Tropical Fish Breeding for Beginners

Tropical Fish Breeding for Beginners

Breeding fish is considered to be a very complicated procedure by many beginners. People believe that one needs expert knowledge to make fish breed while in captivity, but this is far from the truth. Breeding, like any other aspect of fish keeping, is a science. If you get your facts right, and follow the right procedures, you will find your fish multiplying fast.

Several livebearing fish species will spawn even in suboptimal conditions, while egg laying species typically are a larger challenge for a novice. Since it is a new experience, there are some tips and techniques that will make the whole procedure easy as well as enjoyable. For successful breeding of fish, the first step of course is to be able to distinguish between the sexes. When you have grown both the sexes of the same species and feel that they are ready to spawn, the next logical step would be to recreate the natural surroundings that will best suit breeding. Natural conditions stimulate the spawning process.

Spawning Methods

Sexually, fish can be classified into two groups: the sexually dimorphic and the sexually isomorphic species. The sexually dimorphic species show obvious primary and secondary characteristics of their gender. The males of this species are often larger and more colorful, and they usually have a much more elaborate finage. The sexually isomorphic species show hardly any apparent differences in the two sexes. It is therefore very difficult to distinguish between the two sexes in this group. Often, the only deciding factor could be the shape of the genital papilla. This becomes visible at the time of spawning. In some of these species, the female have a more rounded belly or is slightly larger than the males. There are some species that show no visible difference at all between the two sexes.

External fertilization followed by egg laying is the way most fish in aquariums will reproduce. Egg layers are classified into five groups:

Egg Scatterers

These species, as the name indicates, scatter their eggs on any surface. The eggs may be adhesive or non adhesive. After laying eggs, the parents do not look after them, and may even eat their own eggs. These are mostly schooling fish, and they often spawn in groups. Their eggs hatch fairly quickly.

Egg Depositors

These fish deposit their eggs somewhere on the substrate. They lay fewer eggs than egg scatterers. Some species within this group show advanced care for the eggs and fry. They will deposit eggs in an enclosure, cave, a pit or similar, and protect and clean the eggs. Some species of Cichlids come under this category. Not all egg depositing species care for their young. Some just deposit their eggs and then abandon them. Egg depositing species generally don’t eat their own eggs. Their eggs are usually larger than those of the scatterers.

Mouth Brooders

There are two basic types of mouth brooders. In some species, the female fish carries the eggs and/or larvae in its mouth. The female in this group receives a mouthful of sperm from the male, and the fertilization takes place in the mouth of the female. In the second type of mouthbreeders, the females lay the eggs on a substrate and guard these eggs till they hatch. Once the eggs hatch, she picks up the fry and carries them in her moth till the fry have become a little bigger. There are also paternal mouthbrooders where the offspring is carried by the male fish.

Nest Builders

These fish build a kind of nest that is made of plant debris and saliva. They may also dig a pit in the substrate to lay eggs. They take care of their young ones.


Livebearers are fish that do not lay eggs. The fry come already hatched out of the mother fish. Livebearers are able to give birth to young ones because of internal fertilization which takes place inside the female. Sometimes contact between the cloacal apertures of the male and female fish leads to fertilization. In some species, the eggs produced by the livebearer will be heavily yoked. In other species, the young are in direct contact with the mother and are fed and nourished by her. In this case, the mother carrying the young ones needs more nutrition and overall care.

Fry of livebearing fish usually takes about 30-32 days to develop. Many factors will affect this development period, e.g. the water temperature, the female’s age and her level of nutrition. The good thing about livebearer females is that they are immediately ready to breed again after they drop their young ones. The competition to get to these females is intense among the males.

For beginners livebearers are the easiest fish to breed. If given enough space, the livebearers will do most of the hard work. Once the fry become noticeable and have started swimming, they need to be removed from the aquarium unless the aquarium is densely planted. Failure to do so will surely land a large percentage of them into the stomachs of bigger fish. Many people breed livebearers to provide food for predatory fish. Some livebearers will cross breed with other fish and to avoid hybridization these species should not be kept together.

