Psopheticus vocans Guinot, 1985

Castro, Peter, 2007, A reappraisal of the family Goneplacidae MacLeay, 1838 (Crustacea, Decapoda, Brachyura) and revision of the subfamily Goneplacinae, with the description of 10 new genera and 18 new species, Zoosystema 29 (4), pp. 609-774 : 743-744

Psopheticus vocans Guinot, 1985

Psopheticus aff. stridulans – Guinot & Richer de Forges 1981b: 256 (part), fig. 12, pl. 5, figs 6, 7, 7a [ New Caledonia].

Psopheticus vocans Guinot, 1985: 19 , figs 3B 1, B 2, 4D-G, pl. 3, figs F, G; 1990: 334 [in key], 335 [in table], 346, figs 19-28, 47-49 [ New Caledonia].

TYPE MATERIAL. — New Caledonia, ♂ holotype, cl 24.8 mm, cw 31.6 mm ( MNHN-B 6805); ♀ paratype, cl 12.6 mm, cw 16.1 mm, same data as holotype ( MNHN-B 10531) (paratype indicated, together with holotype, in the specimen bottle but not in the published description [ Guinot 1990] or in an earlier listing of the material [ Guinot & Richer de Forges 1981b]).

TYPE LOCALITY. — New Caledonia, Boulari Pass, 400m.

MATERIAL EXAMINED. — Vanuatu. MUSORSTOM 8, stn 1083, 15°51.91’S, 167°19.42’E, 397-439 m, 5.X.1994, 1 ♀ ( MNHN-B 29280).

BOA 1, stn CP 2479, 16°45.00’S, 167°51.80’E, 350- 358 m, 15.IX.2005, 1 pre-adult ♂, 1 ovig. ♀ ( MNHN-B 30094).

Chesterfield Islands. EBISCO, stn DW 2546, 21°06’S, 158°37’E, 488-493 m, 11.X.2005, 1 ♂♂ (MNHN-B 30119). — Stn DW 2548, 21°06’S, 158°35’E, 604-632 m, 11.X.2005, 2 ♀♀ (MNHN-B 30123).

New Caledonia. Passe de Boulari, trap, 400 m, ♂ holotype ( MNHN-B 6805), ♀ paratype ( MNHN-B 10531).

Passe de Poum, 400 m, 2 ♂♂, 1 ♀ ( MNHN-B 29178).

LAGON, stn CP 1062, 20°14.9’S, 163°53.0’E, 300- 320 m, 5.V.1988, 1 ♂, 1 ♀ ( MNHN-B 29198).

BATHUS 1, stn DW 664, 20°57.34’S, 165°36.70’E, 650-700 m, 13.III.1993, 1 ♂ ( MNHN-B 29343).

BATHUS 2, stn CP 738, 23°02.1’S, 166°56.6’E, 558- 647 m, 13.V.1993, 1 ♀ ( MNHN-B 29281). — Stn CP 770, 22°09’S, 166°04’E, 400-402 m, 18.V.1993, 1 ♂ ( MNHN-B 29206).

HALIPRO 1, stn CP 868, 21°14.539’S, 165°55.847’E, 430-450 m, 23.III.1994, 1 ♂ ( MNHN-B 29322). — Stn CP 869, 21°14.84’S, 165°55.49’E, 450-490 m, 23.III.1994, 1 ♂ ( MNHN-B 29182).

BATHUS 4, stn DW 888, 21°00.84’S, 164°27.28’E, 430- 436 m, 2.VIII.1994, 1 ♂ ( MNHN-B 29209 ). — Stn CP 889, 21°00.83’S, 164°27.34’E, 416-433 m, 2.VIII.1994, 1 pre-adult ♀, 1 ovig. ♀ ( MNHN-B 29190 ) ; 1 ♂ ( MNHN- B 29210). — Stn CP 899, 20°16.68’S, 163°50.26’E, 500-600 m, 3.VIII.1994, 1 ♂ ( MNHN-B 29187 ) ; 1 ♂ ( MNHN-B 29208 ). — Stn CP 900, 20°16.74’S, 163°50.06’E, 580 m, 3.VIII.1994, 1 ♂ ( MNHN-B 29180 ) ; 1 ♂ ( MNHN-B 29207 ) ; 5 ♂♂ ( MNHN-B 29183 ). — Stn CP 946, 20°33.81’S, 164°58.35’E, 386-430 m, 10.VIII.1994, 1 ♂ ( MNHN-B 29179 ) .

