Tilapia breeding guide

Tilapia breeding colony quick start checklist

The following instructions are designed to get you up and running fast. These steps represent just one of the many tilapia breeding methods. We urge you to read the more in-depth explanations that follow this quick start checklist.

Note: For the purposes of these instructions, consider a newly breeding male as four inches long.

Set up an aquarium that is at least 6 times longer than the length of your male. Please note that tilapia will outgrow a minimally sized aquarium very fast. For this reason, we recommend that you consider using an aquarium that is at least 48 inches long.
Fill the aquarium with dechlorinated water.
On one end of the aquarium, place a terra cotta flower pot that is at least 1.5 times deep and wide, as the length of your male. Place the pot exactly 1.5 times the length of the male from end of the aquarium, with the open side of the flower pot facing the end of the aquarium.
In the middle of the aquarium, place 5 sections of PVC pipe that are at least 1.5 times as long as your females. the diameter of the PVC pipe should be 1.5 times the height of the female with her dorsal (top) fin retracted. Bigger is not better! Stack and glue the PVC sections into a pyramid shape using PVC cement. The PVC pyramid should be placed with the open ends facing the front of the aquarium, to keep the females out of the line of sight of the male, while he's at his flower pot.
At the opposite end of the aquarium, as far away from the flower pot as possible, place a 2" cylinder air stone.
Filtration inlets and returns can go anywhere in the aquarium, except at the end with the flower pot. Be careful to not create a water flow through the flower pot with your filtration return, as it will sweep out the eggs, while the male attempts to fertilize them.
Set your breeding aquarium temperature to 85º. Use a metal heater that has an alarm and an external thermostat if possible. Tilapia tend to bash into their heaters daily, and can easily break glass units.Maintain a pH of exactly 8.0. Do not rely on test strips, use an electronic pH meter for testing.
Use a UV sterilizer if possible to eliminate green water caused by the phytoplankton in healthy aquariums.
Feed your breeding colony a high protein diet. Feed no more than 1/2 teaspoon per day to the whole colony to minimize growth.
When your female is carrying eggs she will look as if she's sucking on a jawbreaker. She won't open her mouth to breathe, and she will not eat when you feed her companions. She will swim at the food as if she wants to eat, but she will stop short of taking any in. Wait two days before proceeding to the next step.

Note: The next three steps are intended for casual breeders. Commercial hatcheries use a variety of methods to incubate eggs, none of which allow the mother to remain in contact with her eggs.

Carefully move the female to an aquarium that is at least 3 times her length. This aquarium needs to be fully equipped with filtration and an air stone. Give her a section of PVC pipe to hide in. Also cover the filtration inlet with a fine mesh netting to prevent eggs and fry from getting sucked in.
Keep the temperature in the mothers aquarium at 85º. Do not feed her during this period.
In a few days she will release her tilapia fry, and you can carefully move her back to the main breeding colony aquarium.
Feed the tilapia fry a combination of algae discs and/or professional quality fry food. You can make a good substitute for professional fry food by crushing AquaMax 300 into a powder.

Interesting point: For laboratory study, when controlling the exact time of fertilization is required, we can remove the eggs and sperm from the tilapia and then combine them in a beaker. This is commonly done to compare how different species respond to specific conditions or feed ingredients at various stages of growth.

Aquarium tilapia breeding

For this guide we will focus on just one type of tilapia breeding, known as aquarium breeding. It is by far the easiest method of breeding tilapia fingerlings for use in aquaponics, fish farming, and other recirculating aquaculture systems. Other methods of tilapia breeding, that are mentioned here for completeness, but aren't a part of this guide are:

Cage - Including cages in ponds.
Pen - Including pens with cages.
Pond - Including ponds with cages and pens.
Tank - Including tanks with pens.

The clear glass of the aquarium allows you to constantly monitor the activity of your tilapia breeding colony. You will be able to witness aggressive behavior, and position additional retreats if necessary. You will be able to see any injuries while there is still time to treat. And most importantly, you will be able to determine the exact date that your female(s) begin to carry eggs.

What is a tilapia breeding colony?

Basically a male, and two or more female tilapia, constitute a breeding colony. If it was just one of each, it would most likely be called a breeding pair, or couple. But aside of the nomenclature, a breeding colony is called such because it consists of several members.

