Genetic differentiation in the southern population of the Fathead MinnowPimephales promelasRafinesque (Actinopterygii: Cyprinidae)

Abstract

The North American cyprinid Pimephales promelas is a species with a wide distribution range, occurring in distinct hydrographic basins in Mexico, Canada, and the United States. Previous morphological and meristic analyses of P. promelas concluded that at least three subspecies exist in the midwestern and northeast region of the United States. No studies have been carried out on the Mexican population of P. promelas, but the findings of cryptic diversity in United States populations of this species, as well as in other codistributed fish species in Mexico could be an indication that Mexican populations of P. promelas consist of cryptic species. Using the mitochondrial gene cyt b and the first intron of the S7 ribosomal protein-coding nuclear gene we carried out phylogenetic and phylogeographic analyses of populations of P. promelas across its distribution range in northwestern Mexico. Using this information were analyzed the structure and differentiation level between populations of P. promelas from distinct river basins in the region in identifying cryptic diversity. Twenty-four sequences were obtained for cyt b, and 30 for S7, which included the two heterozygous alleles. The results revealed the existence of four well-differentiated lineages: (1) Yaqui in the Pacific slope; (2) Santa Maria, and (3) Casas Grandes in the Guzman Basin; and (4) Nazas+Conchos in Chihuahua state. This challenges the current taxonomy of P. promelas. Differences in the relationships between markers and the small sample size for the Santa Maria population (n = 1), indicate that our results must be corroborated with more data and morphological analyses. Biogeographic analysis of these findings suggest that the evolutionary history of P. promelas is associated with the fragmentation of the ancestral Rio Grande river system since Miocene in northwestern Mexico consistent with findings for codistributed fish species.

Genome resequencing clarifies phylogeny and reveals patterns of selection in the toxicogenomics model Pimephales promelas

“…1 originated from Atlantic watersheds, if reported, whereas our P. notatus samples were midwestern in origin). Overall, these results are in line with other instances of phylogeographic structure and nuclear-mitochondrial discordance reported for Pimephales populations ( Ballesteros-Nova et al, 2019 ; Schönhuth et al, 2016 ).…”

Metabarcoding: una herramienta prometedora para el estudio de la ecología trófica de peces mexicanos

“…Por ejemplo, en México, la Conabio reconoce 27 cuencas continentales distribuidas en 2 ecoregiones (Neártica y Neotropical) (https://www.biodiversidad.gob. mx/region/ecorregiones-dulceacuícolas) y varios estudios que evalúan la distribución taxonómica y genética de organismos dulceacuícolas han encontrado un gran número de endemismos o linajes evolutivos independientes, restringidos a las cuencas o incluso a cuerpos de agua particulares (Ballesteros-Nova et al, 2019;Beltrán-López et al, 2017Domínguez-Domínguez et al, 2006;García-Morales et al, 2021;Mercado-Salas et al, 2018;Pedraza-Lara et al, 2012).…”