A killifish is any of various oviparous (egg-laying) cyprinodontiform fish (including families Aplocheilidae, Cyprinodontidae, Fundulidae, Nothobranchiidae, Profundulidae, Rivulidae and Valenciidae). Altogether, there are some 1270 different species of killifish, the biggest family being Rivulidae, containing more than 320 species. Although killifish is sometimes used as an English equivalent to Cyprinodontidae, some species belonging to that family have their own common names, such as the pupfish and the mummichog. The name killifish is derived from the Dutch word “kilde”, meaning small creek, puddle. Because of living in ephemeral waters, the eggs of most killifish can survive periods of partial dehydration. Like seeds, the eggs can be sent by mail without water and this often how Killifish are sold.
These Killifish tropical fish profiles cover the most common Killifish you are likely to come across and show the different variants available.