Understanding breeding propensity

Not all tilapia have a natural tendency to spawn. Many amateur fish keepers make the mistake of labeling a non-productive male as being "impotent", which would indicate that the male was unable to spawn, but it's not that simple. In fact, most tilapia males are not driven to procreate at all. Even in a "colony" where a breeding male has his chromatophores displaying perfect breeding colors, the females still make all of the decisions. If she doesn't have the inclination to breed, every few weeks she will simply bear down on her egg sack at first morning light and let her tank mates enjoy a meal of fresh eggs.

Understanding the breeding process

Inside of a female tilapia there is an egg sack that can hold approximately four eggs for every gram of her body weight. The female produces eggs as an involuntary biological process and they are stored in the egg sack. As the egg sack fills, the female begins to bloat and she starts to feel some internal pressure. Now she has to make a decision: either propagate or evacuate. Nobody knows for sure how a female with the propensity to breed arrives at her decision, but many experts agree that her actions are primarily based on environmental conditions and perceived threats to the survival of her species. It should also be noted that she may feel the need to evacuate her egg sack before it is completely filled, giving the impression to the fish keeper that she is producing more eggs than other females, but it's just fewer eggs more frequently.

Trade secret: If a colony gets too comfortable, they are content to swim around thinking about their next easy meal, but if they get too stressed they won't breed at all. Lakeway Tilapia employs several methods to keep them somewhere in the middle. The trick is to keep them "thinking" that there is an imminent threat to their numbers so that they are driven to procreate for the survival of their species.

So let's explore evacuation first. The female is feeling pressure and has decided that she doesn't want to spawn with the male. Maybe she doesn't perceive any threats to their species, or perhaps she simply doesn't have the inclination to breed. She may also perceive the male as weak and she doesn't want her offspring to inherit his inferior traits. All that is left for her to do is bear down and push her eggs out into the water. Within seconds, they are gone.

Now let's explore the flip-side. She has decided to spawn with the male. So she leaves the safety of her hiding spot and shows the male her bloated belly. Assuming that he has the propensity to spawn, he responds by displaying his "breeding colors". Tilapia contain light reflecting cells in their scales called chromatophores. This gives them the ability to change colors, signaling the female that they are in the "breeding spirit". The male will also prepare a clean spot in his "lair", in our case a flower pot, for the female to place her eggs. The pair will then swim in circles around each other as if chasing each other's tails. In between their "dances" the male will dart into his lair in an effort to lure the female to the area that he has prepared.

Eventually, the female will go to his prepared spot and bear down on her egg sack, pushing out a few eggs while the male guards the entrance. As the female swims out, the male will go inside and fertilize the eggs. After he leaves, she will go back inside and pick up the eggs into her mouth then turn around and push out a few more. This process will repeat until the eggs sack is empty or until spawning is interrupted, usually by an aggressive female, known as an "alpha female"

Important point: One of the most common problems in tilapia breeding is the alpha female. As the name implies, she believes that she is the ruler of the colony. She may even mimic the coloration of the male and take up residence in the lair in an effort to fool everyone that she is a male. It is thought that this is an instinctual self-defense behavior.

The female will carry the fertilized eggs in her mouth while they incubate. At 85 degrees fahrenheit it takes about 48 hours for the eggs to form tails. Within 96 hours the eggs have a head and tail and are commonly referred to as "egg sack fry". By the seventh day, the fry are venturing out of their mother's mouth and exploring the world

What about breeding colonies with two males?

This is another area where amateurs and YouTuber's are highlighting their lack of knowledge. If you put two males with a genetic propensity to breed in the same tank, they will focus on killing one another until one is dead, no ifs ands or buts. You simply cannot have two bull males in the herd (think elk). The only answer is that one or both of the males do not possess the necessary traits to breed. So if you have one breeding male in a two male colony, the non-breeding male is taking up space at the very least, or interrupting breeding at the worst.

