The rainwater killifish, Lucania parva, is native to much of eastern North America, Texas, and New Mexico, but it is not native to Utah. In Utah, the species has become established in Timpie Springs, near the southern edge of the Great Salt Lake, and in an area of the West Desert.
The rainwater killifish eats small invertebrates and mosquito larvae. The species spawns during the spring and summer, and eggs hatch in six days. The rainwater killifish is most often found in slow-moving backwaters and marshes. In some states, the rainwater killifish is used as an effective biological control against mosquitoes.