SRAC
Reproduction
In all Oreochromis species the male
excavates a nest in the pond bottom
(generally in water shallower than 3
feet) and mates with several females.
After a short mating ritual the
female spawns in the nest (about
two to four eggs per gram of brood
female), the male fertilizes the eggs,
and she then holds and incubates the
eggs in her mouth (buccal cavity)
until they hatch. Fry remain in the
female�s mouth through yolk sac
absorption and often seek refuge in
her mouth for several days after they
begin to feed.
Reproduction is best at water temperatures
higher than 80o F and does
not occur below 68o F. In subtropical
regions with a cool season, the number
of fry produced will decrease
when daily water temperature averages
less than 75o F. After 16- to 20-
day spawning cycles with 1/2-pound
Nile tilapia, fry recovery was about
600 fry per female brooder at a water
temperature of 82o F, but only 250
fry per female at 75o F.