Moloha tumida, Kumar, 2015

Ng, Peter K. L. & Kumar, Appukuttannair Biju, 2015, The species of Moloha Barnard, 1946, from the western Indian Ocean, with the description of a new species from India (Crustacea: Brachyura: Homolidae), European Journal of Taxonomy 166, pp. 1-25 : 17-22

Moloha tumida sp. nov.

urn:lsid:zoobank.org:act:25B20CDD-06DA-4A14-BB61-1F7954ED6357

Figs 1B, 3B, 4C, 5B, 9, 13, 14B, 15 D–G, 17B

Diagnosis

Carapace with pseudorostral and supraocular spines long, subequal; supraocular spine with distinct submedian accessory spine; gastric region with many sharp granules in addition to 3 major spines; branchial regions distinctly inflated; subhepatic region swollen, with 2 large dorsal and 3 small ventral spines; protogastric region with 2 major spines; basal antennal spine acute; P2–P4 long, slender, subcylindrical, merus with 8–10 spines on dorsal margin, outer surface with 1–13 small spines, ventral margin with 19–28 spines; P5 with 2 spines on dorsal margin, 2 small spines on outer surface, 4 spines on ventral margin, subchelate structure stout, propodus with 3 large basal spines, rest of margin with distinct, closely arranged, similarly sized spines. G1 stout, short, groove on ventral surface submedian, dorso-median surface flat, distal part less rounded, opening large, auriculiform, directed towards median part of sternum.

Etymology

The species is named after the relatively swollen carapace.

Material examined

Holotype

INDIA: ♂ (tcl 64.4 mm, cl 55.7 mm, tcw 56.1 mm, cw 50.6 mm), Kerala, 300–350 m, 3 Dec. 2014 ( DABFUK).

Description

Medium-sized species, spiny on carapace, appendages, chelipeds and ambulatory legs ( Figs 1B, 3B, 4C, 5B, 13, 14B). Dorsal surface of carapace with deep grooves, well marked regions ( Figs 1B, 3B, 4C, 5B, 14B). Pseudorostral spine simple, as long as or slightly longer than supraorbital spines ( Figs 1B, 3B, 14B). Proepistome with sharp spine. Supraocular spine long, straight, with prominent laterally directed accessory spine on anterior third ( Figs 1B, 3B, 4C, 5B, 14B); infraorbital spine long, gently curved outwards, about ⅔ length of supraorbital spine, visible in dorsal view ( Figs 4C, 5B); buccal spine prominent, just visible in dorsal view ( Figs 4C, 5B); basal antennal spine sharp, acute ( Figs 4C, 5B); protogastric region with 2 major spines and smaller spinules posterior and lateral to them ( Figs 1B, 2B, 5B, 14B); mesogastric region with 1 large median spine ( Figs 1B, 2B, 5B, 14B); mesobranchial region with 5 or 6 large, laterally directed spines and numerous spinules behind them ( Figs 1B, 2B, 5B, 14B); subhepatic region swollen, with 2 large dorsal spines, 1 median spine and 2 small ventral spines ( Figs 1B, 2B, 4C, 5B, 14B); anterolateral spine distinct, pointing obliquely anteriorly, with smaller spine below it ( Figs 1B, 2B, 5B, 14B); posterolateral spines distinct, 3 largest laterally directed, first largest, with many spinules between them ( Figs 1B, 2B, 5B, 14B); cardiac region small, with 1 short spine ( Figs 1B, 2B, 4C, 5B, 14B). Cervical groove shallow, but clearly visible ( Figs 1B, 2B, 14B); transverse cardio-intestinal groove shallow ( Figs 1B, 2B, 14B). Posterior carapace margin strongly concave; lateral margins of branchiostegite almost smooth ( Figs 1B, 2B, 14B). Eyes short; podophthalmite short, stout; basophthalmite slender, elongate; cornea bulbous ( Figs 1B, 2B, 4C, 5B, 14B). Antennules with a swollen basal article, other articles long, slender, with elongate flagellum ( Fig. 4C). Antennae short, first article with large urinary article ( Figs 4C, 5B). Epistome truncate; posterior margin gently sinuous, with median part weakly triangular, lateral parts gently concave ( Fig. 4C). Third maxilliped subpediform, elongated; inner margins lined with dense, long setae; basis-ischium with 4 submedian tubercles; merus with 1 large subproximal tubercle, anterolateral margin dentate; carpus short, unarmed; propodus and dactylus elongated, unarmed ( Fig. 13A).

