Tilapia are prolific breeders. With the proper environmental conditions, tilapia can easily reproduce and provide ample fish for home consumption or for growout for commercial farms.
Tilapia are classified as either mouth brooders or substrate spawners.
The members of the Oreochromis genus are maternal mouth brooders and are a common choice for aquaponics or aquaculture. In terms of popularity, the Nile tilapia (O. niloticus) is the most widely cultured tilapia, followed by Blue tilapia (O. aureus) and Mozambique tilapia (O. mossambicus).
The Oreochromis display an elaborate courtship behavior. After building a nest, the male aggressively repels other males that enter in proximity to the nest. When ready to spawn, the male displays a darkened color and leads a female to the nesting area. The fish then swim around the nest and the male will butt against the female genital area to induce egg laying. The courtship is often brief, lasting only a few minutes in many cases and seldom more than a few hours.
The female tilapia lay their eggs in pits (nests) and after fertilization by males, the female collects the eggs in her mouth (buccal cavity) to maintain them until hatching.
Other tilapia display different mouth brooding behavior. Sarotherodon galilaeus are biparental , with both parents brooding the eggs and defending the newly hatched fish.
The male Sarotherodon melanotheron is the parent that performs the mouth brooding, while the female leaves the nest.
Members of the Tilapia genus are substrate spawners. The male and females will build a nest and defend it together. A male and female will typically form a bonded mating pair and courtship can last up to a week, but usually takes place over several days.
Females will first lay their eggs in pits (nesting area) dug in the bottom of a lake or pond. You can simulate this condition in a tank by adding some substrate (e.g. gravel) which allows the tilapia to evacuate a nesting area. The male will then spawn and fertilize the eggs. After fertilization, the parents guard the eggs, chasing away predators and making sure proper aeration is maintained for hatching.
Tilapia rendalli and Tilapia zillii are two popular commercially-raised species that are substrate spawners.