Galacantha rostrata A. Milne-Edwards, 1880

Published, First, 2007, Species of the genus Munidopsis Whiteaves, 1784 from the Indian and Pacific Oceans and reestablishment of the genus Galacantha A. Milne-Edwards, 1880 (Crustacea, Decapoda, Galatheidae), Zootaxa 1417, pp. 1-135 : 18-19

Galacantha rostrata A. Milne-Edwards, 1880

( Fig. 10I, J)

Galacantha rostrata A. Milne-Edwards, 1880: 52 .— Smith, 1882: 21, pl. 9, figs. 2, 2a; 1884: 355.— Milne-Edwards &

Bouvier, 1894: 271.— Faxon, 1895: 78, pl. B, figs. 1, 1a.— Milne-Edwards & Bouvier, 1897: 60, pl. 4, figs. 21–24;

1900: 308, pl. 6, fig. 9.— Hansen, 1908: 35.— Stebbing, 1908: 20.— Barnard, 1950: 494, fig. 92e–f.— Kensley,

1968: 292. Munidopsis rostrata .— Smith, 1885: 493; 1886: 45, pl. 6, figs. 1, 1.— Chace, 1942: 75.— Khodkina, 1975: 263, figs. 1,

3.— Baba, 1982: 112; 1988: 161; 1994: 18; 2005: 180, 294.— Wenner, 1982: 370.—de Saint Laurent, 1985: table

2.— Baba & Poore, 2002: 239, fig. 5.— Ahyong & Poore, 2004: 56.— Macpherson & Segonzac, 2005: 41. Galacantha Talismani Filhol, 1885 : pl. 3 (not Galacantha talismanii of Henderson, 1888: 167, pl. 20, fig. 1). Galacantha investigatoris Alcock & Anderson, 1894: 173 ; 1895: pl. 12, figs. 4, 4a. Galacantha rostrata var. Investigatoris .— Alcock, 1901: 276. Galacantha faxoni Benedict, 1902: 304 (new name for seven specimens of M. rostrata from “Albatross” St. 3362, 3400,

3414 reported by Faxon (1895)). Not Galacantha rostrata .— A. Milne-Edwards & Bouvier, 1900: pl. 6, fig. 9 (= G. spinosa A. Milne-Edwards, 1880 ). Not Galacantha rostrata .— Alcock, 1901: 275 (= G. bellis Henderson, 1885 ).—Alcock & Anderson, 1901: pl. 55, figs.

5, 5a.— Tirmizi, 1966: 206, figs. 23, 24. Not Munidopsis rostrata .—Miyake, 1982: 144, pl. 48, fig. 4 (= G. subspinosa n. sp.) (see Baba, 1988).

Material examined. Madagascar (A. Crosnier collection), Stn 132, 1800–2000 m: 2 M 20.2–27.7 mm (MNHN-Ga1438).— Stn CH 138, 1800–2000 m: 1 M 14.0 mm, 1 F 14.2 mm (MNHN-Ga1439).— Stn 141, 1600–1725 m: 1 F 12.4 mm (MNHN-Ga1440). NE Madagascar, Mozambique Channel, BENTHEDI, Stn 13, 2300–2500 m: 1 F 17.9 mm (MNHN-Ga1574).— Stn 31, 1800 m: 1 F 27.3 mm (MNHN-Ga1575) . New Caledonia, BIOGEOCAL, Stn 260, 1820– 1980 m: 1 M 21.5 mm, 1 ovig. F, 28.0 mm, 1 F 26.0 mm (MNHN- Ga 5456).— Stn 273, 1920– 2040 m: 3 males 22.5–29.0 mm (MNHN-Ga5457) .

Remarks. G. rostrata is clearly differentiable from the other species of the genus by the shape of the rostrum and the relative size of the lateral spines of the carapace. The rostrum has always 2 lateral divergent spines at the end of the horizontal portion, clearly discernible in dorsal view. Furthermore, the first and second lateral spines of the carapace are large and usually subequal. The specimens from New Caledonia have the mesogastric spine with the posterior margin straight, whereas this margin is slightly convex in the Atlantic material. As in G. bellis , additional studies, including molecular analyses, are recommended to elucidate the existence of a single or several species.

The specimens identified as G. faxoni by Benedict (1902) and deposited in the USNM (a figure of a male from Cocos Islands, Albatross Stn 3362, was kindly provided by K. Baba), have the first lateral (anterolateral) spine of the carapace clearly smaller than the second (hepatic) spine. Considering that most specimens of G. rostrata have the first and second lateral spines of the carapace subequal, the existence of a separate species from the Eastern Pacific should be considered. A more complete comparison of specimens from the Atlantic and Pacific Oceans would clarify their taxonomic status.

Distribution. The species is known from numerous localities of the western and eastern Atlantic, Indian Ocean, and western and eastern Pacific, from low to high latitudes (see Baba 2005 for the list of localities). The species occurs between 1600 and 3294 m. The present material was collected in Madagascar (1600–2500 m) and New Caledonia (1820–2040 m).