Munidopsis austellus, 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 : 41-43

Munidopsis austellus n. sp.

( Fig. 21)

Material examined. French Polynesia, BENTHAUS, Stn 1911, 900– 1300 m: 1 M 6.5 mm (holotype, MNHN-Ga5558) .

Etymology. From the Latin austellus , gentle south wind, in reference to the southern origin of the species. The name is considered as a substantive in apposition.

Description. Carapace 1.2 times longer than broad; dorsal surface moderately convex from side to side, covered with small granules, nearly devoid of setae; regions well delineated by furrows including distinct anterior and posterior cervical grooves. Median branchial region well marked. Posterior cardiac region bluntly triangular, preceded by deep transverse depression on each side. Posterior margin preceded by granulated ridge. Rostrum triangular, horizontal in lateral view, 0.3 length of remaining carapace, 0.3 as wide as carapace; dorsal surface with longitudinal carina; lateral margins carinate. Frontal margin with antennal spine, concavely transverse behind ocular peduncle, slightly oblique between antennal spine and anterolateral corner of carapace. Lateral margins granulated, weakly convex and subparallel, anterolateral angle with small spine, distinct notch at end of anterior cervical groove, and shallow notch at end of posterior cervical groove.

Pterygostomian region granulated, anteriorly ending in acute angle.

Sternum as long as wide, maximum width at level of sternite 7. Sternite 3 moderately broad, nearly 2.5 times broader than long, anterior margin divided into 2 lobes by deep median notch, lateral margin of each lobe convex. Sternite 4 wide anteriorly; surface depressed in midline, with some short ridges on anterior part; greatest width 2.5 times that of sternite 3.

Abdomen smooth, unarmed; segments 2ñ4 each with 2 slightly elevated transverse ridges, but segments 5–6 lacking such ridges; segment 6 with weakly produced posterolateral lobes and nearly transverse posteromedian margin. Telson composed of 7 plates; posterior plates combined nearly 1.5 times as wide as long.

Ocular peduncle scarcely movable, unarmed; cornea subglobular, slightly narrower than eyestalk, without spine or tooth between eye and antennal peduncle.

Basal article of antennular peduncle with long dorsolateral and distolateral spines; distomesial margin with crest of small tubercles.

Antennal peduncle overreaching tip of eye by distal margin of article 3; article 1 with distomesial and laterodistal processes; article 2 armed with 2 small distal spines on mesial and lateral margins; article 3 with minute distomesial spine; article 4 unarmed.

Mxp 3 ischium slightly shorter than merus measured on extensor margin; 19 or 20 corneous denticles on crista dentata; merus with flexor margin with 2 strong and 2 small spines; extensor margin with small distal spine.

P1 long and slender, nearly devoid of setae, left slightly longer than right; right P1 2.3 times longer than carapace, covered with small granules on merus to dactylus, those on fingers reduced in number. Merus with 2 strong spines at midlength and at distal part of mesial margin, a few minute spines on dorsal side. Carpus more than twice longer than high, with strong mesial spine. Palm unarmed, slender, 1.2 length of carpus, and slightly longer than fingers. Fingers unarmed, opposable margins nearly straight, not gaping, distally spooned.

P2–P4 slender, nearly devoid of setae, somewhat compressed laterally, decreasing in size posteriorly; P2 longest, nearly reaching end of P1 carpus. P2 merus moderately elongate, 0.6 times length of carapace, 4 times longer than high and twice carpus length, dorsal margin serrated, distal spine small; lateral surface with small granules; ventral margin serrated; carpus with granulated crest along dorsal margin and lateral surface; propodus slightly shorter than merus, 7 times longer than high and twice dactylus length, covered with numerous small granules, 1 movable distal spinule on flexor margin; dactylus moderately curved, flexor margin straight, with 6 teeth decreasing in size proximally, and situated on distal half, each with slender corneous spinule.

Epipods absent from P1–P4.

Remarks. The new species is closely related to M. cidaris Baba, 1974 from northeastern Australia (off Queensland), the Solomon Islands and the Philippines (see below). The two species are characterized by a triangular rostrum, dorsal carapace surface covered with small granules, without epigastric spines, abdomen unarmed, eye-spine absent, and P2 not reaching end of P1. Munidopsis austellus can be differentiated from M. cidaris by the following features:

— The epipods are absent in the new species and present in P 1 in M. cidaris .

— The antennal spine is absent in M. cidaris , present in M. austellus .

— The rostrum bears a distinct dorsal carina in midline in M. austellus , whereas this carina is nearly obsolete in M. cidaris .

— The P1 bears a strong spine at midlength on the merus, and another near the distal end of carpus in the new species, whereas these margins are unarmed in M. cidaris .

— The dacyli of P2–4 have the flexor margin unarmed in M. cidaris , instead of bearing some teeth in the new species.

Distribution. French Polynesia (Austral Islands), between 900 and 1300 m.