Breeding Tilapia joka

[freshwaterfishfan]

Hi all,

I need some help breeding Tilapia joka. I have a group of 4, of which two have paired up nicely and have spawned now 3 times. The first two times I left the eggs with the parents and nothing. Third time, I took the flower pot with the eggs, kept in in the same tank in a net divider, aerated it and hoped. Some eggs fungused but a majority hatched. But from there the numbers just started dwindling day by day and by day 6 I was left with nothing. I got 4 "fry" to the stage of looking like fish but with very large yolk sacs. They did not live 24 hours. The tank is a 40G breeder. Moderately soft, acidic (pH6), tea colored water, temp about 80.
First question: Am I doing something wrong with the water parameters?
Second: I have read about using methlyene blue to help with fungus, etc. I plan on setting up a 10G with a sponge filter and extra aeration to try and hatch the next batch. How much m. blue do I use per gallon?
Thanks
Steve Thornton

 

[retro_gk]

What exactly do you mean by the fry dwindling in numbers? Did they die or just vanish from the net breeder? If they vanished, it is possible the other fish just sucked them out of the net.

The water in your tank is a bit too soft and acidic, IMO. Go with a neutral pH and low to medium hardness.

Also, give them time. I've had fish take 6 or 7 attempts to get it right. There is no hurry, unless you are dealing with very rare fish. If you decide to raise the fry separately, I do not recommend methylene blue. You will not have problems with fungus if your hatching tank is filled with water that is similar to the one in your tank but, not from the tank itself.

 

[tjudy]

Ahh... to blue or not to blue? That is always the question.

I agree with Rahul that is the water the eggs are in is the same as what they were laid in the viable eggs probably will not fungus if there is no blue. Bad eggs will fungus with or without it. Acriflavine works too, and is probably better than blue because blue is toxic to most plants.

That being said, I use meth. blue if I am moving eggs to a different hatching tank with different water. I have also found that eggs that get constant care from parents (like cichlids) some fungal prevantative helps. Eggs that are scattered (rainbows, barbs, danios, etc) rarely need it.

If you can get the fry to hatch with parental care, separating them into an incubator will improve survival.. I do not use net breeders... as mentioned teh adult fish can suck fry right through the mesh. Here is what I use:

http://www.tedsfishroom.com/incubator.html

 

[Randall]

Tilapia joka

Hello Steve,

Looks like you're getting some good advise here. I have only a few things to add.

Moderately soft, acidic water should be good (GH: 2-3, pH: 6.0-6.6, conductivity low (<200)). Tilapia joka is found in coastal regions in Sierra Leone and Liberia and eats plants, so a planted tank and supplimenting their diet with algae waffers is recommended. Also, is your pair's spawning site in close proximity to the filter intake tube? If it is, position the tube far from the spawning site. As Rahul suggests, sometimes young fish experience a few false starts before getting it right. Each failed spawning attempt, however, strengthens the pair bond.

As for the methylene blue and/or Acriflavin, both are powerful dyes that kill nitrifying bacteria. For this reason, I wouldn't recommend using either. Additionally, Acriflavin has been linked to infertility in fish. As Ted suggests, unfertilized and/or defective eggs will not develop weather you use dye or not.

Good luck!

All the best,

Randall Kohn