Broodstock are adult fish that produce eggs and sperm. The broodstock at Jackson National Fish Hatchery are reared for three years to adult size, at which time eggs can be taken and fertilized with sperm. The eggs are then incubated, hatched out and raised to stockable sizes.
Trout spawn once a year. The cutthroat trout at this hatchery spawn during the spring and early summer months. Eggs are taken from each female by gently pressing her abdomen. If she is "ripe" she will readily release her eggs into a shallow pan.
Sperm is collected from male fish in the same manner and is mixed with the eggs to fertilize them. The fertilized eggs are placed in incubators, which resemble a chest of drawers, where a steady flow of 48 degree Fahrenheit water supplies oxygen to the developing embryos. The eggs take about five or six weeks to hatch into tiny "fry". The fry are nourished for several weeks by the remaining yolk sac until it is used up and they swim to the surface in search of food.
Hatchery trout are fed a specially formulated dry food which, when the fry first begin to feed, is about as fine as table salt. As the young fish grow, the particle size of their diet is increased. Trout grow at the rate of about 1/2 inch per month in 48 degree Fahrenheit water. The trout are stocked into lakes and streams at sizes ranging from one to eight inches long, depending on the requests of state and federal biologists.
Last updated: January 13, 2012