Rainbow and steelhead trout are the most widely known trout in the world and are highly sought after by anglers because of their strong fighting abilities. In Alaska, there are two commonly recognized forms of the rainbow trout and these sub-groupings or “forms” are based primarily on where they spend their time feeding and maturing. The most common rainbow trout in Alaska is the stream-resident form that lives its life entirely in freshwater with maybe short periods of time spent in estuarine or near-shore marine waters. The second form is commonly known as steelhead and these rainbow trout leave freshwater as juveniles and migrate long distances in the ocean where they grow to maturity before migrating back to their original home waters.
Since rainbow and steelhead trout are the same species there are no major physical differences between them, however, the nature of their differing lifestyles has resulted in subtle differences in color, shape, size, and general appearance. Juvenile steelhead are indistinguishable from juvenile rainbow trout during the first few years of their life. Young trout have eight to thirteen parr marks on their sides and five to ten parr marks between the top of the head and dorsal fin. The adipose fin usually has a continuous outline of black surrounded by a clear window and the lower jaw (maxillary) typically does not extend past the back margin of the eye. Prior to their seaward migration juvenile steelhead go through a series of physical changes called smoltification which allows them to survive in saltwater; during this process the fish lose their parr marks and become silvery in color.
Within a year or so of hatching the stream resident form of rainbow trout possess the well-known streamlined salmonid form, though body shape and coloration vary widely and reflect habitat, age, sex, and degree of maturity. The body shape may range from slender to thick. The back may shade from blue-green to olive. There is a reddish-pink band along each side about the midline that may range from faint to radiant. The lower sides are usually silver, fading to pure white beneath. Small black spots are present over the back above the lateral line, as well as on the upper fins and tail. In some locations, the black spots of adults may extend well below the lateral line and even cover the entire lower side. Rainbow trout are positively identified by the 8 to 12 rays in the anal fin, a mouth that does not extend past the back of the eye, and the lack of teeth at the base of the tongue. River or stream residents normally display the most intense pink stripe coloration and heaviest spotting followed by rainbows from lake and lake-stream systems. Spawning trout are characterized by generally darker coloration.
Adult steelhead which have spent 1 to 3 years in the ocean are generally heavily spotted with irregularly shaped dark spots both above and below the lateral line. Small spots are also scattered along the top of the head, along the sides, on the dorsal and both lobes of the caudal fins. Steelhead are typically silvery or brassy in color but may range from steely blue and emerald green to olive. Steelhead fresh from the ocean can be very bright and much more silver in color than resident rainbow. The classic band of color along the lateral line, which rainbow trout are named for, can range from light pink to deep red with mature males having the brightest colors. Although typically larger in size, steelhead are generally more slender and streamlined than stream resident rainbow trout. On steelhead the typical colors and spots of the trout appear to be coming from beneath a dominant silvery sheen which gradually fades in fresh water and steelhead become difficult to differentiate from mature resident rainbow trout. The distinct and beautiful coloration of steelhead during the freshwater spawning period is important for mating and reproduction while the silvery sheen and streamlined shape of ocean-bright steelhead is essential to survival in the ocean environment.
Stream resident rainbow trout and juvenile steelhead can usually be distinguished from their close relative the cutthroat trout because rainbow trout do not have the classic red or “cutthroat” slash on the underside of their lower jaw. However not all cutthroat trout have this slash and there are naturally occurring rainbow/cutthroat trout hybrids which have physical markings of both. Biologists often use the presence/absence of small teeth at the base of the tongue called basibranchial teeth as a means to distinguish between steelhead (teeth absent) and cutthroat trout (teeth present).
Length up to 45 inches; Weight up to 55 pounds
4 – 11 years
Throughout the Pacific Rim from southern California through the Gulf of Alaska to the Kamchatka Peninsula in Russia
Zooplankton, insects, crustaceans, mollusks, fish eggs and other fish
Other fish, birds of prey, otter, mink, seals, humans
A Note from Captain Steve on Trout…
Starting in June and ending about November we catch Rainbow Trout that are all native. They range from small to almost twenty pounds. You’re allowed one over 32 inches but we practice catch and release anyways. We mostly fish the upper Kenai River on drift boats and from the banks on sandbars. When the salmon start laying their eggs, the trout come out of the lakes and gorge themselves on eggs and the decaying salmon flesh. We use many sinking flies and beads to match the run of spawning salmon at the time. Also, we fly to the west side of the Cook Inlet to fish the more remote rivers and see the bears!
In addition to the Rainbow Trout, we catch Dolly Varden, Arctic Char or Bull Trout some people call them. They are small to almost ten pounds. All these are caught with fly and spinning rods, 6 to 12 pound test monofilament.
Season: June – November