Selwynia punctata, Ng, Peter K. L. & Rahayu, Dwi Listyo, 2016

Ng, Peter K. L. & Rahayu, Dwi Listyo, 2016, On the genera Selwynia Borradaile, 1903, and Gandoa Kammerer, 2006, with descriptions of two new species from Papua New Guinea and French Polynesia (Crustacea: Decapoda: Brachyura: Aphanodactylidae), Zootaxa 4092 (3), pp. 339-370 : 358-363

publication ID	https://doi.org/ 10.11646/zootaxa.4092.3.2
publication LSID	lsid:zoobank.org:pub:547625D1-70CC-48A1-9C36-3A0DD41B83A5
DOI	https://doi.org/10.5281/zenodo.6081364
persistent identifier	https://treatment.plazi.org/id/F56987A9-FFB0-FFE8-FB8F-FA74FCCB7BA8
treatment provided by	Plazi
scientific name	Selwynia punctata
status	sp. nov.

Treatment

Selwynia punctata n. sp.

( Figs. 13–16 View FIGURE 13 View FIGURE 14 View FIGURE 15 View FIGURE 16 )

Material examined. Holotype: ovigerous female (7.0 × 4.0 mm) (UF), BMOO 15737, east side of Opunohu Bay, about 1 km north of Criobe, near white tower in water, Moorea, northwest of Tahiti, 17.51012ºS 149.85129ºE, French Polynesia, 3–11 m, coll. D. Uyeno & A. Anker, 19 November 2010. Paratype: 1 male (4.3 × 3.3 mm) (ZRC 2015.280), BMOO 15730, same data as holotype.

Description (female holotype). Carapace ( Figs. 13 View FIGURE 13 B, 14A) oval, about 1.6 broader than long; dorsal surface smooth, region poorly demarcated, flattened to gently concave on mesogastric region, pit on each hepatic region. Front ( Figs. 13 View FIGURE 13 C, 14B) strongly deflexed, medially concave in dorsal view. Orbital margin ( Figs. 13 View FIGURE 13 C, 14B) entire, slightly narrower distally, narrow gap between cornea, external orbital angle. Anterolateral margin entire, convex laterally, not cristate, continuous with posterolateral margin. Epistome ( Fig. 14 View FIGURE 14 B) short, medially sunken. Antennule ( Fig. 14 View FIGURE 14 B) folding transversely in fossa. Antenna ( Fig. 14 View FIGURE 14 B) with stout basal antennal article, not reaching distolateral angle of carapace; antenna enters orbit. Ocular peduncles ( Fig. 14 View FIGURE 14 B) movable, short, stout, subconical, cornea small, well pigmented.

Third maxillipeds ( Fig. 13 View FIGURE 13 C) covering four-fifths of buccal cavern when closed; ischium 1.4 times length of merus; exopod slender, reaching midlength of merus; flagellum long.

Thoracic sternites 1, 2 fused, sternites 2/3 separated by deep furrow, sternites 3/4 demarcated by shallow ridge; sternites 4–8 laterally demarcated by shallow sutures; sutures between sternites 4/5, 6/7 longer than others, vulva rounded, on distal three-fourths of sternite 6.

Chelipeds ( Fig. 13 View FIGURE 13 C) equal. Merus triangular in cross section, dorsal margin rugose, dorsal margin, outer surface setose. Carpus smooth, inner angle absent. Chela with smooth surfaces, palm about 1.2 times longer than dactylus; immovable finger with weakly sinuous cutting edge, cutting edge convex medially, lined with small teeth; movable finger with cutting edge concave on distal half.

Ambulatory legs (P2–P5) ( Figs. 13 View FIGURE 13 B, C, 16H, I) relatively short, P3 longest, P5 shortest; upper surface glabrous, setae on margins, lower surfaces of carpus, propodus. Merus as long as or slightly longer than combined length of respective propodus, dactylus, extensor margin unarmed, flexor margin armature of P2–P5 as follows: P2 1+0/1+0, P3 1+0/1+0, P4 1+0/1+0, P5 0+0/1+1. Flexor margin of basis-ischium of P5 unarmed. Dactylus very short, claw-like.

Abdomen ( Figs. 14 View FIGURE 14 C, 16G) with all somites, telson distinct, mobile.

Description (male paratype). Carapace ( Figs. 13 View FIGURE 13 A, 15A) subquadrate, about 1.3 broader than long; dorsal surface smooth, regions poorly demarcated, shallow depression on each hepatic region. Front ( Fig. 15 View FIGURE 15 B) strongly deflexed, medially concave in dorsal view. Orbital margins ( Fig. 15 View FIGURE 15 B) entire, oval, no gap between cornea, external orbital angle. Epistome longer than that of female, posterior margin slightly concave. Antennule, antenna as in female. Eyes ( Fig. 15 View FIGURE 15 B) short, stout, with distinct cornea.

Third maxillipeds ( Figs. 15 View FIGURE 15 C, 16A) covering four-fifths of buccal cavern when closed; similar to female third maxillipeds except for more rounded distomesial angle.

Thoracic sternites 1, 2 fused, sternites 2/3 demarcated by distinct suture, 3/4 demarcated by low ridge, sternites 4–8 demarcated by shallow, narrow sutures, press button of abdominal locking mechanism present on distal quarter of sternite 5; penis emerging from near anterior border of sternite 8.

Chelipeds ( Fig. 15 View FIGURE 15 C) relatively strong, slightly unequal in size. Merus triangular in cross section, ventro-outer margin granulated, dorsal margin rugose, dorsal margin, outer surface setose. Carpus smooth, inner angle rounded. Chelae, ambulatory legs ( Figs. 13 View FIGURE 13 A, 16C, D) as in female.

Flexor margin armature of P2–P5 as follows: P2 0+2/0+1, P3 1+5/1+3, P4 1+7/1+3, P5 1+1/1+1. Flexor margin of basis-ischium of P5 unarmed. Dactylus very short, claw-like.

Abdomen ( Fig. 16 View FIGURE 16 B) with all somites, telson distinct, mobile, relatively narrow, somite 2 broadest, somite 3 to telson forming straight lateral margins. G1 ( Fig. 16 View FIGURE 16 E, F) simple, stout, proximal five-sixths straight, distal onesixth bent inwards towards median part of sternum.

Colour. In life, the overall carapace, chelipeds, and legs are dirty white; the dorsal surface of the carapace with several orange spots ( Fig. 13 View FIGURE 13 ). The setae lining the sides of the carapace and legs are light brown, and the cornea was bright yellow ( Fig. 13 View FIGURE 13 ).

Etymology. The name is derived from the presence of orange dots on the dorsal surface of the carapace in life, a distinctive feature of this species.

Remarks. Selwynia punctata n. sp., differs from congeners in having proportionately the stoutest G1 ( Fig. 16 View FIGURE 16 E, F), longest ischium of the third maxilliped (1.4 times length of merus) ( Fig. 16 View FIGURE 16 A), the possession of only a single tooth on flexor margin of the male P2–P5 merus ( Fig. 16 View FIGURE 16 C, D), and presence of dense long setae on the chelipeds and ambulatory legs ( Figs. 14 View FIGURE 14 C, 15C).

Biology. The present specimens were collected by yabby-pumps and the hosts are not known.

Distribution. Known only from Moorea, French Polynesia.