What is totoaba? Totoaba is a highly endangered species of fish. It is found in the Gulf of California, Mexico, only. Totoaba’s swim bladder is highly treasured in Traditional Chinese Medicine (TCM) and specialist restaurants. The fishing of totoaba has been banned since 1975 but the illegal trade in this endangered fish continues. The large gillnets used to catch totoaba also trap vaquita. The vaquita is now the world’s rarest marine mammal and is on the brink of extinction.