Rainbow Trout are native to the western half North America (from Alaska down to Mexico), though they have been naturalized in many parts of the world including the UK and the rest of North America. They have white mouths and gums, and black spots on their tails. They are very similar to Steelhead Trout, except the Steelhead ventures into salt water.
The average Rainbow Trout caught weighs 5 pounds (2 kg), though they can be up to 16 pounds (7 kg) when 6 years old. The upper life span tends to be 7 years.
They do not die after spawning.
The colour of the flesh can depend on what the fish ate. The flesh of farmed trout tends to be a very pale pink that turns beige when cooked. Trout caught in the wild has pinker flesh. Both have a very mild flavour.
The usual size of Rainbow Trout that was sold at fish markets used to be 8 to 10 oz (225 to 275g) after cleaning. Now, larger sizes of 1 1/2 pounds cleaned (700g) are available. Two fillets can be cut from these larger ones.
It is best to cook Rainbow Trout with the skin on to help hold the flesh together. Another benefit of leaving the skin on during cooking is that there is a thin fat layer under the skin which also helps stop the flesh from drying out during cooking. The skin is edible when cooked, if that's to your liking.
Introduced into eastern half of North America in the late 1800s.
The scientific name of the fish was changed when scientists realized that Rainbow Trout were related to Pacific salmon