Dynomene praedator, A. Milne-Edwards, 1879

Mclay, Colin L., 2001, Dynomenidae and Dromiidae (Decapoda, Brachyura) from Guam, Philippine Islands, Tonga and Samoa, Zoosystema 23 (4), pp. 807-856 : 818

Dynomene praedator A. Milne-E>dwards, 1879

Dynomene praedator A. Milne-Edwards, 1879: 8 , pl. 14, figs 20-26. — McLay 1999: 481, figs 3b, 8a-b, 11, 12 d, 14 b, 17 b, 19 a-g.

MATERIAL EXAMINED. — Guam. Piti Reef, 13°27’N, 144°47’E, among rocks, 1.5 m, 22.VII.1993, 2

8.5 × 6.5 ( GUM 268). — Among rocks, 1.5 m, 22.VII.1993, 1 13.0 × 10.3 mm ( GUM 270). — Among rocks, 1 m, 1.VIII.1993, coll. H. T. Conley, 1 7.8 × 7.0 mm ( GUM 300). — Outer reef margin, 1 m under rubble pile, 1-4 m, IV.1998, 1 9.5 × 7.5 mm, coll. S. Norby, 1 (ovig.) 9.7 × 7.1 mm ( UGI no registration number, ZRC 2000.0743).

SIZE. — Maximum size for males is 13.5 × 10.7 mm, and for females 12.0 × 9.6 mm. All specimens from Guam are smaller than these sizes. The above oviger- ous female, with about 160 eggs ready to hatch, was captured during April and so conforms to the reproductive period recorded elsewhere of from January to June.

DEPTH AND HABITAT. — Depth range intertidal to approximately 50 m among coral. All the Guam specimens came from shallow water, 1- 4 m.

DISTRIBUTION. — D. praedator is a widespread Indo- West Pacific species which has already been recorded from the Mariana Islands (see McLay 1999).

DISCUSSION

Dynomene praedator has been recently redescribed and illustrated by McLay (1999) where a full synonymy can also be found. D. praedator , along with D. hispida , are the two most common shallow water dynomenids throughout the Indo- West Pacific, so it is surprising that D. hispida has not yet been found in Guam. D. hispida has been collected from the northern Mariana Islands of Maug East and Maug North ( Takeda et al. 1994) so it is likely to be present in Guam. If it is found, it will mean that Guam will have the richest shallow water dynomenid fauna (four species) in the world.

While all the specimens came from among rocks, one specimen was excavated from 1 m below the rubble surface. This is a much neglected habitat, where we do not usually expect to find crabs.