The zebrafish (Danio rerio) is a tropical freshwater fish belonging to the minnow family (Cyprinidae) of the order Cypriniformes. Native to the Himalayan region, it is a popular aquarium fish, frequently sold under the trade name zebra danio.
The zebrafish is named for the five uniform, pigmented, horizontal, blue stripes on the side of the body, which are reminiscent of a zebra's stripes, and which extend to the end of the caudal fin.
The approximate generation time for Danio rerio is three months. A male must be present for ovulation and spawning to occur. Females are able to spawn at intervals of two to three days, laying hundreds of eggs in each clutch.
Zebrafish are omnivorous, primarily eating zooplankton, phytoplankton, insects and insect larvae, although they can eat a variety of other foods, such as worms and small crustaceans, if their preferred food sources are not readily available.
In late 2003, transgenic zebrafish that express green, red, and yellow fluorescent proteins became commercially available in the United States. The fluorescent strains are tradenamed GloFish; other cultivated varieties include "golden", "sandy", "longfin" and "leopard".