Paradynomene tuberculata Sakai, 1963

Mclay, Colin L., 2001, Dynomenidae and Dromiidae (Decapoda, Brachyura) from Guam, Philippine Islands, Tonga and Samoa, Zoosystema 23 (4), pp. 807-856 : 820

Paradynomene tuberculata Sakai, 1963

Paradynomene tuberculata Sakai, 1963: 231 , fig. 8. — McLay 1999: 543, figs 4e-f, 6e-f, 7c, e, 10b-d, 14a, 25d, 32a-g.

MATERIAL EXAMINED. — Guam. 13°27’N, 144°47’E, North West Luminao Reef, 21 m, among dead coral, 29. V.1993, coll. H. T. Conley, 22.7 × 21.3 mm, 1 16.1 × 16.1 mm ( GUM 310) ( ZRC 2000.2122). — Piti Lagoon, 1.2-7.5 m, in dead coral, 26. V.1994, 1 21.7 × 20.0 mm. — Piti Lagoon, 4-8 m, among dead coral, 5. VI.1994, 1 17.2 × 16.4 mm. — Piti Lagoon, 1.5-5 m, in coral rubble, 12. V.1997, 1 (ovig.) 20.5 × 19.4 mm. — Luminao Reef, 21-24 m, among coral rubble, 7. V.1998, coll. H. T. Conley, 1 8.6 × 8.8 mm ( UGI no registration numbers) ( ZRC 2000.0750).

SIZE. — Maximum size for males is 22.0 × 22.8 mm, and for females 20.6 × 21.4 mm. The largest male from Guam, 22.7 × 21.3 mm, is about the same size as the largest male. The ovigerous female, 20.5 × 19.4 mm, was carrying about 840 small eggs, diameter = 0.5 mm, indicating that P. tuberculata has a planktonic larval stage.

DEPTH AND HABITAT. — Before these specimens were collected from Guam, the known depth range was 35- 402 m, but it now appears that P. tuberculata occurs at shallower depths than previously thought. The depth range is now 1.5-402 m on dead coral and rocky bottoms.

DISTRIBUTION. — P. tuberculata is known from the Gulf of Aden in the Indian Ocean, Japan and New Caledonia in the West Pacific and now Guam.

DISCUSSION

Paradynomene tuberculata has been welldescribed and illustrated by McLay (1999) where a full synonymy can be found. Amongst the dynomenids, it is very distinctive in having a strongly calcified, oblong carapace, with an areolate and granulated surface. McLay (1999) noted the similarities of P. tuberculata to some dromiids like Epigodromia McLay, 1993 . These similarities include the carapace surface, the tridentate rostrum and having a front or “face” with a dromiid conformation. These similarities may indicate evolutionary convergence in the two families wherein the species achieve a cryptic appearance by resembling their coral surroundings McLay (1999: 549).