What the heck is a Triploid?
{by ODFW Biologist Chris Kern 1999} I have been getting a lot of questions about triploid Kokanee. Some of you may have heard that ODFW is experimenting with a way to make Kokanee grow larger and not spawn (so they won’t die because of spawning). Hopefully, this will help explain some of this, although I am still available for questions. Basically, triploidy refers to manipulation of chromosome numbers during cell division right after fertilization of the egg. By shocking the eggs with pressure, temperature (what we use), or chemicals, cell division is manipulated, resulting in three of each chromosome, instead of two (diploid) which is normal for most animals and plants. The result in the case of Kokanee and many other fish is sterility. The same thing is done with plants to influence their growth rates, etc. The theory here with Kokanee is that by making the fish sterile, they won’t mature sexually and won’t spawn and die, like they normally do. In addition, they should be able to de
