Aquarium Lore: Danio

Data Sheet
Scientific Name:	Brachydanio ~
Other Names:	Zebra Danio, Pearl Danio, Leopard Danio, Gold Danio
Family:	Cyprinidae
Origin:	Asia,
Adult Size:	2 inches (6cm)
Social:	Peaceful schooling fish
Lifespan:	5 years
Tank Level:	All
Minimum Tank Size:	20 gallons
Diet:	Omnivore, eats most food
Breeding:	Egg layer
Care:	Easy - hardy fish that eats anything.
Ideal pH:	6.5-7
Temperature:	64-74 F (18-24 C)
Tank setup:	Danio should be provided with plenty of lighting and an open swimming space, together with some vegetation.
Sexing:	Females are usually larger and have a fuller body than males.

Zebra Danio

Spotted Danio

Pearl Danio

Description:

All Danios are torpedo-shaped fish, usually small (except for giant danio), and very fast. Some Danios, such as the Zebra Danio and the Leopard Danio, have very beautiful body patterns.

Habitat/Care:

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

Mixing with other fishes:

Danios are highly peaceful fish that can be mixed with most other fish of similar size. A schooling fish, it prefers to be in groups of six or more.

Because they are very fast, they tend to be among the first to feed at meal times, so you need to ensure that slower eaters have some food to eat.

Diet:

Danios are omnivorous. In the wild, these fish consume various small aquatic insects, crustaceans, worms as well as plankton. For this reason, they can be used to reduce mosquito larvae populations in ponds and ditches.

Floating flake food and freeze dried blood worms are popular food for Danios. Both of these foods are available in most stores that sell pet fish. Danios also relish an occasional feeding of a few live Black Worms and live or frozen brine shrimp.

Some text noted that Danios are relatively fast, and are often among the first to feed.

Breeding:

Danios are somewhat unique, as they are quite loyal to their chosen mate. Mated pairs remain together, and rarely spawn with others, even if one mate dies.

The breeding tank should be set up with shallow water, approximately six inches deep. Furnish the tank with fine-leaved 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 F, and can be trigged 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. They 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.

Disease

Danio are susceptible to Oodinium, (Velvet disease).

Oodinium - microscopic parasite that block the gills of fish.
Symptoms:
Scratchs against hard objects
Fish is lethargic
Loss of appetite and weight loss
Rapid, labored breathing
Fins clamped against body
Fine yellow or rusty colored film on skin
In advanced stages skin peeks off
Initially the fish rub against hard objects trying to dislodge the parasites. As the disease progresses the fish becomes lethargic, fins are held close to the body, appetite is reduced and the fish loses weight. A key symptom is difficult breathing, resulting in rapid gilling.
Perhaps the most telltale symptom is the appearance of a velvety film on the skin that resembles gold or rust colored dust. The film may be difficult to see, but can be more easily detected by directing a beam of a flashlight on the fish in a darkened room. The parasite is most often seen on the fins and gills.
Treatment :
Raise water temperature
Dim lights for several days
Add aquarium salt
Treat with copper sulphate for ten days
Discontinue carbon filtration during treatment

Variants:

Zebra Danio - The fish is named for its five uniformly, pigmented, horizontal blue stripes on the side of the body; all extending to the anal fin onto the end of caudal fin rays of its tail. The males have gold stripes between the blue stripes and females have silver stripes instead of gold.
Pearl Danio - pearly blue-violet hued body is accented by an orange-red stripe running from tail to mid-body. Males are smaller, slimmer, and more colorful, often showing a red tint along the ventral aspect.
Leopard Danio - have spots on its body similar to that of a leopard spots.
Gold Danio - are similar to Zebra Danio in that it also have strips yellow-golden and white strips on the sides of the body;
Spotted Danio - have a blank line in their side, and below the line, small black spots can be seen.
Giant Danio - this danio can grow to 6 inches (15 cm). They are characterized by a blue and yellow torpedo shaped body with gray and clear fins.