RESEARCH PAPER Diversity of the Astyanax scabripinnis species complex (Teleostei: Characidae) in the Atlantic Forest, Brazil: species limits and evolutionary inferences Jonathan Pena Castro • Mauricio Osvaldo Moura • Orlando Moreira-Filho • Oscar Akio Shibatta • Mateus Henrique Santos • Viviane Nogaroto • Marcelo Ricardo Vicari • Mara Cristina de Almeida • Roberto Ferreira Artoni Received: 22 April 2014 / Accepted: 4 November 2014 Ó Springer International Publishing Switzerland 2014 Abstract The Astyanax scabripinnis species com- plex with its wide geographical distribution is an excellent model for evolutionary studies. Populations are usually geographically isolated but also, in some cases, occur in sympatry. In this study, five allopatric and/or sympatric populations of A. scabripinnis were analysed using geometric morphometry, cytogenetic markers, assays for induced breeding and phyloge- netic inferences to draw conclusions on species limits and speciation processes in a natural setting. The morphometry of individuals indicated that the popu- lations were well differentiated from each other. Cytogenetic evidence revealed a more conserved karyotypic macrostructure; however, molecular cyto- genetic results obtained by in situ hybridization indicated 5S and 18S rDNA gene probe locations specific to each population. The reproduction tests for three locations suggest isolation between populations and the phylogenetic analyses suggest that the fish evaluated cluster in a monophyletic group. The combined data indicate that individuals are adapted to different environments in a complex evolutionary scenario, with linkage of populations during a recent geological period. However, due to reproductive isolation, the populations are evolving independently, reinforcing the existence of distinct cryptic species. Keywords Fish Á Biodiversity Á Climate variability Á Evolutionary analysis Á Geometric morphometry Á Cytogenetic Introduction The Atlantic Forest, in the Neotropical region, has a high diversity of habitats and is considered one of the J. P. Castro Á M. H. Santos Á V. Nogaroto Á M. R. Vicari Á M. C. de Almeida Á R. F. Artoni (&) Programa de Po ´s Graduac ¸a ˜o em Biologia Evolutiva, Departamento de Biologia Estrutural, Molecular e Gene ´tica, Universidade Estadual de Ponta Grossa, Avenida Carlos Cavalcanti 4748, Ponta Grossa, PR 84030-900, Brazil e-mail: rfartoni@gmail.com M. O. Moura Departamento de Zoologia, Centro Polite ´cnico, Universidade Federal do Parana ´, Avenida Coronel Francisco Hera ´clito dos Santos, 210, Jardim das Ame ´ricas, Curitiba, PR 81531-980, Brazil O. Moreira-Filho Departamento de Gene ´tica e Evoluc ¸a ˜o, Universidade Federal de Sa ˜o Carlos, Rodovia Washington Luis, Km 235, Monjolinho, Sa ˜o Carlos, SP 13565-905, Brazil O. A. Shibatta Departamento de Biologia Animal e Vegetal, Centro de Cie ˆncias Biolo ´gicas, Universidade Estadual de Londrina, Rodovia Celso Garcia Cid, Campus Universita ´rio, Londrina, PR 86051-970, Brazil 123 Rev Fish Biol Fisheries DOI 10.1007/s11160-014-9377-3