title: Redescription of Astyanax guianensis Eigenmann 1909 (Characiformes: Characidae), a poorly known and widespread fish from the Amazon, Orinoco and Guiana Shield drainages.
abstract: Astyanax guianensis is redescribed based on the holotype, paratypes, and additional specimens from the rio Essequibo in Guyana, rio Orinoco in Venezuela and from several localities in the Amazon river basin in Brazil, Colombia and Bolivia. Astyanax guianensis is diagnosed by having five to 10 maxillary teeth, 31 to 35 pored lateral-line scales, 21 to 25 branched anal-fin rays, and a dark vertical humeral blotch followed by a clear area and then by a dark longitudinal stripe, ending before the caudal-fin rays. In addition, comments on the importance of revisionary studies on the species of the Characidae are provided.
authors.affiliation: Museu de Zoologia da Universidade de São Paulo, Caixa Postal 42494, 04218-970, São Paulo, SP, Brazil.; Email: manumfm@yahoo.com.br.
authors.forename: Manoela M F
authors.initials: MM
authors.lastname: Marinho
authors.affiliation: Museu de Zoologia da Universidade de São Paulo, Caixa Postal 42494, 04218-970, São Paulo, SP, Brazil.; Email: pricamelier@gmail.com.
authors.forename: Priscila
authors.initials: P
authors.lastname: Camelier
authors.affiliation: Departamento de Biologia Animal e Vegetal, Universidade Estadual de Londrina, Caixa Postal 10001, 86057-970, Londrina, PR, Brazil.; Email: josebirindelli@yahoo.com.
authors.forename: José L O
authors.initials: JL
authors.lastname: Birindelli
mesh_terms: D063147:Animal Distribution; D000825:Animal Structures / Q000033:anatomy & histology / Q000254:growth & development; D000818:Animals; D049628:Body Size; D001938:Brazil; D060126:Characidae / Q000033:anatomy & histology / Q000145:classification* / Q000254:growth & development; D017753:Ecosystem; D005260:Female; D006172:Guyana; D008297:Male; D009929:Organ Size; D014687:Venezuela