Cryptodromia tuberculata Stimpson, 1858

Mclay, Colin L. & Ng, Peter K. L., 2005, On a collection of Dromiidae and Dynomenidae from the Philippines, with description of a new species of Hirsutodynomene McLay, 1999 (Crustacea: Decapoda: Brachyura), Zootaxa 1029 (1), pp. 1-30 : 7-9

Cryptodromia tuberculata Stimpson, 1858 ( Fig 2 )

Cryptodromia tuberculata Stimpson, 1858: 239 .— Ihle 1913: 119.— Buitendijk 1939: 225.— Sakai 1976: 13, figs. 3a, b.— McLay 1993: 199 (key).— McLay 2001a: 838 (for detailed synonymy).

Material. 1 male, 10.3 x 10.0 mm, 2 females, 10.5 x 9.5 mm, 10.5 x 10.2 mm, Dec 2000, ZRC 2001.391 ; 2 males, 11.2 x 11.4 mm, 11.4 x 11.3 mm, 2 ovigerous females, 9.2 x 9.3 mm, 9.2 x 9.3 mm, 28 Nov 2001, ZRC 2001.520 ; 4 males, 9.0 x 8.6 mm, 9.4 x 9.0 mm, 9.8 x 9.5 mm, 10.5 x 10.0 mm, 28 Nov 2001, ZRC 2001.522 ; 2 males, 6.8 x 6.1 mm, 18.1 x 18.1 mm, Jun 2002, ZRC 2002.630 ; 7 males, 9.8 x 9.4 mm – 12.5 x 12.7 mm, 1 ovigerous female, 11.1 x 10.6 mm, 25–30 Jul 2003, ZRC 2003.670 ; 1 male, 10.2 x 10.0 mm, 1 ovigerous female, 10.2 x 9.5 mm, Jul 2003, ZRC ; 1 male, 5.5 x 5.4 mm, Dec 2003, ZRC ; 1 male, 11.2 x 10.9 mm, Jan 2004, ZRC ; 1 ovigerous female, 9.3 x 9.1 mm, Nov 2003 – Apr 2004, MNHN ; 2 males, 9.2 x 9.1 mm, 10.7 x 10.4 mm, 2 March, 2004, ZRC ; 4 males, 9.2 x 8.7 mm, 10.1 x 9.9 mm, 11.2 x 10.8 mm, 12.0 x 12.3 mm, 2 Mar 2004, ZRC / NMCR ; 1 male, 12.0 x 11.9 mm, 29 May 2004, ZRC . All locations in Balicasag Island , Panglao, Bohol, Visayas, Philippines; purchased from local shell fishermen, obtained by tangle nets .

Remarks. The identities of C. tuberculata and the closely allied C. pileifera Alcock, 1901 , had been uncertain. The latter species was described as a subspecies of C. tuberculata , but some authors (e.g. Alcock 1901, Tan et al. 1986, Tan & Ng 1988) have regarded it as a distinct species while others (e.g. McLay 1993, Lim et al. 1994) have regarded the two taxa as synonymous. McLay (1993: 198) commented that “Following earlier authors, Cryptodromia pileifera Alcock, 1901 , is regarded as a synonym of C. tuberculata Stimpson, 1858 , ….” but argued that both were distinct taxa when he reexamined the genus later ( McLay 2001a: 840) with more material. It is clear that the two should be regarded as separate taxa. The differences are as follows: in C. tuberculata the lateral rostral teeth are very short and blunt (blunt, but larger in C. pileifera ) ( Fig. 2A, B versus Fig. 3A, B ); the median rostral tooth longer than lateral teeth (median tooth shorter) ( Fig. 2A versus Fig. 3A ); there are five sub­hepatic teeth arranged in a row with three being larger and visible dorsally (versus only two large teeth present, one visible dorsally) ( Fig. 2A, B versus Fig. 3A, B ); the branchial groove is not evident (versus groove wellmarked) ( Fig. 2A versus Fig. 3A ); the chelipeds are strongly tuberculate (versus less tuberculate) ( Fig. 2A, C versus Fig. 3A, C ); and the distal margins of the articles of the first two walking legs are very tuberculate (versus not tuberculate) ( Fig. 2A versus Fig. 3A ). A key to the species of Cryptodromia can be found in McLay (2001a: 827).

In both C. tuberculata and C. pileifera , the brood size is relatively small with only 40 to 80 eggs of a relatively large size each (ca. 0.8 mm in diameter). The larval development of C. pileifera has been shown by Tan et al. (1986) to be very abbreviated, so it is likely to be the same for C. tuberculata . The smallest female of C. tuberculata examined (9.3 by 9.1 mm) had 30 to 40 eyed eggs (diameter 1.1 mm) while the others had more eggs: a female 10.2 by 9.5 mm had 90 to 100 new eggs (diameter 0.95 mm) and another 11.1 by 10.6 mm carried 70 to 80 eggs (diameter 0.8 mm).

Distribution. Cryptodromia tuberculata has been recorded from Japan, South China Sea, Philippines, Indonesia and Singapore. Existing records suggest that C. tuberculata is a shallow water species, typically found in the intertidal zone, the deepest confirmed record being 20 m.

Figures

FIGURE 2. Cryptodromia tuberculata Stimpson, 1858. Male, 18.1 x 18.1 mm, ZRC 2002.630, Philippines. A, overall dorsal view; B, frontal view; C, outer view of right chela.

FIGURE 3. Cryptodromia pileifera Alcock, 1901. Male, 6.6 x 5.8 mm, Panglao, Philippines, ZRC. A, overall dorsal view; B, frontal view; C, outer view of right chela.