Paramunida microrhina, 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 : 30-32

Paramunida microrhina n. sp.

( Figs. 6, 14B)

Material examined. Holotype: Chesterfield Islands . EBISCO, CP2562 , 20º30.108’S, 158º42.035’E, 13 October 2005, 196– 213 m: ov. F 5.1 mm (MNHN-Ga7483).

Paratypes: Chesterfield Islands . EBISCO, CP2562 , 20º30.108’S, 158º42.035’E, 13 October 2005, 196– 213 m: 5 ov. F 4.8–5.3 mm, 1 F 6.1 mm (MNHN-Ga7484). — Stn CP 2563, 20º28.900’S, 158º41.400’E, 13 October 2005, 235– 280 m: 1 ov. F 5.8 mm, 1 F 7.3 mm (MNHN-Ga7485). Etymology. From the Greek, rhinos, nose, and micros, small, referring to the small rostral spine .

supraocular spine; without median row of spines behind rostral spine. Mesogastric region with small median spine. Cervical groove distinct. Cardiac and anterior branchial regions slightly circumscribed. Cardiac region with a median row of 3 well-developed spines, first thicker than others. Each branchial region with row of moderately-sized spines near cardiac region. Frontal margin slightly concave. Lateral margins convex, with some spines and iridescent setae on anterior half. Anterolateral small spine, nearly reaching sinus between rostral and supraocular spines. Rostrum short and triangular, with thin dorsal longitudinal carina; supraocular spines as long as the rostrum; margin between rostral and supraocular spines straight or slightly concave ( Figs. 6A, B).

Sternum: Thoracic sternite 4 with few arcuate striae; sternites 5–6 with few striae on each lateral side ( Fig. 6C).

Abdomen: Abdominal somites 2–3 each with 4 moderate–sized spines on anterior ridge, posterior ridge with 2 median spines. Abdominal somite 4 with 4–6 spines on anterior ridge; posterior ridge without distinct single median spine ( Fig. 6A).

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

Antennule: Segment 1 exceeding corneae, with distomesial spine as long as the distolateral; about twice longer than wide, with fringe of long setae along lateral margin; lateral margin with distal slender portion about half as long as proximal inflated portion.( Fig. 6D).

Antenna: Anterior prolongation of segment 1 clearly overreaching antennular segment 1 by about onethird of its length. Segment 2 about twice length of segment 3 and 1.5 times longer than wide, ventral surface with small scales; distomesial spine very small, cleary not reaching midlength of segment 3, and clearly not reaching midlength of anterior prolongation of segment 1, distolateral spine small, not reaching midlength of segment 3; segment 3 as long as wide and unarmed( Fig. 6D).

Maxilliped 3: Ischium about twice length of merus measured along dorsal margin, distoventrally bearing one spine; merus with small median spine on flexor margin; extensor margin unarmed ( Fig. 6E).

Pereopod 1: Long and slender, squamate, 6.6–7.0 times carapace length; carpus 0.8–0.9 times palm length, and 14.5–15.1 times longer than height; palm nearly twice finger length. Base of carpus without bundle of setae ( Fig. 6F).

Pereopods 2–4: Long and slender, with scales on ventrolateral sides of meri and carpi and few scales on propodi; scales with short setae. P2 4.0–4.1 times carapace length, merus 1.7–1.8 times longer than carapace, 16–19 times as long as high, 4.2–4.4 times as long as carpus and 1.5–1.7 times as long as propodus; propodus 12–14 times as long as high, and 1.6–1.7 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; row of small spines along ventrolateral margin. Carpus with some small dorsal spines, distal spine on dorsal and ventral margin. Propodus with small movable ventral spines. Dactylus compressed, slightly curved, with longitudinal carinae 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 slightly longer than P2 merus; propodus and dactylus longer than those of P2. P4 as long as P2 length; merus 1.9–2.0 times carapace length; propodus and dactylus slightly longer than those of P3; merocarpal articulation clearly exceeding end of anterior prolongation of first segment of antennal peduncle ( Figs. 6G–I).

Remarks. The new species is close to P.hawaiiensis from the Hawaiian Islands, from which it can be easily differentiated by the following characters:

— The antennal segment 2 has a minute distomesial spine in the new species, whereas this spine is well developed in P. hawaiiensis .

— The distolateral spine of the antennal segment 2 falls short the end of the antennal segment 3 in the new species, whereas this spine almost reaches the end of the antennal segment 3 in P. hawaiiensis .

— The mesogastric region has a median row with 3 well-developed spines in P. hawaiiensis , whereas this region only has a small median spine in the new species.

Distribution. Chesterfield Islands, between 196 and 280 m.