Allozyme and cytogenetic analysis in two species of Hypostomus (Siluriformes: Loricariidae) from the Paraguai River basin, Brazil: occurrence of B microchromosome and intrapopulation heterochromatic polymorphism in H. boulengeri

• DOI: 10.1590/1982-0224-2023-0117
• Publication Date: 2024-07-22T10:50:09Z
• Authors: Suzana de Paiva; Fernanda Errero P...; Flávio José Codog...; Carlos Alexandre ...; Margarida Maria V...; Luciana Andreia B...; Ana Luiza de Brit...; Claudio Henrique ...; Erasmo Renesto; Isabel Cristina M...
• Keywords: Loricariidae

Abstract Hypostomus is distributed by Central and South America basins, with diverse species taxonomic conflicts. This way, the integration of auxiliary techniques contributes to understanding systematics phylogeny group. Thus, this study aimed investigate cochliodon H. boulengeri from Onça stream (Paraguai River basin) allozyme cytogenetic techniques. showed a diploid number 68 chromosomes (14m+14sm+18st+22a), multiple NOR revealed Ag-NOR 18S rDNA FISH, polymorphism heterochromatin in acrocentrics presence B microchromosome. 64 (16m+26sm+14st+8a); despite single NOR, some individuals both telomeres detected FISH. Isozyme identified two diagnostic loci (Idh-A Gdh-A) between unique alleles boulengeri. The genetic variability indicated mean heterozygosity (He) was 0.2461 0.0309 cochliodon,respectively.Thus, reports first data for isozymatic cochliodon. presented evident isoenzymatic differences obtaining exclusive markers providing support future evolutionary studies