Distinguished from all other species of that genus by a combination of the following: greatest body depth 3.1-4.1 (3.8); least body depth 8.0-9.9 (9.2); origin of pectoral to anus 2.8-3.1 (3.0), all in SL. Eye 2.6-3.5 (2.9) in head. Dorsal process of premaxilla 1.4-2.2 (1.8) in eye. Lips in premaxilla 2.6-3.7 (3.1). Predorsal scales 10-12 (10.9). Origin of first dorsal from one scale behind to 2.5 scales in front of tip of pectoral fin (Table 1). Unique in dentition and length of spines in first dorsal fin. Differs osteologically from other members of the genus by a combination of the following: shape of premaxilla and maxilla; lateral ramus of premaxilla with greatly reduced secondary process; shape of nasal bone; and with basibranchial toothplate present. Differs genetically from other species only in allele frequencies at the following loci: FUM, MDH and MPI (Ref. 26703).