Differs from two other congeners, i.e. Rectoris mutabilis and R. posehensis, by having a dumbbell-like (vs. slender) posterior chamber of the gas bladder, almost equal to (vs. twice as long as) the anterior chamber, and longer rostral barbels (vs. shorter) than eye diameter, with their lengths 21.0-24.7% of HL (vs. 10.2-18.8). Similar to R. posehensis in having a longitudinal black stripe running along the lateral line on the flank, but can be further diagnosed from this species in having a slightly papillated posteromedian patch on the median plate of the lower lip (vs. no patch); and similar to R. mutabilis in the shared presence of a papillated posteromedian patch on the median plate of the lower lip, but further differs from this species in its longitudinal black stripe running along the lateral line on the flank (vs. stripe absent) (Ref. 93096).