Preliminary Ecological Modelling predicts niche overlap between Yaqui catfish (Ictalurus pricei) and channel catfish (Ictalurus punctatus) in northwest Mexico.

Authors: Alexsandre Gutierrez-Barragan, Alejandro Varela-Romero, Francisco Leon, José Romo-León, Mariana Mateos, José Grijalva-Chon, John Garza

Year: 2025

Abstract

The Yaqui catfish, Ictalurus pricei, is native to northwestern Mexico and southwestern United States and is endangered by habitat alteration, water over-extraction, and the introduction of non-native species. Among these, competition and hybridization with the introduced channel catfish, Ictalurus punctatus, represent a major threat to remaining Yaqui catfish populations. Here, Ecological Niche Modeling (ENM) was used based on historical and contemporary occurrence records of both species to assess niche overlap and potential geographical areas of co-ocurrence. Due to hybridization risks, only pure Yaqui catfish individuals previously identified through mitochondrial and nuclear genes were considered in recent records. The ENMs were calibrated considering fifteen uncorrelated environmental variables in the natural distribution areas of the species. Minimum Volume Ellipsoid (MVE) approach was used to characterize each species’ niche and project those niches geographically. The MVE showed a broader ecological niche for channel catfish than for Yaqui catfish. Significant niche overlap between Yaqui and channel catfish (p < 0.05) was found, and geographical projection in the Yaqui catfish distribution, revealed multiple areas of suitable habitats shared by both species. These results reflect the niche similarity between both species, which is expected due to its close phylogenetic relationship, highlighting the risk of extirpation of the remnant Yaqui catfish populations due to competition and hybridization with channel catfish. We recommend expanded sampling across the Yaqui catfish range and integrated use of genetics, genomics and niche modeling to guide conservation and management actions aimed at preserving the genetic integrity and persistence of Yaqui catfish.