These
two forms are vastly similar and the only
major difference is that the steelhead
is a sea-going fish and the rainbow trout
inhabits fresh water.
DESCRIPTION
- The average length of a rainbow
trout is 12-18 inches and the steelhead
is 20-30 inches. A mature steelhead usually
weighs 8-9 pounds but has been known to
reach 36 pounds. The body is somewhat
compressed with a rounded snout and a
large mouth. The spawning male experiences
minor changes to its head, mouth and color.
Stream residents and spawners are darker
with more intense coloring and lake residents
are lighter, brighter and more silvery.
They range from steel-blue, blue-green,
yellow-green to almost brown. Steelhead
tend to be more silvery. All have a number
of small black spots. The coloring chamges
drastically over the whole of its range.
DISTRIBUTION
- The native range of this species is
the eastern Pacific Ocean and the fresh
water mainly west of the Rocky Mountains.
It has also been introduced into New Zealand,
Australia, South America, Africa, Japan,
southern Asia, Europe and Hawaii.
BIOLOGY
- This species spawns from March to August
in smaller streams. The female digs and
spawns in several nests depositing 800-1000
eggs in each redd. These eggs usually
hatch 4-7 weeks later. The life expectancy
can be as low as 3-4 years but generally
the steelhead lives 6-8 years. They first
feed on plankton then insects and as they
grow older, crustaceans and other fish.
RELATION
TO MAN - The rainbow trout and steelhead
are rated in the top five sport fish in
North America because of the hard fight
they put up. The difficulties of landing
a hooked steelhead in a swift, rocky river
in winter are legendary. The flesh of
this fish is usually bright red and rich
in smaller individuals and pink to white
in larger lakes where they feed on fishes.
