Munidopsis ternaria, Published, 2007

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 : 111-113

Munidopsis ternaria n. sp.

( Fig. 51)

Material examined. New Caledonia, VOLSMAR, Stn 5, 620– 700 m: 1 M 7.8 mm (MNHN-Ga5579). NOR- FOLK 2 , Stn 2047, 759– 807 m: 1 M 3.7 mm (MNHN-Ga5578), 1 M 9.4 mm (MNHN-Ga5577). Stn 2084, 586- 740 m: 1 F 8.4 mm (with bopyrid) ( MNHN) .

Type material. The male of 9.4 mm from NORFOLK 2 (Stn 2047) is the holotype (MNHN-Ga5577) . The other specimens are paratypes.

Etymology. From the Latin ternarius, thrice, in reference to shape of the rostrum.

Description. Carapace slightly longer than broad; dorsal surface moderately convex from side to side, with numerous granules, each granule usually with some short simple setae; regions well delineated by furrows including distinct anterior and posterior cervical grooves. Epigastric region with 2 small spines. Posterior cardiac region preceded by deep transverse depression. Posterior margin preceded by weakly elevated ridge. Rostrum trifid, moderately compressed, horizontal and slightly upcurved distally, nearly half length of remaining carapace, maximum width 0.3 times carapace breadth, terminating acutely; dorsal surface with longitudinal ridge; lateral margins slightly convex. Frontal margin slightly concave behind ocular peduncle, leading to acute antennal spine, then nearly transverse toward anterolateral corner of carapace. Lateral margins weakly convex and subparallel (except in holotype, infested by bopyrid); anterolateral spine slightly shorter than antennal spine, without spine behind it, anterior end of anterior and posterior cervical grooves without notch.

Pterygostomian flap smooth, with small short striae and granules, anteriorly produced.

Sternum smooth, longer than wide, maximum width at sternite 7. Sternite 3 narrow, nearly 1.7 times wider than long, anterior margin not divided into 2 lobes, with deep median notch. Sternite 4 nearly contiguous to third, narrowly elongate anteriorly; surface depressed in midline; greatest width nearly 4 times that of sternite 3.

Abdomen unarmed, with some short striae; segments 2ñ4 each with 2 ridges weakly elevated, separated by transverse groove, segments 5–6 smooth; segment 6 with weakly produced posterolateral lobes and nearly transverse posteromedian margin. Telson composed of 8 plates; posterior plates combined nearly 1.2 times as wide as long.

Ocular peduncle movable, unarmed, cornea subglobular, as long as peduncle. Well-developed spine ventral to front margin between ocular and antennal peduncles.

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

Antennal peduncle nearly reaching tip of cornea; article 1 with strong distomesial and distolateral spines; article 2 armed with short distolateral and distomesial spines; articles 3–4 unarmed.

Mxp 3 ischium as long as merus measured on extensor margin, flexor and extensor margins terminating in blunt spine; 19 or 20 corneous denticles on crista dentata; flexor margin of merus with 2 strong and 2 small spines, extensor margin with distal spine.

P1 moderately stout, subequal, twice carapace length, with numerous soft plumose and simple setae and some short striae and granules on merus to dactylus. Merus with 3 distal spines (lateral, mesial, and dorsal), and some strong spines along mesial margin. Carpus 1.5 times longer than high, with one strong mesial spine, and distomesial and dorsolateral spines. Palm 1.5 times longer than carpus, and slightly longer than fingers. Fingers distally spooned; prehensile edges each with row of subtriangular teeth; fixed and movable fingers ending in several distal teeth; fixed finger without denticulate carina along distolateral margin.

P2–P4 moderately slender, decreasing in size posteriorly, with numerous short striae on dorsal side, meri to dactyli with numerous soft plumose and simple setae more numerous along dorsal and ventral margins. P2 not reaching end of P1; merus nearly half carapace length, 2.5 times longer than high, more than 1.5 times length of carpus and less than twice length of propodus, dorsal margin with row of short spines, with long distal spine, also present on P3 and P4, ventral margin with acute striae, distally produced; carpus with dorsal margin serrated, ending in small spine, lateral side with longitudinal crest; propodus more than 3.5 times as long as high, unarmed except for 2 corneous distal spines on ventral margin; dactylus slightly shorter than propodus, distal claw short, moderately curved; flexor margin nearly straight, with 10 teeth decreasing in size proximally, each with single short seta, ultimate tooth close to distal claw.

Epipods absent from pereiopods.

Remarks. The new species belongs to the group of species with a trifid rostrum, unarmed abdominal segments, carapace surface unarmed or at most with pair of epigastric spines, and meri and carpi of P2–P4 with row of spines along dorsal margin. This group contains M. mina Benedict, 1902 , from the Galapagos Islands at 717 m, and M. trifida Henderson, 1885 (see above).

The new species is easily distinguished by the lateral margins of the carapace: 4 spines in M. mina and M. trifida , being unarmed (except anterolateral spine) in M. ternaria . The dorsal surface of the carapace is granulated in M. ternaria , being smooth in M. mina and M. trifida . Furthermore, P2–P4 meri are more slender and spinose in M. trifida than in M. ternaria .

Distribution. Only known from the type locality, New Caledonia, at 586– 807 m.