SALAMANDRA 52(1) 11–22 30 AprilChromosome 2016 ISSN reduction 0036–3375 in Pseudopaludicola Evidence for independent instances of chromosome number reduction in the genus Pseudopaludicola (Anura: Leptodactylidae) Darío Cardozo1, Juan Martín Boeris1, Juan Martín Ferro1, Claudio Borteiro2, Francisco Kolenc2, Pablo Suárez3, Flavia Netto4, Francisco Brusquetti4,5 & Diego Baldo1 1) Instituto de Biología Subtropical (IBS UNaM/CONICET), Laboratorio de Genética Evolutiva, Félix de Azara 1552, CPA N3300LQH, Posadas, Misiones, Argentina 2) Sección Herpetología, Museo Nacional de Historia Natural, 25 de Mayo 582, 11000, Montevideo, Uruguay 3) Laboratório de Citogenética, Instituto de Ciências Biológicas, Universidade Federal de Pará, Tv. Augusto Correia 1 Belém, 66075-900, Belém, Pará, Brazil 4) Instituto de Investigación Biológica del Paraguay, 1429 Asunción, Paraguay 5) Instituto de Biociências, UNESP–Universidade Estadual Paulista, Departamento de Zoologia, 13506-970 Rio Claro, Brazil Corresponding author: Darío Cardozo, e-mail:
[email protected] Manuscript received: 4 July 2014 Accepted: 27 November 2014 by Edgar Lehr Abstract. We describe the chromosome morphology, C-bands, NORs position, and DAPI/CMA3 staining of five species of Pseudopaludicola (P. boliviana, P. canga, P. falcipes, P. mystacalis, and P. ternetzi) from several populations from Argentina, Brazil, Paraguay, and Uruguay. In addition, the telomeric sequence locations of P. mystacalis and P. canga are evaluated us- ing FISH. We re-analyse the progressive reduction of chromosome numbers recently proposed for the genus by optimisa- tion of character basic chromosome numbers (x) and fundamental chromosome numbers (FN) on current phylogenetic hypotheses. Our evidence supports a progressive reduction of chromosome numbers in Pseudopaludicola, and multiple origins of the karyotype 2n = 20.