Protecting Endemic Freshwater Fish and Biodiversity: Assessing the Impact of Invasive Alien Aquatic Fauna to Native Species in Cuatro Ciénegas, Mexico.

Authors: Dileri Berdeja, Scott Hinch, Topiltzin Contreras, Dean Hendrickson, Michael Tobler

Year: 2025

Abstract

Cuatro Ciénegas, Coahuila, Mexico, is one of the most unique freshwater ecosystems in North America, containing more than 200 aquatic bodies that sustain exceptionally high levels of endemism (CONANP, 2000, Programa de Manejo del Área de Protección de Flora y Fauna Cuatrociénegas, Coahuila; Pronatura Noreste, 2017, Programa de control y erradicación de especies exóticas invasoras en Cuatro Ciénegas, Coahuila; Minckley, W.L., D.A. Hendrickson, and C.E. Bond, 2022, Fishes of Cuatro Ciénegas Basin: Diversity, Endemism, and Threats, Univ. of Arizona Press). The basin supports several endemic and micro-endemic fishes, including the Cuatro Ciénegas Shiner, Cyprinella xanthicara; Longfin Gambusia, Gambusia longispinis; Cuatro Ciénegas Platyfish, Xiphophorus gordoni; Interior Killifish, Lucania interioris; Cuatro Ciénegas Pupfish, Cyprinodon atrorus; Bifasciate Pupfish, Cyprinodon bifasciatus; Cuatro Ciénegas Darter, Etheostoma lugoi; Potosí Darter, Etheostoma segrex; Minckley’s Cichlid, Herichthys minckleyi; and Rascon Shiner, Tampichthys rasconis. These endemic species face critical threats from invasive alien species (IAS) such as Blue Tilapia, Oreochromis aureus; Common Carp, Cyprinus carpio; Jewel Cichlid, Hemichromis guttatus; Louisiana Crayfish, Procambarus clarkii; and the Asian Snail, Melanoides tuberculata. These invasives have disrupted ecological balance by altering native fish assemblages, increasing interspecific competition, and degrading aquatic habitats, leading to sharp declines in native fish populations (CONANP, 2000; Pronatura Noreste, 2017; Minckley et al., 2022). Although the Comisión Nacional de Áreas Naturales Protegidas (CONANP) has implemented invasive species control programs in Cuatro Ciénegas, their long-term effectiveness has not been formally evaluated. Our study aims to fill this knowledge gap by (1) assessing current fish assemblages, (2) quantifying the abundance and distribution of native and invasive species, and (3) evaluating the effectiveness of past control strategies. Using a combination of field surveys, stomach content analyses, and literature review, we are producing an integrated dataset describing the status of native and invasive fishes. This dataset will underpin a science-based management framework for the effective removal of high-impact IAS and long-term conservation of native freshwater biodiversity in the Cuatro Ciénegas Basin.