Typhlocarcinops tonsuratus Griffin & Campbell, 1969

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 : 41-42

Typhlocarcinops tonsuratus Griffin & Campbell, 1969

( Fig. 34 )

Typhlocarcinops tonsurata Griffin & Campbell, 1969: 147 , figs. 3, 6B; Ng 1987: 78.

Typhlocarcinops tonsuratus — Ng et al. 2008: 144.

Material examined. None.

Diagnosis. Carapace ( Fig. 34A ) 1.2 times as broad as long, surface smooth, covered by short setae, with long setae on lateral margin; regions indistinct, H-shaped gastro-cardiac grooves distinct; carapace appears vaulted; anterolateral margin arcuate, with 3 low, broad lobes; posterolateral surface and margin with low granules. Front ( Fig. 34A ) slightly bilobed, with shallow median cleft, margin of each lobe slightly convex. Orbit ( Fig. 34A ) short, broad, filled by immovable ocular peduncles; cornea small, rounded, partly visible. Epistome weakly concave posteriorly. Antennal peduncles relatively short, stout. Third maxilliped ( Fig. 34B ) with merus slightly broader than long, outer and inner margins straight, ischium slightly broader, much longer than merus, inner margin slightly shorter than outer margin, lower margin slightly oblique; exopod relatively slender. Chelipeds relatively short ( Fig. 34C ), outer surfaces of merus, carpus and chela smooth medially, upper and lower outer margins with small granules, covered by short tomentum and long setae; chela about as long as high; inner angle of carpus with minute granules, without prominent tooth. P2–P5 covered by tomentum; dorsal and ventral margins with long setae. Male pleon relatively slender ( Fig. 34D ), evenly tapering from base of somite 4 to rounded tip of telson; telson 1.8 times as long as somite 6. G1 prominently sinuous ( Fig. 34 E‒G), distal part gently curved upwards, tip upcurved, with 2 series of short to moderate bristles distally (modified from Griffin & Campbell 1969).

Remarks. The type and only known specimen of this species (in the Queensland Museum) was described from a depth of 30 ft, about 8 miles east of Scarborough in Moreton Bay in Queensland, Australia. Griffin & Campbell (1969) described the species at length and their figures are sufficient to diagnose the species.

The G1 of the species ( Griffin & Campbell 1969: fig. 6B; present Fig. 34 E–G) is very distinctive, being strong sinuous and the distal part is gently upcurved. It superficially resembles that of T. marginatus in the structure of the distal part ( Fig. 56B, C ) but the tip is upcurved and distinctly longer in T. tonsuratus ( Fig. 34F, G ).

Type locality. Scarborough , Queensland, Australia .

Distribution. Known only from type locality. On soft sediments at depths of 10 m.

Figures

FIGURE 34. Typhlocarcinops tonsuratus Griffin & Campbell, 1969, holotype male (8.8 × 7.2 mm) (Queensland Museum W2911), Queensland, Australia.A, dorsal view of carapace; B, left third maxilliped; C, outer view of right cheliped; D, thoracic sternum and pleon; E, sternopleonal cavity with G1 (right one broken); F, distal part of left G1 (ventral view); G, distal part of left G1 (dorsal view). After Griffin & Campbell (1969: figs. 3, 6B). Scales = 1.0 mm.

FIGURE 56. Typhlocarcinops marginatus Rathbun, 1914, holotype male (8.1 × 6.3 mm) (USNM 46345), Palawan, Philippines. A, left third maxilliped; B, left G1 (ventral view); C, left G1 (dorsal view). Scales = 0.5 mm.