Dynomene Desmarest, 1823

Mclay, Colin L., 2001, Dynomenidae and Dromiidae (Decapoda, Brachyura) from Guam, Philippine Islands, Tonga and Samoa, Zoosystema 23 (4), pp. 807-856 : 809

Genus Dynomene Desmarest, 1823

DIAGNOSIS. — Carapace shape wider than long, moderately convex, commonly sub-circular. Surface may be smooth or sparsely granulate, covered with coarse setae, which may short or long, and often arranged in tufts. Lateral carapace margin always well-defined and armed with distinct small teeth or granules. Frontal groove well-marked, splits in two posteriorly, cervical, postcervical and branchial grooves usually evident. Frontal carapace margin broadly triangular, continuous, no rostrum or teeth, eyestalks short, eyes protected by well-defined orbits. Female sternal sutures 7/8 end well-apart on low tubercles behind bases of second walking legs. Antennule can be concealed inside the orbit at the base of the eyestalk. Antennal flagella shorter than carapace width. All segments of antenna moveable, first segment (urinal) always beaked medially and second segment has an exopod firmly fixed. Third maxillipeds opercular, completely covering the buccal cavern, separated at their bases by a plate at the same level as the sternum, basis and ischium of endopod fused but joint always marked by a shallow groove. Crista dentata present. Chelipeds equal, stouter than walking legs, dactyl strongly curved, fingers gaping basally. Last pair of legs very reduced, dactyl rudimentary, forming an obsolete sub-chelate mechanism with an extension of the propodus. Gills usually 19 (including six podobranchs) + seven epipods. Gills variable in shape. Abdomen of six segments and telson, folded loosely under the thorax, uropods large. The lateral movement of the abdomen is restricted by a small sternal tubercle at the base of each of the first walking legs which lies alongside each uropod. Both sexes have five pairs of pleopods, first pair rudimentary in female, last three pairs vestigial in the male. First male gonopods very uniform in structure, consisting of a stout, setose semi-rolled tube with an apical plate, second pair simple, needle-like, with varying numbers of subterminal spines (after McLay 1999).