Tropical places have successfully raised tilapia because it is hardy and tolerant of intensive farming (high population density). It grows swiftly, reproduces easily, resists illness, and can bear handling. It may be raised in cages, concrete tanks, or earthen ponds.
After carp and before salmon, tilapia is the fish that is farmed the most globally. With 1.8 million tonnes produced in 2015, China was the leading country.
The Nile, Mozambique, and Aureus tilapia are the three species that are employed in aquaculture the most commonly. They consume little amounts of largely agricultural byproducts (oil cakes made from plants that produce oil, cotton, or corn), organic fertilizer (liquid manure), and granules up to four times a day due to their small stomachs. The fingerlings receive additional animal byproducts (meat meal, blood meal, fish meal, and fish oil), vitamins, and more protein than the adults do.
Eggs can be laid every three to four months by mature females (from the 12th week in the case of the Nile tilapia). The males build the nests where the females lay their eggs, and the females carry the fertilized eggs in their mouths until the eggs hatch. Once the fingerlings are big and strong enough, they are kept nearby (10 millimetres). Three females are fertilized by one male to increase fertility. Water temperature must be meticulously controlled because tilapia can only breed at a minimum of 22 degrees Celsius. To avoid cannibalism, larger fingerlings are kept apart from smaller ones in the nesting area.
Growth varies depending on the breed, sex, and variation (density of fish, food, water temperature, saltiness of the water). In intensive aquaculture, Nile tilapia gain between 1 and 2 grams per day in water maintained at 25 degrees Celsius. Males and improved breeds kept at a low population density at 30 degrees Celsius produce better outcomes. These fish can weigh up to 650 g after seven months in the ocean, however with a high population density, they only weigh 300 g. As soon as the fish are caught, they are immediately packed in ice and shipped to the location where they will be sold fresh or processed. Tilapia are especially prized in processed meals like fish fingers due to their lengthy shelf life.
How Many Eggs Are Produced by Tilapia?
Each time, tilapia typically produce 200 to 1000 eggs. Some species have an annual egg production capacity of up to 1,200.
Per gram of body weight, the egg sack of a female tilapia may carry about 4 eggs. The process of producing eggs is forced. The female begins to bloat as the bag fills, at which point she determines whether to breed or expel the egg sack. Although it is unclear exactly what influences this choice, researchers think that perceived dangers and other contextual factors play a big role.
Recognizing the breeding procedure
A female tilapia has an egg sack inside of her that can hold about four eggs for every gram of body weight. As a result of an uncontrollable biological process, the female produces eggs, which are then kept in the egg sack. The female starts to bloat and experience some inside pressure as the egg sack swells. She now has to choose between spreading or leaving. No one is certain how a female with a predisposition to reproduce makes her decisions, but most experts concur that she bases most of them on the environment and perceived risks to the survival of her species. It should be noted that she could feel the urge to leave her egg sack before it is fully developed, giving the fish keeper the appearance that she is generating more eggs than other females when in reality she is only doing so more frequently and with fewer eggs.
So let’s first examine evacuation. Due to pressure, the female has decided she does not want to mate with the male. Maybe she doesn’t see any risks to their species, or maybe she just doesn’t want to reproduce. She can also view the man as weak and not want her children to inherit any of his flaws. She simply needs to press forward and expel her eggs into the water. They vanish in a matter of seconds.
Let’s now examine the opposite. She has made the decision to mate with the man. She then exits her hiding place and displays her protruding belly to the man. He responds by showing his “breeding colors,” indicating that he has the predisposition to spawn. Tilapia have chromatophores, or light-reflecting cells, in their scales. They are able to change colors as a result, letting the female know they are in the “breeding spirit.” Additionally, the male will make an area in his “lair” that is spotless for the female to lay her eggs, in this example a flower pot. The two will then begin to swim in circles around one another as though tagging each other. The male will dash into his lair in between their “dances” in an effort to entice the female to the location he has prepared.
The female will eventually approach his planned position, bear down on her egg sack, and force a few eggs out as the male keeps watch at the entrance. The male will enter the female as she swims away and fertilize the eggs. She will return inside after he has left, pick up the eggs in her mouth, and then turn around and put out a few more. Repeating this cycle will stop spawning after the egg sac is empty or until an aggressive female, sometimes known as a “alpha female,” intervenes.
The alpha female is one of the most prevalent issues in tilapia breeding. As the name implies, she feels that she is the ruler of the colony. In an effort to convince everyone that she is a male, she might even adopt the colors of the male and settle in the lair. This is seen as a natural self-defense response.
While they are incubating, the female will carry the fertilized eggs in her mouth. The eggs produce tails after around 48 hours at 85 degrees Fahrenheit. The eggs become “egg sack fry” after 96 hours when they have a head and tail. By the seventh day, the fry are leaving their mother’s mouth and venturing out to see the outside world.
