Very expensive to do. They're a cross between a female white crappie and a male "blackstriped" black crappie. The blackstriped crappie, which is native to the White River basin in Arkansas, has a dark stripe from its dorsal fin all the way down the top of its head and mouth to its throat.


"The offspring -- the triploid crappie that won't reproduce -- retain that black stripe, and that's a good thing for us," Wilkens said. "It just makes it really easy for us to monitor their population after stocking. We can tell the difference really easily."

When female crappie begin forming eggs at the hatchery, officials harvest them into a small plastic bowl by gently squeezing the abdomen of the female. A substance called "milt" is then obtained from the male, activated with a small amount of water and quickly poured over the eggs.

Here is why this works:
Fertilized eggs are then pressure-shocked to induce a state known as "triploidy," which causes sterility. Triploid fish have three sets of chromosomes instead of the normal two sets possessed by fertile diploid fish. "You get a couple of great benefits from the triploid crappie," Wilkens said. "First, obviously, they won't overpopulate small fisheries. But also, because these magnolia crappie don't reproduce, they may put more energy into growth and may grow larger than a normal fish in a similar environment.



Last edited by ewest; 10/20/11 07:33 PM.