The quantity of eggs that an Atlantic salmon lays is usually dependent on its size. The bigger the salmon, the more eggs it can carry. The rough estimate for how many eggs a salmon will lay is 2,500 to 7,000.

Salmon, like many other animals, will dig out nests in the gravel of the river to lay their eggs in. These nests are called "redds." After the eggs have been laid, the salmon will cover them with gravel to protect them. Eggs usually hatch around late April to early May. 

Salmon eggs are a deep orange color and have two small black dots. These are their eyes. If you look closely, you may even be able to see the outline of their body and organs. Eggs don’t gain their black dots until fertilized. 

Alevins are the newly hatched baby salmon! For a few weeks, they will feed off their egg yolk and sack. Alevins hatch with their eggs attached to their stomachs. During this stage, they stay close to the bottom of their gravel homes to stay protected.

As they get older, they will start to absorb their eggs and grow bigger. After they have fully absorbed their eggs, they have entered the fry stage. This is called being “buttoned up.”

 Alevin are also very easy to identify! They are small, almost translucent fish with a bright orange, oval-shaped belly. Late in the alevin stage, they will start to develop some of their green color and a dorsal fin.

Once they are fry, the salmon finally begin to look like what we think of when we hear “fish.” Atlantic salmon fry are green on the top and silver on the bottom. They have small elongated dots across the upper parts of their bodies. These are called parr marks. Parr marks are part of the salmon's natural camouflage. When they reach the parr stage, these marks are fully developed and more prominent.

In the fry stage, all of their fins have developed. Fry are roughly an inch long. 

Once they are fry, the salmon start to move out of their gravel-bed homes to forage for food. Fry feed on various micro and macroinvertebrates.

Salmon remain fry from around 6 months to two year. Fry may take longer to become parr due to lack of access to sufficient food and ideal water temperatures.

As the Atlantic Salmon grows out of the fry stage and becomes bigger, they are called parr. Salmon become parr roughly around 1 year. 

Parr are usually 3-9 inches long. Their parr marks are fully developed. The green from the fry stage has turned into a cold dark gray. The midsection is a very pale green accompanied by their silver bellies. All of their features are purpose-built to help them blend into their environment.

In the parr stage, their diet is made up of small insects and invertebrates.

Towards the end of the parr stage, their bodies slowly begin to prepare to migrate to seawater. They move towards the estuaries where they will live in their next stage. 

When salmon are between 1-3 years old they are called smolt.

The smolt stage marks when the salmon bodies will begin to acclimate to saltwater. For this to happen, the smolts spend much of their time in this stage in estuaries.

Smolt feed on fish like capelin and sand eels. 

This stage is crucial to their growth. During it, they grow much larger and become more effective at evading predators. Later in the smolt stage, they will finally migrate into the ocean.

Kelt are salmon that have bred and ventured back to the ocean after breeding. Unlike Pacific salmon, Atlantic salmon continue life after they spawn.

In this stage, the salmon are usually pretty worn down and weak. If they are fortunate enough to make it back to the ocean, they will spend their time eating in hopes to be able to spawn again.

When kelt swim back to freshwater to breed, they have already adapted to eating saltwater fish. When they return to the freshwater, they are unable to eat for the duration of time they spend in the river. 

Kelt usually look like a much thinner version of regular Atlantic salmon. If they are physically able to, they will come back year after year to breed again.

Since kelt are thinner and weaker, by nature they are more susceptible to diseases and easier targets for predators.