Rainbow Trout Species Breakdown
Scientific Name: Oncorhynchus mykiss
Also Known As: Coastal rainbow

Rainbow trout are members of the trout and salmon subgroup of the Salmonidae family. Trout are one of the most popular freshwater species to fish for.. They are also one of the best tasting freshwater fish.
How to Identify a Rainbow Trout
You can identify a rainbow trout by their blue-green or olive green coloring with black spots throughout their body. Adults have a broad reddish strip along their lateral line.
Juvenile rainbow trout have dark vertical bars that are typical of most salmonid juveniles.
Rainbow Trout Size
Rainbow trout can grow up to 40 inches long and weigh up to 48lbs. They are more commonly found in the 15-25 inch or 1-5lbs range.
Rainbow Trout Size Chart – Length to Weight Conversion
Length | Weight |
10″ | 0.5 lb |
11″ | 0.68 lb |
12″ | 0.8 lb |
13″ | 1 lb |
14″ | 1.2 lbs |
15″ | 1.5 lbs |
16″ | 1.8 lbs |
17″ | 2 lbs |
18″ | 2.5 lbs |
19″ | 2.8 lbs |
20″ | 3.3 lbs |
21″ | 4 lbs |
22″ | 4.5 lbs |
23″ | 5 lbs |
24″ | 5.9 lbs |
View World & State Rainbow Trout Records
Where Rainbow Trout Are Found
Rainbow trout are native to the north western United States but can now be found in over 45 countries across the globe.
In rivers and streams rainbow trout like gravel bottom, shallow, well oxygenated water.
In lakes rainbow trout are typically found in deeper water with close access to sufficient food. Lakes need access to rocky streams for the rainbow trout population to be self-sustaining.
Lifespan of a Rainbow Trout
The lifespan of a rainbow trout is typically 6-7 years but they can live up to 11 years old. Rainbow Trout typically take 3 years to grow to 12″ long. From years 3-6 is when they typically grow the quickest.
You can tell the general age of rainbow by referring to the table below.
Rainbow Trout Age Chart
Age | Length |
---|---|
3 Years Old | 5 – 13 inches |
4 Years Old | 13 – 18 inches |
5 Years Old | 18 – 23 inches |
6 Years Old | 23 – 27 inches |
7 Years Old | 27 – 29 inches |
8 Years Old | 29 – 33 inches |
9 Years Old | 33 – 34 inches |
10 Years Old | 34+ inches |
Fishing for Rainbow Trout
Are rainbow trout hard to catch?
Rainbow trout are one of the easiest trout to catch. With that said, wild trout are more difficult to catch than other game fish like bass.
To make catching rainbow trout easier target quicker moving water. This will give them less time to study your flies.
In slow water rainbow trout have more time to look over your fly and be picky.
What size hook do you use for rainbow trout?
The best all around hook size for rainbow trout is a size 12 single barb hook.
What type of bait is for rainbow trout?
My favorite bait when fishing for rainbow trout is Berkley Powerbait.
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Frequently Asked Questions
What size rainbow trout is best to keep?
The best size rainbow trout to keep is 10-12 inches long. This is the best size to eat. Be sure to check your state’s size limit.
What do rainbow trout eat?
Rainbow trout eat insects, larvae, worms, and small fish.
Are rainbow trout endangered?
Rainbow trout are endangered in some areas of the United States due to dams blocking their migration route.
Do rainbow trout have scales?
Rainbow trout have very small thin scales. Their scales are so thin you don’t need to remove them before eating.
Are rainbow trout good eating?
Rainbow trout are delicious They are one of the best tasting freshwater fish. Rainbow trout are lean and have a very mild fish flavor.
Do rainbow trout fish bite humans?
Rainbow trout have teeth and can bite humans. They aren’t aggressive or attack humans but they can cut you if aren’t careful when removing your hook. Bites from trout won’t cause any lasting damage.
Is rainbow trout a salmon?
A rainbow trout is not a salmon. They are both apart of the same Salmonidae family though.
What eats rainbow trout?
Bass, muskie, walleye, and other predator fish all eat rainbow trout. Herons, eagles, osprey, otters, racoon, and bears are also known to eat rainbow trout.