Abstract
Although known to be distinct genetically and recently treated as different species taxonomically, two Japanese bagrid catfishes, Pseudobagrus aurantiacus (Temminck and Schlegel) and P. tokiensisDöderlein, have not been previously scrutinized as to their morphological differences. Examination of morphometric and osteological characters revealed that the former species differs from the latter in having a higher dorsal fin, the pectoral spine more prominently serrated on the anterior edge, more densely serrated on the posterior edge, and with 1-3 antrorse serrations at the base, a broader supraoccipital process, the supraneural as long as or longer than the supraoccipital process, a broader posterior process of the cleithrum (posterior tip angle>20°), and the hyomandibular widely separated from the metapterygoid.In addition, the body color pattern of young fish differs in the two species.
