Killifish

A killifish is any of various oviparous (egg-laying) cyprinodontiform fish,[1] including families Aplocheilidae, Cyprinodontidae, Fundulidae, Nothobranchiidae, Profundulidae, Aphaniidae and Valenciidae.

Killifish are found mainly in fresh or brackish waters in the Americas, as far south as Argentina and as far north as southern Ontario and even Newfoundland and Labrador.

Such killifish are common in the Americas (Cyprinodon, Fundulus and Rivulus) as well as in Africa and Asia (including Aphyosemion, Aplocheilus, Epiplatys, Fundulopanchax and Lacustricola) and southern Europe (Aphanius).

Examples include the African genus Nothobranchius and South American genera ranging from the cold water Austrolebias of Argentina and Uruguay to the more tropical Gnatholebias, Pterolebias,[6] Simpsonichthys and Terranatos.

The American Flagfish (Jordanella floridae) feeds heavily on algae and other plant matter as well as aquatic invertebrates.

[13] Nothobranchius furzeri shows no signs of telomere shortening, reduced telomerase activity, or replicative senescence with age, despite its short lifespan.

[14][15] Nonetheless, lipofuscin accumulates in the brain and liver (associated with age-related neurodegeneration), and there is an increased risk of cancer with age.

[10] By targeting multiple genes, including telomerase, the killifish can now be used as an attractive vertebrate model organism for aging and diseases (such as Dyskeratosis congenita).

The golden topminnow (Fundulus chrysotus) is also native to the United States and often available at auction, but care must be taken with these fish to stop them from jumping out of the tank.

Sequencing the genomes of the adapted individuals showed a common set of mutations among the pollution-tolerant fish, many of which help to deactivate or turn off a molecular pathway responsible for a large part of the cellular damage caused by the chemicals.