A revision of two genera of goodeid fishes (Cyprinodontiformes, Osteichthyes) from the Mexican Plateau

" A taxonomic revision is presented of Characodon and Xenotoca of the Goodeidae, a family of vivaparous fishes that is virtually restricted to the Mexican Plateau. The most recent family classification was based on anatomical characters of the ovary and trophotaeniae; these characters of the two genera were restudied and evaluated here in combination with added "conventional" information on morphological features and new information on karyotypes, courtship behavior, hybridization experiments, and discrimination tests. The distinctiveness of Characodon and Xenotoca is confirmed. The monotypy of Characodon with C. lateralis is supported, but Xenotoca is found to consist of three species: X. variata, the type species of the genus, X. eiseni, a species here withdrawn from synonymy with variata, and X. melanosoma, a distinctive new species described herein "