Bull Trout
Scientific Name: Salvelinus confluentus
Distribution: western North America from British Columbia south to Oregon and east to Montana
Habitat: cold freshwater lakes and streams in the mountains
Life Span: 10-12 years
Size: length 26 centimeters (resident); 89 (migratory)
Weight: 4-9 kilograms
Coloring: olive-green to brown back with pale yellow or orange spots; gray or silver on the sides; males change to red or orange during the breeding season
Eyes: round, yellowish
Eggs: round, white; each clutch 5000-12000 eggs; hatch in 100-120 days
Diet: insects, fish (whitefish, trout, salmon fry, sculpins, darters), frogs, snakes, mice, ducklings
Predator(s): American char, birds, lake trout
Behavior: locally migratory
Reproduction: breeding season August to October; adults migrate to smaller streams to mate and lay eggs
Conservation Status: vulnerable (IUCN 2.3)
Major Threats: habitat loss and degradation due to logging, road building, mining, and overgrazing; overfishing; invasive species (brook trout, brown trout, rainbow trout); climate change
Conservation Action(s): listed as threatened under the U.S. Endangered Species Act
Other Notes: selective predators that check insect populations
Interesting Facts:
Distribution: western North America from British Columbia south to Oregon and east to Montana
Habitat: cold freshwater lakes and streams in the mountains
Life Span: 10-12 years
Size: length 26 centimeters (resident); 89 (migratory)
Weight: 4-9 kilograms
Coloring: olive-green to brown back with pale yellow or orange spots; gray or silver on the sides; males change to red or orange during the breeding season
Eyes: round, yellowish
Eggs: round, white; each clutch 5000-12000 eggs; hatch in 100-120 days
Diet: insects, fish (whitefish, trout, salmon fry, sculpins, darters), frogs, snakes, mice, ducklings
Predator(s): American char, birds, lake trout
Behavior: locally migratory
Reproduction: breeding season August to October; adults migrate to smaller streams to mate and lay eggs
Conservation Status: vulnerable (IUCN 2.3)
Major Threats: habitat loss and degradation due to logging, road building, mining, and overgrazing; overfishing; invasive species (brook trout, brown trout, rainbow trout); climate change
Conservation Action(s): listed as threatened under the U.S. Endangered Species Act
Other Notes: selective predators that check insect populations
Interesting Facts:
- The bull trout is a bioindicator species; its state of health can be used to monitor the health of its environment.
- Bull trout are classified into 2 groups: resident and migratory. Resident bull trout spend their entire lives in the same stream, while migratory bull trout move to larger bodies of water during the winter and back to smaller streams to breed. Migratory bull trout are bigger than resident bull trout.
- The bull trout is not a true trout. It is actually a type of char. Char do not have teeth on the roof of their mouth. They have light-colored spots on a dark background and no spots on their dorsal fins, unlike trout.