``How do fish make babies...and can I watch?''
Fish breed in many ways, and yes you can watch. In fact, watching fish breed is one of the great fascinations in the hobby because there are so many interesting breeding strageties among fish.
Egglayers have many methods of laying their eggsEgg scatters usually scatter eggs around weeds, or onto gravel. The male chases the female during spawning, and the eggs are fertilized as they fall. Spawning runs can be spectacular to watch since the fish race around the tank and ignore anything else, including food. Examples of egg scatterers are tetras, barbs, rasboras, and danios.
Breeding and Aggression
``Help! Why have my angelfish (or kribs or African cichlids) started killing everything in my tank?''
``Why did my female platy just turn around and eat her babies?''
``I think my tetras spawned. Where are the eggs?''
``My fish just laid eggs. How do I keep the eggs or babies from being eaten?''
``I have fish in a breeding setup, but they just won't breed.''
``Why do my fishes' eggs keep fungusing and the fry dying?''Many fish will not breed successfully without specific requirements. These include:
- A mix of male and female fish.
- I know this sounds obvious, but some fish are not easy to sex. In species that are difficult to sex, is best to start out with at least six young fish so that you are certain of getting both males and females. Starting with many fish also gives monogamous fish a chance to pick compatible mates. Sometimes if a single male and female are introduced, they will not breed. Other fish, like livebearers, killifish, and polygamous cichlids need more females that males so that females are not harassed by amorous males.
- Extremely clean water.
- Most fish will not breed if there is any ammonia or nitrite present, and large amounts of nitrate are toxic to baby fish. Some fish, especially tetras, must be bred in a breeding tank that is bare and sterile so that their eggs do not fungus.
- A varied diet.
- Fish that are producing eggs need better food that fish that are just living in a community. Breeders call the process of specially feeding parents conditioning. Conditioning foods include live foods, fresh frozen foods, or spirulina based foods. Find out the specific requirements of the fish you intend to breed.
- The correct environment.
- Fish that breed on substrates need proper substrates to breed on, like peat, rocks, shells, or plants. Some fish are shy and require a lot of cover, caves, or dim light. There are also fish that require a particular water chemistry to breed. Examples are discus, which require very soft, acid water or African cichlids which require very hard, alkaline water.
- External cues.
- Many tropical fish breed in the rainy season. When it rains, streams flood, the water hardness drops, and there is thunder and lightning. Adventuresome breeders with rainy season fish may try large water changes with distilled water, watering cans to simulate rain, strong currents, and even flashing lights and loud noises. Temperature changes may also stimulate spawning, as may changes in the light/dark cycle.
``My fish bred, but I cannot raise the fry to adulthood.''
Rearing fish can take some work. Baby fish require clean water, and some require special foods.