The talitrid amphipod genus Talorchestia from the South China Sea to the Indonesian Archipelago (Crustacea, Senticaudata) Author Azman, B. A. R. text Zootaxa 2017 2017-09-13 4319 3 401 434 journal article 32118 10.11646/zootaxa.4319.3.1 4b84979a-e3de-4956-b9c7-91e178dd46b1 1175-5326 892245 67558747-9346-4561-8Ca5-Fb15Cdc7840B 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. 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. 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).