Neoleptastacus rectus, 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 : 38

Neoleptastacus rectus sp. nov.

https://zoobank.org/ C916BDF2-CD13-421B-A8C2-8DFDE9D80D9F

Arenopontia? gussoae Cottarelli, 1973a sensu Mielke (1982b) [partim: material from Isla Nalunega, Panamá]

Original description. Mielke (1982b —as Arenopontia? gussoae ): 204; Figs 4I , 6D , 7D ).

Type locality. Panamá, Atlantic seaboard; Comarca de Guna Yala, San Blas Islands , Isla Nalunega ; sandy beach, fine-medium sand with medium amount of detritus .

Body length. 360–380 μm (♀), 310–330 μm (♂) [ Mielke 1982b].

Etymology. The specific epithet (derived from the Latin rectus , meaning straight) refers to the shape of the paired anal processes which are not dorsally recurved as in most other members of the gussoae -subgroup (except N. longiremis ).

Remarks. Mielke (1982b) recorded “ Arenopontia? gussoae ” from both oceanic seaboards of Panamá. His specimens from the Atlantic seaboard are similar to N. gussoae in the relative length of the caudal spinous process (45% of ramus length) and the length ratio of the rami of P1 (endopod 1.3 times longer than exopod) but differ from the Cuban population in (1) the paired anal processes are straight and pointed, (2) the caudal ramus is more angular and its terminal process is not recurved in its distal half, (3) P1 enp-1 is 1.45 times longer than enp-2 (vs 1.25), and (4) the female P5 is atypically short and broad (length/maximum width 1.7 vs at least 2.0 in other members of the gussoae -subgroup ( Table 4). Mielke (1982b) also mentioned that the rostrum is less tapered towards its apex (compared to N. abbreviatus sp. nov.) and that the free endopodal segment of the antenna has long hairs on its posterior surface (this feature possibly refers to the endopodal surface frill) but both characters are of limited value for comparing N. gussoae with the Isla Nalunega population. Note that Mielke (1982b: Fig. 6D ) illustrated a fine outer seta on the basis of P1 but this must be an observational error.

The differences displayed by the Isla Nalunega population are here considered as sufficient evidence to accord it distinct specific rank. The female specimen illustrated by Mielke (1982b: Figs 4I , 6D , 7D ) and deposited in the Zoologisches Institut und Museum der Universität Göttingen is here designated as the holotype of N. rectus sp. nov. in accordance with ICZN Arts 16.4, 72.5.6 and 73.1.4. The species can be differentiated from its congeners in the gussoae -subgroup by the characters listed above (ICZN Art. 13.1).

Figures

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

FIGURE 6. Neoleptastacus emendatus sp. nov. (♀): (A) habitus, dorsal; (B) habitus, lateral; (C) anal somite and caudal rami, dorsal; (D) anal somite and right caudal ramus, lateral.

FIGURE 7. Neoleptastacus emendatus sp. nov. (♀): (A) urosome, ventral; (B) antennule, dorsal; (C) antenna, outer; (D) antennary endopod, medial; (E) rostrum, dorsal; (F) midventral hook-like processes [indicated by arrows] on pedigerous somites; (G) hook-like process, lateral. [lateral endopodal spines indicated by arrows in C–D]