Munidopsis trichodes, 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 : 113-115

Munidopsis trichodes n. sp.

( Fig. 52)

Material examined. Madagascar (A. Crosnier collection), Stn CH 131, 1490– 1640 m: 1M 11.9 mm (MNHN-Ga5580), 2 M 4.6–8.5 mm, 1 F 4.0 mm (MNHN-Ga1408).

Type material. The male of 11.9 mm from Madagascar, Stn CH 1131, is the

holotype (MNHN-Ga5580). The other specimens are paratypes.

Etymology. From the Greek trichodes , hairy, in reference to the long setae on the carapace.

Description. Carapace slightly longer than broad, with numerous short striae, each with moderately long simple setae; gastric region moderately convex, with 2 epigastric spines; cardiac region faintly delineated in triangular shape, anteriorly without distinct transverse ridge but preceded by shallow concavity anterolateral to it on each side. Rostrum triangular, tip mucronated, nearly horizontal, not carinate dorsally, bearing sparse simple setae; length 0.3 that of remaining carapace, maximum width one-quarter carapace breadth. Front margin oblique, with strong antennal spine. Lateral margins somewhat convex, with 4 spines, anterolateral (first spine) smaller than antennal spine, directed forward, second spine larger than first, third and fourth spines small, last one at midlength of carapace; each end of anterior and posterior branches of cervical groove with notch.

Sternite slightly longer than broad, maximum width at sternite 7. Sternite 3 very narrow, anterior margin divided into 2 lobes by deep median notch, more than 1.5 times longer than wide. Sternite 4 narrowly elongate anteriorly, width nearly 4.5 times that of preceding sternite.

Abdominal segments spineless, segments 2–4 each bearing 2 ridges separated by shallow groove. Segment 6 having posterolateral lobes flap-like, not overreaching transverse posteromedian margin. Telson broader than long, divided into 10 plates; posterior plates combined twice as wide as long.

Ocular peduncle hardly movable, relatively broad, bearing lateral and mesial eye-spines, lateral one small, mesial one strongly produced beyond cornea. Cornea small and lateral, wider than eye-spine.

Basal article of antennule with long dorsolateral and distolateral spines and denticulate distomesial process.

Antennal peduncle well-developed; basal article with acute distomesial process somewhat larger than distolateral, both strong; article 2 with well-developed distolateral and 1 minute distomesial spine; article 3 with distomesial and distolateral spines.

Mxp 3 ischium with 21 or 22 closely placed denticles on crista dentata, extensor margin with distinct distal spine. Merus slightly longer than ischium; flexor margin with 7–9 low, obtuse processes of irregular size, extensor margin distally produced into spine.

P1 more than 1.5 times carapace length, with numerous short setiferous striae. Merus exceeding rostrum, bearing row of 4 mesiodorsal spines and 3 distal spines (mesial, dorsomesial, and lateral). Carpus slightly longer than high, with 3 distal spines and a few spines on mesial margin and dorsal surface. Palm longer than carpus, uanrmed. Fingers shorter than palm, distally spooned; fixed finger with denticulate carina on distolateral margin.

P2–P4 slender, somewhat compressed laterally, decreasing in size posteriorly; P2 longest, not reaching end of P1; ischium to propodus with short striae; dactylus with tufts of short simple setae. P2 1.5 times carapace length, with merus moderately elongate, 0.8 times length of carapace, nearly 4 times longer than high and twice carpus length, with row of spines along dorsal crest, terminal spine long, several distal spines along ventral margin; carpus with dorsal marginal spines increasing in size distally, longitudinal crest along lateral surface; propodus 4.5 times longer than high, 2 movable distal spinules on ventral margin; dactylus less than half propodus length, moderately curved; flexor margin straight, with 11 or 12 teeth deceasing in sizes proximally, each with slender seta.

Epipod absent from pereiopods.

Remarks. Munidopsis trichodes resembles M. similis Smith, 1885 , from the northwestern Atlantic and M. verrilli Benedict, 1902 , from northeastern Pacific, Makassar Strait and Tasmania ( Mayo 1974, Baba & Poore 2002, Baba 2005) in having the rostrum without lateral spines, two epigastric spines, abdomen unarmed, P2 not reaching end of P1, mesial and lateral eyespines present and epipods absent from the pereiopods. The new species is differentiated from these two species by the presence of a denticulate carina on the distolateral margin of the fixed finger. However, the presence or absence of this denticulate carina may be considered with caution after Baba (2005). This author indicated that the carina is present in several individuals of M. verrilli (absent in the holotype) and additional material would be necessary to clarify the validity of this difference. Nevertheless, the palm of P1 has some spines along the mesial margin in M. similis and M. verrilli , whereas these spines are absent in the new species.

Munidopsis trichodes is also close to M. nitida A. Milne-Edwards, 1880 (see above). However, P1 is shorter than P2 and epipods are present on P 1 in M. nitida .

Distribution. Madagascar, between 1475 and 1490 m.