Glyptoxanthus cavernosus ( A. Milne-Edwards, 1878 )

Mendoza, Jose Christopher E. & Guinot, Danièle, 2011, Revision of the genus Glyptoxanthus A. Milne-Edwards, 1879, and establishment of Glyptoxanthinae nov. subfam. (Crustacea: Decapoda: Brachyura: Xanthidae), Zootaxa 3015, pp. 29-51 : 36-37

Glyptoxanthus cavernosus ( A. Milne-Edwards, 1878)

( Figs. 3 , 10 B)

Actaea cavernosa A. Milne-Edwards, 1878: 226 (type locality: Cape Verde Is.). — Monod 1933: 523.

Xantho vermiculatus, Osorio 1906: 149 . Not Cancer vermiculatus Lamarck, 1818 .

Actaea (Glyptoxanthus) cavernosa, Monod 1956: 298 , fig. 362. — Serène 1961: 198 (list).

Glyptoxanthus cavernosa, Balss 1921: 61 . — Forest & Guinot 1966: 79.

Glyptoxanthus cavernosus, Bouvier 1922: 66 , pl. 6 fig. 3, 5. — Guinot 1967: 551, 553, 556, fig. 31; 1971: 1073; 1979: 68, fig. 18C, pl. 6 fig. 5. — Manning & Holthuis 1981: 135. — d’Udekem d’Acoz 1999: 229. —Ng et al. 2008: 199 (list).

Material examined. Cape Verde Is.: 1 male, 49.6 × 35.8 mm (MNHN-B8329), Stn 148, 10– 20 m, Sylvana, coll. Le Comte J. Polignac, 8 May 1913; 1 male, 26.7 × 19.1 mm, 1 female, 24.9 × 17.9 mm (MNHN-B8330), La Praya, 10–30 m, Talisman, 1883 ; 1 male, 21.7 × 15.5 mm, 1 female, 27.2 × 19.7 mm (RMNH-D40250), stn CANCAP 7.D15, scuba, Baia de Ribeirinha, W coast of São Vicente, coll. 7 Sep. 1986; 1 male, 24.7 × 17.8 mm, 1 female, 26.7 × 19.0 mm (RMNH-D40251), stn CANCAP 7.K18, snorkelling, intertidal to shallow sublittoral, shallow lagoon with corals, SE coast of Sal, coll. 29 Aug. 1986; 1 female, 13.7 × 9.7 mm (RMNH-D40253), 42 m, grab, SW of São Tiago, coll. 20 Aug. 1986; 1 female, 15.0 × 10.8 mm (RMNH-D40254), stn CANCAP 6.D11, scuba, Baia de São Pedro, SW coast of São Vicente, coll. 20 Jun. 1982.

Canary Is.: 1 female, 19.8 13.8 mm (RMNH-D40252), stn CANCAP 6.K01, rocky littoral, tidal pools, near los Christianos, SW Coast of Tenerife, coll. 27, 30 May 1982.

Diagnosis. Carapace transversely ovate, width-to-length ratio about 1.4; carapace vermiculations thick, petaloid, like a pavement of lobules; lobules smooth without traces of individual granules; furrows between lobules deep, relatively narrow, setose; 2M completely divided longitudinally, inner branch separated from 1M by shallow transverse furrow; 3M independent from 2M, posterior region bridged medially with 4M; 2L, 3L, and 4L distinct, 5L fused with 6L; 1P distinct, independent, without any smaller cavities. Front quadrilobate, with deep lateral notches. Anterolateral margin with 4 feeble lobes. External surfaces of thoracic sternum, pereopods and abdomen with similar sculpturing as carapace. Margins of ambulatory legs fringed with long setae. G1 long, slender, bluntly tipped; apex devoid of any setae, but studded with spiniform granules; G2 about one-fourth length of G1.

Remarks. Alphonse Milne-Edwards (1878) described Actaea cavernosa from the Cape Verde Islands, and later transferred it to his new genus, Glyptoxanthus . Glyptoxanthus cavernosus is easily distinguished from its congeners by the sculpturing on the dorsal surface of its carapace: in particular, the completely independent 3M region and the closely packed, non-elongate lobules and vermiculations, which have distinctly petaloid outlines. In fact, these vermiculations resemble the closely packed granules of some species of Actaea (see Guinot 1979: fig. 10), and also of some Euxanthus such as E. boletarius ( Rathbun, 1911) (see Serène 1984: pl. 11 fig. E).

According to Monod (1956), the type specimen was deposited in the MNHN, Paris, but it could not be found. However, this is a distinctive species that was well described and we have no doubt over the identity of our present material, most of which is from the type locality, Cape Verde Islands.

Ecology and geographical distribution. Glyptoxanthus cavernosus is only known from the Cape Verde Islands and from the Canary Islands, off the northwestern coast of Africa, and has been collected from intertidal to shallow subtidal zones, amidst rocks and coral.

Figures

FIGURE 3. Glyptoxanthus cavernosus (A. Milne-Edwards, 1878), male, 49.6 × 35.8 mm (MNHN-B 8329), Cape Verde: A, dorsal view; B, anterior view; C, ventral view; D, left chela, external view.

FIGURE 10. Glyptoxanthus spp. gonopods (G 1). A, G. angolensis (Brito Capello, 1866); B, G. cavernosus (A. Milne-Edwards, 1878); C, G. erosus (Stimpson, 1859); E, G. c o r ro s u s (H. Mile Edwards, 1834); E, G. labyrinthicus (Stimpson, 1860), (LACM CR 1935.075.3); F, G. meandricus (Lockington, 1877), neotype (LACM CR 1940.65); G, G. vermiculatus (Lamarck, 1818). (A – C, D, G, after Guinot 1979).