Accepted by M.R. De Carvalho: 11 Mar. 2013; published: 3 May 2013 ZOOTAXA ISSN 1175-5326 (print edition) ISSN 1175-5334 (online edition) Copyright © 2013 Magnolia Press Zootaxa 3646 (3): 265–276 www.mapress.com/ zootaxa/ Article 265 http://dx.doi.org/10.11646/zootaxa.3646.3.5 http://zoobank.org/urn:lsid:zoobank.org:pub:064C4B43-8D79-49ED-8247-91D74F93FAAC Monophyly of the Agoniatinae (Characiformes: Characidae) FERNANDO C.P. DAGOSTA 1,2 & ALÉSSIO DATOVO 1,2 1 Laboratório de Ictiologia de Ribeirão Preto, USP, FFCLRP, Departamento de Biologia, PPG Biologia Comparada, Av. Bandeirantes 3900, 14040-901 Ribeirão Preto, São Paulo, Brasil. E-mail: ferdagosta@yahoo.com.br 2 Museu de Zoologia, Universidade de São Paulo, Caixa Postal 42.494, CEP 04218-970, São Paulo, SP, Brasil. E-mail: adatovo@gmail.com Abstract The Characidae is the most diverse family of Neotropical fishes, currently encompassing more than one thousand valid spe- cies. Some subgroups within this family still lack phylogenetic definitions, being diagnosed on the basis of combination of characters, a common procedure in pre-cladistic studies. Agoniatinae, currently composed by two valid species, Agoniates anchovia and A. halecinus, is one of them. In the present study the Agoniatinae is redefined using a phylogenetically oriented comparative survey that included the two Agoniates species plus 114 species representing all the major clades of the Charac- idae and their closest relatives. Six derived morphological characters are identified as synapomorphies for the Agoniatinae: deep notch on the posterior region of the maxilla joining the ventral margin of the infraorbital 2; dentigerous portion of pre- maxilla shorter than the ascending process of this bone; dentary canine preceded by tricuspid teeth; ventral margin of the urohyal markedly convex; base of the uppermost ray of the ventral lobe of the caudal fin much expanded, being as deep as the distal margin of hypural 2; and levator arcus palatini muscle with a posterodorsal bundle of fibers attaching to the dorsal face of the sphenotic spine. Key words: Agoniates, morphology, osteology, myology, systematics Introduction The Characidae includes 1027 valid species (Eschmeyer and Fong 2012) distributed throughout inland waters of large portions of the Americas. The family contains several subunits whose phylogenetic relationships have been differently interpreted recently (Reis et al. 2003; Mirande 2010; Oliveira et al. 2011). Noteworthy is the conflicting results of the two most recent comprehensive studies dealing with phylogenetic relationships of the Characidae (Mirande 2010; Oliveira et al. 2011) producing remarkably divergent classifications. The subfamily Agoniatinae is represented by the single genus Agoniates Müller and Troschel, originally erected to allocate A. halecinus Müller and Troschel from Guiana. A second species, A. anchovia Eigenmann, was described by Eigenmann (1914) based on specimens from Río Beni, upper Amazon River basin, Bolivia, collected by J. D. Haseman. A third species was described by Géry (1963) as A. ladigesi, but Zarske and Géry (1997) synonymized this species with A. anchovia. Agoniates halecinus is widespread in the Amazon basin, while A. anchovia apparently occurs primarily in the upper Amazon (Lima and Zanata 2003). The genus Agoniates was allocated into the group Tetragonopterina by Günther (1864) and partially based on the conclusions of Géry (1963), Uj (1990) raised Agoniatinae to family rank. Lima and Zanata (2003) defined Agoniates as being the sole member of the Agoniatinae, a similar arrangement proposed by Mirande (2010) and Oliveira et al. (2011). In the present study, we follow these recent classifications in assigning a subfamilial rank for the genus. The first authors to make evolutionary inferences about the genus were Cuvier and Valenciennes (1849) who commented that Agoniates was intermediate between “Hydrocyns” and “Tétragonoptères”. Regan (1911) suggested the possible close relationship between Agoniates and Salminus Agassiz. Eigenmann (1912) commented about the similarity between Agoniates and Hydrolycus Müller and Troschel and Howes (1976) admitted that some features shared by agoniatines and cynodontines might represent derived specializations. Géry (1963), in a pre-cladistic context