[6] All members of the family Chalceidae are sometimes referred to as tucanfishes, but C. erythrurus is the species to which it is most often applied.

[11] Henry Watson Fowler described it as Pellegrinina heterolepis in 1907, but Jacques Géry proved it to be a member of the Chalceus genus in 1977.

[12][13] The name Chalceus erythrurus was once mistakenly applied to C. macrolepidotus, and they are sometimes confused with one another.

[14] They can be told apart because of the tucan fish's bright-yellow ventral fins, as well as a few other coloration patterns.

[1][13] Like others in the genus Chalceus, the tucan fish is primarily a carnivore, targeting aquatic invertebrates (such as insects and crustaceans).