Paraqianlabeo lineatus can be diagnosed by having longitudinal dark stripe along side of body. It possesses a uniquely modified oromandibular morphology; i.e., arched, wide, rudimentary sucker formed by raised front and lateral margins of lower lip, postlabial groove and mental groove between middle and lateral lobes of lower lip chevron-shaped. Other unique combination of characters useful to identify this species include: anteroventral margin of rostral cap arched, thin and papillose; rostral cap not overlying upper lip, upper lip connected with lower lip around corners of mouth; well developed upper lip free from upper jaw; lower lip divided into two lateral fleshy lobes and one central plate, these two lateral fleshy lobes small and short, median lobe of lower lip large; anterior and anterolateral edges of upper and lower lip finely papillose; shallow, straight groove between lower lip and lower jaw; lower jaw bearing thin, cornified cutting edge; scales in ventral medial region from pectoral fins to pelvic fins half-hidden and subcutaneous; 3 scale rows below lateral line; and 7½-8 branched dorsal-fin rays (Ref. 96827).