Paramunida salai, Cabezas & Macpherson & Machordom, 2009

Cabezas, Patricia, Macpherson, Enrique & Machordom, Annie, 2009, Morphological and molecular description of new species of squat lobster (Crustacea: Decapoda: Galatheidae) from the Solomon and Fiji Islands (South-West Pacific), Zoological Journal of the Linnean Society 156 (3), pp. 465-493 : 480-482

PARAMUNIDA SALAI SP. NOV. ( FIG. 7 )

Material examined: Solomon Islands. SALOMON 1. Stn 1831, 10°12.1′S, 161°19.2′E, 5 October 2001, 135– 325 m: 93 M, 6.4–11.5 mm; 49 ov. F, 8.2–10.7 mm (holotype ov. F, 8.6 mm, MNHN-Ga6517); 21 F, 6.7–8.8 mm (paratypes, MNHNGa-6516). Stn 1834, 10°12.2′S, 161°17.8′E, 5 October 2001, 225– 281 m: 2 ov. F, 8.8–9.0 mm (paratypes, MNHN-Ga6518) .

Etymology: This species name is dedicated to Enric Sala, for his contributions to marine conservation biology.

Description: Carapace nearly as long as broad, excluding rostrum. Dorsal surface covered with numerous spinules. Gastric region with two epigastric spines and a median row of three spines, with the first thicker than the others. Cervical groove distinct. Cardiac and anterior branchial regions slightly circumscribed. Cardiac region with a median row of three well-developed spines, with the first thicker than the others. Frontal margin slightly concave. Lateral margins convex, with some spines and iridescent setae on anterior half. Anterolateral spine short, clearly not reaching the sinus between the rostral and the supraocular spines ( Fig. 7A ). Rostral spine spiniform, with thin dorsal longitudinal carina; supraocular spines well-developed, and half as long as, and more slender than, rostrum ( Fig. 7B ).

Fourth thoracic sternite with a few arcuate striae, fifth to seventh nearly smooth, with one or two striae on each side ( Fig. 7C ).

Second and third abdominal somites each with two well-developed median spines on anterior and posterior ridge; ridges with numerous spinules and a few small spines. Fourth abdominal somite similar to preceding ones, but posterior ridge with distinct single median spine.

Eye large: maximum corneal diameter about 0.3 times the distance between the bases of the external orbital spines.

Basal segments of antennule (distal spines excluded) exceeding corneae, with distomesial spine small, and slightly shorter than distolateral spine ( Fig. 7D ). Anterior prolongation of first segment of antennal peduncle clearly overreaching antennular peduncle by about 0.25 of its length. Second segment (spines excluded) about twice the length of the third segment, and twice longer than wide, ventral surface without scales, with longitudinal carinae along ventrolateral margin; distomesial spine mucronated, reaching or slightly overreaching antennal peduncle, overreaching midlength of anterior prolongation of first article, although not reaching end of basal article of antennule (excluding distal spines), distolateral spine reaching or overreaching third segment, dorsomesial margin with longitudinal carina; third segment nearly twice longer than wide, and unarmed ( Fig. 7D ).

With Mxp 3 ischium about 1.5 times the length of the merus, measured along the dorsal margin, and bearing a spine distoventrally; merus with median well-developed spine on flexor margin; extensor margin unarmed ( Fig. 7E ).

With P1 long and slender, between 4.8 and 5.9 times the carapace length; carpus slightly longer than palm, and 5.5 times longer than high; palm of chelipeds nearly as long as fingers. Mesial margins of merus, carpus and palm with small spines and acute scales ( Fig. 7F ).

With P2–P4 long and slender, with numerous scales on lateral sides of meri, carpi, and propodi. P2 slightly shorter than P3, and longer than P4. P2 about 3.5 times the carapace length; merus 1.5 times longer than carapace, about 10–12 times as long as high, 4.5 times as long as carpus, and 1.4–1.6 times as long as propodus; propodus about ten times as long as high, and 1.2–1.4 times the dactylus length ( Fig. 7G ). Merus with well-developed spines on dorsal border, increasing in size distally, ventral margin with a few spines, and one well-developed distal spine; row of small spines along ventrolateral margin. Carpus with some small dorsal spines, well-developed distal spine on dorsal and ventral margin. Propodus with small movable ventral spinules. Dactylus compressed, slightly curved, with longitudinal carinae along mesial and lateral sides, ventral border unarmed. End of P2 carpus nearly reaching end of P1 merus. P3 with similar spination and article proportions as P2. Merus slightly shorter than P2 merus; propodus and dactylus slightly longer than those of P2 ( Fig. 7H ). P4 length 0.8–0.9 times P2 length. Merus about 1.2 times the carapace length. Propodus and dactylus slightly shorter than those of P3 ( Fig. 7I ). Merocarpal articulation slightly exceeding end of anterior prolongation of first segment of antennal peduncle.

Remarks: As mentioned above, P. salai sp. nov. is closely related to P. belone from New Caledonia, Futuna, Fiji, Tonga, and the Bali Sea ( Macpherson, 1993, 2004; Baba, 2005), and P. lophia sp. nov. from the Solomon Islands. The three species can be distinguished from one another by several aspects.

Paramunida belone is easily differentiated from the two new species ( P. lophia sp. nov. and P. salai sp. nov.) by the following characters.

1. The gastric region has only one median spine in P. belone , whereas this region has a median row of three spines, the first thicker than the others, in both P. lophia sp. nov. and P. salai sp. nov.

2. The walking legs (P2–P4) are longer in P. belone than in P. lophia sp. nov. and P. salai sp. nov. The P2 merus is more than twice the carapace length in P. belone , and is about 1.5 times that in the two new species.

Furthermore, P. salai sp. nov. and P. belone can also be differentiated by the antennal peduncle. The distomesial spine of the second article of the antennal peduncle clearly exceeds the end of the antennal peduncle, and reaches or slightly overreaches the basal article of the antennular peduncle in P. belone ; whereas this spine only slightly overreaches the end of the antennal peduncle, and clearly does not reach the end of the basal article of the antennular peduncle, in P. salai sp. nov.

The antennal peduncles are also different in P. salai sp. nov. and P. lophia sp. nov. The distomesial spine of the second segment clearly exceeds the antennal peduncle in P. lophia sp. nov., whereas it only reaches or slightly overreaches the antennal peduncle in P. salai sp. nov. Furthermore, the second segment (spines excluded) is about 1.5 times the length of the third segment, and is less than 1.5 times longer than wide in P. lophia sp. nov. This segment is twice the length of the third segment and twice longer than wide in P. salai sp. nov. Finally, the P1 palm is 1.4–1.5 times longer than the fingers in P. lophia sp. nov., whereas it is nearly as long as the fingers in P. salai sp. nov.

Distribution: Solomon Islands, at a depth of between 135 and 325 m.

Figures

Figure 7. Paramunida salai sp. nov., ovigerous female holotype, 8.6 mm (MNHN-Ga6517). Solomon Islands. A, carapace and abdomen, dorsal view. B, carapace, lateral view. C, sternum. D, left antennule and antenna, ventral view. E, right third maxilliped, lateral view. F, right cheliped, lateral view. G, right P2, lateral view. H, right P3, lateral view. I, right P4, lateral view. Scale: A, B, C = 1 mm; F, G, H, I = 2 mm; D, E = 0.5 mm.