If you are keeping tetras, chances are you are breeding tetras, even if unknowingly. In the wild, tetras normally breed during the rainy season, but in the aquarium, they may breed year round. Female tetras are egg-scatters that typically fill with eggs every ten to fourteen days.
The female tetra indiscriminately sprays her eggs into clumps of fine-leaved plants. The eggs are adhesive and stick to the plants. However, tetras as well as other tank mates often find tetra eggs and small fry an irresistible delicacy.
If breeding tetras is your goal in keeping them, the best thing to do is to separate males and females. This allows you to keep control of breeding and improves your chance of achieving a successful hatch of fry. Smaller species of female tetras become sexually active at nine to twelve months old with larger species ready to breed at 1 ½ to 2 years of age.
Male tetras are generally a month or two older than females for successful spawning to take place.
Males are typically slimmer and more colorful than their female companions are. When viewed from above, the female tetra is distinguishably plumper and rounder because of the build-up of eggs within her body.
Two weeks before breeding tetras, separate males and females within the same tank. This is done simply by putting a clear divider between them, which not only gives you control of breeding but also stimulates spawning behavior since the fish are kept within sight of each other. Breeding tetras is also encouraged during the pre-spawn period by feeding them with high-quality live foods.
When ready to breed tetras, you’ll get the best results by using a separate breeding tank, prepared with a peat filter and clean, aged water in which clumps of fine-leaved plants have been strategically placed. Three ways to complete your tank for breeding tetras are:
- Drape the tank with nylon netting to allow the eggs to fall to the tank floor away from hungry adults.
- Cover the tank floor with marbles to hide the eggs and protect them from cannibalism.
- Plant fine-leaved plants or artificial spawning mops in seed trays filled with coarse gravel to trap the eggs and prevent them from being eaten.
Females should be placed in the breeding tank earlier than the males, usually the night before breeding. In addition to allowing her to settle in, it also puts the male in the position of having to court her on her own turf. This technique can deter any aggressive tendencies he may display. After introducing the male to the breeding tank, it’s best to watch hisintroductory moves.
Males often show aggressive behavior during spawning. If the male attacks a female, remove her and re-separate the pair. Another female can be tried or alternatively, two to three females can be introduced to the breeding tank to keep the male from focusing his attention on only one. Remove adult fish from the breeding tank immediately after breeding tetras
