Cytotaxonomic and evolutionary considerations about karyotipic data of fishes from the Igua?u River Basin in South of Brazil

摘要

The cytogenetic data available in the literature about the ichthyofauna of the Igua?u River basin were analyzed in this review. The ichthyofauna was characterized by the high level of endemism and by the low diversity of species. Twenty-four of the eighty-one species were already karyotyped; six Characiformes, fourteen Siluriformes and four Perciformes. The chromosomal data showed the taxonomic and systematic complexity of the groups. Hypothesis related to the evolution of some Characiformes and Siluriformes groups from the Igua?u River are proposed, as well as the utilization of karyotypic data for cytotaxonomy.