White crappie (Pomoxis annularis) and black crappie
(Pomoxis nigromaculatus) are popular sport fish.
Some of the best crappie fishing in North America occurs in
Mississippi. However, management of crappie populations in
small impoundments presents some difficult challenges.
Crappies are prolific spawners that can quickly overpopulate
small impoundments resulting in many undesirable fish less than 6
inches. Fisheries biologists have tried to manage this
problem but strongly discourage stocking crappie into small
In the 1990s MDWFP and the University of Mississippi teamed up
to create a sterile crappie that would not overpopulate a small
impoundment. The result was the Magnolia
This crappie is a cross between the female white crappie and the
male blackstriped black crappie. The blackstriped crappie has
a dark stripe from the dorsal fin down the top of the head and
mouth to the throat. This is a naturally occurring color
The offspring retain this blackstripe making it easy for
biologists to monitor the population after stocking.
Fertilized eggs are pressure shocked to induce triploidy which
causes sterility. Triploid fish have three sets of
chromosomes instead of the normal two sets (diploid).
Because this crappie cannot reproduce they may put more energy
into growth and may grow larger than a normal fish in a similar
Spawning may begin in February and extend into May at water
temperatures of 59 - 65°F. Crappie are collected from the
wild and transported back to the hatchery for spawning.
At the hatchery, eggs are collected in a small plastic bowl by
gently squeezing the abdomen of the female.
Milt is obtained from the male by removing and then chopping up
the testes. It is activated with a small amount of water and
quickly poured over the eggs.
The eggs and milt are gently stirred together for 1 - 2 minutes
using a turkey feather. The turkey feather is used because it
is gentle on the eggs.
After 5 minutes the fertilized eggs are transferred into a
pressure chamber and subjected to an 8,000 psi pressure shock to
Then, the eggs are poured from the pressure chamber into a bowl
and rinsed. After rinsing, they are transferred to a McDonald
hatching jar for incubation. The eggs hatch in 2 - 3 days at
62 - 65°F.
Fry (newly hatched fish) are then stocked into a hatchery pond
(100,000 fry/acre) where they eat natural food items. The fish are
harvested in the fall and stocked when they are 4 inches.
Before stocking, a sample of fish is sent to the lab to
determine triploid percentage. The target is 100% to eliminate
unwanted reproduction, but 90% is considered good. The
process, although gaining in effectiveness, is still an art with
many tricks yet to be discovered.
Fisheries biologists now have a better way to manage crappie
populations and anglers can catch bigger crappie in small