Calappa exanthematosa Alcock & Anderson, 1894

Kumar, Biju A., Kumar, M. Sushil & Galil, Bella S., 2013, Calappid and leucosiid crabs (Crustacea: Decapoda: Brachyura) from Kerala, India, with the description of a new species of Mursia Desmarest, 1823, from the Arabian Sea and redescription of M. bicristimana Alcock & Anderson, 1894, Zootaxa 3746 (4), pp. 529-551 : 531

Calappa exanthematosa Alcock & Anderson, 1894

( Fig. 3 a, b)

Calappa exanthematosa Alcock & Anderson 1894a: 177 ; 1895: pl. 15, figs 1, 1a.—Alcock 1896: 146.—Ng et al. 2011, figs. 1, 2, 4, 5b, 6b, 7b, 8c, d, 9d–f.

Calappa japonica —Sankarankutty & Subramanian 1976: 21.—Galil 1997: 301, figs 10d, 13d, 15.—Ng et al. 2008: 48 (list, part), not Calappa japonica Ortmann, 1892 .

Kerala material examined. Neendakara, 08˚56'N 76˚32'E, 70–100 m, 31 Aug. 2007, 1 ♀ (CW 78.8 mm); 31 Oct. 2007, 1 ♂ (CW 58.1 mm); 12 Jan. 2013, 1 ♂ (CW 123.8 mm) (DABFUK). — Ponnani, 10˚47'N 75˚55'E, 70–100 m, 29 Aug. 2007, 1 ♂ (CW 46.8 mm) (DABFUK).

Additional material examined. India. Bay of Bengal, 13.1'06"N 80 36'56"E, 196 m, 1 ♂ (CW 84.1 mm) (ex. Indian Museum, Calcutta (NHM 1896.9.8.8), lectotype of Calappa exanthematosa Alcock & Anderson, 1894 , designated by Lai & Ng (2006).

Colour. The striking coloration resembles that of the Sri Lanka specimen (Ng et al. 2011, fig. 2a, b) and fits the description given by Alcock & Anderson (1894a: 178): dorsal surface of carapace purplish anteriorly “covered with numerous large smooth isolated mammillary tubercles, which by their coloration (red base and shining yellow apex) exactly resemble ripe small-pox pustules. In the posterior half of the carapace the place of these well-defined "pustules" is taken by equally well-defined round or oval slightly-raised red patches, which exactly resemble the "papules" of the earlier stage of small-pox.” The upper external surface of the palm similarly displays “pustules” and “papules” ( Figs 3 a, b).

Distribution. Originally described from the Bay of Bengal, India, this species has since been recorded from the Iranian coast of the Gulf of Oman, Pakistan and Mumbai, Maharashtra, India (Ng et al. 2011). New record for Kerala.

Figures

FIGURE 3. Calappa exanthematosa Alcock & Anderson 1894, Neendakara, India, 12 Jan 2013, ♂, CW 123.8 mm; a. dorsal view of carapace; b. external view of chelae. Photo by Bella Galil.