San Sebastian Splitfin Xenotoca doadrioi

The San Sebastian Splitfin was, until 2016, considered the same as the Redtail Splitfin (X. eiseni), a goodeid from western central Mexico around the Santiago River area. It and another (X. lyonsi) are now considered separate species. The male of all 3 has the bright red tail. Females are plain and grow to some 7cm long. The San Sebastian inhabits the Magdelena Lagoon. It is critically endangered.