Paramunida haigae, Cabezas, Patricia & Macpherson, Enrique, 2014

Cabezas, Patricia & Macpherson, Enrique, 2014, A new species of Paramunida Baba, 1988 from the Central Pacific Ocean and a new genus to accommodate P. granulata (Henderson, 1885), ZooKeys 425, pp. 15-32 : 17-20

Taxon classification Animalia Decapoda Munididae

Paramunida haigae sp. n. Figs 1, 2, 3

Material examined.

Holotype: Christmas (Kiritimati) Island, Line Islands, Kiribati, 01°51.3'N, 157°30.4'W, February–March 1973, 183 m (NOAA RV Townsend Cromwell Cruise): male, 16.6 mm ( LACM–CR 1973-3312). Paratypes: collected with holotype: 9 males 11.4-17.2 mm (2 broken), 3 females, 13.5-14.1 mm, 2 ovigerous females, 11.6-14.2 mm ( LACM–CR 1973-3313).

Description.

Carapace: As long as broad, dorsal surface covered with spinules; each spinule usually on short arcuate striae, with few short uniramous setae. Epigastric region with 2 spines, each behind supraocular spine; with median row of spinules behind rostral spine. Mesogastric region with median row of 3 small spines. Anterior branch of cervical groove with short setae. Cervical groove distinct. Cardiac and anterior branchial regions slightly circumscribed. Cardiac region with a median row of 3 small 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, reaching sinus between rostral and supraocular spines. Rostral spine spiniform, with thin dorsal longitudinal carina; supraocular spines well developed and slender and shorter than rostrum (Figs 1A, B, 3).

Sternum: Thoracic sternite 4 with few arcuate striae; sternites 5-7 smooth (Fig. 1C).

Abdomen: Abdominal somites 2-3 each with 4 well-developed spines on anterior ridge, posterior ridge with 2 median spines. Abdominal somite 4 with 4 spines on an terior ridge; posterior ridge with distinct single median spine. Ridges with numerous spinules and a few small spines (Fig. 1A).

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

Antennule: Article 1 slightly exceeding corneae, with distomesial spine small and as long as distolateral; about 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 convex portion (Fig. 1D).

Antenna: Anterior prolongation of article 1 overreaching antennular peduncle by about one-third of its length. Article 2 about twice length of article 3 and twice longer than wide, ventral surface with scales; distomesial spine spiniform without tuff of setae, overreaching end of article 3, not reaching end of antennal peduncle, reaching mid-length of anterior prolongation of article 1, and clearly not reaching end of basal article of antennule, distolateral spine not reaching end of article 3; article 3 about 1.5 times longer than wide and unarmed (Fig. 1D).

Maxilliped 3: Ischium about twice length of merus measured along extensor margin, flexor margin bearing long distal spine; merus with well-developed median spine on flexor margin; extensor margin unarmed (Fig. 1E).

Pereopod 1 (cheliped): Long and slender, squamate, between 6.5-7.5 times carapace length; carpus about as long as palm, and 7-10 times longer than high; palm 1.1-1.5 times fingers length. Base of carpus without bundle of setae (Fig. 2 A–C).

Pereopods 2-4 (P2 lacking in holotype): Long and slender, with scales on lateral sides of meri, carpi and propodi; scales with short setae. P2 2.5-3.5 times carapace length, merus 1.1-1.6 times longer than carapace, about 8-10 times as long as high, 4 times as long as carpus and 1.5 times as long as propodus; propodus about 7-10 times as long as high, and 1.4-1.7 times dactylus length. Merus with well-developed spines on extensor margin, increasing in size distally; flexor margin with few spines and one well developed distal spine; row of small spines along flexolateral margin. Carpus with few small extensor spines, small distal spine on extensor and flexor margin. Propodus with small movable flexor spines. Dactylus compressed, slightly curved, with longitudinal carinae along mesial and lateral sides, flexor border unarmed. End of P2 carpus not reaching end of P1 merus. P3 with similar spination and article proportions as P2; propodus slightly longer than P2 propodus, merus and dactylus as long as those of P2. P4 as long as P2; merus 1.1-1.3 times carapace length; propodus and dactylus slightly longer than those of P3; merocarpal articulation clearly exceeding end of anterior prolongation of article1 of antennal peduncle (Fig. 2 D–G).

Etymology.

This species is dedicated to the renowned carcinologist Janet Haig (1925-1995) who first classified the material examined.

Remarks.

Paramunida haigae sp. n. closely resembles Paramunida antares Cabezas, Macpherson & Machordom, 2010 from New Caledonia. The new species is readily separated from Paramunida antares in having the rostrum spiniform rather than triangular. Moreover, the mesogastric region in Paramunida antares has 3 well-developed spines, but these spines are very small in Paramunida haigae sp. n. The two species also differ in the article 2 of the antennal peduncle: twice as long as wide in the new species but only 1.5 times in P. antares. Finally, the distomesial spine of antennal article 2 clearly overreaches the end of article 3 in the new species, but this spine only reaches the end of the article 3 in Paramunida antares .

The new species is also very close to Paramunida achernar Cabezas, Macpherson & Machordom, 2010 from Tonga. Paramunida haigae sp. n. can be distinguished from Paramunida achernar by having 3 small mesogastric spines (vs. 3 well-developed spines in Paramunida achernar ). Furthermore, the anterior prolongation of antennal article 1 is clearly longer in Paramunida haigae sp. n., overreaching the antennular peduncle by about one-third of its length but only by one-fourth in Paramunida achernar , and the distomesial spine of antennal article 2 overreaching the end of article 3 in the new species (vs. only reaching the end of the article 3 in Paramunida achernar ). Finally, the merocarpal articulation of P3 clearly exceeds the anterior prolongation of the antennal article 1 in the new species, only slightly exceeding the anterior prolongation in Paramunida achernar .

Of the regional Central Pacific Paramunida species, Paramunida haigae sp. n. can be easily distinguished from Paramunida hawaiiensis Baba, 1981 from Hawaii in having the rostral spine larger than supraocular spines instead of smaller or at most equal to supraocular spines. Furthermore, the distomesial spine of article 2 reaches end of antennal peduncle in Paramunida hawaiiensis but never reaches it in the new species. The new species can also be easily distinguished from Paramunida echinata Macpherson, 1999 from Marquesas Islands in having the rostral spine spiniform instead of triangular. Finally, Paramunida haigae sp. n. is also easily distinguishable from Paramunida spatula Macpherson, 2006 from the Austral archipelago by the shape of the anterior prolongation of antennal article 1.

Distribution.

Christmas (Kiritimati) Island, Kiribati, at 183 m depth.