Neoleptastacus pacificus ( Mielke, 1985 ), 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 : 27

Neoleptastacus pacificus ( Mielke, 1985)

Arenopontia pacifica Mielke, 1985

Arenopontia (Arenopontia) pacifica Mielke, 1985 : Bodin (1988: 162)

Neoleptastacus pacificus ( Mielke, 1985) Sak et al. (2008: 412)

Original description. Mielke (1985): 209–215; Abb. 3A, 18–21.

Type locality. Chile, Los Lagos Region, Chiloé Province , east coast of Isla de Chiloé, Quellón, beach of Quellón Viejo; primarily coarse sand.

Body length. 340–430 μm (♀), 300–390 μm (♂).

Remarks. Neoleptastacus pacificus can readily be differentiated from other members of the spinicaudatus - group by (1) the absence of the inner seta on P4 exp-3, (2) the presence of two-three coarse spinules at the dorsal outer corners of the anal somite, either side of the operculum (in the same position as the anal processes in the acanthus -group), and (3) an extremely long, spinous, caudal process which is as long as the rest of the ramus (vs distinctly shorter) and virtually straight (vs typically dorsally recurved). The two spiniform elements on the P5 of both sexes are also larger than those of the other members of the species-group. The multiseriate egg-sac typically contains six eggs.

Mielke (1985) reported the species also from Viña del Mar (Reñaca) in Central Chile (Valparaíso Region) and noted slight variability between the Reñaca and Quellón populations in body size, slenderness of the swimming legs, and in the length of the spines on the P5 of both sexes and the terminal process of the caudal ramus. His claim that the male P6 shows a supernumerary seta (dorsal to the outer basal seta) is extremely unlikely and probably based on a misinterpretation of a different structure such as a sensillum or posterior somite margin.