Fiji. MUSORSTOM 10, stn CP 1317, 17°12.0’S, 178°14.1’E, 471-475 m, 6.VIII.1998, 2 ♂♂ ( MNHN-B 29255). — Stn CP 1327, 17°13.3’S, 177°51.6’E, 370- 389 m, 7.VIII.1998, 1 ♂ ( MNHN-B 29254).

BORDAU 1, stn CP 1411, 16°05’S, 179°28’W, 390- 403 m, 26.II.1999, 2 ♀♀ ( MNHN-B 29202). — Stn CP 1493, 18°43’S, 178°24’W, 429-440 m, 11.III.1999, 1 ♂ ( MNHN-B 29201). — Stn CP 1500, 18°42’S, 178°26’W, 366-389 m, 12.III.1999, 1 ovig. ♀ ( MNHN-B 29177). — Stn CP 1505, 18°12’S, 178°37’W, 420-450 m, 13.III.1999, 2 ♂♂ ( MNHN-B 29199).

Tonga. BORDAU 2, stn CP 1528, 21°14’S, 174°59’W, 587-592 m, 3.VI.2000, 3 ♂♂ ( MNHN-B 29256).

DISTRIBUTION. — New Caledonia ( Guinot & Richer de Forges 1981b) and now Vanuatu, Chesterfield Is, Fiji, and Tonga. Depth: 300- 700 m.

COLOUR

Photographs of a freshly collected male specimen from New Caledonia ( MNHN-B 29322) and a female from Fiji ( MNHN-B 29202) showed a light orange anterior half of the carapace divided from the white posterior half by two thin bands, one dark orange and the second white. The ambulatory legs were pinkish white. This colour pattern is similar to that given by Ikeda (1998: 138, pl. 58, as P. stridulans ) for P. musicus .

REMARKS

Diagnostic to the species is the presence of small teeth along the P3-P5 carpi and propodi ( Guinot 1990: figs 26-28), in contrast to a close species, P. stridulans , where the teeth are absent in the propodi, at least to the naked eye ( Guinot 1990: figs 4-6). Other than the ornamentation of the ambulatory legs, the characters given by Guinot (1990: 348) to separate both species are not always consistent. The triangular outer orbital teeth and the relatively short and triangular anterolateral teeth of P. vocans are also characteristic of P. musicus . In contrast to P. musicus , however, the P3-P5 carpi and propodi of P. vocans are always dentate, at least one member of a particular pair of legs.

As in other species of Psopheticus , there is much variation in the ornamentation and on the development of teeth on the ambulatory legs. Some of the observed variation was between the right and left members of the same pair of ambulatory legs. A male (cl 22.6 mm, cw 28.4 mm, MNHN-B 29179) had a smooth P2 right merus (the characteristic dorsal, subdistal tooth on the left P2) and a relatively smooth (almost microscopic teeth) P3 right propodus, but there were well developed teeth on the left P3.

Three of nine specimens from Fiji (female, cl 20.6 mm, cw 27.6 mm, MNHN-B 29202; male, cw 25.3 mm, MNHN-B 29199; ovig. female, cl 20.3 mm, cw 25.0 mm, MNHN-B 29177) had two dorsal teeth on the P2 merus instead of one. Each of the P2 carpi of these specimens had a tooth that was smaller than in the typical specimens. The ornamentation of P3-P 5 in these three specimens was similar to the remaining specimens except that the teeth on the propodi were smaller. The P3-P5 carpi of the three males from Tonga (cl 17.9 mm, cw 23.5 mm, cl 12.7 mm, cw 17.2 mm, cl 12.4 mm, cw 16.8 mm; MNHN-B 29256), however, had one well developed tooth and many small teeth. There were no important differences in the shape and ornamentation of P1 and P2, carapace, G1, G2, and the relative length of the ambulatory legs (P2-P5) between the Fiji and Tonga specimens on one hand and those of P. vocans from New Caledonia, including the holotype ( MNHN-B 6805) and paratype ( MNHN-B 10531). The P3-P5 meri of the Tonga specimens are similar to those of P. insolitus Guinot, 1990 (= P. stridulans Wood-Mason, 1892 ), which was described from one specimen from Makassar Strait, Indonesia, and of a small female from New Caledonia (cl 10.4 mm, cw 14.2 mm; MNHN-B 29281) in having one well developed tooth and many small ones. The P2 merus, however, had three teeth in P. insolitus instead of the single tooth in P. vocans and the Tonga and New Caledonia specimens. It thus seems that the observed variations in the Fiji and Tonga specimens are part of the normal morphological variation of P. vocans . These specimens are treated here as members of populations of what appears to be the extreme eastern limit of the distribution of P. vocans rather than as a different species.