As my Tilapia mature ...

[Bob Vento]

My fingerling tilapia are beginning to mature, The 20 fingerlings were introduced to the empty fish tank in March and are growing bigger each day. (Some more than others)

- Is there a minimum age of the fish before they begin to breed?
- When can I expect them to start breeding?
- How will I know they are breeding? 
- Is there an optimum water temperature for breeding to be encouraged? 

All water quality levels, which I test every 2 days, are right on the money.

I would appreciate any and all information that can help in this process.

Thanks,
Bob

[Ken Elrich]

Hey Bob, looks like you and I are on track with each other. I started with 25 during the first or second week of march.

Most of my fish are 6 - 8 inches in length now. the are showing signs of breeding now by chasing of the females and trying to lure them back to the males defended area. Tilalia are said to be able to breed at roughly 4 - 6 months of age. they will breed when the mood strikes them, just like us! lol. If they breed to soon the egg count is way lower! small egg counts as low as 100 -  150. it is all based on the brooding mothers size, body weight in grams is usually quoted here. Mine being around 8" in length I am hoping for 1000 to 2500 eggs. you will notice a male and female hanging around together and rubbing against each other, until you see the female dropping her eggs and the male depositing milt on them then the female will pick them up and hold them in her mouth. As far as temp, I have seen 80 - 88 degrees F. I keep mine around 84 - 85 F. Tilapia are real hardy fish and water quality even thou very clean water is nice isn't all ways necessarily. I have visited a few commercial grow houses and alot of their breeder tanks were far from clean.  The biggest problem I find is the sexing of the fish. But I am getting better at it. My males are real pale in color with bright orange to red fins, when the mood to breed their fins turn dark black and the chase is on! the females will mimic the males a bit, but when the mood hits them they turn a dark blue almost black color. I have set up a nursery tank for my expecting mothers and I have isolated my first breeding pair (1 Male and 3 females) to a 55 gallon tank and the rest I have placed into a 650 gallon tank for grow out. (some of them will also breed within the school of fish in the 650 tank)     

[Bob Vento]

Ken,

WOW your fish grew a lot faster than mine did. They are growing out well but hardly in the 7"- 8" range.

What are you feeding them ... Miracle Grow?     How often are you feeding them?

Do you find that the males are larger than the females? Is that how you determine the sex? Cuz I have a few larger than the rest tilapia that seem to be the dominant fish in the tank.

Regards,
Bob

Ken Elrich said:

Hey Bob, looks like you and I are on track with each other. I started with 25 during the first or second week of march.

Most of my fish are 6 - 8 inches in length now. the are showing signs of breeding now by chasing of the females and trying to lure them back to the males defended area. Tilalia are said to be able to breed at roughly 4 - 6 months of age. they will breed when the mood strikes them, just like us! lol. If they breed to soon the egg count is way lower! small egg counts as low as 100 -  150. it is all based on the brooding mothers size, body weight in grams is usually quoted here. Mine being around 8" in length I am hoping for 1000 to 2500 eggs. you will notice a male and female hanging around together and rubbing against each other, until you see the female dropping her eggs and the male depositing milt on them then the female will pick them up and hold them in her mouth. As far as temp, I have seen 80 - 88 degrees F. I keep mine around 84 - 85 F. Tilapia are real hardy fish and water quality even thou very clean water is nice isn't all ways necessarily. I have visited a few commercial grow houses and alot of their breeder tanks were far from clean.  The biggest problem I find is the sexing of the fish. But I am getting better at it. My males are real pale in color with bright orange to red fins, when the mood to breed their fins turn dark black and the chase is on! the females will mimic the males a bit, but when the mood hits them they turn a dark blue almost black color. I have set up a nursery tank for my expecting mothers and I have isolated my first breeding pair (1 Male and 3 females) to a 55 gallon tank and the rest I have placed into a 650 gallon tank for grow out. (some of them will also breed within the school of fish in the 650 tank)     

[Bob Campbell]

I started with 2" fingerlings in February. They are 6" to 8" now.  They bred a couple months ago and those fingerlings are now about 2".   I have a feeling the fish I purchased were a bit stunted, because my 2" fingerlings look more muscular than the 2" fingerlings I purchased.

I know most literature says to feed twice a day, but I feed mine many times per day in small amounts, and I try to keep duckweed available throughout the day, but lately I have had to concentrate on replenishing the duckweed.

I'm just starting to introduce regular pond food to my fingerlings.  Up till now I have been feeding them spirulina and an expensive tropical fish food from the pet store.  Well spirulina is expensive too, but I think it's important to give them a good start.

I've read that 80F to 85F is ideal, but that's too warm for aquaponincs.  I keep my tanks at about 75F.

