Ibo

In addition, there appear to exist two colour forms based on male dorsal-fin morphology and patterning; one in which the 4th ray of the first dorsal-fin is longest with a square bluish-black blotch on the anterior ⅔ of the fin, and a second in which the 2nd and 3rd rays of the first dorsal-fin are longest with the fin itself paler and lacking dark markings.

Despite being a wholly unsuitable aquarium subject, C. idella is often traded as such, with an albino form having been developed specifically for the ornamental market. Individuals which have outgrown their aquarium or pond should never be released into natural waters, either, since this species has proven capable of causing serious environmental damage under a wide range of climatic conditions.

This species can be distinguished from other members of the genus by the following combination of characters: absence of dark spots on body in adults; body elongate with slightly convex dorsal profile; head longer than body is deep; snout much longer than postorbital head length; lips well developed, lateral lobes of lower lip broad and thick with folds, median process small; barbel thickness shorter or equal to eye diameter; dorsal spine strong, ⅔ of HL; dorsal-fin origin closer to tip of snout than caudal-fin base base; 15+ gill rakers; 6½ branched anal-fin rays; posterior simple dorsal-fin rays ossified and spinous.

A predominantly riverine fish preferring clear, well-oxygenated, running waters with substrates of sand, gravel, rock or mud, where adults tend to form schools just above the substrate in slower-moving sections.