Study of karyotype evolution of species in the genus Ancistrus (Siluriformes: Loricariidae) streams from region Cuiabá/MT

Abstract

Among the Siluriformes, Loricariidae family is considered the second largest family, divided into six subfamilies and fish representative of these subfamilies are popularly known as armored catfish. Within the Hypostominae subfamily, belonging to the Loricariidae family, is inserted the genus Ancistrus that is one of the most diversified of Ancistrini tribe. The species of the genus Ancistrus arouse interest among researchers because they have interesting features like large karyotypic diversity, presence of sex chromosomes systems, presence of suprarnumerary chromosomes and chromosomal polymorphisms. The few cytogenetic studies published have shown that the karyotypic form of the species of this genus seems to be little preserved and show interesting evolutionary trends. Given the few studies involving chromosomes, the interesting genetic and taxonomic problem involving this group of fish, the objective of this work is to characterize the chromosomes of Ancistrus' species from different locations in the region of Cuiabá/MT, based on cytogenetics classical techniques, with the C-banding and Ag-RON and molecular cytogenetics, studying specific genes by fluorescence in situ hybridization (FISH), focusing on identification of sex systems. The results will contribute to the increased information on the species of this genus, helping taxonomists in the new species description, increasing the data for evolutionary explanations of this genus associated with phylogenetic studies may clarify phylogenetic relationships among species. (AU)