title: A new species of Hisonotus (Siluriformes: Otothyrinae) from the upper rio Paraná and rio São Francisco basins, Brazil.
abstract: A new species of Hisonotus is described from the upper rio Paraná and rio São Francisco basins. The new species is distinguished from congeners by (1) completely exposed abdomen with no development of dermal plates (with the exception of extremely small platelets present near the urogenital pore in some specimens) and the combination of the following characters: (2) lack of a conspicuous tuft of enlarged odontodes on posterior tip of parieto-supraoccipital; (3) rectangular dorsal-fin spinelet; (4) complete mid-lateral plate series; (5) higher number of vertebrae, 29-30; (6) dark brown coloration on caudal fin with one pair of circular hyaline colored regions at center of both lobes; (7) absence of broad light stripes on dorsolateral surface of head; (8) odontodes not forming longitudinally aligned rows on head and trunk; and (9) apex of teeth yellowish in color.
authors.affiliation: Universidade Estadual Paulista, Departamento de Morfologia, Laboratório de Biologia e Genética de Peixes, Botucatu, São Paulo State, Brazil; Email: roxoff@hotmail.com.br.
authors.forename: Fábio F
authors.initials: FF
authors.lastname: Roxo
authors.affiliation: Universidade Estadual Paulista, Departamento de Morfologia, Laboratório de Biologia e Genética de Peixes, Botucatu, São Paulo State, Brazil; Email: unknown.
authors.forename: Gabriel S C
authors.initials: GS
authors.lastname: Silva
authors.affiliation: University of Louisiana at Lafayette, Department of Biology, Lafayette, LA, USA; Email: unknown.
authors.forename: Brandon T
authors.initials: BT
authors.lastname: Waltz
authors.affiliation: Pontificia Universidad Javeriana, Departamento de Biología, Facultad de Ciencias, Unidad de Ecología y Sistemática (UNESIS), Bogotá, Cundinamarca State, Colombia; Email: unknown.
authors.forename: Jorge E G
authors.initials: JE
authors.lastname: Melo
mesh_terms: D063147:Animal Distribution; D000825:Animal Structures / Q000033:anatomy & histology / Q000254:growth & development; D000818:Animals; D049628:Body Size; D001938:Brazil; D002397:Catfishes / Q000033:anatomy & histology / Q000145:classification* / Q000254:growth & development; D017753:Ecosystem; D005260:Female; D008297:Male; D009929:Organ Size