Rainbow Trout

Salmo gairdneri

Other Names
bow, redsides, red-band trout, silver trout, steelhead, kamloops

Description
Unlike cutthrout trout, these have no teeth under the tongue. Their backs are blue/green with a red horizontal band along the silver side. The tail has numerous rows of black spots.

Typical Habitat
Rainbows prefer cool, clear streams and lakes. They also live in warm water lakes only if clear, oxygenated water is available. Steelheads found in open waters (i.e large larkes and at sea) are reputed to roam very long distances.

Feeding Habits
Rainbows eat insects, crustaceans, fish eggs, and plankton. They also eat some smaller fish, but not as commonly as other trout.

Age and Growth
A rainbow trout's growth rate depends upon its environment. Fish living in small lakes with limited food supply may grow drastically slower (one pound in a year) than those that live in large bodies of water and feed freely. Rainbows will normally live between 4 and 6 years, but some have been recorded up to 11 years.

Sporting Qualities
The rainbow trout's knack for striking insects on the water's surface makes them a favorite among fly fishermen. They usually leap 5 or 6 times before capture. They are also very popular on conventional light tackle. Rainbows will hit a variety of baits, spoons, spinners, and plugs.

Food Quality
Their meat can vary in color from red to white depending on each fish's diet. Rainbow trout taste excellent either smoked or served fresh, and can often be found in fine restaurants.

World Record
42 lbs. 2 ounces Bell Island, Alaska

Preferred Temps
55 to 75

Where Are They?

Kauai

The map above shows a portion of Kokee State Park on the island of Kauai. The three main streams to find wild Rainbow Trout are Kauaikinana, Kawaikoi, and especially the upper sections of Koaie Stream. There are mostly pan-sized trout in the first two streams, but Koaie Stream has trout that reach nearly 20 inches!

How to tempt the rainbow trout Kokee region of Kaua’i with flies

Several of the remote cold water streams that drain the Alaka’i plateau of Kaua’i support self-sustaining populations of rainbow trout which have descended from trout stocked decades ago. Getting there involves 4-wheel driving and backpacking through some gorgeous but very rugged country. Wet wading with studded boots, carrying a 2-5 wt outfit is best. The most successful technique involves using a sparsely tied dark woolly bugger fished deep and retrieved slowly. Dead drift it in current or twitch along the bottom of bigger pools. Not exciting, but effective. During the spawning time, the trout are more aggressive and will hit flashy streamers. Unfortunately, dry flies are not effective, unless you encounter a pool full of very cooperative juvenile fish. Catch & Release is practiced almost exclusively, as successful natural reproduction is limited to every 3-5  years, when we get very cool weather. Good luck!

Dr. Jim DiMarchi