Eirmotus furvus Tan & Kottelat 2008

Differs from all congeners by having a wide, very conspicuous and contrasted black bars on the body (width of bar 5 equal to 1½ to 2 lateral row scales). Additional distinguishing characters of this species include bar 1 on snout conspicuous, simple dorsal-fin rays black throughout its length, black pigmentation sometimes reaching the interradial membrane before first branched ray, posterior tip of dorsal fin with a distinct black mark which appears as part of 6, pectoral fin with black upper margin; simple anal-fin rays black on their entire length in adults; all fins dusky with scattered chromatophores on all rays; posterior edge of last simple dorsal-fin ray with 17-21 serrae; presence of a small and distinct black mark immediately anterior to anus, visible in lateral view; mouth terminal with lower jaw wide and anteriorly rounded (Ref. 78741).

Dorsal soft rays (total): 11; Analsoft rays: 8; Vertebrae: 30

This is the only member of the genus Eirmotus which occurs in the black waters of peat swamp forest. Encountered only in deep inside the forested area in a less disturbed portion (Ref. 78741).

Eirmotus furvus is a species of cyprinid in the genus Eirmotus. It lives in Sumatra, Indonesia, and has a maximum length of 3.4 cm (1.34 inches).