The mouth brooders
Aquaponics and aquaculture frequently employ the maternal mouth brooders of the Oreochromis genus. The Blue tilapia (O. aureus), Mozambique tilapia, and Nile tilapia (O. niloticus) are the three most popular varieties of tilapia (O. mossambicus).
The Oreochromis engage in intricate courtship rituals. The male fiercely repels other males who approach the nest after he has constructed a nest. The male guides a female to the nesting place when he is ready to lay his eggs. After that, the fish circle the nest, with the male butting up to the female’s genitalia to encourage egg laying. The courtship is frequently brief, seldom lasting longer than a few hours and frequently lasting only a few minutes.
The eggs are laid by female tilapia in pits (nests), and after being fertilized by males, the female gathers the fertilized eggs in her buccal cavity, where she will keep them until they hatch.
Different tilapia exhibit mouth brooding behavior. Because Sarotherodon galilaeus are biparental, both parents care for the eggs and protect the hatchling fish.
While the female Sarotherodon melanotheron leaves the nest, the male undertakes mouth brooding.
It makes sense to stock one male to three females for best hatchery practices. The eggs should be taken out to stop the females from incubating their eggs orally. This makes hatching easier to manage and enables the female to lay the following batch of eggs.
Large numbers can be reared in ponds or hapas; lesser numbers can be spawned in spawning tanks.
Jar hatching has also been discovered to be a successful method for producing more eggs without much supervision.
Tray hatching may be a more effective technique to employ for fostering the best health conditions and for having the most control. The disadvantage of this, though, is that it requires a lot of labor and isn’t the most economical method.
How quickly do tilapia reproduce?
If the conditions in the tank are good enough, a single female will normally produce 200–1000 eggs per spawn, and she will spawn every 4-5 weeks or so (“decent” is pretty easy for tilapia).
By using methods including manual sex separation, hybridization, chromosomal modification, and hormone sex reversal, it is possible to produce only male tilapia. The most effective and affordable technique is sex reversal with 17a-methyl testosterone.
The most frequently cultivated fish on earth and the second most common species raised in aquaculture are tilapias. The top five producers of tilapia are all Asian nations, namely China and Indonesia. Due to enhanced breeding techniques, hybridization, and sex reversal, consumer markets have significantly increased over the 2000s. Tilapia is among the top ten fish that Americans consume, according to the National Fisheries Institute. If you’ve ever had fish at a restaurant, there’s a good chance you’ve had tilapia.
Range: Because tilapia are exclusively native to Africa, many U.S. States classify them as invasive or non-native species. Tilapia have been purposefully introduced into fresh and brackish waters all over the world to limit the growth of aquatic plants. Wild tilapia populations exist in the United States in Southern California as well as various lakes and streams in Texas.
Tilapia are robust, quickly developing fish that can grow to ten pounds in weight and live up to ten years. Tilapia have the same shape as a sunfish or crappie, and they can be distinguished from other fish in the Chiclid family by having an interrupted lateral line. They have long dorsal fins and deep, laterally compressed bodies. The dorsal fin’s leading edge is highly spined. The pelvic and anal fins both have spines. They are often broad, vertical bands of dark coloring that can be seen along the sides of fingerlings, fry, and even adults.
Tilapia can be found in murky rivers and lakes in the wild. Biology and Life History: They are herbivores that primarily consume algae, plankton, and other types of plant matter. They do not build up poisons in their body as a result of their eating habits. Wild tilapia can spawn at any time of the year, and females can lay up to 1,200 eggs in a single spawn. Some species lay their eggs in nests, while others mouth-brood their young, keeping them in the males’ lips to keep them safe from predators. The mouth brooding species are the most commonly farmed because, while laying fewer eggs, their fry have a substantially greater survival rate. Both intensive and extensive aquaculture systems are used to raise tilapia. The majority of farmers favor outside clay ponds. When farming is done properly, females spawn every 17 days. Market-sized fish can be produced in seven to ten months if water quality and temperature conditions are optimized. To prevent unintentional imports of the species into local waters, which could harm sport fish populations, tilapia production is closely regulated in some southern U.S. regions.
Stocking: It is customary to place 5,000–8,000 fish per acre in order to produce one pound of fish. 20,000 to 28,000 males per acre in aerated static water ponds with a 20% water exchange. To transport and store tilapia, Texas Parks and Wildlife states that an exotic species permit is necessary.
Administrative Code of Texas:
I Subject to adhering to SS57.116(d) of this title, a person may transport Mozambique tilapia or triploid grass carp to a private pond or facility or possess Mozambique tilapia in a private pond or facility (relating to Exotic Species Transport Invoice). Only if they have been gutted or beheaded are mozambique tilapia and triploid grass carp that are kept in a private pond or facility allowed to be taken.