The fish at Mt. Parnell typically spawn from about mid-April until early July. Most of the broodfish will spawn several times in this period. Spawning is carried out by the pond spawning method or the heated pool spawning method although in both cases the desired end result is to have fertilized eggs on the spawning mats.
Selected broodfish are placed in spawning ponds that are equipped with racks to hold spawning mats a few inches from the surface of the water. Early in the spring the males can be seen chasing the females around the pond, signifying that spawning may occur at any time. When the female is ready, one or more males will follow her on top of the spawning mat. The female releases her eggs and the male(s) simultaneously releases milt (seminal fluid containing sperm) and fertilizes the eggs.
Heated Pool Spawning
Selected broodfish are placed in concrete pools overnight where the water temperature is heated. The next morning the broodfish spawn the same way as in the pond spawning method, except they are confined to constantly be on top of the spawning mats.
In this method of pond stocking, a specified number of spawning mats containing fertilized eggs are taken to an outdoor production pond that is partially filled with water. The fertilized eggs should hatch into fry in about three to five days.
In 2004 eight hatching tubs were added to enhance production at Mt. Parnell. Spawning mats with fertilized eggs are moved from the brood ponds to a hatching tub. The eggs hatch into fry in three days and are moved to an outdoor production pond several days later. Stocking ponds using the fry transfer method eliminates some of the guesswork regarding how many fry/fish are within each given pond.