The Salmon Life Cycle

Hi there, my name is Fred and I LOVE fishing! I was out fishing today and I saw a fish I had

never seen before. My Dad tells me its called

a Salmon. I took a picture, let me show

you!

Salmon

I don’t know much about salmon…I would like to find out more about how they grow up!

Lets start at the very beginning….Eggs

The first stage of the life cycle. A femaleSalmon deposits as many as 10,000 brightpink eggs, about one-fourth inch in diameter.They are laid in the gravel of a stream. Afterabout a month, eyes become visible within

theeggs.

Lets think

Let’s think …..

• To protect them from predators and direct sunlight

• Were you correct?

Answer

Why do you think the eggs are laid in

the gravel of a stream?

AlevinIn late winter and spring, salmon eggs hatch andbecome alevins (pronounced ay-le-vins) .The alevin is a fragile creature with huge eyes and a large yolk sac protruding from its belly. The vitelline vein, running throughthe center of the sac, extracts oxygen from thewater. The at this stage remains under gravel,protected from predators and other hazards. Agood flow of pure water is critical to alevin survival.

Lets think

Let’s think …..

• The orange yolk sac contains a balanced diet of protein, carbohydrates, vitamins, and minerals for the Alevin to live off.

• Were you correct?

Answer

What could the large yolk sac be

for?

Fry

Alevins absorb their yolk sacs and emerge from

the gravel as fry in late spring and summer. About

an inch long, they are easy prey for larger fish.Fry feed on plankton and small insects. At thisstage, important survival requirements includegood streamside cover and an ample food supply.

Smolt

The fry loose their stripes and turn aSilvery colour. At the smolt stage, theyHead downstream. Four to six inches long,They swim seaward in late May during the

spring rains, and enter salt water, wherethey grow to

adulthood.

Adult

Ocean adult salmon spend varied amounts oftime in the sea, ranging up to five years. Theyeat as much as possible and grow rapidly in theOcean feeding grounds.

Spawning AdultUsually in the early summer of their maturing year, salmon begin to head back to their home streams, navigating at least partially by their sense of smell. They stop feeding as they enter fresh water, living on stored body fats. They struggle sometimes for weeks

againstfalls and obstructions to reach the same spawning beds in which

theythemselves were hatched. When a pair of salmon reaches itsspawning ground, the female digs a nest to lay her eggs in. The

maleFertilizes them by covering them with a milky substance known as

milt.The female then covers the eggs with gravel to complete the

spawningprocess. The salmon’s life is finished and within a short time it

dies andthe body drifts downstream, providing nutrients to the stream

systemas it decays

Nest Facts

Nest Facts

• The Salmons nest is also known as a redd

• The redd can be up to 16 inches deep in the gravel.

Lets see how much you have learned

Label the stages of the life cycle