Evolutionary dynamics of the B chromosomes in the fish species Prochilodus lineatus Valenciennes, 1837 of the Paraná River Basin

By

Penitente, Manolo
Goes, Caio
Dos Santos, Rodrigo Zeni
Utsunomia, Ricardo
Foresti, Fausto
Porto-Foresti, Fabio

Type

Article

Date of Publication

2025

Original Publication

Comparative cytogenetics : international journal of plant & animal cytogenetics, karyosystematics and molecular systematics

Volume

19

Pages

1--12

Subjects

Cytogenetics , migratory fish , Neotropical fishes , supernumerary chromosomes

Contributed by

Pensoft Publishers

Language

English

Published by

St. Petersburg, Russia [Published] with technical support of Zoological Institute RAS [2007]-

Identifiers

DOI: https://doi.org/10.3897/compcytogen.19.135127

 

Abstract

The fish species Prochilodus lineatus has an interesting B chromosome system, with three morphological types as acrocentric, metacentric, and submetacentric. However, most cytogenetic studies on this species are restricted to the natural population of the Mogi Guaçu River. Given this, the present work aimed to study the structure karyotypic profile as well as the occurrence of supernumeraries in P. lineatus in several localities in the Paraná River basin, where this species is abundant. The results obtained showed a predominantly conserved karyotypic macrostructure and the presence of B chromosomes in all the seven localities studied, with the exception of the Apa River. Additionally, new variants of morphological characteristics were found in the population of the Batalha River (Reginópolis). These results allow us to infer that there is a large occurrence of B chromosomes in this species, with important differences in B chromosome frequency between the populations, especially in acrocentric and submetacentric B variants. Considering the possible origin and evolution of B chromosomes in P. lineatus, our results allow us to describe the dispersion of metacentric B variants, in contrast with the elimination observed in acrocentric and submetacentric variants.