The Basics Of Fish Breeding
One ambition that many fish keepers have is to breed their own fish, the first time that this is achieved can be a very exciting time for the owner but often we are caught unaware by accident as our fish produce young in the main aquarium, leaving us ill equipped to raise these young and get the full benefit from the fish. Being forewarned with useful information can help us to prepare for breeding programmes or even how to deal with unexpected young should the event arise.
Purposely attempting to breed fish should not be a decision taken lightly, being overrun with juvenile fish is not only unfair to the fish but can also be upsetting as they start to die off due to the lack of tank space available for them to grow on.
It is wise to always have a spare tank to move the young into, it is quite natural for many species of fish to attempt to eat their young or the eggs and moving them avoids this issue, also if the fry are in their own tank they can be provided with the special needs that are required to raise them successfully.
As mentioned above, these tanks are known as growing on tanks, in some cases two of these may also be required if the fry develop at different rates and the young need sizing to keep similar sized juveniles in the same tank.
If you do not intend to keep all of the juveniles, if any it is always wise to find someone who will take them off your hands, many aquatic stores will do this but do not expect money for them unless they are a well sought after species, in most cases the stores will offer you credit which will cover the cost of feeds, small tank accessories etc.
Some species of fish will require a separate tank just for the breeding pair and no other fish so you see that things do have to be planned of the projects are going to work and you have the best conditions for breeding.
Fish can be divided into separate groups as regards the breeding which are as follows, live-bearing and egg laying fish, with the egg layers there are variations on the methods used to raise the young by the fish but these will be covered later.
Live Bearing Fish
This group of fish are usually the first that keepers gain any experience from as regards their fish producing young. They tend to be more tolerant of water parameters and usually breed profusely as long as they are in water!. The also seem to be the cheaper species of fish to purchase and can provide valuable experience before moving onto egg layers that tend to be more fussy. Included in this group are Mollies, Platys and Guppies. The young are produced as miniatures of the parent fish and can hide away as soon as they are born to prevent themselves from becoming instant fish food. Their colours may be slightly different to the parent fish, but as they mature these colours will develop.
When breeding live-bearers it is wise to add hiding places in the tank, floating plants are great for providing these and the breeding cycle is usually every 4 weeks. The females are usually capable of storing sperm so dont be surprised if you get unexpected fry in the tank from a new fish even if there are no males present.
Males develop a modified anal fin, this is known as the “Gonopodium” and is used to transfer the sperm to the female, the anal fin literally curls onto itself to make a tube, with the females, their anal fin always stays the same.
To get most Live bearers to breed you literally have to just let them get on with it, as long as the water quality is high and there are hiding places for the fry, you should always get plenty of young fish. Another advantage is that because the young are so well developed they will take the same diet as the parent fish but you do need to crush it into smaller pieces as obviously they do have smaller mouths. There are commercial foods available for live born fish if you wish to use these instead.
Egg Laying Fish
When t comes to breeding these species it can be trickier than breeding live bearers. Some egg layers will still breed readily while others are very fussy about their conditions etc. Researching through fish profiles will give you a good idea of which species are suited for you. Just to make things even more complicated, egg layers as such can also be divided into smaller subgroups which are as follows :-
Egg Scatterers, Bubble Nest builders, Mouthbrooders and Substrate and Cave Spawners. The groups are pretty self-explanatory but a quick description of each is starting with the egg scatterers, this group will spread their eggs all over the tank, this can include the substrate, the tank glass and any equipment such as filter pipework or even heater guards. You tend to find with these that the amount of parental care is very minimal if any and the fry are left to their own devices once hatched, you may also have to separate the parent fish from the eggs before they become a tasty snack.
Bubble nest builders are fascinating to watch, when the males are ready to breed they build a nest of bubbles for the eggs by using debris as well as the bubbles and the eggs are deposited in this nest, any that fall out are quickly returned by the male as he assumes the parental care.
Mouthbrooders are usually associated with African Cichlids, when the female lays her eggs they are incubated in the mouth of the female, even after hatching the young are safely kept in there until they are large enough to look after themselves, initially the parent lets the fry leave the mouth for short periods, shepherding them back at the first sign of danger.
Substrate and cave spawners use similar methods for depositing the eggs, cave spawners are more secretive and like to hide away when spawning out of the way of prying eyes, substrate spawners deposit the eggs on the substrate or flat rocks, these can be added to breeding tanks to encourage the spawning.
Many species of egg layers may take a few attempts to become good parents so dont get disheartened if they eat their first few batches of eggs, this is often the case with such fish as Angelfish, they will become good parents in time and care for the eggs and the fry. Patience is the key with fish breeding and time is also involved as water changes become a must, with the fry tanks this is performed on a daily basis.
The satisfaction of successful spawns totally outweighs the effort required to produce juvenile fish especially at the start of new projects and I would recommend keepers to attempt this if they have the time and facilities to care for the young and parent fish properly!!