Equipment management while breeding fish

The first and foremost need for successful spawning of many species is space. Fish often become territorial when their breeding time approaches. Most males are very aggressive during this time, and will chase away any potential competitors. This becomes especially dangerous for the younger fish, and more so if they are unable to get to a safer place, out of reach of the aggressive male. The primary need of fish that are going to breed is enough space for them to chase, hide and move. There are species that needs very little space and that don’t get especially aggressive, such as the very popular Guppy.

Some species of fish get into the spawning mode when they are fed highly nutritious food. Thus it is a good practice to give the breeders some special attention. This kind of special attention aims at bringing the fish to their topmost reproductive state. If you have some extra aquariums, place the two sexes separately in the two aquariums.

A delivery aquarium is advisable when your fish are ready to spawn. This will save the fry from being eaten up as food by the other fish. A tight cover should be placed on the aquarium as some fish species can become very nervous during this stage and show a tendency to jump. The conditions in the delivery aquarium should be as close to those in the original aquarium as possible. This will save the parent fish from any undesirable stress at such a critical stage in the breeding cycle.

A special aquarium for rearing fry is also advisable. This can be the same aquarium as the delivery aquarium if the parents are moved from the aquarium once the eggs are laid. If the species guards their young, they should not be removed until they have stopped rearing the fry and started to prepare for a new spawning. The needs and requirements of fry are very different from bigger fish. They need special kinds of food, at least till they grow a bit bigger. Filtration too has to be varied in order to accommodate fry. As the fry start developing you can perform a 10% water change the first few days, and than raise this up to a 40% water change every day to keep the water clean. Clean water helps keep your fry healthy and fast growing. Optimal survival of the fry is ensured if you segregate the fry depending on their size. The fastest growing fry are almost always the males. The bigger fry will eat the smaller ones if they are not separated.

Some people use a breeding trap as the place where the female livebearer can drop her fry. The fry are thus out of reach as they will be dropped into a separate plastic compartment attached to the rim of the aquarium. If the breeding aquarium is too small to accommodate the female, the chances of her miscarrying while struggling to escape are very high.

The spawning aquariums for different kinds of fish should be set up according to their particular characteristics. Egg scatterers will eat their own eggs. So, care should be taken that their eggs fall away from the reach of the parents. For small species of this kind of fish, a 5-10 gallon aquarium would be the best. The parents should be removed after spawning. If the fish lays non-adhesive eggs, it is better to put nylon netting just above the aquarium floor. The eggs will then fall out of the reach of the parents. In case the eggs are adhesive, then they will be laid among the leaves of plants.

Egg depositors should get aquariums decorated in accordance with their egg depositing behavior. If they are the types that care for their young, the parents can stay in the aquarium after laying the eggs. It is advisable to provide these fish with broad-leafed plants, flat stones, upturned flowerpots, coconut shells, or rocky caves. If your fish species inhabit rocky areas in the wild, they will appreciate caves or flat stones as breeding sites, and so on. Putting in plants and caves will give fish a sense of security even if they are not plant spawners.

Mouth brooders can be left in the main aquarium even when they are spawning because the eggs as well as the young are well protected by the parent. Brooding does however bring out aggression and brooding fish can cause harm to any other fish in the aquarium. For this reason alone, it may be better to put these fish into a new aquarium while they are breeding.

Setting up a new aquarium for breeding purposes is fairly easy. You do not have to go through all the steps and wait for the Nitrogen cycle, plant your aquarium etc since you can use water and bacteria from your established aquarium. An additional aquarium for breeding purpose need not be very big. Usually an aquarium with a capacity of 2-6 gallons would suffice for most fish. The best way to set up your aquarium easily is to take water from your existing aquarium and use this to start your new aquarium. Since the fish are being transported from the old aquarium, they will already be acclimatized to this water. Using a foam filter for a few weeks in your old aquarium will help you collect a good quantity of beneficial bacteria that can be easily moved to the new aquarium. Decorations and plants can be kept to a minimum for most species. Changing water in this aquarium regularly is a must. The best way to clean out the material wastes in this aquarium is to siphon it out using a flexible pipe. Keep in mind that it is easy to siphon out some fry also along with the waste. So, it is best to siphon out the waste into a clean bucket. This will help you to save any nosey fry.

