Paramunida lophia, 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 : 478-480

PARAMUNIDA LOPHIA SP. NOV. ( FIG. 6 )

Material examined: Solomon Islands. SALOMON 1. Stn 1831, 10°12.1′S, 161°19.2′E, 5 October 2001, 135– 325 m: 1 M, 10.2 mm (holotype, MNHN-Ga6512); 2 M 13 mm (paratypes, MNHN-Ga6513). SALOMON 2. Stn 2191, 08°23.8′S, 159°27.1′E, 24 October 2004, 300 m: 1 ov. F, 10.2 mm (paratype, MNHN-Ga6514). Stn 2199, 7°43.3′S, 158°29.6′E, 25 October 2004, 296– 304 m: 3 M, 9.1–11.8 m (paratypes, MNHN-Ga6515) .

Etymology: From the Greek, lophia , for crest or ridge, referring to the longitudinal carina along the ventrolateral side of the second segment of the antennal peduncle. The name may be considered as a noun in apposition.

Description: Carapace as long as broad, excluding rostrum. Dorsal surface covered with minute spinules, with some scattered small spines and short uniramous setae. Gastric region distinctly separate from hepatic area, metagastric region well-defined; two small epigastric spines behind supraocular spines, and a median row of three well-developed spines, with the first thicker than the others. Cervical groove distinct. Cardiac region circumscribed, feebly convex, with a median row of three well-developed spines, and with the first thicker than the others. Anterior branchial region slightly separated from posterior branchial region. Frontal margin concave behind eye. Lateral margins convex, with some spines and iridescent setae on anterior half. Anterolateral spine short, reaching sinus between the rostral and the supraocular spines ( Fig. 6A ). Rostral spine spiniform, with thin, dorsal longitudinal carinae; supraocular spines well-developed and half as long as, and more slender than, rostrum ( Fig. 6B ). Lateral margins with some uniramous iridescent setae and some plumose non-iridescent setae.

Fourth thoracic sternite with few arcuate striae; fifth to seventh sternites smooth ( Fig. 6C ). Two median well-developed spines on anterior and posterior ridges of second and third abdominal somites. Fourth abdominal somite similar to preceding ones, but posterior ridge with distinct single median spine. Some small spiniform granules along anterior and posterior ridges of each somite.

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) overreaching corneae, with distomesial spine shorter than distolateral spine. First segment of antennal peduncle with anterior prolongation overreaching end of antennular peduncle, with long iridescent setae along mesial lateral margin. Second segment (spines excluded) about 1.5 times the length of the third segment, and 1.3 times longer than wide; distomesial spine long, mucronated, clearly exceeding antennal peduncle; distolateral spine not overreaching third segment. Ventral surface of second segment smooth, with a longitudinal carina along ventrolateral side; iridescent long setae along lateral side of distomesial spine continuing along ventrolateral crest. Third segment elongate, twice longer than wide and unarmed ( Fig. 6D ).

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. 6E ).

With P1 long and slender, between four and five times the carapace length, squamate, with some uniramous iridescent setae and some plumose noniridescent setae, more dense along mesial margins. Mesial margins of merus, carpus, and palm with some small spines and acute scales. Carpus more than five times longer than high. Palm as long as the carpus, and 1.4–1.5 times the length of the fingers ( Fig. 6F ).

With P2–P4 long and slender, subequal in length, with numerous scales on lateral sides of meri, carpi, and propodi; some uniramous iridescent setae and some plumose non-iridescent setae along dorsal and ventral borders. P2 about 3.5 times the carapace length; merus 1.5 times longer than carapace, about 10–11 times as long as high, 4.0–4.5 times as long as carpus and 1.4–1.7 times as long as propodus; propodus 9.5–10 times long as high, and 1.2–1.4 times the dactylus length ( Fig. 6G ). Merus with well-developed spines on dorsal border, increasing in size distally, ventral margin with a few spines, and one welldeveloped distal spine. Row of small spines along lateroventral 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. 6H ). P4 length 0.8–0.9 times the P2 length. Merus about 1.2–1.3 times the carapace length. Propodus and dactylus subequal to those of P3 ( Fig. 6I ). Merocarpal articulation falling short of anterior prolongation of first segment of antennal peduncle.

Remarks: The new species is close to Paramunida salai sp. nov. from the Solomon Islands (see below), and to Paramunida belone Macpherson, 1993 from New Caledonia, Futuna, Fiji, Tonga, and the Bali Sea ( Macpherson, 1993, 2004; Baba, 2005). The three species are characterized by having a rostral spine that is larger than the supraocular spines, the thoracic sternites with a few arcuate striae, and the distomesial spine on the second antennal segment mucronated and reaching, or overreaching, the end of the fourth article.

The differences among the three species are provided in the Remarks section of P. salai sp. nov. (see below).

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

Figures

Figure 6. Paramunida lophia sp. nov., male holotype, 10.2 mm (MNHN-Ga6512). 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.