Munidopsis orcina McArdle, 1901

Published, First, 2007, Species of the genus Munidopsis Whiteaves, 1784 from the Indian and Pacific Oceans and reestablishment of the genus Galacantha A. Milne-Edwards, 1880 (Crustacea, Decapoda, Galatheidae), Zootaxa 1417, pp. 1-135 : 86-89

Munidopsis orcina McArdle, 1901

( Figs. 40, 41, 55J)

Munidopsis orcina McArdle, 1901: 523 .— Alcock & McArdle, 1902: pl. 56, fig. 5.— Baba, 2005: 292.

Material examined. Madagascar (A. Crosnier collection), Stn CH 138, 1800–2000 m: 1 M 12.0 mm (MNHN-Ga1418) . Reunion Island, MD 32 , Stn 105, 1740– 1850 m: 1 M 10.7 mm ( MNHN) . New Caledonia, BIOCAL, Stn 5, 2340 m: 1 ovig. F 11.4 mm (MNHN-Ga5629).— Stn 72, 2100–2110 m: 1 ovig. F 10.5 mm (MNHN-Ga5630). BIOGEOCAL, Stn 260, 1820– 1980 m: 2 ovig. F 11.2–12.6 mm (MNHN-Ga5631) . Vanuatu, MUSORSTOM 8, Stn 1109, 1550– 1620 m: 1 F 9.7 mm (MNHN-Ga5632).— Stn 1110, 1360 m: 1 F 10.1 mm (MNHN-Ga5633) .

Description. Carapace longer than broad; dorsal surface moderately convex from side to side, covered with granules, nearly devoid of setae; 2 small epigastric protuberances, regions well delineated by furrows including distinct anterior and posterior cervical grooves. Posterior cardiac region triangular, preceded by deep transverse depression. Posterior margin preceded by weakly elevated ridge. Rostrum horizontal, subtriangular, granulated, slightly longer than one-third length of remaining carapace; basally broad, about onethird carapace width, margins proximally subparalel, apex blunt, dorsal surface carinate in midline. Frontal margin oblique behind ocular peduncle, without antennal spine, transverse toward rounded anterolateral angle. Lateral margins unarmed, weakly convex and subparallel, anterolateral angle rounded, ends of anterior and posterior cervical grooves each with distinct notch.

Pterygostomian flap granulated, anteriorly unarmed.

Sternum smooth, as long as wide, maximum width at seternite 7. Sternite 3 narrow, nearly twice wider than long, anterior margin divided into 2 lobes, with small median notch. Sternite 4 narrowly elongate anteriorly; surface depressed in midline; greatest width nearly 3 times that of sternite 3.

Abdomen unarmed; segments 2ñ4 each with 2 transverse ridges weakly elevated and granulated, separated by transverse groove, segments 5–6 without ridges; segment 6 with weakly produced posterolateral lobes and nearly transverse posteromedian margin. Telson composed of 10 plates; posterior plates combined twice as wide as long.

Ocular peduncle fixed, blunt mesial eye-spine overreaching end of antennal peduncle, lateral margin without spine; cornea small, lateral, clearly narrower than eye-spine. Spine ventral to front margin between ocular and antennal peduncles.

Basal article of antennular peduncle with strong dorsolateral and distolateral spines, distomesial angle granulated.

Basal article of antennal peduncle with strong distomesial spine and blunt distolateral process; article 2 with short distolateral and distomesial spines; article 3 unarmed.

Mxp 3 ischium as long as merus measured on extensor margin; flexor and extensor margins terminating in blunt spine; 19 corneous denticles on crista dentata; flexor margin of merus with 4 or 5 small spines, extensor margin with distal spine.

P1 subequal, nearly as long as carapace, granulated, with numerous short plumose setae. Merus with some distal spines. Carpus slightly higher than long, with strong mesial spine and several small spines on dorsal side. Palm stout, more than 1.5 times length of carpus, as long as fingers. Fingers distally spooned, fixed finger with denticulate carina.

P2–P4 moderately stout, with numerous small granules, decreasing in size posteriorly; P2 longest. P2 clearly not reaching end of P1, slightly shorter than carapace; merus slightly compressed, 1.2 times P4 merus, 2.5 times longer than high, about twice length of carpus and nearly 1.5 times length of propodus, dorsal margin cristate, with row of small spines, ventral margin granulated, each margin ending in acute spine; carpus with row of spines along dorsal margin, increasing in size distally, lateral side with granulated crest, a few spines proximally; propodus cylindrical, nearly 2.5 times as long as high, dorsal margin with row of spines, lateral side with granulated crest; dactylus nearly 0.8 length of propodus, distal claw short, moderately curved, flexor margin straight, with 8 or 9 teeth decreasing in size proximally, each with single long seta.

Epipods absent from pereiopods.

Colour. Body and appendages light brown or grey; corneae light yellow.

Remarks. The specimens examined agree quite well with the original description and illustrations. No significant differences in morphology among specimens from different localities were observed. The original illustration of M. orcina by Alcock & McArdle (1902) shows that the telson is composed by 8 plates. This difference is considered here as a variation.

Distribution. Previously know from the Arabian Sea at 2105 m. The present material was collected in the southwest Indian Ocean, Madagascar and Reunion Island (740–2000 m), and southwest Pacific, New Caledonia and Vanuatu, between 1360 and 2340 m.