Munida jubata, 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 : 436-440

Munida jubata n. sp.

( Fig. 3 )

HOLOTYPE. — Vanuatu. SANTO 2006 , stn AT54, 15°32.1’S, 167°14.1’E, 68-79 m, 2.X.2006, ovig. ♀ 3.9 mm (MNHN-Ga 6698).

PARATYPES. — Vanuatu. SANTO 2006, stn AT54, 15°32.1’S, 167°14.1’E, 68-79 m, 2.X.2006, 1♂ 3.0 mm, 1 ♀ 3.4 mm (MNHN-Ga 6699).

ETYMOLOGY. — From the Latin, juba, crest in reference to the dorsal ridge along the rostral spine.

DISTRIBUTION. — Vanuatu, between 68 and 79 m.

DESCRIPTION

Carapace slightly longer than wide.Transverse ridges usually interrupted in cardiac and branchial regions, with short, non-iridescent setae; some iridescent setae on each posterolateral angle of carapace and tuft of iridescent setae below first branchial spine. Few secondary striae and scales between main striae. Intestinal region with short scales. Dorsal surface of carapace armed with 15 epigastric spines; one small hepatic and one postcervical spine on each side. Frontal margins moderately oblique. Lateral margins subparallel. First spine well developed, situated at anterolateral angle, far falling short of level of sinus between rostrum and supraocular spines. Second spine in front of cervical groove small, about one-fourth length of anterolateral spine. Branchial margins with 3 or 4 small spines. Rostrum spiniform,0.4 length of remaining carapace, horizontal, dorsally carinated and slightly convex. Supraocular spines short, reaching mid length of rostrum and far falling short of end of corneae, subparallel, directed slightly upwards ( Fig. 3A ).

Fourth thoracic sternite smooth, with few short striae; other sternites smooth. Anterior part of fourth sternite concave medially, slightly narrower than third, contiguous to posterior median margin of third sternite ( Fig. 3B ).

Second and third abdominal somites each with two transverse ridges, anterior ridge of second and third somites with 6-8 and 2 spines, respectively.

Epistomic crest with jump near mouth.

Eyes large, maximum corneal diameter 0.4 times distance between bases of anterolateral spines.

Basal segment of antennule (distal spines excluded) about 0.4 carapace length, elongate, nearly 3 times longer than wide (excluding spines), reaching end of corneae, with 2 distal spines, mesial spine clearly shorter than lateral; 2 spines on lateral margin, proximal one short, located at mid length of segment, distal one long, not reaching end of segment (excluding spines) ( Fig.3C ); distance between distal end of segment and base of dorsolateral spine 0.3 length of remaining proximal portion. First segment of antennal peduncle with short distomesial spine clearly not reaching end of second segment; second segment with 2 subequal distal spines, not exceeding end of third segment; third segment unarmed ( Fig. 3C ).

Mxp3 ischium twice length of merus measured along extensor margin, distoventrally bearing spine. Merus with 2 well-developed spines on flexor margin, distal smaller; extensor margin unarmed ( Fig. 3D ).

P1 subequal in length, squamous, with numerous uniramous iridescent setae and some plumose non-iridiscent setae denser on mesial and lateral borders of articles. Merus 2.5 times carpus length, armed with some spines, strongest spine on distal border, not reaching proximal fourth of carpus. Carpus 3.0-3.5 times as long as high, shorter than palm, several strong spines on mesial border and some small spines on dorsal side. Palm 1.3 times longer than fingers, with row of mesial spines, with some scattered small spines on dorsal side and one row of lateral spines continued with minute spines onto fixed finger and reaching tip. Movable finger with row of spines along entire mesial margin. Fingers distally curving and crossing, ending in sharp point, cutting edges with small teeth of various sizes ( Fig. 3E ).

P2 about 3 times carapace length, with numerous uniramous iridiscent setae and plumose noniridiscent setae along extensor margins; merus 1.1-1.3 times as long as carapace, about 8 times as long as high, 6 times carpus length and 1.6-1.8 times propodus length; propodus 9-10 times as long as high, and 1.1-1.4 times longer than dactylus ( Fig. 3F ). Dorsal border of merus with row of spines increasing in size distally, flexor margin with row of spines increasing in size distally.Carpus with distodorsal and distoventral spines; distal margin not reaching level of merocarpal articulation of P1. Propodus with 17-20 movable spinules along flexor margin. Dactylus long and slender, slightly curving distally, with 11 or 12 movable spinules along flexor margin, distal third unarmed ( Fig. 3G ). P3 slightly shorter than P2; spination of P3 similar to that of P2 ( Fig. 3H ). P4 length 0.8 times P2 length; merus 0.6-0.7 times length of P2 merus; margins of merus and carpus less spinose than those of P2 and P3 ( Fig. 3I ); merocarpal articulation reaching level of anterolateral spine of carapace.

REMARKS

The new species is closely related to M. parca Macpherson, 1996 from New Caledonia ( Macpherson 1996). The two species have five spines on the lateral margin of the carapace behind cervical groove, eyes moderately large, the second abdominal segment with spines, the lateral parts of the posterior thoracic sternites without granules, the rostrum spiniform, the epistomal crest without a jump near the mouth, the distomesial spine of basal antennular segment clearly shorter than the distolateral, and the distomesial spine of the basal antennal article nearly reaching the end of the third article. The two species are distinguished by the following characters:

– the P1 is clearly longer in the new species than in M. parca . In the new species it is about 4.5 times the carapace length, whereas this ratio is about 2.5 times in M. parca . The carpus is nearly 2.5 times longer than broad in M. parca , whereas it is 4 times longer in the new species;

– the walking legs (P2-P4) are longer in M. parca . The P2 is about 3 times the carapace length in the new species, instead of being slightly more than 2 times as in M. parca . Furthermore, the P2 merus is nearly as long as the carapace in M. parca , instead of being longer as in M. jubata n. sp. Furthermore, the merocarpal articulation ends at level of the anterolateral spine of the carapace in the new species, whereas this articulation slightly exceeds the level of the anterior branch of the cervical groove in M. parca .

Figures

FIG. 3.— Munida jubata n. sp.,holotype,ovig.♀ 3.9 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; I, dactylus of right P2, lateral view. Scale bar: A, B, E-H, 1 mm; C, D, I, 0.5 mm.