There are six main stages of a Trout’s life. Starting with the egg, then Alevin, the Fry, Fingerling & Parr, Juvenile, and Adult.
Egg: Trout eggs have black eyes and a central nervous system that show healthy development. Egg hatching depends on the water temperature. The warmer the water the faster the eggs development and hatch, the colder the water the slower the eggs develop and hatch. The prime incubation temperature for trout is 48 to 50 degrees.
Alevin: Once the eggs have hatched they enter the Alvein stage of their lives. The small fish have a yolk sac that is used as food storage. Each Alevin start to develop adult characteristics. Alvein live close to the bottom floor until they loose their yolk sac.
Fry: When the Alvein stage is over, that is when the baby trout loose their yolk sac, then begins the Fry stage. The young Fry begin to feed of the surface, this is the stage that we begin to feed our small Trout.
Fingerling & Parr: When the Fry grow to 2 to 5 inches they have now entered into the Fingerling stage. When in develops large dark Markings it becomes a Parr. This is the stage we will most likely release our fish.
Juvenile: As a juvenile the trout still avoid predators like birds and even larger fish. They resemble adult trout but are not yet ready to spawn are makes babies.
Adult: In adult stage, is when the trout can spawn and reach sexual maturity? Trout turn bright in color. Once the fish spawn the Trout’s life cycle start allover again.
Questions the Kids Asked?
Q1: What kind of light are the fish sensitive too?
A1: Eggs are sensitive too artificial light, light that is produced in bulbs. It affects their metabolism and they don’t develop correctly. Natural sunlight does not affect the trout.
Q2: How can you tell if a fish is a boy or girl?
A2: You cannot tell if a fish is a boy or girl until they're in the adult stage. Mostly we can tell in the jaw structure of the Fish. Males have more of a hook and Females have more of a pointed jaw.
Q3: How do you tell how old the fish are?
A3: Fish are aged according to T.U.s.
Q4: What are T.U.s?
A4: T.U. stand for temperature units. T.U. measures trout because they are cold-blooded fish. That’s why taking T.U. are so important because they tell us what stage the fish are in and when they reach certain stages.
Q5: Why don’t we raise the temperature of the tank?
A5: If we raise the temperature too much more than their natural habitat they don’t develop correctly and they may die or not even hatch.
We obtained most of our information from www.ndow.org
