|Death Valley pupfish, Cyprinodon salinus spawning|
T. N. Gill, 1865
Pupfish are a group of small killifish belonging to ten genera of the family Cyprinodontidae of ray-finned fish. Pupfish are especially noted for being found in extreme and isolated situations. They are primarily found in North America, South America, and the Caribbean region, but Aphanius are from southwestern Asia, northern Africa and southern Europe. As of August 2006 there were 120 known nominal species, and 9 subspecies.
The common name is said to derive from the mating habits of the males, whose activities vaguely resemble puppies at play.
In spite of their name, the cyprinodonts are not closely related to the Cyprinidae, or carp family. They were formerly considered near allies of the pikes and their relatives, as they share some features: a flat head with protractile mouth beset with cardiform, villiform, or compressed, bi- or tri-cuspid teeth, generally large scales, and the absence of a well-developed lateral line. However, they are now generally assigned to the order Cyprinodontiformes.
Most pupfish are inhabitants of the fresh and brackish waters. Several forms occur in the Oligocene and Miocene beds of Europe. Many species are ovoviviparous, and from their small size and lively behaviour they are much appreciated as aquarium fishes.
Selected North American species
- Cyprinodon variegatus, sheepshead minnow, common to coastal fresh, brackish, and saltwater environments from the Mid-Atlantic United States down to South America and the Caribbean basin.
- Cyprinodon salinus salinus, Death Valley pupfish, endangered, limited to saline spring-fed desert creeks in Death Valley National Park in California.
- Cyprinodon diabolis, Devil's Hole pupfish, vulnerable, limited to a geothermal spring-fed pool in a limestone cavern in southern Nevada.
- Cyprinodon elegans, Comanche Springs pupfish, endangered, limited to spring-fed pools and wetlands around Balmorhea, Texas in Trans-Pecos west Texas.
- Cyprinodon bovinus, Leon Springs pupfish, endangered, limited to parts of the Pecos River and its watershed in in Trans-Pecos west Texas.
- Cyprinodon bifasciatus, Cuatro Cienegas pupfish, endangered, limited to the Cuatro Cienegas Biosphere Reserve in northern Mexico.
- Cyprinodon macularius, Desert pupfish, endangered, limited to the Salton Sea in California, and the Colorado River Delta and Laguna Salada basin in Baja California.
- Cyprinodon tularosa, White Sands pupfish, limited to two springs and small streams in southwest New Mexico.