Galacantha bellis Henderson, 1885

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 : 9-14

Galacantha bellis Henderson, 1885

( Figs. 1–4)

Galacantha bellis Henderson, 1885: 418 ; 1888: 167, pl. 19, fig. 6.

Galacantha areolata Wood-Mason in Wood-Mason & Alcock, 1891: 200.— Alcock & Anderson, 1894: 173.—Alcock & Anderson, 1901: pl. 55, figs. 5, 5a.

Galacantha talismanii .— Henderson, 1888: 167, pl. 20, fig. 1.

Galacantha rostrata Alcock, 1901: 275 .— Tirmizi, 1966: 206, figs. 23, 24.

Material examined. Chile, off Juan Fernandez, CHALLENGER, Stn 300, 2516 m: 4 M 19.8–26.0 mm, 2 ovig. F 26.6 mm and broken (type series, the male of 19.7 mm is selected as lectotype) ( BMNH) . Madagascar (A. Crosnier collection), Stn CH 127, 1715– 1750 m: 5 M 14.4–16.5 mm, 1 ovig. F 19.9 mm (MNHN- Ga 1436).— Stn CH 141, 1600–1725 m: 1 M 16.3 mm, 1 ovig. F 19.1 mm (MNHN-Ga1441). Gulf of Aden , METEOR 5, Stn 257, 2227– 2250 m: 5 M 8.6–16.4 mm, 4 ovig. F 18.9–20.8 mm, 3 F 8.7–17.2 mm ( SMF) .— Stn 262, 1830– 1837 m: 1 M 13.0 mm, 1 F 11.4 mm ( SMF) .— Stn 271, 2276– 2282 m: 4 M 15.4–17.6 mm ( SMF) . W Sri Lanka, SAFARI 2, Stn 3 (CP04), 2475 m: 2 ovig. F 22.0– 23.7 mm (MNHN-Ga1565).— Stn 3 (CP05), 2540 m: 10 M 15.8–19.4 mm, 4 ovig. F 15.6–20.1 mm (MNHN-Ga1563).— Stn 4 (CP06), 1035 m: 2 M 17.5–18.9 mm (MNHN-Ga1564). Central Indian Ocean, SAFARI 2, Stn 17 (CP15), 2895–3800 m: 2 males 13.5–18.3 mm (MNHN-Ga1622) . Indonesia, Makassar Strait, CORINDON 2, Stn 220, 2340 m: 1 ovig. F 18.6 mm (MNHN-Ga1437) . Solomon Islands, SALOMON 1, Stn 1755, 1288– 1313 m: 1 F 7.3 mm (MNHN- Ga5489).— Stn 1764, 1327– 1598 m: 1 M 13.5 mm (MNHN-Ga5490) . New Caledonia, BIOCAL, Stn 62, 1395– 1410 m: 1 M 18.2 mm, 2 ovig. F 14.4–16.5 mm, 1 F 8.5 mm (MNHN-Ga5491).— Stn 63, 2160 m: 2 F 14.0– 14.2 mm (MNHN-Ga5492). BIOGEOCAL, Stn 260, 1820– 1890 m: 1 M 19.0 mm, 2 ovig. F 19.5–28.0 mm (MNHN-Ga5493).— Stn 272, 1615– 1710 m: 2 M 17.0– 19.5 mm, 1 F 8.7 mm (MNHN-Ga5494).— Stn 317, 1620– 1630 m: 10 M 7.3–18.6 mm, 4 ovig. F 16.0– 19.9 mm, 3 F 7.3–13.4 mm (MNHN-Ga5495) . Wallis & Futuna, MUSORSTOM 7, Stn 621, 1280– 1300 m: 1 M 11.3 mm (MNHN-Ga5496).— Stn 623, 1280– 1300 m: 1 ovig. F 18.0 mm, 1 F 13.0 mm (MNHN-Ga5497) .

Description. Carapace slightly longer than broad, covered with simple, scale-like or spine-like tubercles, dorsally armed with 2 well-developed epigastric, one extremely strong laterally compressed mesogastric, and one moderately large cardiac spines. Gastric and cardiac regions somewhat inflated. Lateral margins slightly convex, with 2 prominent anterior spines and lobe-like process at midlength, first spine (anterolateral) smaller than second spine (hepatic). Front margins oblique, without antennal spine. Posterior margin of carapace smooth. Rostrum with 2 small spines at anterior end of horizontal portion, not discernible in dorsal view, some additional granules near each spine; rostral spine slightly smaller than mesogastric spine, upturned distally, forming variable angle of 45–90º with horizontal portion; width of rostrum (measured at level of end corneae) subequal to that of corneae; horizontal portion reaching or slightly overreaching antennal peduncle.

