Creagrutus nigrotaeniatus is distinguished from all its congeners, except C. cracentis and C. maxillaris, by having 8-10 dentary teeth (vs. 4-7) and 4-5 post-anal scales (vs. 1-2). It further differs from most congeners (except C. varii, C. gephyrus, C. cracentis, and C. maxillaris) by having dentigerous surface of the premaxilla longitudinally elongate from ventral view (vs. dentigerous surface triangular). In addition, it can be diagnosed from C. varii by having 8-10 branched rays on anal fin (vs. 15-17) and from C. gephyrus by having 4-5 maxillary teeth (vs. 7-11). It is distinct from C. cracentis and C. maxillaris by having a dark mid-lateral stripe extending from the posterior margin of orbit to the distal tip of middle caudal fin rays (vs. absence of mid-lateral stripe), anterior dentary teeth tricuspid (vs. pentacuspid), and 4-5 maxillary teeth (vs. 8-12) (Ref. 94995).

Description: Dorsal-fin rays ii,8; anal-fin rays iii,8-10; pectoral-fin rays i,12-13; pelvic-fin rays i,7; longitudinal scale rows between lateral line and pelvic-fin origin 3 (Ref. 94995).