Fish live throughout the world in salt water oceans and fresh water lakes, and rivers. It is estimated that there are about 30,000 different kinds of fish in the world. The rivers and lakes of the Rocky Mountains provide home to many different kinds of fish, including several different types of trout. Some of those fish are native to the area, but others are invasive (meaning that at some point they were put there).
Here are some of the common fish in the Rocky Mountains:
Largemouth Bass
Average size: 8-18 inches
Habitat: They like warm, shallow lakes and ponds, slow rivers with vegetation
What is special about it: Large mouth extends to point below rear of eye.
Smallmouth Bass
Average size: 6-18 inches
Habitat: They live in deep lakes, cool clear streams over rocks or near logs.
What is special about it: Mouth extends to a point below front of eye.
Brook Trout
Average size: 10-26 inches
Habitat: They live in lakes, ponds, and streams.
What is special about it: On the top of their bodies there are many pale, olive, wavy lines. The side has red spots with blue halos. The bottom fins are mostly red with a white stripe on edge.
This is a very colorful fish. It has a reddish belly. When spawning in the fall, the males belly becomes a brilliant red color.
Brook Trout are native to the Eastern USA and the upper Midwest. But, now they are common in the Rockies and are often the only trout in small streams.
Brown Trout
Average size: 16-32 inches
Habitat: They live in steams, ponds, and lakes.
What is special about it: Their sides are olive brown. They have many or a few dark brown or red spots with a white halo.
They live on average 5 years, but can live up to 20 years old.
They will eat almost anything, even small mammals that fall in the water such as mice.
Brown trout travel upriver to spawn (reproduce).
They are active both during the day and night.
Brown Trout are originally from Europe and were brought to the USA. Now, they are fairly common in rivers in the Rockies.
Cutthroat Trout
Average size: 6-40 inches.
Habitat: They live in gravel bottomed rivers, streams, and lakes.
What is special about it: They have a bright red slash on the throat (the lower jaw).
Cutthroat Trout are native to the Western United States.
These are monogamous pair spawners, which means that one male and one female come together and to make babies.
Grayling
Average size: 6-16 inches
Habitat: They live in cold streams with pools, high lakes.
What is special about it: Its sides are silvery, brownish, or purplish with a few black spots forward. Its tail fin is forked.
It has a very large dorsal (on top) fin.
Rainbow Trout
Average size: 8-18 inches
Habitat: They live in gravel bottomed rivers and streams with swift currents, and deep, clear lakes.
What is special about it: It has a reddish line that runs down both sides of its body.
Rainbow trout are native to the Pacific Coast of North America – meaning originally they lived in California, Oregon, Washington, Alaska, and the western coast of Canada. Now, they are the most common trout species across the USA and can be found throughout the world.