Hypostomus Fuscomaculatus (teleostei: Loricariidae), a New Armored Catfish from the Upper Rio Paraguay Basin, Brazil

Since 1996, in field monitoring for the construction of the Manso Reservoir in the Rio Manso basin, a peculiar black -blotched morphotype of Hypostomus was found that differed from several congeners from the region. This species is already used to aquarium trade being labeled Hypostomus sp. L233. The aim of the present work is to describe L233 as a new species to science, Hypostomus fuscomaculatus . The new species is distinguished from congeners by having conspicuous, large (usually larger than eye diameter) and widely spaced black blotches on living specimens. In preserved specimens, the blotches usually fade to brown but keep still evident for a long time under proper fixation and storage. Other important diagnostic traits are the flattened head, large eyes, absence of keels on lateral series of plates, robust and moderate number of teeth, and plates covering most part of abdominal region.