Hypostomus macushi, a new species of the Hypostomus cochliodon group (Siluriformes: Loricariidae) from Guyana

Abstract

Hypostomus macushi is described as a new species of the H. cochliodon group based on the presence of a light background with widely separated black spots. The only members of the H. cochliodon group with similar coloration are H. cochliodon, H. ericae, H. ericius and H. paucipunctatus. Hypostomus macushi can be separated from H. cochliodon by lacking a longitudinal ridge on the pterotic-supracleithrum and a lack of longitudinal dark stripes; from H. ericius by lacking keels formed from sharp odontodes on the lateral plates; from H. ericae and H. paucipunctatus by lacking a buccal papilla; from H. ericae by having spots in the distal dorsal and caudal fins not combining (vs. spots combining to form wavy lines); and from H. paucipunctatus by having medium to large spots (vs. very small spots). Hypostomus macushi is found in tributaries of the Essequibo and Negro Rivers of Guyana. The range of H. taphorni is additionally expanded to cover much of the Essequibo River basin in Guyana and a single locality in the Takutu River drainage. Addition of H. macushi and H. sculpodon to the phylogeny of the Hypostomus cochliodon group collapsed most of the clades found in a previous analysis. Only the H. cochliodon group, the wood-specializing species, and H. ericius + H. oculeus are supported as clades. Copyright © 2005 Magnolia Press.