The Basics of Angelfish Breeding
Angelfish who are ready to breed will select mates on their own. If they are in a group of fish, they will choose an area of the tank to claim as their own and then protect it from their tank mates. Once they have privacy, the pair of fish will choose a flat surface in the tank. They will prepare the surface by cleaning it for around 24 hours. Then the female will lay the eggs and the male, following closely behind her, will fertilize them. They will repeat the pattern several times for around two hours, and after 24 hours the eggs will be completely fertilized. The parents will watch over the eggs and the fry once they hatch, as angelfish are not prone to eating their babies.
Signs of Spawning
The most noticeable sign that spawning is about to occur between a pair of angelfish is the pairing-off behavior. Females who are ready to spawn will display a bulging belly and may become more aggressive towards tank mates. Two adult angelfish that are ready to spawn will spend time grooming each other. As the time for spawning draws even closer, the parent fish will begin cleaning a spawning site.
Finding a Breeding Pair
The most difficult part about breeding angelfish in captivity is determining which fish are males and which are females. This is nearly impossible until mating has begun. For this reason, most aquarium owners will keep around six adult fish in their tank. This provides a good probability of having at least one of each gender. The fish are then watched closely for signs of pairing off. Angelfish who have been on a healthy, live-food diet will be ready to breed when they reach 8 to 12 months of age. At this age they are at least 2 inches in length.
Breeding Angelfish in Captivity
Angelfish do not need any special setup to reproduce in captivity. If the tank is large enough for the fish it contains, with a male and female of breeding age, they will likely spawn. Aquarium owners who wish to encourage spawning can provide their angelfish with a spawning slate. This allows the owner to remove the eggs to place them in another tank if desired. This can encourage faster breeding, as fish that are not caring for their young can breed again within 10 days. Whether they are left with the parents or hatched in a separate tank, the eggs will hatch between 48 and 72 hours after they were laid. The fry do not need to be fed at first, as they will live off of their yolk sacks until about the fifth day after hatching. The best food for new angelfish fry is freshly hatched brine shrimp.