The most important factor in keeping rainbowfishes in captivity, apart from their obvious attractiveness, is the ability to breed the species in your care. This is even more important when it comes to the captive maintenance of endangered species. Everyone has their own favourite way of breeding their rainbowfishes and some don't breed them at all. To these people I say - "Breeding is not only an important part of being an aquarist but it can also be very enjoyable". I really can't imagine any person not wanting to breed them after seeing their magnificent spawning colours and behaviour.
The spawning of rainbowfishes is regulated by external environmental factors that trigger internal biological functions. In captivity, spawning can be controlled by maintaining the fish in an appropriate environment. The internal biological functions that regulate spawning are similar for most fishes. External environmental factors that control spawning, however, vary considerably among species. Environmental factors that have shown to play a significant role in the reproduction cycle are: photoperiod; water temperature; water quality (e.g. dissolved oxygen, pH, hardness, salinity, alkalinity); flooding and water flow; cycles of the moon; weather cycles (e.g. atmospheric pressure, rainfall); spawning substrate (e.g. aquatic plants, gravel); availability of food; disease and parasites; and presence of other fish. These factors do not function independent of each other, but are interrelated. Fortunately, rainbowfishes are very adaptive and will breed in a wide variety of water conditions.
Breeding rainbowfishes is relatively simple. Raising the fry might be a bit more involved but with a little experience, that's not difficult either. First of all, you do not breed your fish, they breed themselves. What you have to do is provide them with suitable conditions and they will do the rest. You must also know your fish and be able to pick males and females. Don't laugh, I have seen many people trying to breed fish with all males or all females. This situation is doomed right from the beginning. Generally speaking, rainbowfish can be sexed by the colour and finnage of the fish. Males are generally more colourful and have extended finnage, while females are pale by comparison and have smaller or more rounded appearance in the fins. In some species, males change colour during the spawning ritual. These physical changes make it relatively easy to identify sexually mature males. However, female characteristics such as plumpness of the abdomen are subjective and can be misleading. If you are unable to sex your fish, then have someone with more experience do it for you.
By far the best combination for breeding that I have found is 3 males and 2 or more females. With 2 males one will dominate the other and in effect prevent him from breeding. One male on his own will cause undue pressure on the female/s. Three, on the other hand will spread the aggression, both on the other males and the females. In a large aquarium it is possible for each male to have their own spawning site. This will allow the females to choose their own male and in doing so, a wider variety of genes will be passed on to the next generation. Also, this method should provide you with more eggs. Of course, if you have only a pair, then there is nothing else you can do.
Group spawning with multiple males and females is more natural. In the wild a female has the choice of either spawning or fleeing. In captivity, the flight of the female is reduced or confined to the size of the breeding aquarium. Therefore, the size of the breeding aquarium is vitally important. Sizes less than 90 cm, depending on species, should not be used. To breed rainbowfish you need to give them an aquarium on their own with a water temperature above 22°C. Water hardness and pH are not a major factor providing extremes are avoided (hardness can be maintained somewhere between 50 and 250 ppm and pH 6.8 to 7.8). Few rainbowfishes will do well in low pH acidic water - most prefer alkaline water, often with the addition of a small amount of salt or seawater. Many well-meaning hobbyists in their quest to duplicate the water conditions of the fishes natural habitat, fiddle about with various chemicals and compounds trying to maintain pH and hardness levels. While duplicating the water conditions under which the rainbowfishes were collected may seem ideal, this often causes more problems than it solves. Most domestic water supplies should be adequate for maintaining rainbowfishes once chlorine or chloramine compounds have been removed.
Top Next
NetPets® Main Pagecontact information
The Fish Center
