You can purchase eyed ova or harvest your own. Those tiny little eggs seem so delicate, don't they? They are, but you can handle them with a little tenderness and care. Give them what they need and they'll reward you. Soon, they'll hatch out and become alevins, the second stage of their lives.
For the DIY fish farmer with a stock of eyed ovum, it's time to really get started. The rearing boxes should already be resting in the ponds for several weeks before the ova are ready. The edges of the boxes will be about 6 inches above the water and they box itself is moored so it won't move.
Now it's time to hang the hatching trays. The trays are suspended inside the rearing boxes with the water level coming up to the top edge. This is where your ova will be calling home until they hatch and are strong enough to swim out into the rearing box.
The ova will need to be carefully washed before they can be added to the hatching tray. The technique for cleaning the ova is quite simple. A large container is filled with water and ova, the water is drained off and clean water added. This process is repeated until the water runs clear.
After washing, the ova can be placed on the hatching trays. This can be done by tenderly ladeling the ova, a few at a time, out of the cleaning container. Hold the ladel very close to the tray and empty the ova as gently as possible. Never pour the ova from a height, the impact will certainly kill them.
ova will hatch at a far higher rate if they are spread into a single layer. This is a very delicate process and requires a soft touch. A feather is just the tool for the job. Gently running the feather over the ova will spread them out with minimal damage.
Despite taking all the necessary precautions, some of the ova will not make it. They can be easily identified by their white or opaque color. Dead eggs need to be removed from the hatching trays immediately. Leaving them in the trays can lead to fungus growth that can damage your entire stock.
A natural way to clean out dead ova is to introduce fresh-water shrimps to your hatching trays. They will only eat the dead ova and won't damage live ones. These mini fish farm housekeepers will clean out animal and plant debris the water too.
Keeping a lid over the rearing boxes will also help to protect ova from fungus growth. Fungus loves light and a lid will cut off the light and keep growth down. A lid is also a great way to protect ova and young fish from predators.
In a short time, the first fish will begin to hatch. These young fish, known as an alevin, will have a large bag on their underbelly. This is the yolk sac. The fish will require no food to begin with. They will feed off of their sac for the next six weeks or so.
Eventually, the DIY fish farmer will see that some of his alevins have started to move away from the pack at the bottom of the hatching trays. They'll begin to swim up against the current.
Now's the time to start feeding them finely processed foods. Their yolk sacs are nearly gone now and they're moving on to the next stage of their lives.
In the next article of this series, we'll check out the "fry" stage of fish and the steps the DIY fish farmer does to ensure their survival. From Http://Fish-Farm.BiblioFlip.Com
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