Abstract
Within the order Siluriformes, Loricariidae is a family composed of about 1,000 species and six subfamilies: Hypostominae, Loricariinae, Hypoptopomatinae, Delturinae, Rhinelepinae, Lithogeninae. Within the Hypoptopomatinae there are 19 genera and 139 species, including the genus Hisonotus with 33 valid species. Hisonotus depressicauda apparently represents a complex of species, and popula…