Ichthyological Differentiation and Homogenization in the Pánuco Basin, Mexico

Norma Martínez-Lendech,Humberto Mejía-Mojica,Ana P Martínez-Falcón,Norman Mercado-Silva,Gabriel I Cruz-Ruíz,Valentino Sorani-Dalbón,Juan Jacobo Schmitter-Soto

doi:10.3390/d12050187

Abstract

Species introductions and extirpations are key aspects of aquatic ecosystem change that need to be examined at large geographic and temporal scales. The Pánuco Basin (Eastern Mexico) has high ichthyological diversity and ecological heterogeneity. However, freshwater fish (FWF) introductions and extirpations since the mid-1900s have modified species range and distribution. We examine changes in FWF species composition in and among four sub-basins of the Pánuco by comparing fish collection records pre-1980 to 2018. Currently, the FWF of the Pánuco includes 95 species. Fishes in the Poeciliidae, Cyprinidae, and Cichlidae, respectively, comprised most records over time. Significant differences in species composition were found between the first (pre-1980) and last (2011–2018) study periods, but not for periods in-between. Eight independent species groups were key for explaining changes in Pánuco river ichthyofauna; one group was dominated by invasive species, and saw increases in the number of records across study periods (faunal homogenization). Another group was formed by species with conservation concern with a declining number of records over time. Thirteen (2 native and 11 non-native) species were responsible for temporal turnover. These results strongly suggest high rates of differentiation over time (via native species loss) following widespread non-native species introductions.

Highlights

Rapid ecosystem and species loss results from pollution, as well as land use and climate change [1].Human activity does not solely lead to species loss; it can lead to increases in faunal similarity by the alteration of species range [2] via species introductions and species loss
The number and manner of species loss and introductions occurring can result in different levels of biological homogenization and differentiation [5,6]
Processes of homogenization and differentiation have been documented for freshwater fish faunas in North America and Europe [8,9,10,11]

Summary

Introduction

Rapid ecosystem and species loss results from pollution, as well as land use and climate change [1].Human activity does not solely lead to species loss; it can lead to increases in faunal similarity by the alteration of species range [2] via species introductions and species loss. Anthropogenic introductions expand a speciesrange beyond its natural dispersal capacity; species loss can result from human driven ecosystem and habitat deterioration [2,3,4,5]. The number and manner of species loss and introductions occurring can result in different levels of biological homogenization and differentiation [5,6]. Loss of species shared among two sites will generate biological differentiation [5,7]. Human-caused biological homogenization and differentiation are serious threats to global biodiversity [8,9,10]. Trends in both biological homogenization and differentiation can be used as tools for the development of conservation strategies [7]. Processes of homogenization and differentiation have been documented for freshwater fish faunas in North America and Europe [8,9,10,11]

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Results

Discussion

Conclusion