Cytogenetic and molecular studies in species of the Ancistrini tribe from Southern Brazil

The southern region of Brazil is rich in hydric and biogeographic resources, contributing to the formation of distinct ichthyofaunistic niches and facilitating the isolation of some species. Despite the great ecological importance, there are few cytogenetic and molecular studies on the ichthyofauna of these basins. Therefore, specimens of Ancistrus abilhoai and Hemiancistrus fuliginosus were analyzed by combining cytogenetic and mitochondrial markers. Cytogenetic analysis revealed a diploid number of 2n = 48 for A. abilhoai and 2n = 56 for H. fuliginosus and Sites rDNA (by fluorescent in situ hybridization-FISH) were identified with 18S and 5S probes in synteny in pair 16 of A. abilhoai. At the same time in H. fuliginosus, these sites are located in separate pairs. Considering the Ancistrus cluster, based on COI molecular data, specimens of A. abilhoai were close to A. cirrhosus having as sister group A. multispinis and A. brevipinnis. Regarding Hemiancistrus, H. fuliginosus specimens showed the same haplotype as the sequences of this species, available in the database, forming a distinct clade with H. aspidolepis as a sister group. The results of our work helped to better define the taxonomic status of A. abilhoai and H. fuliginosus, species endemic to southern Brazil and which have few studies within their respective genera.