Munidopsis concava, 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 : 53-55

Munidopsis concava n. sp.

( Fig. 26)

Material examined. Solomon Islands, SALOMON 2, Stn 2245, 582– 609 m: 1 M 6.3 mm (MNHN-Ga5537) . Vanuatu, BOA 0, Stn 2313, 421– 482 m: 1 ovig. F 8.6 mm (MNHN-Ga538). BOA 1, Stn 2432, 630– 705 m: 2 M 6.8–11.2 mm, 3 ovig. F 7.1–7.6 mm (MNHN-Ga5539).—Stn 2470, 568– 591 m: 9 M 3.3–7.0 mm, 2 ovig. F 6.1–7.5 mm, 9 F 3.1–6.4 mm (MNHN-Ga5540) . Fiji, MUSORSTOM 10, Stn 1337, 635– 670 m: 1 ovig. F 7.2 mm (MNHN-Ga5551) .

Types. The ovigerous female of 7.2 mm from MUSORSTOM 10, Stn 1337 is the holotype (MNHN- Ga5551). The other specimens are paratypes.

Etymology. From the Latin concavus, concave, in reference to the concave margin of the rostrum.

Description. Carapace longer than wide, moderately arched from side to side, weakly convex from anterior to posterior end; bifurcated cervical groove weakly marked. Dorsal surface pubescent, unarmed, with some small striae. Gastric region indistinctly bordered from rostrum. Rostrum lanceolate, straight horizontal, dorsal surface carinate, lateral margins finely denticulate in distal third, concave in proximal third, ventral surface flattish on proximal half, somewhat carinate in midline on distal half; length nearly one-third that of remaining carapace, maximum width about one-fourth carapace breadth. Front margin oblique, bearing strong antennal spine, leading more obliquely to minute anterolateral blunt spine. Lateral margin somewhat convex, with notch at end of anterior cervical groove, followed by large blunt spine.

Sternum as long as wide, maximum width at seternite 7. Sternite 3 roughly quadrangular, anterior margin with submedian granules and blunt lateral process on each side. Sternite 4 more than 4 times as broad as preceding sternite, lateral margin with 2–4 spines plus minute spines, anterior-most larger.

Abdomen unarmed on surface, pubescent. Segments 2–4 each with slightly elevated anterior ridge, followed by shallow transverse groove. Segment 6 having transverse posterior margin flanked by very week lat- eral lobe. Telson composed of 8 plates; posterior plates combined more than twice wider than long.

Pterygostomian region with strong acute projection at anterior end.

Ocular peduncle immovable. Cornea well exposed, semicircular in dorsal view. Well-developed eye-spine continuous with eyestalk, about as long as remaining eyestalk in dorsal view.

Basal article of antennule with distolateral and dorsolateral spines, latter smaller, two small spines at base; distomesial angle granulated.

Antennal peduncle having basal article with strong distomesial spine, nearly reaching end of article 2, distolateral spine well-developed; article 2 with small distolateral and distomesial spines; article 3 with minute distomesial, distolateral and distoventral spines.

Mxp 3 ischium slightly shorter than merus, crista dentata with 18–20 denticles. Merus with 3 blunt spines on flexor margin, extensor distal margin lacking distinct spine.

P1 short, setose, slightly longer than carapace. Merus with a few distal spines, some additional dorsal spines. Carpus as long as high, bearing some mesial and dorsal distal spines, and several small spines on dorsal side. Palm slightly longer than carpus, spineless. Fingers slightly shorter than palm, spooned at tip, prehensile edges straight, crenulate; fixed finger with denticulate carina on distolateral margin.

P2–P4 setose. P2 as long as carapace, reaching or slightly overreaching end of P1; merus triangular in section, half as long as carapace, nearly 2.5 times as long as high, about 1.5 times length of carpus and less than 1.5 times length of propodus, relatively high and compressed, dorsal crest with row of small spines increasing distally, ventral border with two serrated ridges; carpus with row of dorsal spines, with subparalleling striate ridge, terminal spines on dorsal crest strong; propodus 3 times as long as high, distal part of flexor margin ending in pair of movable spines preceded by a single spine somewhat distantly proximal to it; dactylus about two-third propodus length, ending in relatively short, strongly curved claw preceded by 9 or 10 proximally diminishing teeth on nearly straight flexor margin, corneous seta-like spine arising from each tooth, ultimate tooth closer to penultimate one than to end of terminal claw.

Epipod absent from P1–4.

Remarks. The new species is closely related to M. pilosa Henderson, 1885 (see below). Both species have the carapace surface smooth, usually setose, rostrum without lateral spines, lateral carapace border not crested, P2 reaching or overreaching P1, main eye-spine on median part of corneae and continuous with eyestalk. However, the following characters can differentiate these two species:

— The lateral margins of the rostrum are straight or slightly convex in M. pilosa , but concave in the proximal third in M. concava .

— The P2–P4 bear strong spines along the dorsal margins of the meri and carpi in M. pilosa , whereas these spines are clearly smaller in the new species.

Distribution. Solomon Islands, Fiji and Vanuatu, between 421 and 705 m.