Acentronichthys leptos is the only species of catfish (order Siluriformes) in the genus Acentronichthys of the family Heptapteridae.[2] This species occurs in coastal streams in Brazil from Rio de Janeiro to Santa Catarina State, in São Mateus, Espírito Santo State and on Leopoldina, Minas Gerais.[2] This species grows to 9.1 cm (3.6 in) in SL.[3]