Gymnotocinclus anosteos

Gymnotocinclus anosteos is a species of armored catfish (Loricariidae) endemic to Brazil, where it is found in the Tocantinzinho River in the Tocantins River basin. This species grows to a length of 4.4 cm SL.

The genus Gymnotocinclus is unusual among the Loricariidae due to its extremely reduced armor plates that are characteristic of the family, giving the fish a relatively naked body. This fish probably has a basal position in the subfamily Hypoptopomatinae.