Breeding pet fish can be an engaging and intriguing experience. Most aquarium fish such as goldfish, guppies and koi are relatively easy to breed. While you may or may not be around to observe the actual mating process, the body language of your pet fish can give you an indication that they are ready for mating. Different aquarium fish display a wide range of fascinating courtship behaviour which signals that the mating ritual has begun.
Look for a male fish chasing a female fish, or several male fish pursuing a single female fish. During courtship, male Oscars, bettas, goldfish and koi chase the females. The male acts rough, rubs the sides of the female with its head and shoves it around to squeeze the eggs out and fertilise them. Some females get injured and stressed in the process, and may even jump out of the tank if it is not covered.
Watch out for a pair of fish caught in a lip-lock or jaw-lock. Cichlids and Oscars perform a variety of rituals, including locking lips with each other during mating.
Observe male bettas and cichlids preening in front of the females. These male fish show off their colourful fins, vibrate their bodies and perform a mating dance while courting the females.
Look for bubble nests on the surface of the aquarium water. Male bettas and gouramies use the bubbles from their saliva and plant debris to produce a bubble nest for the female to lay eggs.
Observe mating activity of pet fish reared in a pond during the morning hours. Fish tend to mate when the water rapidly heats up between dawn and 9 a.m.