You should only keep one species of Labyrinth fish per tank. Labyrinth fish include Bettas, Gouramis and Paradise fish. These fish are highly territorial and will fight and kill each other. Paradise fish grow much bigger than Bettas and will easily kill the Betta.
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The different varieties of Siamese fighting fish are all the same species. They just have different colours and fin sizes and shapes.
The breeders go to a lot of trouble to breed fancy varieties so if you want to keep the nice fins and colours, you try to breed the same type of fish. eg: blue with blue and long fin with long fin, etc.
Having said that, you can breed red with blue or whatever colours you like, and the same with fins (short with long), but if you do this, all the young will not look like the parents. Some of the young will look like the mum, some like the dad, and most will be a mixture and look like neither parent.
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To breed Bettas, have the male and female in separate tanks but have them near each other so they can see each other. Have floating plants on the surface and use an air operated sponge filter in the tanks. Raise the water temperature to 26-28C (79-82F), and put a coverglass on the tank.
Feed the male and female 3-5 times per day with dry, live and frozen (but defrosted) foods. Raw/ cooked prawn/ shrimp is a great food for bringing fish into breeding condition, mozzie larvae are too.
Do a 75% water change and gravel clean the substrate every day or every couple of days to keep the water clean.
The male will build his bubblenest and hang around it. When he has had a nest for a week you can introduce the female. She should be fat and her white ovipositor should be clearly visible sticking out her butt. Monitor the 2 fish and make sure the male doesn't bash the female.
If the two fish are compatible, the male will display to the female but he won't attack her. They will swim next to each other and press their sides together for a moment, and the female will expel some eggs and the male will fertilise them. The male will then grab the eggs in his mouth and spit them into his bubblenest. The fish will continue to release eggs and sperm until the female has no eggs left. Then the male will chase the female away. You need to remove the female now or should could be killed.
A few days after this, the eggs hatch and the clear baby fish (called fry) will stick to the glass and plants. The male will try to put them back in the bubblenest but some don't go back.
A few days after that, the babies start to swim around. When they start swimming around, you start feeding them.
Baby Labyrinths are very small and need small food. The following link has information on culturing foods for baby fish. You need to start the cultures a month or more before you breed the fish because it takes time for the cultures to grow. If you get baby fish and don't have live food for them, you can use the yolk form a boiled egg or buy powdered or liquid "fry food for egglayers", from pet shops. A boiled egg works well tho.
A couple of weeks after they have been swimming around and you add newly hatched brineshrimp and watch them grow. You need to do small 10-20% water changes and have an air operated filter in the tank with the baby fish. Keep the cover on for the first 2 months so the babies don't get exposed to cold air at the surface.
http://www.fishforums.net/threads/back-to-basics-when-breeding-fish.448304/
You remove the male after a couple of weeks or when he no longer shows any care for the young.