Cheliped relatively long, slender, spiny ( Figs 1B); coxa with 2 short spines; ischium subtrigonal in crosssection, with 3–7 short spines; merus with 3 rows of short or long spines: dorsal row with 17–19 spines, outer surface with 12 or 13 spines, ventral margin with 14–18 spines ( Figs 1B, 9D); carpus elongate, outer surface granulated, not spinose ( Figs 1B, 9 D–E). Palm slender, covered with small granules and setae, those on inner surface denser and longer; fingers shorter than palm, with hooked tips, pigmented throughout most of length except near base, that of pollex not extending substantially into palm; cutting edges blade-like; dactylus with 1 low subproximal tubercle ( Figs 1B, 9 E–F).

Ambulatory legs long, slender; meri subcylindrical; P3 longest ( Figs 1B, 13 B–H). P2 coxa with 3 spines; ischium with 4 short spines; merus with 3 rows of short or long spines: dorsal row with 9 or 10 spines, outer surface with 1–13 spines, ventral margin with 19–21 spines ( Fig. 13B, E). P3 coxa with 3 spines; ischium with 4–7 short spines; merus with 3 rows of short or long spines: dorsal row with 9 spines, outer surface with 10–13 spines, ventral margin with 20–25 spines ( Fig. 13C, F). P4 coxa with 2 or 3 spines; ischium with 3–6 short spines; merus with 3 rows of short or long spines: dorsal row with 8 spines, outer surface with 11 spines, ventral margin with 26–28 spines ( Fig. 13D, G). P5 coxa with 1 spine; ischium with 2 short spines; merus with 3 rows of short or long spines: dorsal row with 2 spines, outer surface with 2 spines, ventral margin with 4 spines; carpus elongate, unarmed; propodus and dactylus forming subchelate structure; propodus curved, relatively shorter, flexor margin with 3 large, curved spines and 4 or 5 smaller spines anterior to it in a row, dactylus curved with 6–9 small spines on flexor margin ( Fig. 13 H–I).

Male pleon ovate, completely covering thoracic sternal surface; telson pentagonal, with distal half triangular, with sharp tip, basal part quadrate, lateral margin convex to distinctly convex ( Fig. 9 A– B); somite 6 trapezoidal, with deeply concave lateral margins, distal median margin with prominent spine ( Fig. 9 A–B); somites 4 and 5 subquadrate, with lateral margins expanded, triangular, somite 5 distal median margin with distinct tubercle, somite 4 with median tubercle ( Fig. 9B); somites 2 and 3 trapezoidal, with long median spine; somite 1 short, with sharp median tubercle ( Fig. 9B). Sternopleonal cavity deep, smooth; thoracic sternites 1–5 without median longitudinal line, suture between sternites 5 and 6 shallow, complete; pair of partially flattened prominences (homolid button, cf. Guinot & Bouchard 1998: 635, fig. 9c) on sternite 4 at margin of sternopleonal cavity, fits into pair of sockets on internal marginal surface of somite 6 ( Fig. 9C).

G1 short, stout, distal part rounded; opening directed towards median part of thoracic sternum; groove submedian; dorso-median surface flat; distal part less rounded; opening auriculiform ( Figs 9C, 15 D–F); marginal and submarginal surfaces along distal part with long setae ( Fig. 15 D–F). G2 stout, as long as G1, basal part dilated, with long setae; distal part cup-like ( Fig. 15G).

Colour

In life, the carapace and chelipeds are red; the ambulatory legs are red with patches of white and the ventral surfaces are dirty white ( Fig. 17B).

Distribution

The species is known only from southwestern India.

Remarks

See the Discussion section.