Munidopsis pectinata, 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 : 89-91

Munidopsis pectinata n. sp.

( Fig. 42)

Material examined. Reunion Island, MD32 , Stn CP 112, 740– 780 m: 1 F 4.9 mm, holotype (MNHN- Ga5563) .

Etymology. From the Latin pecten, comb, in reference to the characteristic spination of the antennular peduncle.

Description. Carapace slightly longer than broad; dorsal surface moderately convex from side to side, covered with numerous granules and acute tubercles; cervical grooves distinct, regions well defined, gastric and cardiac regions more convex than branchial. Gastric region with transverse row of 7 epigastric spines. Cardiac region triangular, preceded by deep transverse groove. Rostrum broad, triangular, horizontal in lateral view, less than 0.3 length of remaining carapace, maximum width one-fourth carapace width; margins of proximal half subparallel, apex acute; dorsally carinated, dorsal and lateral surfaces granulated. Frontal margin concavely oblique behind ocular peduncle, leading to srong antennal spine, then obliquely toward anterolateral corner of carapace; anterolateral spine well-developed, smaller than antennal spine. Lateral margins weakly convex, with distinct notch at end of anterior cervical groove, followed by numerous spines and granules. Posterior margin preceded by elevated spiniform ridge.

Pterygostomian flap granulated, anterior margin angular.

Sternum smooth, as long as broad, maximum width at sternite 7; sternite 3 narrow, not clearly bilobate, about 3 times wider than long; sternite 4 about 3 times wider than sternite 3.

Abdominal segments 2–4 each with 2 slightly produced transverse ridges separated by shallow groove; posterior ridge of segment 2 with some small median spines; anterior ridge of segment 3 with 2 median small spines, posterior ridge smooth; ridges on segments 4 and 5 smooth; segment 6 with weakly produced posterolateral lobes and nearly transverse posteromedian margin. Telson composed of 7 plates; posterior plates combined about 1.5 times as wide as long.

Ocular peduncle slightly movable, with short mesial eye-spine not reaching end of cornea; cornea subglobular, longer than remaining eyestalk, reaching end of antennal peduncle. Acute spine ventral to front mar- gin between ocular and antennal peduncles.

Basal article of antennular peduncle with strong dorsolateral and distolateral spines, and some small spines at base; lateral margin with numerous well-developed spines; distomesial margin granulated, with some small spines.

Basal article of antennal peduncle with strong distomesial and distolateral spines; article 2 with strong distolateral and small distomesial spines; article 3 with small distolateral spine; article 4 unarmed.

Mxp 3 ischium granulated, as long as merus measured on extensor margin, flexor and extensor margins terminating in small acute spine, 16ñ18 corneous denticles on crista dentata. Flexor margin of merus with 3 spines decreasing in size distally, and several minute spines; extensor margin with some spines, distal spine longer than others.

Left P1 (right missing) moderately slender, more than 1.5 times longer than carapace, with numerous small granules and some soft setae on merus to fingers. Merus more than twice length of carpus, with 3 distal spines (mesial, dorsal and lateral) and 2 well-developed spines at midlength of mesial margin, some minute spines on dorsal surface. Carpus twice longer than high, with rows of spines along mesial, dorsal and lateral sides, one strong spine on mesial margin. Palm slender, nearly 1.5 times length of carpus, unarmed. Fingers as long as palm, opposable margins nearly straight, not gaping, distally spooned; fixed finger without distolateral carina.

P2–P4 moderately slender, coarsely granulated, with some setae, decreasing in size posteriorly. P2 longest, nearly 1.5 times carapace length, and not reaching end of P1; merus slightly shorter than carapace length, about 4 times longer than high, 3 times length of carpus and less than 1.5 times length of propodus; dorsal margin with row of small spines, ventral margin granules, each margin ending in well-developed spine; carpus with granulated crest on lateral surface, numerous spines along dorsal margin, ending in well-developed spine; propodus 5 times as long as high, dorsal margin with row of small spines, ventral margin unarmed except for 1 or 2 distal corneous spines; dactylus half length of propodus, curved, flexor margin slightly curved, with 8 teeth decreasing in size proximally, each tooth with seta.

Epipods absent on pereiopods.

Remarks. Munidopsis pectinata resembles M. margarita Faxon, 1893 , from the Galapagos Islands, in having the carapace surface granulated, rostrum triangular, without lateral spines, abdominal segments 2–3 with spines, short mesial eye-spine, antennal spine present and P2 clearly not reaching end of P1. The following characters can easily differentiate the two species:

— The rostrum is spiniform in M. margarita , being broadly triangular in M. pectinata .

— The gastric region bears some well-developed spines, in addition to epigastric spines, in M. margarita , whereas these spines are absent in M. pectinata .

— The spines along the lateral margins of the carapace are stronger and more numerous in M. margarita than in the new species.

— The median spines on the anterior ridge of abdominal segments 2–4 are well-developed in M. margarita , whereas these spines are small or absent in M. pectinata .

— The spines along dorsal and ventral margins of P2–P4 meri are well-developed in M. margarita , whereas these spines are small in the new species.

Distribution. Only known from Reunion Island, at 740– 780 m.