I am collecting eggs from my female Tilapia every 2 weeks. I seem to have got the formula just right because my females are producing a steady stream of eggs. This time (with the help of the Jobug Cuzzie Wuzzie) I rinsed eggs from 13 females and placed them (the female fish) into a container. If the female wasn’t holding eggs I placed her in another container. 18 females were holding no eggs. This is a fantastic ratio (42%) There must have also been 9 females that I didn’t catch as I should have 40 females in this tank.
What I need is a third container to place the captured males because I find myself catching the same males over and over again and at the end of the process the fish seemed rather stressed.
Amongst the eggs there are always some hatched or partially hatched babies. These I catch and put directly into the hatchery tank. The eggs go into the trusty incubator. I am a little concerned this time because I have quite a few thousand eggs and I am worried that the water flow in the incubator won’t be sufficient to turn all the eggs over. This results in a fungus forming and killing the egg before it hatches.
My last batch of fry I treated with MT (Methyl Testosterone) feed for 2 weeks which converts them all into males. These males are much faster growing and seem to show no ill effects from the “tweaking” of their sexual orientation. I have found that the mortalities amongst treated fry is quite high (about 30%) compared to untreated fry (under 10%). I have decided to split todays batch and treat only half of them to get a direct comparison.
Here are some shots of the eggs collected today (Batch 2008/12/B)
Time for a beer.