Paramunida tricarinata ( Alcock, 1894 )

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 : 56-58

Paramunida tricarinata ( Alcock, 1894)

( Figs. 15H, 18I)

Munida tricarinata Alcock, 1894: 324 (Andaman Sea, 205 m); 1901: 246 (Andaman Sea and Arabian Sea off N. Maldive Atoll, 205–384 m). — Alcock & Anderson 1895: pl. 12, fig. 1 (no record).

Paramunida tricarinata Baba 2005: 304 (key, synonymies). — Baba et al. 2008: 175 (list of occurrences). — Baba et al. 2009: 283, figs. 260–261 (Taiwan).

Paramunida scabra Wu et al. 1998: 145 , figs 41, 42G (Taiwan). — Macpherson 1993: 462 (in part) (not P. scabra ( Henderson, 1885)) .

Dubious identity:

Munida tricarinata Laurie 1926: 138 (Providence and Saya De Malha Bank, 281– 275 m). — Tirmizi 1966: 202, fig. 21 ( Zanzibar and Maldives, 183–457 m).

Paramunida tricarinata . — Baba 1990: 968, fig. 15b ( Madagascar, 308–444 m). — Macpherson 1993: 469, fig. 11 ( Maldives Islands and Madagascar, 238–428 m).

Material examined. Taiwan. Dashi fishing port (no depth recorded), Yilan County, 05 August 1982: 1 M 8.0 mm. — 09 September 1989: 1 ov. F 7.0 mm, 2 F 8.3–8.5 mm. — 03 March 1991: 1 M 8.4 mm, 2 ov. F 7.9–8.1 mm, 1 F 5.2 mm. — 19 April 1995: 1 M 9.1 mm, 1 ov. F 9.1 mm. — 13 June 1995: 1 M 8.9 mm. — 09 November 1995: 4 M 10.2–12.7 mm, 2 F 10.4–12.7 mm. — 28 January 1997: 1 M 9.6 mm. — 01 September 1997: 1 ov. F 9.8 mm. — 23 September 1997: 1 M 9.8 mm, 1 ov. F 9.5 mm. — 30 October 1997: 1 ov. F 10.1

mm. — 18 November 1997: 1 M 8.6 mm. — 05 December 1997: 1 M 10.1 mm, 1 ov. F 8.9 mm. — 26 January 1999: 1 M 9.0 mm. — 23 March 1999: 1 M 9.8 mm. — 09 December 2003: 1 F 11.5 mm. — 16 December 2004: 6 M 10.8–11.6 mm, 1 ov. F 11.4 mm.

Philippines. MUSORSTOM 2. Stn 31, 13°40'N, 120°54'E, 24 November 1980, 204– 230 m: 5 M 8.7–11.6 mm, 2 ov. F 8.5–9.0 mm (MNHN-Ga3430). — Stn 35, 13°28'N, 121°12'E, 160–198 m: 2 M 7.7–9.0 mm, 3 ov. F 9.0– 9.6 mm, 1 F 7.3 mm (MNHN-Ga3431) .

Diagnosis. Rostrum spiniform, larger than supraocular spines, with thin dorsal carina; margin between rostral and supraocular spines straight or slightly concave. Spinules on gastric and hepatic regions forming groups arising from scale-like striae and with few short uniramous setae. Mesogastric region with row of 3 well-developed spines. Cardiac region with 3 or 4 well-developed spines. Tufts of long and dense setae setae along anterior branch of cervical groove. Sternal plastron with numerous striae on sternites 4–7. Lateral margin of antennular segment 1 with distal slender portion about half as long as proximal inflated portion. Antennal peduncle with anterior prolongation of antennal segment 1 spiniform; segment 2 slightly longer than broad, with distomesial spine spiniform, slightly overreaching end of antennal peduncle, distolateral spine not reaching end of segment 3; segment 3 1.4 times longer than broad. Base of P1 carpus without bundle of setae. P2 propodus about 9 times as long as wide, and 1.2–1.4 times dactylus length.

Remarks. Paramunida tricarinata is very similar to P. crinita n. sp., from the Philippines, and P. ascella n. sp., from Vanuatu.

P. tricarinata can be differentiated from P. crinita by the following characters:

— A row of 3 or 4 distinct spines instead of 1 (rarely 2) well-developed spines.

— The distomesial spine of the antennal segment 2 overreaches instead of never reaching the end of the antennal peduncle.

P. tricarinata is easily distinguished from P.ascella by the following aspects:

— Rostrum is spiniform rather than triangular.

— The distomesial spine of the antennal segment 2 is spiniform instead of mucronated. Furthermore, this spine distinctly overreaches the antennal peduncle in P. tricarinata , whereas the spine never exceeds this peduncle in P. ascella .

The genetic divergences between P. tricarinata and the other two species were: P. crinita 1.13% (16S rRNA) and 2.06% (ND1), and P.ascella 1.41% (16S rRNA) and 2.19% (ND1).

Paramunida tricarinata is also closely related to P. marionis n. sp. from Madagascar, and they can be differentiated by the following characters:

— P. marionis has a very spiny gastric region with well developed spines, whereas in P. tricarinata the spines are fewer and smaller in size.

— The distolateral spine of the antennal segment 2 never reachs the end of the antennal segment 3 in P. tricarinata , whereas this spine slightly overreaches the end of the third segment in P. marionis .

The occurrences of P. tricarinata along the western Indian Ocean (coast of Africa, Madagascar, Arabian Sea) (e.g. Laurie 1926; Tirmizi 1966; Baba 1990) should be considered with caution. Most of Paramunida species show restricted geographic ranges so it is not unlikely that such records may correspond to the new species described herein ( P. marionis and P. mozambica ), which are morphologically very close related to P. tricarinata . Therefore, a careful comparison would be desirable in order to confirm their identity.

Distribution. Arabian Sea, Maldives Islands, Andaman Sea, Taiwan and Philippines, between 205 and 384 m. The occurrences in other localities require confirmation (see above).