The dark-edged splitfin (Girardinichthys multiradiatus) is a species of fish in the family Goodeidae endemic to Mexico. It is a live-bearing, cold-water fish from the mountains of Mexico. The species is incredibly temperature sensitive. If water is too cold, all offspring turn out to be male. If water is too hot, females will birth their first brood of only 1–3 fry and then die shortly thereafter, which makes it very difficult to maintain a colony. It is also a primarily carnivorous species that eats a variety of insects. Girardinichtys multiradiatus is an endangered species with multiple population threats with little conservation efforts put in place to protect the species.

...