title: Comparative cytogenetics among populations of Hollandichthys multifasciatus (Teleostei: Characidae).
abstract: Two populations of Hollandichthys multifasciatus from headwaters of adjacent river coastal basins in Paraná state, southern Brazil, were cytogenetically studied in order to evaluate intraspecific divergences. Both populations presented 2n = 50 chromosomes, divided into 14m + 18sm + 18st in the sample from Antonina and 14m + 20sm + 16st for the population from Guaraqueçaba. Analyses of active nucleolar organizer regions (Ag-NORs) and fluorescent in situ hybridization (FISH) with 18S rDNA probes revealed a single metacentric pair bearing marks at proximal positions on the short arms. The location of the 5S rDNA and GC-rich sites showed chromosomal divergence between both populations. Therefore, several population markers were detected, reflecting a population differentiation, possibly driven by the formation of Paranaguá Bay and Serra do Mar mountain range. Since the existence of a species complex in H. multifasciatus has been previously characterized by morphological, molecular, and karyotype population differentiation, this species needs to be taxonomically studied in detail.
authors: Departamento de Genética, Universidade Federal do Paraná, Centro Politécnico, Curitiba, Paraná 81531-990, Brazil.
authors: Rafael Ernesto
authors: RE
authors: Balen
authors: Rafael Bueno
authors: RB
authors: Noleto
authors: Marcelo Ricardo
authors: MR
authors: Vicari
authors: Roberto Ferreira
authors: RF
authors: Artoni
authors: Marta Margarete
authors: MM
authors: Cestari
mesh_terms: D000818:Animals; D001938:Brazil; D060126:Characidae / Q000235:genetics*; D003710:Demography; D017753:Ecosystem; D014644:Genetic Variation; D059785:Karyotype; D045483:Rivers