Most fishkeepers take it as a compliment when fishes in their care breed, as it confirms that they must be doing things right although some would say their fish breed despite the conditions they're kept in!

Whatever your own personal atitude, it is a great day when you find you have more fish than you started off with, through no effort on your part. So how difficult is it to deliberately get your fish to breed?

Well, the basics demand that you must have a genuine pair of fish - one male, one female. Then you must ensure they are ready to breed and then give them adequate conditions to do so. After that, all you've got to do is find enogh extra tank space to raise however many babies you are presented with.

Finding a Pair

With livebearing fish, especially the cultivated species such as Guppies, Platies, Swordtail and Mollies there are few problems in sexing the fish. The male has a modified, rodlike anal fin whilst that of the female is the traditional fan shape. In other livebearer species, the male's anal fin may just have a notch in it somewhere near its front.

Egglayers are more difficult to sex although the general rule that males are more colourful with longer finnage usually holds true.

Creating the Right Conditions

Again starting with livebearers, the problem is more how to stop them breeding, particularly if you want to keep the colour strain pure; the fact that the females of cultivated types can produce several broods from one mating (without further recourse to a male) doesn't help - and neither does the fact that the different colour varieties within a species fish will interbreed without hesitation!

To get egglayers in the right mood for spawning, employ the 'absence makes the heart grow fonder' technique.
Separate the sexes and condition them in separate tanks for a couple of weeks, feeding on high-quality and live foods. When rejoined in a spawning tank the pair should then spawn within a few hours - usually the morning following their reunion.

You will need to take some precautions to prevent egg-scattering species from eating their own eggs, and the accompanying diagrams show what techniques you can use.

Some eggs are sensitive to light, those of Characins, for example: in this case, shade the tank with some brown paper or a towel for the first few hours as the fry hatch. Covering the hood with a towel also keeps cold draughts out, often an important precaution to take when breeding Gouramies and other bubblenesters.

Obviously with egglaying species which exercise parental care you can leave the fish to get on with it. Killifish eggs can be collected from spawning mops or bottom layers of peat and stored, semi-mosit, in plastic bags for the require time period (a couple of weeks to a couple of months) before re-immersion in water triggers off the hatching.

Raising the Fry

Livebearer fry are usually large enough to take crumbled fake foods and any small. cultured live foods right from the start. Egglayer fry be extremely tiny and so their first foods need to be almost microscopic in size. Green water or a hard-boiled egg-yolk squeezed into water through a cloth can be considered useful starting foods. All growing fry will grow rapidly if fed newly-hatched Brine Shrimp, sifted live foods, Grindal and Micro-worms.

The most important thing when raising fry is to give them plenty of food coupled with plenty of space.

What Fish to Keep?
Aquarium Size & Water Preparation
Heating, Filtration Systems
Setting-up and Running-In
Fish & Plants
Feeding & Water Management
Useful Hints

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Last updated April 1, 2002