Danio Balabaricus – Giant Danio
By: Dr. Thomas R. Reich PhD
General Information on Giant Danio
The Giant Danio or Danio Balabaricus belongs to the family Cyprinidae and was first imported in 1909. As its name suggests, this is the largest of the Danios; it used to be known under the scientific name of Danio Malabaricus. The Giant Danios originates from southwestern parts of India and Sri Lanka. It is pale blue in color with three or four pale yellow stripes or blotches running down the sides of its body. The dominant individuals in a group of these fish will be the dominate male, and this fish should be selected for breeding.
Further, the body is slim, elongated, strongly compressed at the sides, and up to 4 inches long. The back is steel-blue, the flanks greenish, behind the gills there are two to three transverse golden bars, and the sides are decorated with blue and goldfish longitudinal stripes. The male is usually smaller and has more distinctive coloring. In the spawning season he has orange pectoral fin.
In its natural surroundings in India, it is quite common and lives in clear, stagnant and running waters along the Malabar Coast, and grows up to 8 inches in length, but that would be an exceptional specimen even in a large stream. Tank raised specimens will rarely grow larger than 4 inches. The mouth has two sets of barbells, although captive specimens are usually missing the barbells on the upper jaw.
In spite of its large measurements, this fish can be kept with other, smaller species. An extremely peaceful fellow, it is very tolerant of other fishes in its environment. It very much appreciates a little morning sunlight in its tank!
Sexing a Breeding Pair of Giant Danio
The sexes are easy to tell apart by the slimmer, more attractive appearance of the male, and the “stuffed” belly of the female. This Danio is known for its incredible speed, noticeably faster than that of other species. It is practically impossible to remove this fish from a well planted community tank without creating a great deal of disorder, unless you take its flight direction into account and capture it between the net and the receiving jar or second net.
The Breeding Process of the Giant Danio
The breeders, 1 female and 2 females should be conditioned on live food and kept separately for 7 to 10 days. Set up the breeding tank (at least 10 gallons, though 15 or 20 long is ideal) the same as with Zebra Danios, with the marble bottom, however, the water depth needs to be 8 inches, and you must add several nice clumps of fine leaved plants. The manner of fertilizing the eggs is characteristic of other Danios, and a steady temperature of 75F t0 79F is great. However, during mating, the male pushes himself against the female and brings his anal fin, which he has rolled up into a kink of a bag, under the female’s anus.
The eggs are caught in this “bag” and are fertilized at once. The male then scatters the fertilized eggs among the plants. The number of eggs per meeting is small – only 5 to 20, but this process is repeated many times over about a 2 hour period and a total of 200 to as many as 400 eggs are produced fertilized and laid.
The eggs are clear as glass, not adhesive, so most will fall through the plants into the marble base and be fully protected from the breeders. The eggs measure about 1mm in diameter, much larger than the Zebra and its other close relatives. Once the breeders activities have stopped remove the breeders at once.
After two days after the eggs have been laid, the first young fish appear. Depending on various factors, however, it can take as long as a week before the last egg has hatched out. Temperature is not the least of these factors.
Just How Hardy are the Giant Danio Fry
I once had an interesting experience with a group of Danio’s I was breeding (a trio of Long fin Blue Leopard Danios). I set up the breeding tank in the usual way, and after a day or so, I was convinced the fish had not bred. I thought, since they were a very fancy strain, something had gone wrong and that they had failed to breed. I returned the breeders to the conditioning tanks, and dumped the water in the tank, setting outside in the cold, about 41F at night for a day, then brought the tank back in to prepare it for breeding again, this time Fire Neons.
I decieded not to sterilize the marbles on the bottom and to just fill the tank with fresh aged water. On the evening of the second day, the tank was filled with the aged water, and readied for breeding. The temperature was raised to 75F for breeding the Fire Neons and the breeders introduced the evening of the fourth day. The next morning, when I was observing the behavior of the pair of Fire Neons, I observed hundreds of slivers hanging from the glass sides of the tank. Not knowing what was actually going on I removed the Fire Neons. I did not know if the fry were fast hatching Neons or what? I decided to raise the fry and as the days passed other fry appeared.
I raised the young and both the Blue Longfined Leopard Danios and Fire Neons grew up happy and healthy together! This shows that the fry of the Bracydanio and Danios species are much heartier than anyone could have expected, left with nothing but the slightest amount of moisture for over 24 hours and exposed to temperatures as low as 41F, the eggs survived and hatched with no ill effects. Further, that the fry learn to survive in adversity, even when combined at birth with other species!