Introduction to Breeding Tropical Fish: Live-bearers, Egg Layers, and Mouth Brooders
Veterinary & Aquatic Services Department, Drs. Foster & Smith

Sooner or later every fish hobbyist wants their fish to breed and have offspring. This desire may come from accepting the challenge of providing the correct environment for a favorite fish or the sudden spawning of two fish in the display aquarium. Sometimes, visions of dollar signs inspire our efforts. Despite the source of your inspiration, it will take some serious planning, time, and additional aquariums to do it right. This article will outline some of the steps you can take to achieve your goal.


Our first experience with fish babies is often the result of one of the live-bearing fish having babies. Mollies and Swordtails are commonly the first parents in the aquarium, and often pregnant females will have babies after being brought home from the store. These babies are relatively easy to raise. If you do not have a separate aquarium to set up for the babies, one of the breeder traps will work. These small plastic or net containers will attach to the trim of the aquarium, or float on the surface. The pregnant female can be placed into the trap, and then removed after giving birth. Put a sprig of live plant or spawning grass in the breeder trap to give the babies a place to hide and feel secure. The babies can be fed baby food or regular flaked food which has been ground into a powder, 4-6 times a day.

Since it will usually take the babies 4-6 weeks to be large enough to be released, a separate rearing aquarium is a better option than a breeder trap. This could be a 5-20 gallon tank with a sponge filter and a bare bottom. Having no substrate makes it easier to see uneaten food and vacuum it out after feeding. Plastic plants with plant weights are a great way to provide some cover for the fish.

Egg Layers

Our first experience with an egg-laying fish is usually the Convict Cichlid, a.k.a. The "Breeding Cichlid." The first sign that egg laying is imminent will usually be a pile of gravel moved out from behind a rock, and other fish being chased by the breeding pair. The female has a bright red belly and is usually smaller than the male. The eggs are laid on a rock and will take 3-5 days to hatch. Then the babies will be "Wigglers" for 1-2 more days. During this time, it is not unusual to see the parents using their mouths to move the fry to a more secure location. After the fry are free swimming, the parents will herd the babies for a few days until the effort is too much. At that point, the babies have to fend for themselves, and the parents are ready to spawn again.

Once again, if you want to raise the babies, it is best to remove the rock with the eggs attached to a hatch-out/rearing tank. Fill this tank with water from the display aquarium. Do not allow the rock and eggs to be exposed to air during the transfer; encircle it with a plastic container or bag before removing it from the aquarium. You can feed the babies freshly hatched brine shrimp or standard flakes which have been ground into a powder.

Other egg-laying African Cichlids can be set up in a "species tank," often with spectacular results. Julidochromis and Neolamprologous species can be placed in tanks providing 20 to 55 gallons of water. You will need to nearly fill the tank with rocks to provide the cover and security for the spawning pair. It is best to start with at least 6 fish, allowing them to sort out the pairs. The "odd-man-out males" will usually end up hiding in the corners and it is best to get them out of the aquarium. The breeding pair will select a cave and disappear into it for up to 10-14 days, and suddenly there will be a small cloud of babies. Unlike other Cichlids, these will tolerate the babies and breed again until the tank is full of many generations of fish.

So do your research on your individual species, provide them with their own fry tank, and then sit back and enjoy all of the new offspring.

Mouth Brooders

Perhaps the next level of difficult fish to breed is the mouth-brooding African Cichlid. The challenge here is to keep the males from killing the females, and providing a big enough aquarium for them to be able to spawn. If serious about breeding the African Cichlids, you will usually set up the aquarium with lots of PVC pipes for the females to hide in and to make catching them easier. Use a PVC tube just big enough for the female, but too small for the male. If aesthetics are an issue, you can take the PVC pipe and rub aquarium sealant all over it and then roll it in some sand or fine gravel to make it look more natural. Or even use an Epoxy Stick to stick small rocks on it to give it a more irregular shape.

Most mouth brooders will require several females to each male, and usually just one male of the species per tank. After spawning, the female will carry the babies in her mouth for up to 2 weeks. It is best to carefully catch the female and remove her to a separate aquarium about 5 to 7 days after spawning. If the female spits the babies out during the transfer to the raising tank, she will usually pick the babies back up. During this time, the female will usually refuse to eat, although on occasion, females may eat some flaked food with the eggs still in their mouth. Again, a bare bottom tank is best, but more cover is required to make the female "at home"; plastic plants and more PVC pipes will do the trick.

Once the female has released the babies, you need to move her to another aquarium and feed her really well for a week or two. This will give her time to recover from not eating while carrying the eggs/babies. Then the whole cycle will start again. The babies are ready to start eating ground Spirulina flakes, and even chew on a Spirulina disc as it sits in the aquarium. Frequent water changes will be the key to rapid growth of the babies to a marketable size.

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