Non-native freshwater mollusks in Mexico: current status and new records

estado actual y nuevos registros

Abstract

Freshwater mollusks top the lists of both threatened and endangered species, as well as non-native species potentially harmful to local fauna. The introduction, establishment, and proliferation of non-native freshwater mollusk species have caused significant impacts on the structure and function of aquatic ecosystems, altering feeding patterns, resource competition, and triggering cascading effects throughout local trophic chains. Mexico is particularly vulnerable to these species due to its navigational infrastructure, which facilitates their introduction. The rising popularity of exotic species as pets and the intentional introduction of economically attractive species for artisanal exploitation in certain water bodies further increases the risk. This study presents an updated list of non-native/exotic freshwater gastropod and bivalve species based on a review of geographic records in the literature, data from the National Mollusk Collection, and citizen science platforms. Recent literature revealed new records of exotic species. A total of 13 non-native mollusk species were identified. A total of 496 records were compiled, with the state of San Luis Potosí showing the highest occurrence and Veracruz the greatest diversity of exotic species. All Mexican states, except Campeche and Tlaaxcala, have at least one record of non-native species. Most of these species have ecological, economic, or clinical impacts, with some classified among the 100 worst invasive exotic species. The aquarium trade has been identified as the main probable vector of introduction. It is also likely that unrecorded invasions exist within the country.