[4] B. transmontanus originates from Baudó, San Juan, Patía and Durango river basins.

The first pattern, in B. raninus, B. transmontanus and B. acanthochiroides, is a light caudal fin, with a dark band on the posterior third.

The second pattern, in B. villosus, is a light caudal fin, with dark dots irregularly distributed.

The coloration pattern is useful for separating species, but apparently does not allow inferences about phylogenetic relationships to be safely made, since this character is widespread in this family.

When young, B. raninus feeds on micro-crustaceans and aquatic insect larvae, then shifts its diet to fishes of notable size.