Suzuki & Okano, 2000
Diagnosis: Penultimate segment of male first gonopod slightly curved laterally, ultimate segment strongly curved mesially, cone-shaped, with terminal aperture. Ocular peduncle swollen proximally, cornea small. Gastric cristae stout, H-shaped median gastro-cardiac depression distinct. In life, carapace and pereiopods chocolate brown or dark red with scattered black speckles.
Description: Carapace much broader than long, smooth, devoid of setae; faint, short oblique striae on epibranchial and postero-lateral regions; epi and urogastric regions distinct, former divided into 2 stout gastric cristae by deep median groove; H-shaped median gastro-cardiac depression deep, wide; deep transverse groove between cardiac and intestinal regions; cervical groove obsolete on epibranchial region. Antero-lateral margin of carapace cristate, lined with fine rounded granules; epibranchial notch rudimentary. Posterior margin of epistome divided into 3 parts by 2 deep notches, granules present on lower edge of epistome, absent medially. Lower orbital margin and groove between subhepatic and pterygostomial regions lined with faint granules.
Eyestalk short, proximally swollen, distally slender. Cornea small, slightly wider than distal portion of ocular peduncle.
Merus of third maxilliped broad, squarish, with deep depression. Palp 3-segmented, connected on inner distal angle of merus, tip of palp not below distal margin of ischium. Exopod slender, longer than ischium, with small 5-segmented flagellum.
Chelipeds asymmetrical in males, symmetrical in females; movable finger of large cheliped strongly curved in large male (not so in small male); palm smooth, outer surfaces convex. Carpus of large cheliped almost smooth, with stout inner tooth, below which is a low projection. Carpus of small cheliped without any projection below stout inner tooth.
Palp of mandible 3-segmented; distal segment uniramous, sickle-shaped; median segment longer than wide, distal half expanded; proximal segment short, stout.
Penultimate segment of adult male first gonopod gently curved laterally, synovial membrane short, about 3 times as long as broad, ultimate segment strongly curved mesially, cone-shaped, with terminal aperture. Male second gonopod slender, flat, weakly convex at proximal part, a small cup-like structure on distal one-fourth, tip of G2 concave. G2 shorter than G1, tip of G2 not protruding from aperture of G1 when coupled.
Colour in life: Carapace and pereiopods chocolate brown or dark red with scattered black speckles. Lower part of palm and immovable finger of both chelipeds white in large male, movable finger and upper part of palm of chelipeds chocolate brown. In small males and females, lower part of palm of both chelipeds white, fingers and upper part of palm dark red. Otherwise, no colour variation observed between sexes and sizes. (Suzuki H. & Okano, 2000)
Type locality: Anboh River, Yaku-shima, Kyushu, Japan.
Range: Japan - Yaku-shima (Suzuki H. & Okano, 2000).