Sternites smooth. Sternite 3 bilobate, separated by notch, about one-third width of sternite 4; each lobe slightly wider than long, with lateral margin rounded, anterior margin granulated; ridges demarcating sternites 4–7 feebly granular; sternite 4 truncate subtriangular, relatively narrow anteriorly.

Adominal tergites 2–4 with 2 moderately elevated transverse ridges, each anterior ridge with prominent median spine, spine on tergite 4 clearly smaller than preceding spines; tergite 4 with transverse groove between ridges not interrupted medially. Pleura of tergites 2 and 3 with numerous granules of variable sizes, less numerous on tergite 4. Tergite 5 smooth, anterior ridge low, usually with a few small granules. Tergite 6 having slightly convex posterior margin, not overreaching posterolateral lobes. Telson divided into 10 plates, midlateral plates with stiff setae in male; posterior plates combined nearly twice as wide as long.

Eye movable and spineless, corneae subglobular.

Basal article of antennule with one very small distomesial, one strong distolateral, and one small dorsolateral spines, last one occasionally absent; distoventral margin with broad, thin, dentate process.

Antennal peduncle nearly spineless; basal article with small distomesial process, and slightly wider than basal article of antennular peduncle.

Mxp 3 merus with 3 or 4 spines on flexor margin, proximal spine largest extensor margin unarmed; mesial ridge of ischium bearing 16–21 denticles.

P1 covered with tubercles and granules, 1.2–1.6 (females), 1.5–1.9 (males) times carapace length, nearly spineless; merus and carpus with a few terminal spines, carpus as long as palm, 1.3–1.6 times longer than wide; palm 1.3–1.7 times longer than wide, fingers distinctly longer than palm, distally spooned, prehensile edges crenulate.

P2–P4 long, slender, with numerous granules, subcylindrical; P2 overreaching P1, and 1.6–2.0 times carapace length. P2 merus 5–7 times longer than high, 3.0–3.5 times length of carpus, 1.5 times length of propodus, slightly longer than that of P3 and 1.3–1.4 times that of P4, slightly overreaching rostrum, having distal spine on dorsal margin; carpus with dorsolateral granulated crest; propodus 6.5–8.0 times longer than high, 1.4–1.8 times dactylus length, ventral margin unarmed; dactylus compressed laterally, flexor border moderately curving, bearing 10–13 proximally diminishing low teeth, ultimate tooth rather remote from end of dactylus and much closer to penultimate; distal half of extensor margin with numerous unirramous setae.

Variations. The rostral spine forms a variable angle of 45–90º with the horizontal portion. In the type series, as well as in the other specimens examined, the angle is 45º–60º, but in some specimens from Madagascar, the angle is nearly 90º ( Fig. 3), as in the original illustrations of G. areolata (Alcock & Anderson, 1901) . The pleura of the abdominal segments 2–5 are strongly granulated in some specimens ( Fig. 4), being smoother in the type series. Furthermore, P 1 and P2–P4 are often more slender in the individuals from Sri Lanka and the western Pacific than in the type series. The two small spines at anterior end of horizontal portion of the rostrum are always not discernible in dorsal view, and the first spine (anterolateral) of the carapace is also always smaller than the second spine (hepatic) .

Remarks. Galacantha bellis belongs to the group of species with the rostrum having two small and subparallel spines at the end of the horizontal portion, not visible in dorsal view, the second spine (hepatic) of the carapace margin clearly longer than the first spine (anterolateral), the fourth abdominal tergite with a transverse groove between ridges not interrupted medially, and the pleura of second and third abdominal tergites with numerous granules, less numerous on the fourth tergite. The closest species is G. subrostrata n.sp. from the northeast Atlantic (see below for the differences between both species).

The morphological variations among specimens from different localities are not constant, suggesting the presence of a single variable species. Unfortunately, the types of G. areolata have not been examined. However, the similarity with the illustrations provided by Alcock & McArdle (1901), suggests that all specimens belong to the same species. The rostrum of some small specimens, clearly longer than in large individuals, suggests that the juvenile of G. talismanii collected in the Banda Sea by Henderson (1888) could be referred to the present species. Therefore, the variations observed in G. bellis require further study, including molecular data, in order to confirm the existence of a single or several species.

Distribution. Chile, off Valparaiso (2516 m); Bay of Bengal, Laccadive Sea (1958–2397 m). The present material was collected from Madagascar, the Arabian Sea, Sri Lanka, central Indian Ocean, Makassar Strait ( Indonesia), Solomon Islands, New Caledonia, and Wallis and Futuna area, between 1035 and 3800 m.