Tilapia are good breeders when the conditions are anywhere near compatible to the survival of the brood.  Water temperatures above 80 degrees Fahrenheit, good water quality, abundant food, and relatively quiet places for the female to nest are all that are required.  The female will, in general, lay down eggs which the male will fertilize.  The fertilized eggs will be taken up by the female into her mouth and will remain there until hatched out.  Once hatched, the tiny fish fry will swim in groups like clusters of dark eyelashes nearby the mother.  At the slightest sign of danger, the fry will flee back into the mother’s open mouth and disappear.  In years past this gave the impression that these wonderful fish were cannibalistic as many other species are.  However, far from being cannibals, mouth brooders, as they are referred to, behave in the most favorable manner for the highest survival rate of their young.  This type of nurturing lowers mortality rates greatly and gives the tilapia a tremendous advantage over other species in the wild, often to the point of crowding out native species.  This is why culturing tilapia is done with a license and under conditions that will inhibit any escape into local rivers or streams.

            The fish farmer, like all livestock farmers, is usually at pains to replace his sold stock.  Tilapia, however, provide abundant replacement stock at no cost.  The clouds of fry or fingerlings can be netted from the raceway walls where they tend to congregate and placed into grow out tanks.  This is an important step for two reasons.  One, there is a single stage of maturation during which tilapia young will eat one another.  The fingerling, up to about two inches, will make a meal of the tiny fry.  But once grown beyond this size, tilapia generally do not predate on other tilapia.  Nevertheless, if left in the raceway, despite the mouth-brooding mother’s best efforts, some fry stock will be lost to fingerlings.  Thus removal to separate grow out tanks is beneficial.  Additionally, fry require a feed which contains a higher level of protein than larger fish in order to achieve maximum growth rates.

            Tilapia, being omnivores, thrive on protein.  The general rule is that the higher the protein diet the faster the fish will grow.  The faster the fish grow, the sooner to market or your family’s dinner table they go.  Tilapia grow at approximately the same rate, one tenth of total body weight per month, throughout their life cycle.  Yet to watch fry grow under maximum growth conditions, one would think the fry must be expanding at some explosive rate and then slowing in growth as they get larger.  This is just a trick of ratio.  A tiny fish which gains a tenth of size grows in all directions at once and goes from eyelash size to noodle size in what seems no time at all.  It has actually only been increasing by ten percent a month though.  As the fish grows larger that same ten percent appears on the animal as an almost undetectable addition to the eye.  Thus the larger fish seem to slow in growth though they are really still growing at the same ideal rate. This ten percent growth rate is one of the most productive in the animal kingdom, fish, fowl, or mammal.  Combined with the previously mentioned conversion rate of food to size, the tilapia is the most efficient and quickest to table livestock in the world.