Munida mica, Macpherson, 2009

Macpherson, Enrique, 2009, New species of squat lobsters of the genera Munida and Raymunida (Crustacea, Decapoda, Galatheidae) from Vanuatu and New Caledonia, Zoosystema 31 (3), pp. 431-451 : 440-442

Munida mica n. sp.

( Fig. 4 )

HOLOTYPE. — Vanuatu. SANTO 2006 , stn AT13, 15°27.8’S, 167°15.7’E, 146-153 m, 19.IX.2006, ♂ 3.6 mm (MNHN-Ga 6700).

PARATYPES. — Vanuatu. SANTO 2006, stn AT13, 15°27.8’S, 167°15.7’E, 146-153 m, 19.IX.2006, 2 ♂♂ 3.2, 3.4 mm, 6 ovig. ♀♀ 3.8-5.0 mm, 2 ♀♀ 2.3, 5.7 mm (MNHN-Ga 6701). — Stn EP32, 15°36.6’S, 167°02.0’E, 100 m, 14.X.2006, 1 ♀ 5.1 mm (MNHN-Ga 6702). — Stn DB77, 15°27.9’S, 167°14.7’E, 42-45 m, 29.IX.2006, 1 ovig. ♀ 3.6 mm, 1 ♀ 2.7 mm (MNHN-Ga 6703).

ETYMOLOGY. — From the Latin mica , bit, grain, in reference to the small size of the species.

DISTRIBUTION. — Vanuatu, 42- 153 m.

DESCRIPTION

Carapace 1.2 times longer than wide.Main transverse ridges usually not interrupted in cardiac and posterior branchial regions, with very short, non-iridescent setae, and some scattered long iridiscent setae. Few secondary striae between main ridges. Intestinal region without scales. Dorsal surface of carapace armed with 10 or 11 epigastric spines; usually one small parahepatic, one anterobranchial and one postcervical spine on each side. Frontal margins strongly oblique. Lateral margins slightly convex. First spine situated at anterolateral angle, clearly not reaching level of sinus between rostrum and supraocular spines. Second spine in front of cervical groove small, about 0.3 length of anterolateral spine. Branchial margins with 5 spines.Rostrum spiniform, 0.5-0.7 length of remaining carapace, horizontal. Supraocular spines well developed, reaching mid length of rostrum and not reaching end of corneae, subparallel, slightly directed upwards ( Fig. 4A ).

Fourth thoracic sternite smooth, with few short striae; other sternites smooth. Anterior part of fourth sternite, contiguous to posterior margin of third sternite ( Fig. 4B ).

Second and third abdominal somites each with two transverse ridges, anterior ridge unarmed.

Epistomic crest with jump near mouth.

Eyes large, maximum corneal diameter about half distance between bases of anterolateral spines.

Basal segment of antennule (distal spines excluded) about 0.4 carapace length, elongate, about 2.5 times longer than wide (excluding spines), reaching end of corneae, with 2 distal spines, mesial spine slightly longer than lateral; 2 spines on lateral margin, proximal one short, located distal to mid length of segment, distal one long, reaching end of distal spines ( Fig. 4C ); distance between distal end of segment and base of dorsolateral spine 0.4 length of remaining proximal portion. First segment of antennal peduncle with distomesial spine reaching end of second segment; second segment with 2 distal spines, mesial spine slightly longer than lateral spine, slightly exceeding end of third segment; third segment unarmed ( Fig. 4C ).

Mxp3 ischium about 1.5 times length of merus measured along extensor margin, distoventrally bearing spine. Merus with 2 spines on flexor margin, distal smaller; extensor margin with distal spine ( Fig. 4D ).

P1 subequal in length, 1.8-2.8 times carapace length, squamous, with numerous uniramous iridescent setae and plumose non-iridiscent setae denser on mesial and lateral borders of articles. Merus shorter than carapace length, 3-4 times carpus length, armed with some spines, strongest spine on distal border, nearly reaching proximal half of carpus. Carpus 1.4- 1.7 times as long as high, shorter than palm, several strong spines on mesial border and some small spines on dorsal side. Palm shorter than fingers, with row of mesial spines, and some scattered small spines on dorsal side and one row of lateral spines continued onto fixed finger and reaching tip. Movable finger with spines along mesial margin. Fingers distally curving and crossing, ending in sharp point, cutting edges with small teeth of various sizes ( Fig. 4E ).

P2 about twice carapace length, with numerous uniramous iridiscent setae and plumose noniridiscent setae along extensor margin; merus 0.8 times as long as carapace, 6.0-6.5 times as long as high, 3.5-4.0 times carpus length and 1.5-1.7 times as long as propodus; propodus 6-7 times as long as high, and slightly longer than dactylus ( Fig. 4F ). Extensor border of merus with row of small spines increasing in size distally, flexor margin with few spines increasing in size distally. Carpus with 1 or 2 extensor spines and one distoventral spine; distal margin not reaching level of merocarpal articulation of P1. Propodus with 11 or 12 movable spinules along flexor margin. Dactylus slightly curving distally, with 7 movable spinules along flexor margin, ultimate spine slightly more remote from tip of dactylus than from penultimate spine ( Fig. 4G ). P3 slightly shorter than P2; spination of P3 similar to that of P2 ( Fig. 4H ). P4 length 0.8 times P2 length; merus 0.7 times length of P2 merus; spines along margins of merus and carpus less spinose than those of P2 and P3 ( Fig. 4I ); merocarpal articulation reaching level of end of cervical groove.

Colour

Ground colour of carapace and abdomen light orange; striae reddish; one red spot on each margin of anterobranchial region. Rostrum, supraocular and anterolateral spines orange. P1-P4 with white and red bands; P2-P4 dactylus whitish.

REMARKS

The new species is closely related to M. pauxilla n. sp. from Vanuatu and Loyalty Islands. Their relationships are discussed under the remarks of that species (see below).

Figures

FIG. 4. — Munida mica n. sp., holotype, ♂ 3.6 mm: A, carapace and abdomen, dorsal view; B, sternal plastron; C, cephalic region, showing antennular and antennal peduncles,ventral view; D, right Mxp3, lateral view; E, right P1, dorsal view;F, right P2, lateral view; G, right P3, lateral view; H, right P4, lateral view. Scale bar: A, B, E-H, 1 mm; C, D, 0.5 mm.