Trichodina mutabilis (Protozoa: Ciliophora: Trichodinidae) from the characid fish Astyanax mexicanus in the Cuatro Ciénegas region, northern Mexico

Abstract

As a part of a series of ongoing studies on trichodinids of freshwater fishes of Mexico, several species from diverse localities in the Cuatro Ciénegas region, Coahuila, northern Mexico, were examined. Wet smears of gills and skin were made fresh and screened for the presence of trichodinids under light microscopy. Additional specimens were fixed for SEM. The only trichodinid species found was Trichodina mutabilis, a parasite of the characid fish Astyanax mexicanus. This ciliate protozoan has been introduced from Asia to many countries, including Mexico, with its original host, the Asian carps. The present record is the first for Mexico and the second in North America, being the first record of a Trichodina species for native wild freshwater fish in a natural environment in Mexico, since all previous records were from exotic cultured fishes.