- Scientific Name: Danio rerio
- Synonym: Barilius rerio, Brachydanio frankei, Brachydanio rerio, Cyprinus chapalio, Cyprinus rerio, Danio frankei, Danio lineatus, Nuria rerio, Perilampus striatus
- Common Name: Striped Danio, Zebra Danio, Zebra Fish
- Family: Cyprinidae
- Origin: Eastern India
- Adult Size: 2 inches (6 cm)
- Social: Peaceful, suitable for community tanks
- Lifespan: 5 years
- Tank Level: All Levels
- Minimum Tank Size: 10 gallons
- Diet: Omnivore, eats most foods
- Breeding: Egglayer
- Care: Easy
- pH: 6.5 - 7.0
- Hardness: 5-12 dGH
- Temperature: 64-74 F (18-24 C)
Originally believed to originate from a wider range that stretched as Myanmar in the east and Pakistan in the west, it is now believed this species originates from a narrower range that is contained to parts of India and Bangladesh. Part of this change in distribution is due to identification of similar species that were once misidentified as Danio Rerio, as well as damage to the environment that has resulted in reduction of habitable areas.
Fish available in the industry today are almost always captive bred. Zebras are easy and inexpensive to raise, making them prime candidates for commercial breeding. While commercial breeding has provided a large and unlimited supply of this species, it has also resulted in a fish that is less robust than the original wild caught species.
Among the most hardy and active of aquarium fish, the Zebra Danio is easily recognized by its distinctive horizontal stripes. Blue-purple horizontal stripes run from gill to tail, setting off the slim compressed silver-gold body of this attractive fish.
The small size of the Zebra Danio, no more than two and half inches, and peaceful nature, make them well suited to a community aquarium. Both sexes have two pairs of barbels and the same stripes, but females are usually larger and more full-bodied than the males.
Albino/golden, veil tailed, and long finned Zebra Danio varieties are available, as well as a popular leopard variety. The leopard variety is characterized by a copious sprinkling of black spots over the entire body. In the past the Leopard Danio was considered a different species. However, genetic studies have proven that it is merely a spotted variation of Danio Rerio. All varieties thrive in schools, and they should never be kept singly.
Zebra Danios are a peaceful fish that get along with most any tank-mates, however they will nip fins of certain species of fish. Any fish with long flowing fins, such as Angelfish, Bettas, and Guppies, are potential targets of the active Zebra looking for something to do.
Zebras are primarily surface dwelling fish that favor moving waters. Technically they are considered cold-water fish, preferring water in the 64-75 degree range. However, they will adapt to a wide range of water conditions. With the advent of commercial breeding, this species has become less robust than species in the wild. If water temperatures are kept low they tend to become more susceptible to disease.
Zebras are extremely active, and although they have a preference for the upper levels of the aquarium, they will move throughout the entire tank. They should be provided with diffuse lighting and an open swimming space, together with vegetation around the periphery of the habitat. Darker substrate will help showcase the color in these fish, and gives the habitat a more natural feel.
Zebra Danios are omnivorous, accepting almost any foods. Although undemanding in diet, they particularly enjoy small live or frozen inverts, and fresh vegetable matter.
Males are a bit smaller and more slender than females. Females will have a somewhat fuller body, which is particularly noticeable when they fill with eggs.
Zebra Danios are ideal for beginners, as they are prolific breeders. A unique quality of the Zebra Danio is that as they are quite loyal to their chosen mate. Mated pairs remain together for life, and rarely spawn with others, even if one mate dies. The best way to obtain a mating pair is to start with a school of a half dozen or more young Zebras, and allow them to choose mates.
The breeding tank should be set up with shallow water, approximately six inches deep. Furnish the tank with fine-leafed plants or a spawning grid on the bottom. Course gravel works well, as the eggs will fall between the gravel pieces and will be protected from the adult fish, which will readily eat their own eggs.
Spawning requires temperatures of up to 78 degrees, and can be triggered by raising the water a couple of degrees near dawn, when spawning normally occurs. 300 to 500 eggs will be scattered across the bottom and on the plants. Remove breeders after spawning, as they will consume the young.
The fry will hatch in two days. Fry are very tiny, and can easily be lost when changing water, so take care when maintaining the grow-out tank. Feed the young commercially prepared fry food, or finely crushed dry foods. Powdered egg may also be added to the fry food to promote growth.