Science and research

Model organisms and fish famous in science. 137 fish on EveryFish so far.

Fish are important in science. Some species are model organisms, small, fast-breeding fish that are studied in depth in laboratories to understand biology in general, from how embryos grow to how genes cause disease. Others are famous for what they reveal about evolution, such as the coelacanth, the blind cave fish and the cichlids of the African lakes. Fish also help scientists monitor the health of rivers and seas.

Zebrafish and medaka

The zebrafish, a small striped danio of South Asian streams, became a major model organism from the 1970s and 1980s. Its embryos are see-through and grow outside the mother, so scientists can watch organs and nerves form under the microscope. It is used to study development, heart and nerve disease, cancer and the effects of drugs and pollutants. The Japanese medaka is another model, and in 1994 medaka became the first vertebrates to mate and produce young in orbit, on a Space Shuttle flight.

Fish that explain evolution

The three-spined stickleback has repeatedly lost its bony armour after moving from the sea into lakes, letting scientists trace the genes involved. Sighted and blind forms of the Mexican tetra show how eyes are lost in caves. The turquoise killifish, which lives only a few months, is used to study ageing. The coelacanth and lungfish shed light on how fish first moved onto land, and the spotted gar's genome helps link fish genes to human ones.