About Fish Breeding

Breeding your own aquarium fish can be a very fascinating, rewarding and sometimes profitable hobby. While some types of aquarium fish will breed with almost no effort from the aquarist and look after their own young, others can be very difficult to breed or it may be necessary to remove the fry from their parents and rear them in a separate tank. Many aquarists are surprised when their cichlids appear from their cave or hiding spot with a swarm of hungry fry, having not cleaned the tank in a while.

Choosing A Breeding Pair

When choosing a breeding pair, its best to buy about six fish and let them choose their partner. In many cases with cichlids in the wild a breeding pair will stay together for life but it is also common in the home aquarium for males to have several partners or to crossbreed readily. The fishes should not be related – breeding incestral fish can be ok for maybe a few generations but eventually this will lead to deformities.

Try to choose fish that appear healthy & disease free, energetic and have strong colours aswell as proper shaping aroung the head, body & fins. When breeding aggressive fish like cichlids it’s usually better to have a female that is larger than the male, a female that is not healthy or strong enough can easily be killed by the male during courtship or continuous breeding. When trying new pairs the aquarist must remain very watchfull & be ready to remove one of the fish if trouble develops. Removing the female to a ‘resting’ tank or adding a divider after a breeding cycle can also be necessary to ensure she regains her strength for the next spawn.

Water Quality & Filtration

It is essential to maintain a high water quality when breeding, smaller baby fish are more sensitive to ph levels, temperature, bacteria & fungi etc. & many fish will eat their eggs or fry if the food or water conditions aren’t sufficient.

Superb water quality can be obtained by using a filter with a high turn over Litre/min packed with a medium that has a large surface area for ‘water-cleansing’ bacteria. eg. bio balls, porous & unglazed ceramic/teracotta pieces, foam/sponge. A filter with a sponge on the inlet should be used to prevent tiny fry from being trapped & if using a powerhead, medium to low currrent is best. Cotton fibre can block up quickly & is really unnecesary in a filter provided regular water changes are done using a syphon with an attachment to remove the garbage accumulated on the floor. Activated carbon can greatly improve water quality & remove toxins but needs to be relaced regularly. A small spoonfull of rock sea salt should be added after a water change to reduce fungi & bacteria growths.

Removing the gravel completely from a breeding tank will also prevent bacteria & rotting particles from building up. When the gravel is removed, a tank with a grey base or black paper underneath & a low wattage light should be used to minimise glare. Water changes can be done weekly or fortnightly but sometimes it’s best not to disturb the pair for water changes whilst the eggs are being layed or hatched.


Feeding your breeding pair correctly is important to stimulate spawning aswell as to keep them alive & healthy. Live food is undoubtedly the best but live worms & other foods can introduce disease to your tank & should be used carefully or quarantined. Frozen & freeze dried foods such as frozen worms, frozen cichlid food or brine shrimp are excellent for keeping your fish healthy & active and are free from disease. Live brine shrimp are simple to prepare & are an excellent & disease free choice for live food also.

To keep your fish healthy & active you should feed them as regularly as possible. Only feed them what they will eat straight away so that no food is left to rot on the floor but do this every couple of hours or so and your breeding pair will grow quickly & remain healthy. Overfeeding your fish will foul the water & create disease.

Breeding Season

Most aquarium fishes in nature breed during the rainy season when the waters are warm and the supply of live food increases. It is the goal of the aquarist to match these conditions in the aquarium and encourage the fish to breed, aswell as to maintain a high water quality, and a suitable place to breed depending on the type of fish.

Breeding Environment

The environment in your aquarium is very important & specific to the fish your are breeding. Generally the ultimate breeding environment for a particular breed of fish is that of it’s origin. Ph, temperature, water hardness, substrate, lighting, plants, rocks/driftwood all need to be considered & replicated where practical while also creating an aquarium that is simple to clean & hygenic.

Some fish will need a substrate of marbles to protect the fallen eggs from being eaten & others like the cichlids will lay eggs on a smooth, flat piece of rock or glass or a broad leaf. Water requirements for your particular fish can be found on the internet.

Courtship & Pre-spawning

Witnessing the courting & spawning of a breeding pair is a fascinating experience. The male betta fighting fish will dance & display its colourfull fins whilst making a nest of bubbles in the presence of a female or fight to the death when placed with another male & wraps around & squeezes the eggs from it’s mate during spawning.

Courting cichlids will often lock mouths together, pushing each other around the tank. The male cichlid will agressively clean a flat piece of rock and swim back and forth, displaying bright colors & vibrating in a peculiar dance to attract the pregnant female. Sometimes with more difficult breeding pairs the aquarist can try to simulate the fish’s natural habitat & induce spawning with water changes, live food & temperature drops/rises using ice/heating.

Separating & Feeding The Fry

Most cichlids care for their eggs and their young until the next breeding cycle when they will kill any fish in their territory. Sudden death or removal of all of the fry or poor water quality/stress can cause the male cichlid to attack and kill the female thus its best to remove about half of the fry with a gentle syphon soon after they hatch.

Livebearers like the guppies, mollies & swordtails will eat their young immediately after giving birth and so a thick garden of plants can be provided as a hiding place or a hatching container can be purchased which will allow the baby fish to swim through small holes to a safe area.

Suitable foods for small fry are freshly hatched brine shrimp, tubes of fry food paste, boiled egg yolk. There are also different grades of powdered foods for fry available from your local aquarium. Larger foods like crushed flakes can kill small fry depending on the type of fish.

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