Typhlocarcinops angustipes Tesch, 1918

Ng, Peter K. L. & Rahayu, Dwi Listyo, 2020, A synopsis of Typhlocarcinops Rathbun, 1909 (Crustacea: Decapoda: Brachyura: Pilumnidae), with descriptions of nine new species from the Indo-West Pacific, Zootaxa 4788 (1), pp. 1-100 : 90

Typhlocarcinops angustipes Tesch, 1918

( Figs. 76 , 77 )

Typhlocarcinops angustipes Tesch, 1918: 214 , pl. 13 fig. 5; Ng 1987: 78; Ng et al. 2008: 144.

Material examined. Lectotype (here designated): ovigerous female (4.5 × 3.2 mm) ( NNM-ZMA Crust De 103.004), station 133, Lirung , Talaut Islands, up to 36 m, coll. M. Webber, Siboga Expedition, 25-27 December 1899 . Paralectotypes: 1 male (3.7 × 2.8 mm, in poor condition), 1 female (sternum partially crushed, 5.5 × 4.7 mm) ( NNM-ZMA Crust De 103.005), station 274, 5°28.2’S 134°53.9’E, north of Aru Islands , 57 m, coll. M. Webber, Siboga Expedition, 26 December 1899 .

Diagnosis. Carapace ( Figs. 76A, B , 77A ) about 1.2–1.4 times broader than long, surface smooth anteriorly, with granules posteriorly, regions not indicated; anterolateral margin arcuate, lined with tiny granules and 1 small tooth; posterolateral surface and margin with scarce, scattered tubercles. Front ( Fig. 76A, B ) bilobed, with shallow median cleft, margin of each lobe slightly convex. Orbit ( Fig. 77C ) short, bulbous ocular peduncles filling orbit, immovable, cornea small, slightly pigmented. Epistome relatively broad, triangular median lobe with median suture. Antennal peduncles relatively long. Third maxilliped ( Fig. 77B ) with merus broad, anteroexternal angle strongly expanded, margin lined with granules, more strongly granules on inner margin, ischium subquadrate, slightly longer than merus, inner margin straight; exopod slender, relatively long, tip reaching beyond distal edge of merus, inner margin with distinct tooth. Chelipeds of males almost equal ( Fig. 76D ), outer surface of fingers of chela smooth, with longitudinal ridge, surface of palm with scattered tubercles, lower margin lined with larger tubercles; upper margin smooth; cutting edges of fingers with prominent teeth; upper outer surface of carpus with small tubercles, inner angle rounded ( Fig. 76A, B ). P2−P5 ( Fig. 76A, B ) proportionally long, fringe by sparse long setae on dorsal and ventral margins; merus of P5 not reaching front when folded. Male pleon ( Fig. 77C ) broad, telson short, 1.5 times as long as somite 6, subtriangular with rounded distal margin. G1 ( Fig. 77D, E ) slender, upper and lower halves subequal, sinuous, distal part short, bent at right angles, with pointed tip.

Remarks. This species is known only from type series from the Indonesian Moluccas. Only three specimens are known, with the only male syntype in poor condition, although fortunately, enough of the sternum remains to obtain the pleon and gonopods ( Fig. 77 C–E). The most intact specimen, an ovigerous female (4.5 × 3.2 mm) (NNM-ZMA Crust De 103.004) is here designated the lectotype for this species.

This species is easily recognized by the short and broad merus of the third maxilliped, with the anteroexternal angle strongly expanded.

Type locality. Lirung , North Sulawesi, Indonesia .

Distribution. Talaut and Aru, Indonesia.

Figures

FIGURE 76. Typhlocarcinops angustipes Tesch, 1918. A, C, D, ovigerous syntype female (4.5 × 3.2 mm) (NNM-ZMA Crust De 103.004), Talaut Islands, Indonesia; B, syntype female (5.5 × 4.7 mm) (NNM-ZMA Crust De 103.005), Aru Islands, Indonesia.A, B, overall habitus; C, frontal view of cephalothorax; D, outer view of chelae.

FIGURE 77. Typhlocarcinops angustipes Tesch, 1918. 1 male (3.7 × 2.8 mm, in bad condition) (NNM-ZMA Crust De 103.005), Aru Islands, Indonesia. A, right side of carapace (denuded); B, left third maxilliped; C, male pleon (telson broken); D, left G1 (ventral view); E, left G1 (dorsal view). Scales: A, C = 0.1 mm; B, D, E = 0.05 mm.