Tilapia breeding colony species selection

Some species breed more actively than others. For example, Blue tilapia breed more readily than Wami. The reason for this seems to be rooted in temperaments between these two species. Wami tilapia tend to be more skiddish, whereas Blue tilapia can get so used to your hand that they let you "pet" them when the conditions are right. In fact, we regularly see Blue tilapia spawning at one end of a 125 gallon aquarium, while we were working on the filtration at the other end, as if we weren't even there. Of course, as any aquarist can tell you, every fish has its own unique "personality"; but generally speaking, the more harmonious the females and the more aggressive the male, the more reliable the spawning, and the more likely that the eggs will survive into fry.

At least as important as the readiness of the species to breed, and arguably even more important, is the purity of the species. Many people are confused about the scientific naming of hybrids. For example, If you cross a male Nile, with a female Blue, scientifically speaking, the offspring should be called "blank" Nile Hybrid Tilapia, where the "blank" is any word that you choose. For example, Lakeway Nile Hybrid tilapia. Unfortunately, people don't do this. Instead, they drop that inconvenient "hybrid" word, and just go with names like Lakeway Nile tilapia. Unfortunately there are huge problems with this practice when it comes to tilapia breeding. Improper naming causes confusion that leads to misidentification of tilapia, contamination of genetic lines, and unreliable rearing and harvesting parameters. This can result in catastrophic financial losses to tilapia farmers.

Now is a really good time for you to read our page on tilapia genetics. It will help you understand tilapia breeding colony species selection better than anything that we could re-write on this page. So seriously, go read it and come back. We'll hold your place on this page until you return.

There are five species of pure strain tilapia common to tilapia breeding in the United States. They are: Blue, Nile, Mozambique, Wami, and Zilli. Blue tilapia are by far the easiest to manage for breeding purposes, as well as the most appropriate species for our overall average climate. Consider Nile a close second because what they lack due to their intolerance to cold water, they almost make up for with their ability to survive in poor water conditions, making them a good choice for the absentee tilapia farmer. Mozambique would have to be the third pure strain species of choice, but only because Wami tilapia are incredibly finicky, and there's only very limited data on breeding Zilli tilapia.

As far as cross breeding tilapia, the first and most famous hybrid is the Red tilapia. A lot of people call this a "Red Nile" but it's no more Nile than it is Cocker Spaniel. If you want more information on red tilapia, check out our tilapia myths page. A far superior cross that was developed in the late 50's, and brought to the United States in the late 70's, is a predominantly-male cross between specially culled strains of Wami and Mozambique. Of course, it would take about 20 more years before tilapia farming took hold in the United States, so there was plenty of time to cull each species for the most desirable traits. The results of these efforts are the Wami hybrids that we have today.

Important Point: To cull a species simply means to take away undesirable traits from each subsequent generation by only breeding pairs with desirable traits. Genetic diversity and inbreeding is avoided by preventing spawning with previous generations. Done properly, it takes many years to bring a naturally occurring trait into dominance.

Other hybrid crosses that get some mention on the Internet are "White Nile", which is a possible hybrid cross between a Blue female and a Nile male; and the Hawaiian gold, which is a possible line of Mozambique. We say that these are "possible" because they appeared on the Internet a few years ago absent any scientific study or documentation, however the results are hypothetically possible. Neither of these tilapia are farmed to any measurable degree, regardless of what their re-sellers would have you believe.

to be continued...

Tilapia breeding questions

I’ve had my breeder colony for just over 10 weeks now, and 3 of my females have been holding eggs within the last 2 ½ weeks. All three held their eggs for about 7 days, then spit them out, and the eggs didn’t look like they had developed much. Is it possible that my male is not mature enough to fertilize the eggs yet?

Because you said that your females were carrying eggs for seven days, I'd be more inclined to blame the water temperature and/or pH. Tilapia females use mouth feel to determine if their eggs are properly fertilized. Normally they will swallow any unfertilized eggs. However, the texture of the eggs in her mouth, and therefore the feel, can be masked by an out-of-range pH. In addition, the water temperature plays an important role in the incubation period of fertilized eggs. At 85 degrees, egg development begins immediately after they are fertilized, and by the fourth day, they should resemble small fish, with a small egg sack attached. By seven days, they should be swimming in and out of their mother's mouth, and by day ten, she should be refusing to allow them to re-enter her mouth.

Double check your pH to make sure it is exactly 8.0, and make sure that your water temperature is 85 degrees. I recommend using a digital pH meter instead of test strips.