Daphnia magna (Crustacea: Anomopoda) in central Mexico wetlands: implications of escape from ecotoxicological laboratories

Daphnia (Ctenodaphnia) magna, a species widely used for ecotoxicological tests, was recorded for the first time in waterbodies of the Mexican protected area and RAMSAR site Cienegas del Lerma. The identity of the species was confirmed using morphological traits and cytochrome oxidase I as a molecular marker. Haplotypes were 100% identical to cultures used in laboratory bioassays in Mexico and Canada. Individuals analyzed are related to strains from Europe, and their sequences differed from natural populations reported from the United States of America and Canada. This Mexican wetland supports a rich community of migratory waterfowl; therefore, D. magna could quickly spread to other waterbodies and cause potential adverse effects on local Daphnia species. The utilization of non-native species in ecotoxicological tests must be undertaken with great care, to ensure escape to natural waters is prevented.

Automated summary

The species of Daphnia (Ctenodaphnia) magna, commonly used in ecotoxicological tests, has been documented for the first time in the waterbodies of the Mexican protected area and RAMSAR site Cienegas del Lerma. The study used morphological traits and cytochrome oxidase I as a molecular marker to confirm the identity of the species. It was found that the individuals analyzed are related to strains from Europe, and their sequences differ from natural populations in the United States and Canada. The potential spread of D. magna to other waterbodies in the area and its potential adverse effects on local Daphnia species should be carefully considered.