A Community and Forum For Aquaponic Gardeners

Flip side, keeping your tilapia from breeding out of control!

Now the other side of tilapia being easy to breed is that they can get distracted from growing into plate size meals if they are too busy getting it on!!!

What methods do you use to control breeding and what are the pros/cons of those methods?

I've used cage culture in my tanks to stop the mixed gender tilapia from being able to pick up the eggs and brood them. However, you can't leave any hides in the tank as they will serve as a surface to pick the eggs up from. I discovered this the hard way last spring. Cage culture is hand since you can lift up the cage to make catching the fish easier. Drawback to cage culture is controlling where the feed goes to make sure the fish in the cage get as much food as they should. Also, it is kinda handy to be able to raise other types of fish in the tank outside of the cage but trying to catch those other fish while there is a cage in the way can be a real challenge.

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Permalink Reply by Jeff Givan on March 6, 2010 at 9:49am

Once again I am not speaking from actual experience, but I read where you can put a net raised a few inches off the bottom of your tank to keep the females from picking up the eggs. Have also heard that in large populations they won't breed either. And some species don't reach sexual maturity until after they reach skillet size! I think this link will provide some insight into breeding the different species of Tilapia as well as some of their traits.
http://www.aquaticcommunity.com/tilapia/Oreochromis-mossambicus.php

Permalink Reply by TCLynx on March 6, 2010 at 10:15am

I suppose there is another way to keep them from breeding. Keep the water too cool for that. However, this doesn't seem to stop the males from trying and pestering the females and with the water cooler they don't eat and grow as well either so I don't recommend it.

And of course there is the option of all male stock.
With all male stock they will grow faster and bigger. Question is, how are you getting all male stock. There are three methods I know of.
1- the cheapest one is they feed the fry hormone laced feed to cause them to all develop as males. I'm not quite sure how I feel about adding more hormones to my food production though.

2-manual sorting to get all male fingerlings for grow out. These will cost more to buy since they have to be a certain size before you can even tell the difference and of course the manual labor involved in handling all the fish. There is also a fairly high chance of error while sorting and some fish don't develop as early as others so it gets really hard to tell sometimes.

3-Cross breeding to get hybrid offspring that will be all male. "penny fish" or some other method.

Permalink Reply by David Hart on March 17, 2010 at 8:49pm

I'm just starting to use cages. I see several positive things by doing this...First, others have already mentioned...the females wont be able to pick up the eggs, lift the cage and there they are.
Other positives, I'm using different cages- that way I can have different age/size tilapia already graded.
I'm keeping the bottom of the cages, just over a foot off the bottom of the tank....I plan on adding some channel cats down there. They should help to keep the bottom clean, plus I get a variety of fish to eat. TC is correct though...it may be a trick to catch the cats with the cages in the way.

I got my first cage from a really nice lady...THANKS TC !

Permalink Reply by James Steven (Steve) Bird on March 19, 2010 at 9:16am

Our grow out tank has several hundred tilapia in it. We control excess recruits by keeping two African catfish (both males) in the tank. Catfish love tilapia fry!

Permalink Reply by AJ Grottke on February 23, 2011 at 8:41am

If i were to put a type of netting to keep them off the bottoms of the FT to prevent babies, how high off the bottom would it have to be? 2"or 3" or do you need more. Also what is the reason for this working?

Permalink Reply by TCLynx on February 23, 2011 at 5:22pm

So long as the netting is a couple inches off the bottom of the tank for the entirety of the cage, then 2 inches should be fine.

This works because Tilapia are mouth brooders. This means that in order to perpetuate the species breeding goes like this. Male creates a nice "love nest" where he clears the bottom of debris and then entices a female to lay her eggs there where he will fertilize them, then She picks the eggs back up in her mouth and broods them there. If the female can't pick the eggs back up, they are not likely to hatch because they need the constant aeration that the female usually provides by pumping water through her mouth with the eggs and tumbling them. So, if the tilapia can't access the bottom of a tank because they are in a cage they are not likely to successfully breed.

Permalink Reply by AJ Grottke on February 23, 2011 at 11:47pm

What kind of material do you suggest using for the cage, will any type of plastic mesh or netting do? Also, is there any issues with eggs being left on the bottom of the tank? Do you have to clean it out before your restock the tank, or do they not even lay eggs because the male cant make his love nest? I would like to find a source of strains ND-21 or ND-41 in small quantities to avoid this breeding frenzy altogether, but im having trouble finding places that sell only 50 fingerlings. Either way, im really excited to get some tilapia going :)

Permalink Reply by TCLynx on February 24, 2011 at 7:47am

I've used fish netting and PVC pipe to make cages before, just have to choose netting small enough to keep the fingerlings from swimming out of the cage while they are still small. There are many types of netting or plastic mesh that can be used for the purpose. Question will be what sorts of plastic are you comfortable with using in your aquaponics system? Does it have to be FDA approved for food contact or are you ok with things that are simply appropriate to aquaculture? You might also want a finer netting around the water line to keep food from floating out of the cage.

I've never worried about eggs that might fall through. I figure they usually got sucked up by the pump or maybe my catfish that were swimming outside the cage ate them. Either way they would be hard to see in a big fish tank.

Permalink Reply by AJ Grottke on February 27, 2011 at 11:12pm

Where can you get the fish netting, at a local outdoor/fishing shop, or online? Im not too concerned about FDA approved but i would like to try and get something that seems safe.

Permalink Reply by TCLynx on February 28, 2011 at 8:28am

I generally got mine online but I've also gotten some from Aquatic Eco Systems. How much and do you want the flexible stuff that you will frame out with PVC or a stiffer cage material that won't require much frame?

Permalink Reply by AJ Grottke on February 28, 2011 at 9:48am

Probably the stiffer stuff, but maybe a little bit of the flexible as well to put at the top of the cage and on my FT outlets, to to prevent the feed from going oustide the cage, or into the GB. Also on a side note, what type of fish net do you use to catch the fish, just a regular one for fishing, or one from online? Thanks for all your info TC :)

Permalink Reply by TCLynx on February 28, 2011 at 12:56pm

I've used just fish nets from sporting goods stores for catching fish. Or aquarium nets for small tanks.

Catfish barbs do tend to get caught in some types of netting and the aquarium nets have some times trapped my small catfish if I wasn't careful.