- Scientific Name: Danio nigrofasciatus
- Synonym: Barilius nigrofasciatus, Brachydanio analipunctatus, Brachydanio nigrofasciatus, Danio analipunctatus
- Common Name: Dwarf Danio, Dwarf Spotted Danio, Spotted Brown, Spotted Danio
- Family: Cyprinidae
- Origin: Myanmar (Burma)
- Adult Size: 2 inches (4.5 cm), usually much smaller
- Social: Small peaceful schooling fish
- Lifespan: 3 years
- Tank Level: All
- Minimum Tank Size: 10 gallon
- Diet: Omnivore, accepts most foods
- Breeding: Egg scatterer
- Care: Easy
- pH: 6.5-7.0
- Hardness: 5 - 12 dGH
- Temperature: 74-82°F (24-28°C)
The Spotted Danio was first described over a hundred years ago and has a long history in the aquarium industry. During the mid-1900s it was a staple in many aquarium fish shops, but its presence began to diminish as new species became available. The history of its home country also factored in, as Burma gained its independence in 1948, only to fall under military rule in the 1960s.
Eventually this impacted exports, which contributed to the decline of the Spotted Danio's availability in the aquarium trade. When the military junta was dissolved in 2011, exports once again increased, resulting in a resurgence of the availability of this attractive species.
This species originates from the lakes, streams, rivers, rice paddies and various still bodies of water in Myanmar (Burma).
The range of this species is relatively limited, having been found only in the central regions of the country, where it is primarily a seasonal fish. During dry periods of the year water sources dry up and this fish diminishes in number. When the monsoons come, bringing copious amounts of water with them, fish populations rebound.
Although this species has not been formally evaluated by the UINC Red List, it is believed to exist in sufficient numbers to not be considered an endangered species.
Although bearing a number of similarities to its cousin, the Zebra Danio, the Spotted Danio is smaller and less active. Overall this is a smaller danio species, rarely reaching more than 1.5 inches (4 cm) in length. The body is silvery in color and iridescent under good lighting. The most defining features of this species is a single bold dark stripe that runs from gill to tail, turning bluer in color as it nears the tail. This stripe narrows when it reaches the tail, but continues on through the tail fin. Above this stripe is a white stripe, which in turn is bordered by a much thinner dark stripe that is the same color as the primary dark stripe. The small stripe often breaks up into a series of small spots as it reaches the area of the tail.
Below the primary dark stripe is a series of small spots that cover the lower part of the body. The fins are relatively colorless for the most part, with the exception of the strip on the tail fin, as well as spots on the anal fin. These spots on the anal fin are a key means to identify this particular species.
In addition to spots, the anal fin also is edged in pale brown. The brown anal fin edging is more predominant in males than females.
Spotted Danios are a peaceful species that get along with other species: however, they are rather timid. This combined with their diminutive size limits their suitability for community aquariums. They will do well when kept with other small species, particularly those from the same part of the world. This includes the Glowlight Danio and Panther Danio, among other species originating from Burma. Small Tetras and Rasboras are also suitable, as well as Cory catfish. Spotted Danios should always be kept in schools of at least a half dozen, preferably more if possible. The larger the school, the less timid this species will be.
Spotted Danios are most comfortable in a habitat that is similar to their native conditions.
They prefer a well-planted aquarium, using live plants if possible, but artificial will do. Darker substrate is ideal for showing off the lighter colors of this species. Overhead lighting will also bring out their delicate coloration. Provide some bogwood and rocks to complete the river type of habitat from which they hail. The aquarium should have a well-fitted cover, as this species is inclined to jump.
Water conditions are not extremely critical, but they are sensitive to build up of toxins, so regular water changes are recommended. Soft to moderately hard water is suitable, with an acidic to neutral pH. Like many in the Danio family, this species can tolerate cooler water temperatures, but when breeding, warmer temperatures are recommended.
This species is omnivorous and will accept almost any food, including flakes, small pellets, freeze-dried, and frozen foods. They particularly relish small live foods, which should be provided as a supplemental food when possible. In lieu of live food, use frozen bloodworms, brine shrimp, and daphnia or mosquito larvae.
Spotted Danios will feed in the upper portion of the tank, but are rather timid, and may not compete well for food with boisterous fish. If they are in a tank with more active species, take care to ensure the Spotted Danio is receiving its fair share of the food. Use of multiple feeding rings can help in these cases
Females are larger overall than males and have a rounder body. The slimmer male is more brightly colored, while females have more subdued coloration. In males, the anal fin has a golden tint with a light brown edging. When well-conditioned for spawning, the male becomes even more vibrantly colored, while the female will become rounder in the belly as she fills with eggs.
Spotted Danios are relatively easy to breed. In fact, in some cases, they spawn without the owner having provided special accommodations, or even being aware that spawning has taken place. However, they are voracious egg and fry eaters.
If the owner wishes to raise most or all of the spawn to adulthood, a separate tank is needed to ensure survival. This can be accomplished by setting up a separate breeding tank that will also serve as a grow-out tank. This tank should be set up with a matured sponge filter, and filled only half to two-third full with water in the range of 77 to 79°F (25-26°C) Lighting should be dim, and the tank should be equipped with either a spawning mat or plenty of fine leafed plants, such as Java Moss. Alternatively, a mesh or marbles can be used on the bottom to allow the eggs to fall out of reach of the adult fish.
Condition the breeders with live foods prior to spawning. When they breeders are ready, place two males and one female in the prepared tank. Males will actively court the female, eventually resulting in the female beginning to deposit eggs. A dozen or so are released at a time, with a maximum of only a couple hundred, usually far less. Promptly remove the adult fish once they finish laying eggs. In approximately 24 to 48 hours, the eggs will hatch, sooner when the water temperature is higher. Lighting should be kept very dim, as the fry are sensitive to light.
After a couple of days, the fry will become free-swimming. Initially, they will feed on infusoria, then move to freshly hatched brine shrimp. If unable to provide infusoria, use a commercially prepared fry food, feeding them frequent small meals. As the fry grow, larger foods can be fed to them.
Interestingly enough, there has been reported cross-breeding between this species and Pearl Danios, as well as other species of Danio. However, the fry produced from these crosses are invariably infertile.