Garthasia Ng, 1993

Hsueh, Pan-Wen, 2020, New species and record of xanthid crabs (Crustacean, Decapoda) from Taiwan, Zootaxa 4809 (3), pp. 535-546 : 536

Genus Garthasia Ng, 1993 , emended

Type species. Garthasia americana ( Garth, 1939) (subsequent designation by Ng 1993)

Diagnosis (after Ng 1993, new feature highlighted in boldface). Carapace distinctly oval, much broader than long, width to length ratio 1.21 –1.35; anterolateral margin distinctly shorter than posterolateral margin, without sharp granules of epibranchial spines; posterolateral margin gently convex. Third maxilliped short, length to width ratio about 2.4– 3.2; merus much wider than long, width to length ratio about 1.3 –2.2; carpus not swollen or slightly swollen. Sternum not greatly elongate, suture between sternum 1 and 2 absent, surfaces of sternites 1 and 2 with or without distinct longitudinal keel. Tips of cheliped fingers sharp. Merus of last ambulatory leg short, slender, length to width ratio about 1.8 –2.7. Male abdomen second segment much broader than long, width to length ratio about 2.1 –3.0.

Remarks. Ng (1993) argued that Kraussia americana Garth, 1939 , is generically different from other kraussiines described from the Indo-west Pacific and erected the genus Garthasia . The overall morphology of the present specimen agrees mostly with diagnoses of Garthasia but has some minor differences (i.e., longitudinal ridge on surfaces of sternites 1 and 2 absent). Hence, the generic diagnosis is slightly emended herein to accommodate the new species. All specimens of G. americana ( Garth, 1939) have been collected from various shallow subtidal habitats on coasts between 29°N to 1°S in the East Pacific. The present study reports a second species for the genus from shallow subtidal habitats in the West Pacific.