Munidopsis stylirostris Wood-Mason, 1891

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 : 108-110

Munidopsis stylirostris Wood-Mason, 1891

( Fig. 50)

Munidopsis stylirostris Wood-Mason, 1891: 201 .— Baba, 2005: 296 (list of occurrences).

Munidopsis (Munidopsis) stylirostris var. africana Doflein & Balss, 1913: 154 , figs 19, 20.

Material examined. W of Sri Lanka, SAFARI 2, Stn 4, CP06, 1035 m: 1 F 19.8 mm (MNHN-Ga1580). Gulf of Aden , DeutschenTiefsee Expedition (Valdivia), Stn 270, 1840 m: 1 F 13.6 mm (syntype of M. stylirostris var. africana ) ( ZMB). METEOR 5 , Stn 249, 1299– 1314 m: 2 M 9.8–13.7 mm, 2 ovig. F 10.5–10.7 mm ( SMF) .— Stn 262, 1830– 1837 m: 4 M 9.2 mm, 13.8 mm, 1 ovig. F 16.1 mm, 3 F 16.1–16.8 mm ( SMF) .— Stn 268, 1654– 1686 m: 4 M 12.5–15.2 mm, 3 ovig. F 13.1–15.2 mm ( SMF) .— Stn 271, 2276– 2282 m: 1 M 10.3 mm ( SMF) .— Stn 277, 1552– 1554 m: 14 M 6.9–14.6 mm, 8 ovig. F 11.4–18.5 mm, 5 F 7.5–16.2 mm ( SMF) .

Description. Carapace longer than broad, moderately convex from side to side, with short striae more numerous on branchial and cardiac regions than on gastric region; cervical groove distinct. Gastric region distinct, posterior part delimited by shallow groove; surface with 2–9 spines on epigastric and mesogastric regions (in a few specimens, without spines). Cardiac region triangular, preceded by deep transverse groove. Rostrum spiniform, upturned in distal half, not carinated dorsally, about 0.4 remaining carapace length, maximum width one-quarter carapace breadth. Antennal spine absent; oblique frontal margin leading to strong anterolateral spine directed laterad, lateral margins usually unarmed (in some specimens, with 4 or 5 small spines on anterior branchial margin). Posterior margin unarmed.

Sternum clearly longer than wide, maximum width at sternite 7, with some short setose striae; sternite 3 wide, bilobate, 3 times wider than long; sternite 4 subtriangular, anteriorly narrow elongate, about 2.5 times width of sternite 3.

Abdomen smooth, segments 2–4 each with 2 elevated transverse ridges; segment 6 bearing median margin clearly not exceeding posterolateral lobes. Telson composed of 12 plates; posterior plates combined more than twice as wide as long.

Eye movable; unarmed, corneae subglobular, slightly longer than peduncle, as wide as third article of antennal peduncle. Well-developed spine ventral to front margin between ocular and antennal peduncles.

Basal article of antennule having dorsolateral spine longer than distolateral, ventromesial process produced and granulated.

Basal article of antennal peduncle with blunt process on distomesial and distolateral angles; articles 2–3 with distolateral spine.

Mxp 3 ischium having blunt spine on extensor and flexor margin, crista dentata with 17 or 18 denticles; flexor margin of merus with 2 well-developed spines and 1 or 2 small spines, extensor margin with distal marginal spine.

P1 longer than carapace, with numeous scale-like elevated rugosities. Merus reaching end of rostrum, with some distal spines and 1 or 2 mesial spines at medlength of article, some additional dorsal spines on proximal half. Carpus with several distal spines, nearly twice longer than high. Palm longer than fingers, unarmed. Fingers distally spooned, prehensile edges crenulated; fixed finger without denticulate carina on distolateral margin.

P2–P4 slender, decreasing in length posteriorly, with scattered short striae more numerous on lateral side of articles. P2 not reaching end of P1; merus 6 times longer than high, 3 times carpus length and 1.5 times length of propodus, dorsal margin with several proximal spines and one distal spine, ventral margin with distal spine; carpus with distal spine on dorsal margin, granulated crest along lateral side; propodus 5.5 times longer than high, one movable distal spine on ventral margin; dactylus half as long as propodus, smoothly narrowed distally, ending in curved sharp spine, flexor margin slightly curving, bearing 6 or 7 proximally diminishing low teeth, ultimate tooth rather remote from end of dactylus and much closer to penultimate, each tooth bearing seta.

Epipods absent from pereiopods.

Remarks. Examination of the type material of M. stylirostris var. africana Balss, 1913 , as well as numerous specimens from the same locality (Gulf of Aden) confirms the variability in the number and shape of the spines on the gastric region and anterobranchial margin. This character was used by Balss (1913) to distinguish the new variety, but is now known to be within the range of intraspecific variation.

Distribution. Laccadive Sea, Arabian Sea, Gulf of Aden, between 1351 and 2000 m ( Wood-Mason 1891, Alcock 1894, 1901, Alcock & Anderson 1894, Anderson 1896, Doflein & Balss 1913, Tirmizi 1966). The material examined here was collected in the southeastern Indian Ocean and Gulf of Aden, between 1035 and 2282 m.