Characodon is a genus of livebearing fish in the splitfin family Goodeidae, restricted to isolated desert springs, streams and spring-fed marshes on the high plateau of north-central Mexico (Chihuahua, Durango and neighboring states). The atlas covers 3 species, all small at 1–2 in: the rainbow characodon (C. lateralis), bold characodon (C. audax) and Parras characodon (C. garmani). As in other goodeids, females bear live young nourished internally via trophotaeniae rather than a true placenta, and males of C. lateralis in particular are known for bright, variable red-and-black or blue breeding coloration that gives the species its common name.
Characodon is one of the most conservation-critical livebearer genera in the atlas: C. garmani, historically known from the Parras basin in Coahuila, has not been found in decades and is assessed Extinct, while the other two species are Endangered and Critically Endangered respectively - casualties of groundwater pumping that has dried up desert springs across their range, plus introduced tilapia, mosquitofish and other non-native fish in what habitat remains. C. lateralis is flagged in the atlas's CARES list. In the hobby these fish survive almost entirely through dedicated goodeid-conservation keepers, who maintain and exchange captive lines precisely because so little wild habitat is left; Characodon is a genus where captive populations may now outnumber wild ones.