Paramunida ascella, Cabezas, 2010

Cabezas, P. E., 2010, Taxonomic revision of the genus Paramunida Baba, 1988 (Crustacea: Decapoda: Galatheidae): a morphological and molecular approach, Zootaxa 2712, pp. 1-60 : 14-16

Paramunida ascella n. sp.

( Figs. 3, 12D)

Material examined. Holotype: Vanuatu. SANTO. Stn AT 9, 15°41.5'S, 167°01.3'E, 17 September 2006, 481 m: M 10.9 mm (MNHN-Ga7472).

Paratypes: Vanuatu. MUSORSTOM 8. Stn CP 1119: 15°08'S, 166°53'E, 09 October 1994, 254– 300 m: 1 ov. F 10.7 mm (MNHN-Ga7473). — Stn CP 1134, 15°39'S, 167°02'E, 11 October 1994, 230– 287 m: 1 M 10.0 mm, 1 ov. F 8.5 mm, 1 F 8.1 mm (MNHN-Ga7474). SANTO. Stn AT 9, 15°41.5'S, 167°01.3'E, 17 September 2006, 481 m: 3 M 7.8–10.9 mm, 12 ov. F 9.8–11.9 mm (MNHN-Ga7475). — Stn AT 11, 15°39.5'S, 167°01.5'E, 17 September 2006, 272– 286 m: 1 ov. F 11.5 mm (MNHN-Ga7476). — Stn AT 63, 15°39.6'S, 167°01.3'E, 04 October 2006, 290– 334 m: 5 M 10.6–12.2 mm, 6 ov. F 9.9–12.3 mm, 1 F 8.7 mm (MNHN- Ga7477) .

Etymology. The name ascella refers to one of the stars of the southern hemisphere (constellation of Sagittarius); used as a noun in apposition.

Description. Carapace: As long as broad. Spinules on gastric and hepatic regions forming groups arising from scale-like striae and with few short uniramous setae. Epigastric region with 2 spines, each behind supraocular spine, without median row of spines behind rostral spine. Mesogastric region with median row of 3 spines, first thicker than others (third spine very reduced in some specimens). Cervical groove distinct, with long setae along anterior branch. Cardiac and anterior branchial regions circumscribed. Cardiac region with median row of 3 well-developed spines, first thicker than others. Each branchial region with row of spines near cardiac region. Frontal margin slightly concave. Lateral margins convex, with some spines and iridescent setae on anterior half. Anterolateral spine well developed, exceeding sinus between rostral and supraocular spines. Rostrum triangular; larger than supraocular spines; margin between rostral and supraocular spines straight or slightly concave ( Figs. 3A, B).

Sternum: Thoracic sternite 4 with some arcuate striae; sternites 5–6 with some striae on each lateral side, sternite 7 smooth ( Fig. 3C).

Abdomen: Abdominal somites 2–3 each with 4 well–developed spines on anterior ridge, posterior ridge

Eyes: Maximum corneal diameter more than one-third distance between bases of anterolateral spines.

Antennule: Segment 1 slightly exceeding corneae, with distomesial spine small and slightly shorter than distolateral; twice longer than wide and with fringe of long setae along lateral margin; lateral margin with distal slender portion about half as long as proximal inflated portion ( Fig. 3D). with scales; mesial margin, including distal spine, straight; distomesial spine mucronated, reaching end of antennal peduncle, not reaching midlength of anterior prolongation of segment 1, distolateral spine not reaching end of segment 3; segment 3 1.5 times longer than wide and unarmed ( Fig. 3D).

Maxilliped 3: Ischium about twice length of merus measured along dorsal margin, distoventrally bearing long spine; merus with well developed median spine on flexor margin; extensor margin unarmed ( Fig. 3E).

Pereopod 1: Long and slender, squamate, 4.6–5.2 times carapace length; carpus 0.8–1.1 times palm length, and 5.5–6.2 times longer than height; palm 1.2–2.0 times fingers length. Base of carpus without bundle of setae ( Fig. 3F).

Pereopods 2–4: Long and slender, with numerous scales on lateral sides of meri, carpi and propodi; scales with short setae. P2 2.9–3.1 times carapace length, merus 1.3–1.4 times longer than carapace, 8.3–10.0 times as long as high, 2.4–3.8 times as long as carpus and 1.6–2.4 times as long as propodus; propodus 8.2–10.0 times as long as high, and 1.6–2.0 times dactylus length. Merus with well developed spines on dorsal border, increasing in size distally, ventral margin with few spines and one well-developed distal spine; few small spines along ventrolateral margin. Carpus with some small dorsal spines, well developed distal spine on dorsal and ventral margins. Propodus with small movable ventral spines. Dactylus compressed, slightly curved, with longitudinal carina along mesial and lateral sides, ventral border unarmed. End of P2 carpus not reaching end of P1 merus. P3 with similar spination and segment proportions as P2; merus as long as P2 merus; propodus and dactylus slightly longer than those of P2. P4 shorter than P2; merus 1.1–1.3 times carapace length; propodus and dactylus slightly shorter than those of P3; merocarpal articulation not reaching end of anterior prolongation of segment 1 of antennal peduncle. P3–P4 dactylus with longitudinal carinae along lateral and mesial margin ( Figs. 3G–I).

Remarks. Paramunida ascella n. sp. is related to P. crinita n. sp. from the Philippines, and P. mozambica n. sp. from Mozambique (see under Remarks for those species).

Distribution. Vanuatu, between 230 and 481 m.