikarianus sp. nov. in accordance with ICZN Arts 16.4, 72.5.6 and 73.1.4 . The species can be differentiated by the characters listed above (ICZN Art. 13.1). Mielke (1987) recorded the species from three different sandy beaches in Arica (Arica and Parinacota Region), Iquique (Tarapacá Region) and La Rinconada (all in northern Chile) but based his illustrations solely on material from the latter which consequently becomes the type locality (ICZN Art. 76.1).At the latter it occurs sympatrically with three members of the spinicaudatus -group, N. clasingi , N. ornamenta , N. spicata , in addition to a fourth species tentatively identified as N.? gussoae (= N. chilensis sp. nov.) ( Mielke 1987).

Figures

FIGURE 4. Neoleptastacus acanthus (Chappuis, 1954) (♀): (A) P1, anterior; (B) P2, anterior; (C) P3, anterior; (D) P4, anterior.