[Ken Elrich]

I have been feeding them Aquamax 500, and I feed them all the time. If i get near the tank and they swarm to the top I feed a hand full. and if they still swarm after it is gone I give them another hand full. I also feed duckweed. I have found it difficult to grow duckweed both inside and outside the basement. So what I do is freeze it and just drop an ice cube size frozen cube in the tank once or twice a day, normally at night before I head to bed. As far as sexing the fish I have referred to pictures and articles. and read as much as I can find. but the most reliable is  when there are less fish in the tank the females seem to stay solid blue color and males go pale with the dark black fins. As, I continue to separate and pair off breeders I just add and remove as I discover who is who. My females have kept up with the males fairly well. I guess due to the amount I feed them. I also have no pebbles, rock, etc on the bottom of my tanks. just bare glass. if I am gone for the day and feeding is less they clean up the tank by eating their own waste. This is a common practice with large fisheries. they will pump other fish species waste to a large canal and fill it with tilapia to dispose of it, then they have another fish for market at no additional feed expense.

[Jon Parr]

I assume you have blues, Bob V? Blues will breed at 8 months, mossambicus at 3 months. Water temp needs to be above 80, and a water change always triggers a spawn. Feed them constantly, as often as you can, a belt feeder is best. First time mothers often have small batches, 25-50. Seasoned girls have 300-500 eggs each time, and 500-1000 for older bigger mothers. Ken, over 1000 eggs is pretty rare, but 2500? Maybe if your mothers are 3 or 4 lbs, but not 8".

Bob V, size doesn't dictate sex, especially with young tilapia. In my experience, the first male to hit 2" becomes dominant, and all he can do is dance for the ladies. His focus is so intense, that ge will neglect eating, and invariably another male will pass him up sizewise and take over the lead role. Once a female starts breeding she doesn't grow much more, or grows very slowly. If you want bigger females, keep them from breeding by segregation or water temps below 75.

[Ken Elrich]

Thanks John nice to know. guess I had high expectations. 

But I will take what ever they give me.

[Sheri Schmeckpeper]

Bob, what kind of tilapia do you have?

[Bob Campbell]

Sheri I was told when I bought them that they are Mozambique Tilapia

[Dr. George B. Brooks, Jr.]

Hi Bob what state are you in? In Arizona I have not seen any Mozambique tilapia in a long time.  Hard to tell at that size and from the video what kind you have. Which of the fish below do the adults look like?:

Mozambique tilapia: http://www.nt.gov.au/d/Fisheries/Content/Image/tilapia/Telapia(1).jpg

Nile tilapia (Notice the tail stripes): http://nas.er.usgs.gov/XIMAGESERVERX/2012/20120530095223.jpg

Blue tilapia (Again note the tail stripes): http://aqua-fisher.narod.ru/Vid/CICHLIDAE/AFRIKA/FOTO/Oreochromis_a...

Nile/Blue Hybrid: http://www.kidsfishing.org/images/nile%20tilapia.jpg

[Dr. George B. Brooks, Jr.]

Couple of notes. Feed them at 3% of their estimated body weight per day and they will grow well. (454 grams = 1 pound)

Here is the calculation: A 10g fish requires .3 grams of feed the first day.

At a FCR (food conversion ratio) of 1.5 to 1 (that is for every 1.5 grams of feed provided, the fish will add 1 gram in weight: yes you can do better but it is an easy number to work with) the second day that fish will weigh 10.2 grams and will need 3% of 10.2 grams of feed and so on. Naturally this degree of precision is not realistic but I wanted to show you how the calculation works. Approximations based on total numbers of fish, average weight, visual estimations on if they are eating all their feed and weekly adjustments work just fine. Also the 3% is an average. They need more as fry and less as adults. But again it a good average number for the farmer to work with.

To add @Jon's reply, depending on the species and hybrid, females can grow slower or faster than males. In the ubiquitous nile/blue hybrid found across the US (very hard, darn near impossible to find pure bred fish..really it is) the level of sexual dimorphism (differences between male and female) can be low. However, female growth rates are naturally slower when they have a mouth full of eggs two weeks out of a month and so are not eating. Backyard farmers growing mixed sex populations tend to harvest the larger fish so may indeed be selecting for small females (they survive and so pass their genes to their offspring).

[Dr. George B. Brooks, Jr.]

Ok, how about this? http://www.wcs.org/~/media/Images/wcs%20org/new%20and%20noteworthy/...

or This?

http://www.bio.txstate.edu/~tbonner/txfishes/BLUE%20TILAPIA,%20juve...

[Bob Campbell]

@Dr George - I spent a few hours looking through pictures on the internet and this is what I believe I have.

Oreochromis mossambicus

There is a spot on the dorsal fin (red arrow).

There are no vertical bands on either the body or the tail

When mating they turn very dark and the tips of the fins and area under the mouth turn red as in a red belly tilapia

The dorsal fin is one continuous fin rather than two prominent lobes.

There is algae on the aquarium glass, the fish do not has spots other than the dark spot on the dorsal fin.

.