Raymunida vittata, 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 : 446-449

Raymunida vittata n. sp.

( Fig. 7 )

HOLOTYPE. — Vanuatu. SANTO 2006 , stn DB16, 15°35.5’S, 167°15.8’E, 32-40 m, 14.IX.2006, ♂ 6.6 mm (MNHN-Ga 6713).

PARATYPES. — Vanuatu. SANTO 2006, stn AT41, 15°36.7-37.0’S, 167°02.7-02.8’E, 88-118 m, 28.IX.2006, 2 ♀♀ 4.4, 4.7 mm (MNHN-Ga 6714). — Stn AT56, 15°36.1’S, 167°01.3’E, 98-105 m, 2.X.2006, 1 ♂ 7.2 mm, 1 ov. ♀ 7.4 mm, 2 ♀♀ 5.3, 5.7 mm (MNHN-Ga 6715). — Stn EP32, 15°36.6’S, 167°02.0’E, 14.X. 2006, 100 m, 1 ov. ♀ 6.8 mm (MNHN-Ga 6716).

ETYMOLOGY. — From the Latin, vittatus, bound with a ribbon, in reference to the white and red bands in the chelipeds.

DISTRIBUTION. — Vanuatu, 88- 118 m.

DESCRIPTION

Carapace slightly longer than wide,bearing transverse ridges with very short, non-iridescent setae, and few long iridescent, simple setae; 2 main transverse striae on posterior part of carapace not interrupted on cardiac region. Gastric region with row of 10 epigastric spines. One parahepatic, 1-3 branchial anterior and 1 postcervical spine on each side. Frontal margins transverse, slightly convex at lateral end of orbit, small spine directly lateral to lateral limit of orbit. Lateral margins slightly convex. First spine, at anterolateral angle, clearly not reaching level of sinus between rostral and supraocular spines; marginal spine in front of cervical groove 0.3 length of anterolateral spine. Branchial margins with four spines; first spine as long as or slightly longer than anterolateral spine. Rostrum 0.6 times carapace length, slender, slightly curved upwards, supraocular spines clearly exceeding mid length of rostrum and end of corneas, feebly divergent and horizontal ( Fig. 7A ).

Thoracic sternites smooth; fourth sternite with few striae. Anterior part of fourth sternite slightly wider than third, contiguous to entire posterior margin of third somite ( Fig. 7B ).

Abdominal somites unarmed, with some long iridescent, simple setae.Second to fourth abdominal somites each with two transverse ridges.

Basal segment of antennule (distal spines excluded), 0.25 carapace length, reaching end of corneae, with 2 distal spines, mesial spine clearly shorter than lateral spine; 2 spines on lateral margin, proximal one short, located distal to mid length of segment, distal one long, reaching end of distolateral spine ( Fig. 7C ).

First segment of antennal peduncle with long distomesial spine exceeding antennal peduncle (only reaching end of peduncle in small specimens) and not clearly reaching end of basal segment of antennular peduncle (excluding distal spines); second segment with 2 distal spines, distomesial spine longer than distolateral spine, not overreaching antennal peduncle, 1 small spine at mid length of mesial border; penultimate segment unarmed.

Mxp3 merus with 2 long spines of subequal size on flexor border, and 1 distal spine on extensor margin ( Fig. 7D ).

P1 with long simple setae more numerous on mesial and lateral borders. Carpus twice as long as high, slightly shorter than palm; fingers 1.5 times palm length. Palm with several spines scattered on mesial and dorsal sides and 1 row of dorsolateral spines continued on to entire fixed finger; movable finger with spines on proximal half of mesial margin ( Fig. 7E ).

P2 about 2.5 times carapace length; merus slightly longer than carapace, 5.0-5.5 times as long as high, 3 times carpus length and 1.4 times propodus length; propodus 7-8 times as long as high and twice dactylus length. Merus with extensor marginal spines increasing in size distally, flexor margin with few distal spines. Carpus with some spines and 1 distoventral spine. Propodus with 4 or 5 movable spines along flexor margin ( Fig. 7F ). Dactylus short, curving distally, extensor margin slightly convex, flexor margin with 5 or 6 movable spinules along entire length. P3 slightly longer than P2. P4 shorter than second and third; length of merus 0.7-0.8 that of P2; height greater than that of P2, 3.5-4.0 times as long as high, with row of laterodorsal spines in addition to dorsal row of spines ( Fig. 7G ). Merocarpal articulation of P4 leg nearly reaching frontal margin of carapace.

Colour

Ground colour of carapace and abdomen red; wide white band along each branchial margin of carapace; some white narrow transverse bands on dorsal surface of carapace. Rostrum, supraocular and anterolateral spines red. P1 with white and red bands, distal portion of fingers white. P2-P4 red, without white bands.

REMARKS

Raymunida vittata n. sp. belongs to the group of species with the mesial spine of the first antennal segment not reaching the end of the basal segment of the antennular peduncle (excluding distal spines), the distomesial spine of the first antennal segment overreaching the antennal peduncle, and the merocarpal articulation of the P4 nearly reaching the frontal margin of the carapace. The new species is very close to R. lineata Osawa, 2005 , from Japan. However, these two species are distinguished by the following differences:

– the second to fourth abdominal somites have a continuous transverse stria preceded by a median long stria in R. lineata . This median stria is absent, or with a pair of short striae in the new species;

– the P1 fingers are longer in R. lineata than in R. vittata n. sp., being twice instead of 1.5 times the length of the palm;

– the colour pattern of R. vittata n. sp., observed in all specimens examined, is also quite different from that of R. lineata : the white bands of the P1 are absent in R. lineata , present in R. vittata n. sp.

Figures

FIG. 7. — Raymunida vittata n. sp.,holotype,♂ 6.6 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, E-H, 2 mm; B-D, 1 mm.