Egg Taking & Spawning
Egg taking and spawning operations for Hagerman take place at Idaho Department of Fish and Game's Sawtooth Hatchery and its East Fork Salmon river satellite station. Steelhead fish darken in color when they are ready to spawn. The fish are collected and examined individually to determine acceptability. Each female will provide as many as 4,000 eggs depending on size.
The eggs are fertilized by taking milt (sperm) from the males and mixing it with the eggs.
Fertilized eggs collected at spawning facilities are washed and placed in incubation trays. Each tray holds about 7,000 eggs. The eggs receive a continuous supply of fresh water to remove wastes and ensure an adequate supply of oxygen. When the eggs reach the "eyed" stage they are shipped to Hagerman Hatchery from late April to early June where incubation will continue in specially designed hatching jars.
Newly Fertilized Eggs
Although life for steelhead begins when the female's egg is fertilized with milt, the naked eye can see little change.
The first visible sign of life in the egg is the eye, a tiny internal network which occurs within a few weeks. At this period of development, the eggs are shipped to Hagerman in insulated boxes.
Sac Fry or Alevins
Eggs hatch about sixty days after spawning. The yolk sac of the egg remains attached to the fry, providing a source of nourishment during the first three to four weeks of life.
Swim Up Fry
After the yolk sac of the egg is absorbed by the fry, they swim to the surface to begin feeding and are called "Swim up" fry.
The fry are provided a specially formulated diet that assures all their nutritional needs are met. As young fish grow, they are fed larger pellets and less frequently.