Recently, I lost about 30 percent of my fishes to cannibalism. It wasn’t a good experience but I hold myself responsible for negligence. This is the reason I am writing this piece. Most breeders don’t know how much is been lost to cannibalism on a per minute basis. Lots of activities go on under the water that we are not aware of, and one of such activities is ‘fish eating fish’. The popular proverb that says bird do not eat other bird’s intestine do not hold for fish. As a matter of fact fish predates on themselves to grow. It is the best example of the survival of the fittest.
Cannibalism is a slow-killer, it is a great reducer of fish population and can lead to monumental loss. This is why Grading fish into groups of similar individual sizes should be a common management practice in fish farming. To fail to observe this is to risk running into Loss.
Apart from losses from cannibalism, there are other benefits of separating your fingerlings into similar individual sizes. These includes the following:
1. It helps to remove the fast-grower from the slow- growers. No matter how hard one try fish do not grow the same. Sorting however helps in separating and similar sizes into the same pond.
2. Sorting helps to reduce cannibalism. As stated earlier, fish predate on themselves to grow. It is an inevitable truth. Apart from mortality, another problem that reduces the fish population drastically is cannibalism. Sorting, done regularly helps to control your fish population greatly.
3. Sorting improves supplementary feeding efficiency. ‘Different strokes for different folks’. Different sizes of fish requires different supplement. You cannot be assured that all your fishes have the required supplement except through sorting. Except you sort, the big ones keeps getting bigger while the smaller ones remains the same. The reason is that the bigger ones takes advantage of the smaller ones by eating the better chunk of the feed while the smaller ones eat crumbs leaving them with a less nutritious feed.
4. It increases the accuracy of stock estimates for better monitoring and feed administration