Choosing the parents

When Charles Darwin laid down the Theory of the Survival of the Fittest, he was only stating what was so very obvious in nature. The best male of the species will try to impregnate the females, and the females prefer the best male since his DNA increases the chances offspring survival. That is why many animals like the lions etc will have only one dominant male who has successfully defeated all other males in the group. This male alone impregnates the sexually active females. He continues to be the leader until a healthier and stronger male defeat him.

There is something very vital in this theory for the aquarist too. When your fish are ready to breed, it will not do to select just any pair. You need to select the male and female very carefully, unless you are breeding to provide food for other fish. Here are some pointers that will help you choose the right pair:

Fish that have brighter colors and good markings are the healthiest in a stock. Fish that have good finage, movements and vitality are also healthy.
The appetite of a fish is often an indicator of its general health and vitality. Only fish that have a good appetite should be selected for breeding.

  • Do not use fish that appear stunted or deformed in any way.
  • The age of the fish is also important while you consider mating partners. It is better to go for younger fish that are in their prime rather than choosing older fish that have almost reached the end of the reproductive lives. An exception from this rule can be if you have an older specimen with exceptional code coloration, finage or other qualities that you want to breed on.

Compatible pairs make good partners. Always see that the pair you are choosing are able to get along well. For instance, in Cichlids, fish form pairs only after they have been put together in an aquarium for many months. If the fish are not compatible, one of them may even bully the other to death.

Unhealthy fish and fish that are not mature enough will not produce healthy fry. You should therefore only choose healthy and mature fish for breeding.
In case you want to experiment crossing two different strains, please keep in mind that the resulting fry may be unattractive. Never sell crossbreed fish as pure fish. Do not mix impure strains with pure strains.

Hybrids made by crossing two different species are often sterile. It is possible to mistake the females of different species, because some of them look very similar. Hybrids should be avoided and should never be sold as anything other than hybrids.

Conditioning the parents

After choosing the parents, you need to condition the fish so that they spawn. One of the most effective ways to do this is to simulate their natural habitats as closely as possible. Making certain changes in the environment will also help you to encourage the fish to spawn.

Providing the right water conditions is one of the first steps. Conditions that are as similar to their natural habitats should be provided. Proper aquarium set-up that provides for enough “security”, hiding places and crevices is essential. The water current, lighting and temperature should also be taken into consideration. Some fish mate only when they are in schools. Isolating these fish will discourage spawning.

Providing the right food is the next important thing to do. The mates that have been selected for spawning should be given food that is very high in protein. Live food seems to be a catalyst in this process. You can feed the fish up to three times a day. Of course, remember to clean up the aquarium after each feeding.

Some fish spawn during the rainy season. It can therefore be a good idea to simulate these conditions in the aquarium too. This is actually a very simple procedure. Reduce the water level in the aquarium to half the normal height. Add 5% of the aquarium volume everyday. Add soft water that is slightly cooler that the aquarium water. A drip system or a spray bar will help to add to the notion. During this time, fish should be fed heavily. This process can be repeated till fish show signs of spawning. Most fish respond to the first change in water conditions – like soft water or altered water temperature.

Tips for effective breeding

Anything that you have placed in the aquarium traps debris. As soon as the fry come out, remove any breeding traps that have been in the aquarium before. You can also add one or a couple of apple snails into the aquarium. Apple snails are very laid back and do not attack any fish. These snails will eat debris, and will also eat any dead fry. Apple snails will not eat live fry. Apple snails also produce a good supply of infusorians and can even provide the fry’s first supply of food.

Keeping a detailed log of the entire process is a very good idea. This will help you when you need to repeat the process. You should keep accounts of the species name, the detailed water chemistry, filtration and aeration methods, approximate ages of the parents, when the female was added, the date on which the fry was released/hatched, the fry’s first food and the body size of the fry till it reaches about three months of age.

