Zebra Danio (Zebrafish)

Characteristics, Origin, and Helpful Information for Hobbyists

Zebrafish (Danio rerio) aquarium fish
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Zebra danios are a favorite of freshwater fish hobbyists because of their ease of care, and they are prolific breeders and the easiest type of egglayers to breed. These fish are easy recognize with its attractively striped, black and white zebra-patterned body. They are active swimmers. Zebrafish are very durable and can withstand an impressive range of water temperature and conditions. They will generally do just fine without a water heater as they are comfortable at temperatures down to the low 60s F.

Also, they are loyal to their breeding partner and mate for life.

Characteristics

Scientific Name

Danio rerio

Synonym

Barilius rerio, Brachydanio frankei, Brachydanio rerio, Cyprinus chapalio, Cyprinus rerio, Danio frankei, Danio lineatus, Nuria rerio, Perilampus striatus

Common Names

Striped danio, zebra danio, zebrafish

FamilyCyprinidae
OriginEastern India
Adult Size2 inches (6 centimeters)
SocialPeaceful, suitable for community tanks
Lifespan5 years
Tank LevelAll levels
Minimum Tank Size10 gallon
DietOmnivore
BreedingEgglayer
CareEasy
pH6.5 to 7.0
Hardness5 to 12 dGH
Temperature64 to 74 F (18 to 24 C) 

Origin and Distribution

Zebra danios were originally thought to have originated from a wider range that stretched from Myanmar in the east and Pakistan in the west; however, the current consensus is that this species originates from a narrower range that is contained to parts of India and Bangladesh. 

Wild zebra danios are found in a variety of habitats, ranging from fast-moving streams to slow-moving, nearly stagnant ponds.

Part of this change in distribution is due to the identification of similar species that were once misidentified as Danio rerio, as well as damage to the environment that resulted in a 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 species.

Colors and Markings

Among the hardiest 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 peaceful nature and small size of the zebra danio, no more than two and a half inches, make them well suited to a community aquarium.

Albino, golden, veil-tailed and long-finned zebra danio varieties are available, as well as a popular leopard variety. The leopard strain is characterized by a copious sprinkling of black spots over the entire body. In the past, the leopard danio was considered a different species, but 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 as singles.

Tankmates

Zebra danios are a peaceful fish that get along with most tankmates, however, they will nip fins of certain species of fish. Any fish with long flowing fins, such as angelfishbettas, and guppies, are potential targets of the active zebra looking for something to do.

Good potential tankmates may include barbs, corydoras catfish, similar-sized gouramis, loaches, and swordtails. 

They are best kept in a school of five or more of their own kind. Groups of this fish can be hierarchal, and a pecking order may emerge in the school, but nothing will come of it. Select tankmates that are similar in temperament. You want tankmates that can keep up with the fast-paced lifestyle of this danio. Mellower fish that need a less hectic environment can become stressed.

Zebra Danio Habitat and Care

Zebras are primarily surface dwelling fish that favor moving waters. Technically considered a cold-water fish, this fish prefers water in the 64 to 75 F 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 too 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. Provide them with diffuse lighting and an open swimming space, together with vegetation around the periphery of the habitat. A darker substrate will help showcase the color of these fish and gives the habitat a more natural feel.

Zebra Danio Diet

Zebra danios are omnivorous, accepting almost any foods. Although undemanding in diet, they particularly enjoy small live or frozen invertebrates and fresh vegetable matter.

Sexual Differences

Males are a bit smaller and more slender than females. Male zebras appear more torpedo-shaped, while females tend to have a larger belly.  Both sexes have two pairs of barbels and the same stripes, but females are usually larger. More full-bodied than the males, a female's belly balloons when it fills with eggs.

Breeding of the Zebra Danio 

Zebra danios are ideal for beginners as they are prolific breeders, and interestingly, mated pairs remain together for life and rarely spawn with others, even if a 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.

Set up the breeding tank 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 F and can be triggered by raising the water a couple of degrees near dawn when spawning normally occurs. About 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. They are very tiny and can easily be lost when changing water, so take care when maintaining the nursery tank.

Feed the young commercially prepared fry food or finely crushed dry foods. You can also add a powdered egg to the fry food to promote growth.

More Pet Fish Breeds and Further Research

If zebra danios appeal to you, and you are interested in some compatible fish for your aquarium, read up on:

Check out additional fish breed profiles for more information on other freshwater fish.