Suzuki & Tsuda, 1994
Diagnosis: Male first gonopod sabre-like, penultimate segment slightly curved laterally, ultimate segment strongly curved laterally, tapering, genital opening subterminal. Ocular peduncle swollen proximally, cornea small.
Description: Carapace much broader than long, smooth and devoid of hair, postfrontal and postorbital regions indistinctly rugose, faint oblique striae on epibranchial and postero-lateral regions, epi and urogastric regions distinct, former divided into two parts by median depression, cervical groove obsolete on epibranchial region. Antero-lateral margin of carapace cristate, lined with fine rounded granules, epibranchial notch rudimentary. Frontal margin 0.35 (0.33-0.40 in male, 0.31-0.38 in female) times as broad as carapace. Posterior margin of epistome divided into three parts by 2 deeper notches, granules present on lower edge of epistome, absent medially. Lower orbital margin and groove between subhepatic and pterygostomial regions lined with small rounded granules.
Eyestalk short, proximally swollen, distally slim. Cornea small, slightly wider than distal portion of ocular peduncle.
Merus of third maxilliped broad, square, with deep punctum. Three-segmented palp connected on inner distal angle of merus, tip of palp not below distal margin of ischium. Exopod slender, longer than ischium, with small flagellum.
Chelipeds asymmetrical in males over 13.0 mm carapace width (right larger than left in 26 out of 28 males, left larger than right in remainder), symmetrical in all females and in males less than 13.0 mm; large chela 2.09 (1.82-2.27) times as long as high, palm smooth and surfaces relatively rounded, fingers with 2 longitudinal ridges on outer lateral surface. Carpus of large cheliped slightly smooth, with stout inner tooth below which is a low swelling. Carpus of small cheliped without any swelling below stout inner tooth.
Palp of mandible 3-segmented, distal segment uniramous and sickle-shaped, median segment longer than wide, distal half expanded, proximal segment short, stout.
Adult male first gonopod sabre-like, penultimate segment slightly curved laterally, synovial membrane short, about 3 times as long as broad, ultimate segment strongly curved laterally, tapering, with genital opening subterminal in position. Tip of first gonopod papilla-like in specimen 8.7 mm carapace width, and tapered in specimens 11.2 and 14.6 mm carapace width. Male second gonopod slender, flat, weakly convex, with small lamella on distal one-third. (Suzuki H. & Tsuda, 1994)
Type locality: Kimotsuki River, Ohsumi Peninsula, Kagoshima Prefecture, Japan.
Range: Japan - Ohsumi Peninsula, Kagoshima (Suzuki H. & Tsuda, 1994).