Talorchestia sipadan, Azman, B. A. R., 2017

Azman, B. A. R., 2017, The talitrid amphipod genus Talorchestia from the South China Sea to the Indonesian Archipelago (Crustacea, Senticaudata), Zootaxa 4319 (3), pp. 401-434 : 422-425

Talorchestia sipadan sp. nov.

( Figs 16–17 )

Type material. Holotype, male, 11 mm, UKMMZ-1392 (SEM pin and 4 SEM stubs), Sipadan Island , Sabah, Malaysia (4°6.983'N 118°37.767'E), supralittoral, B.A.R. Azman, 11 August 2007 . Paratypes: 3 males, 4 females, 1 female (wet specimen and SEM stub) UKMMZ-1393, same data as holotype .

Type locality. Supralittoral , Sipadan Island, Sabah, Malaysia (4°6.983'N 118°37.767'E).

Etymology. Named for Sipadan Island, the type locality.

Description. Based on Holotype, male, 11 mm, UKMMZ-1392.

Head. Antenna 2 more than half but not exceeding body length (64¾); peduncular articles with marginal row of robust setae, with many small robust setae; peduncular article 1 enlarged, bulbous; article 5 much longer than article 4; flagellar articles final article large, cone-shaped forming a virgula divina, with apical cluster of 'imbricated' setae. Labrum with apical setal patch; epistome without robust setae, epistome with many pores. Mandible left lacinia mobilis with 6 cusps. Labium distolateral setal tuft absent.

Pereon. Gnathopod 1 coxa smaller than coxa 2; carpus longer than propodus, 2.2 × as long as propodus, 2.8 × as long as broad; propodus subrectangular, anterior margin with 5 groups of robust setae (13 robust setae), about 2.2 × as long as broad; dactylus longer than palm, with anterodistal denticular patch. Gnathopod 2 sexually dimorphic; basis anterior margin smooth, slender; ischium with rounded lobe on mid-anterior margin or with subquadrate anterodistal lobe, with distally rounded anterodistal lobe on medial surface; carpus triangular, reduced (enclosed by merus and propodus), posterior lobe absent, not projecting between merus and propodus; propodus 1.6 × as long as wide, palm reaching about 52% along posterior margin, smooth, without protuberance near dactylar hinge, lined with robust setae, posteromedial surface of propodus with groove; dactylus subequal in length to palm, curved, without anteroproximal bump, posterior margin sparsely lined with small robust setae, with shallow posteroproximal sinus. Pereopods 2–4 coxae deeper than wide. Pereopods 3–7 dactyli without anterodistal patch of many rows of tiny setae. Pereopod 4 significantly shorter than pereopod 3; carpus significantly shorter than carpus of pereopod 3. Pereopod 5 propodus distinctly longer than carpus. Pereopod 6 coxa posterior lobe medial view posteroventral corner rounded, posterior margin oblique to ventral margin, posterior lobe with ridge, posterior lobe with 5 or more marginal setae. Pereopod 7 basis lateral sulcus present, slightly pronounced, posterior margin with numerous small robust setae, small posterodistal lobe present, shallow, narrowly rounded; distal articles (merus and carpus) slender; merus posterior margin straight.

Pleon. Epimeron 1 with 1 robust seta along ventral margin. Epimeron 3 posterior margin minutely serrate, with tiny setae, posteroventral corner with small subacute tooth. Uropod 1 peduncle with 14–15 robust setae, distolateral robust seta small (less than 1/4 length of outer ramus); inner ramus subequal in length to outer ramus, with 4 lateral and 5 medial marginal robust setae; outer ramus without marginal robust setae. Uropod 2 peduncle with 10 robust setae; inner ramus with 3 medial and 3 lateral robust setae; outer ramus with 3 marginal robust setae. Uropod 3 peduncle with 5 robust setae; ramus not fused to peduncle, ramus 2.9 × as long as broad, ramus linear (narrowing), ramus with 2–3 marginal robust setae, ramus with about 5 apical robust setae. Telson dorsal midline complete, 8 setae per lobe.

Remarks. See remarks under T. seringat .

Distribution. Malaysia. Sipadan Island, Sabah (this study).

Figures

FIGURE 16. Talorchestia sipadan, male, holotype, 11 mm, UKMMZ- 1392, Sipadan Island, Sabah, Malaysia. Scale line for EP represents 0.5 mm, UL, MD MP represent 0.1 mm, remainder represent 0.2 mm.

FIGURE 17. Talorchestia sipadan, male, holotype, 11 mm, UKMMZ- 1392, Sipadan Island, Sabah, Malaysia. Scale lines represent 0.5 mm.