Munidopsis calvata, 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 : 47-49

Munidopsis calvata n. sp.

( Fig. 23)

Material examined. Madagascar (A. Crosnier collection), Stn CH 49, 400– 550 m: 1 ovig. F 8.6 mm (MNHN-Ga702).—Stn CH 54, 335– 355 m: 1 ovig. F 9.1 mm, 1 F 5.0 mm (MNHN-Ga703).—Stn CH 58, 510 m: 1 M 13.8 mm (MNHN-Ga700).—Stn CH 66, 450– 460 m: 2 M 10.4–15.2 mm (MNHN-Ga701).— Stn CH 87, 250 m: 1 M 9.8 mm (MNHN-Ga842).—Stn CH 89, 620 m: 1 ovig. F 9.7 mm (MNHN-Ga841).—Stn CH 90, 640– 720 m: 2 M 15.8–17.8 mm, 1 ovig. F 11.4 mm (MNHN-Ga845).—Stn CH 94, 400 m: 1 M 8.2 mm (MNHN-Ga844).—Stn CH 98, 600– 605 m: 1 M 14.0 mm (MNHN-Ga1388).—Stn CH 114, 470– 475 m: 1 ovig. F 10.9 mm (MNHN-Ga1389).—Stn CH 115, 450 m: 1 M 17.5 mm, 1 ovig. F 12.5 mm (MNHN- Ga1390). Madagascar, Stn CH 15, 425– 460 m: 1 M 13.6 mm (MNHN-Ga1752).—Stn CH 26, 450– 600 m: 1 M 14.4 mm (MNHN-Ga1754).—Stn CH 28, 450 m: 1 ovig. F 12.1 mm (MNHN-Ga1751).—Stn CH 71, 525 m: 1 ovig. F 15.7 mm (MNHN-Ga4850).—Stn CH 82, 520 m: 1 ovig. F 17.6 mm (MNHN-Ga5423).—Stn CH 100, 600 m: 1 M 15.1 mm, 1 ovig. F 14.4 mm (MNHN-Ga5424).

Types. The male of 9.8 mm from Madagascar (A. Crosnier collection), stn CH 87 is the holotype ( MNHN Ga842). The other specimens are paratypes.

Etymology. From the Latin calvatus, bare, in reference to the absence of spines and strong rugosities on the carapace and abdomen.

Description. Carapace 1.3 times as long as wide, dorsally spineless, covered with fine short setae, bearing very weak, interrupted transverse ridges more distinct on posterior half; gastric region convex, cardiac transverse ridge elevated. Rostrum 0.4 times as long as remaining carapace, maximum width one-quarter carapace breadth, narrowly triangular, dorsally convex and nearly straight horizontal; lateral margins convex and carinated. Front margin obliquely convex on mesial half, lateral half transverse, depressed below level of mesial half. Lateral margins subparallel, each constricted at end of anterior cervical groove, anterolateral angle rounded, not produced.

Sternum elongate, more than 1.5 times longer than wide, maximum width at level of sternites 4 and 7. Sternites smooth, with a few short striae; sternite 3 much wider than long, 0.3 width of sternite 4, anterior margin granulated; sternite 4 subtriangular, anteriorly narrow elongate.

Abdominal segments spineless, setose; segments 2–4 each with anterior ridge slightly elevated, followed by transverse groove; segments 5 and 6 smooth; posterolateral lobes of segment 6 reaching end of nearly transverse posteromedian margin. Telson divided into 12 plates, posterior plates each slightly longer than broad.

Eye movable; cornea unarmed, much longer than remaining eyestalk, feebly curving outward; distinct spine ventral to front margin between ocular and antennal peduncles.

Basal article of antennule having distolateral spine larger than dorsolateral, ventromesial process granulated, with one short distal spine.

Basal article of antennal peduncle distomesially bearing one small spine, distolateral angle rounded and granulated; article 2 with well-developed distolateral spine; articles 3-4 unarmed.

Mxp 3 ischium 0.7 times as long as merus, bearing short process on flexor and extensor margins, lateral surface smooth, 17–19 corneous denticles on crista dentata; merus with 3 flexor marginal spines, distal one small, proximal spine largest, extensor margin with distal spine.

P1 subcylindrical, long and slender, 2.5–3.0 times as long as carapace, surface smooth. Merus about 2.5 times as long as carpus, with 2 terminal spines (mesial and lateral); carpus twice longer than wide and about half as long as palm, sometimes with minute distomesial and distolateral spines; palm 1.5 times as long as fingers, chela spineless, fingers not gaping, distally bearing intermeshing teeth.

P2–P4 barely setose, relatively slender, 3 distal articles subcylindrical; Meri successively shorter posteriorly, slightly depressed, dorsal margins feebly carinate, distally ending in spine, ventral margin with tubercles, distally ending in spine. P2 reaching midlength of cheliped merus, slightly longer than carapace; merus less thant 3 times longer than wide, 1.7 times as long as propodus; dorsal margin of carpus with distal spine; propodus nearly 1.5 times as long as dactylus and 2.5 times longer than high, with distal movable spinule on flexor margin; dactylus curving, somewhat more so on P3 and P4, flexor margin with 6 or 7 proximally diminishing teeth, each with corneous seta-like.

Epipods absent from pereiopods.

Remarks. The unarmed and smooth carapace and the abdomen, the triangular rostrum, P1 longer than P2, movable eye with unarmed cornea that is much longer than the remaining eyestalk and the absence of epipods on the pereiopods link the new species to M. africana Balss, 1913 , from Zanzibar (see above). Munidopsis calvata differs from M. africana in the following features:

— The lateral margins of the rostrum are straight in M. calvata , instead of being convex in M. africana .

— The P1 merus and carpus each bears spines along the mesial margin in M. africana , whereas these spines are absent in M. calvata .

— The dorsal margins of P2–P4 meri each bear a row of small spines in M. africana , instead of being unarmed (except distal spine) in M. calvata .

Distribution. Madagascar at 250– 720 m.