Chiromantes Gistel, 1848

Schubart, Christoph D. & Ng, Peter K. L., 2020, Revision of the intertidal and semiterrestrial crab genera Chiromantes Gistel, 1848, and Pseudosesarma Serène & Soh, 1970 (Crustacea: Brachyura: Sesarmidae), using morphology and molecular phylogenetics, with the establishment of nine new genera and two new species, Raffles Bulletin of Zoology 68, pp. 891-994 : 897-898

Chiromantes Gistel, 1848

Type species. Grapsus (Pachysoma) haematocheir De Haan, 1833 (subsequent designation by Holthuis, 1977: 170). Gender masculine.

Diagnosis. Carapace squarish; frontal margin almost entire or gently bilobed, gently deflexed, subequal to posterior carapace margin; lateral margin entire, posterolateral part gently convex to subparallel; regions of carapace poorly demarcated; postfrontal and epigastric crests separated by relatively shallow grooves, margin relatively sharp, almost straight, appearing contiguous; basal articles of antenna and antennules adjacent to each other, not separated by septum; dorsal margin of palm without longitudinal pectinated ridge, inner surface not swollen, without granulated ridge, outer surface of palm and pollex convex, outer surface of palm smooth; dorsal margin of cheliped dactylus smooth in adult males, juveniles with row of uniformly sized small granules; inner distal margin of merus of cheliped not lamelliform; inner surfaces of first to third ambulatory coxae with only scattered short setae, not arranged into dense tufts; male thoracic sternites 2–4 relatively narrow in adults, suture between sternites 3 and 4 distinct; male sternopleonal cavity reaching to midlength of sternite 4; male thoracic sternite 5 smooth, without depression on anterior part; G1 relatively stout, chitinous part short. Vulva on anterior part of sternite 6, anterior edge just touching sternite 5; anterior and posterior sternal vulvar covers low; opening short, cylindrical, directed obliquely anteriorly.

Included species. Chiromantes haematocheir ( De Haan, 1833) ; Chiromantes ryukyuanus Naruse & Ng, 2008 .

Remarks. As discussed earlier, Chiromantes s. str. is uniquely defined by having the adult male thoracic sternites 2–4 relatively broader than other related taxa, and the sternopleonal cavity being shorter, reaching only to the median point of sternite 4 ( Fig. 9A, D ).

Figures

Fig. 9. Male anterior thoracic sternum and pleon. A, Chiromantes haematocheir, lectotype male (33.7 × 29.7 mm) (RMNH-D160), Japan; B, C. ryukyuanus, holotype male (33.1 × 29.6 mm) (RUMF-ZC-539), Okinawa Island, Japan; C, Orisarma dehaani, lectotype male (39.5 × 35.7 mm) (RMNH-D157), Japan; D, O. neglectum, neotype male (35.6 × 31.8 mm) (ZRC 1998.310), Shanghai, China; E, O. intermedium, lectotype male (23.0 × 19.9 mm) (RMNH-D165), Japan; F, O. sinense, lectotype male (19.0 × 16.6 mm) (MNHN-BP3635a), China; G, O. sinense, male (29.6 × 25.4 mm) (ZRC 1998.1204), Shanghai, China; H, O. patshuni, male (14.2 × 13.0 mm) (ZRC 1998.345), Hong Kong.