Sometimes, even in spite of doing just about everything to ensure success, you will find that your fish just does not breed. All conditions are as they should be, but still there is no success. In this case, it is best to use a “target” fish to jump-start the process. This works best in territorial fish. A target fish is a perceived threat to the territorial fish. The male fish sees the new fish as a possible encroacher in his territory and he will then pair up with the female fish to isolate the target fish. The important thing here is to ensure that your target fish is in reality not a threat to the existing fish or vice versa. For instance, when trying to breed small cichlids, using some zebra danios as target fish will not pose any threat to either fish. It should be noted that some species of fish will kill any kind of target fish, and such situations should be avoided. If this is the case, it will also suffice if you place the target fish in a different aquarium alongside the mating aquarium so that the male can see but not touch.

Sometimes, fish introduced into a new aquarium are too nervous to come out into the open. They will remain hidden for days and will refuse to settle down. Fish that are stressed in this way will never pair up and breed. In such cases, you can use a “dither” fish to calm the other fish. A dither fish is an easygoing, harmless fish. A hyperactive and aggressive fish is definitely not the right dither fish. Calm and peaceful midwater fish makes the best dither fish. Once the nervous fish see the dither fish swimming about happily without being consumed by predators, they too will settle down and come out of their hiding places. This is just to reassure the nervous fish that nothing will harm them when they come out into the open.

Raising Fry

Once the eggs are laid, you can remove the parents in none fry guarding species. This is especially important if the fish are the types that eat their young. In case of fish that care for their brood, it is recommended to keep the parents with the fry.

Taking care of your fry requires some special attention. Some young ones, like the Goldfish, will not eat for the first 40-48 hours of their life, while other species need to be fed immediately. How do you know when to do what? And what are the best conditions for keeping the fry alive. These are some of the many things that you need to keep in mind when the fish start spawning.

In some livebearers, the female may release only a few of the babies at the beginning. She may take a few hours or even a day to release the entire batch of fry; and some of these fry will likely be stillborn or even eggs. Even after this, a female can be full of fertilized eggs that will soon begin to develop into fish. Livebearers can release several more batches of fry even if there are no males around, due to their ability to save sperm.

The fry may take up to a few weeks to develop. Do not expect your fry to come out ready for a swim and a feed. The larvae that hatch have almost nothing in common with their parents. They will be enclosed in a big yellow yolk sac and will not be able to swim at all. The larvae will eat up the egg sac until the yolk is fully gone. Once this is over, the fry begin to get hungry and look for food.

Infusoria is a good food for tiny fry. “Green water” or egg yolk can also be fed to the fry. Powdered flake food is commonly fed to fish fry in aquariums, but powdered flake food is not the best fry food. Powdered flake food is however better than nothing if it is all you got when the fry arrives. Take a plastic bag and put in 1-2 tablespoons of flake food. The bag should not have too much air in it. Then squeeze the bag in your hand and mash the flake as well as you can. The more powdered it is, the better.

Putting in only a small amount of food for the fry is also a bit difficult. The best way to add in small amounts of powdered food is by using a toothpick. Wet the end of the pick in water, and wipe it with your finger so that it is only a little wet. The wet toothpick should now be dipped into the powdered flakes. Touch this tip in the water just above the fry. You will need to feed them several times a day.

This powder is quite fine and is acceptable for many fry to start off with. But some fry find even this too big to eat. For instance, the newly hatched Angelfish cannot eat this powder. It needs to eat infusoria or baby brine shrimp for the first few days.

Baby brine shrimp is a very important food for most fish fry. Most livebearers will eat lots of baby brine shrimp, and this definitely makes them grow faster and healthier even if livebearers are among the fry that can be raised on powdered flake food alone. The eggs of Brine Shrimp are carefully processed and collected and are sold in many pet stores. The aquarist can purchase these eggs, hatch them and use them to feed fry. One advantage in hatching the eggs at home is that these can then be fed special additives that will directly be transferred to your fry. Some fry are too small to be able to eat newly hatched brine shrimp and such fry will need infusoria the first few days before they can start eating brine shrimp.

After they start feeding, the fry usually grow pretty fast. Feeding should be done several times a day for optimal growth. Aquariums that are well lit, well planted and nicely filtered provide the best conditions for rearing fry. Having a fixed feeding schedule also helps the fry grow faster. Frequent water changes are a MUST if you want healthy fry. Remember that the filtration in an aquarium that contains small fry will be less efficient than the filtration in a proper aquarium as the circulation has to be kept lower. The number of feedings is also higher and the wastage will also be more. Thus frequent water changes; stable water chemistry and sufficient warmth contribute greatly towards the well being of your fry.

Failure in Reproduction

Reproductive failure is one of the most frustrating experiences for the aquarist, especially a beginner. These failures can occur at any stage of the reproductive cycle. The first major stumbling block for the beginner aquarist is failure to get the fish to spawn. For success, some species need the perfect set up. A deep knowledge of the species, the right food, the right temperature for the species you select in addition to any necessary spawning triggers have to be used efficiently. For the beginner it is also important to choose the right species to breed as some species are much easier than others to breed. A separate spawning aquarium with or without plants according to the needs of your species is the first step in the right direction. Novice breeders also need to be very careful with the water chemistry. You cannot just put your selected pair in a tub of water and expect them to get on with their work. You have to get a fully working testing kit and learn how to use it. Higher quality in the breeding stock directly influences the viability of the spawn. The quality of the offspring will be affect by the kind of water in which it was bred.

Sexing the fish correctly is the next big step. In some species, differentiating between the two sexes is very difficult indeed. So, this is not to be taken lightly.

Do not keep checking on your fish every few minutes. This will make them stressed. Stressed fish will not spawn. Fish that are too young or too old must be avoided at all costs. Left to itself in nature, the female fish will select the male fish that is in its prime. Males that are too young or too old will not have viable sperms, and the eggs that are laid as a result may not get fertilized.

Once the fish has spawned, problems may arise at the time of hatching too. The biggest impediment to hatching is water quality. Bad water quality is not conducive to spawning, and even if the fish do spawn, the eggs will not develop properly. As a result the eggs may catch fungus and die. If the eggs are removed to a hatching aquarium, care must be taken that they are not exposed to the atmosphere for long. The eggs dry up when they come into contact with air. The water in the hatching aquarium must be as similar to that in the original aquarium as possible. Sudden changes in temperature will halt the development of the egg. Hard water will cause the shells of the eggs to harden, and in very hard water the shells can become too hard and make hatching difficult or impossible. If the water is too soft, the eggs may instead collapse.

Sterility is also a common cause for reproductive failure. In some species, it is seen that the absence of any male will cause two females to pair off. Obviously, no eggs will be fertile after such a spawning. Pairing off a female with a male that is too old or young will also cause the eggs to be underdeveloped. Again, hatching of such eggs will never take place. Disease and vitamin deficiency are some other factors that play a decisive role in the ability of a fish to spawn. Over-feeding the fish and making them obese will rob some male species of their virility.

There are some varieties that are highly suited for the novice to breed. As stated earlier, livebearers are among the easiest to breed and will most likely spawn spontaneously in your aquarium without you even trying to coax them. Of these, the Guppy, the Molly, the Platy and the Swordtail are the easiest to spawn. Mollies and Guppies are very similar in their breeding patterns. However, newborn Molly fry are susceptible to protozoan infection. Sometimes, the Molly may also give birth to unformed fry that appear almost at the same time as the swimming fry. They appear as white eggs and must be disposed off without delay. Among egg-layers, the novice may want to try Steel Blue Killifish, some Dwarf Cichlids like Kribs, the Tiger Barbs, various Danios or the White Cloud Mountain Minnow.

Obviously, breeding fish is a reasonably challenging task, but it can be achieved quite easily, if the right steps are followed. Remember that as in humans the female carrying the eggs as well as the eggs themselves must be in the best possible surroundings. Maintaining the right condition inside the aquarium will help the dwellers of the aquarium to go about their work in a healthy manner.