The Salmonids (Trout)

Salmonids, sometimes called trout, include bull trout, westslope cutthroat trout, and mountain whitefish. Salmonids are usually found in cool, clear streams and lakes.

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  • Other Names

    Salish Name
    The Salish call large bull trout aay and small bull trout ɫʔay

    Scientific Name
    Salvelinus confluentus

    Common Names
    It was once thought bull trout and dolly varden were the same species, and until 1978, bull trout were called dolly varden in Montana. But genetic research has shown that the two are different species. The only name used now is bull trout.

  • Classification

    Bull trout are members of the char subgroup of the salmon family (Salmonidae), which also includes brook trout, dolly varden, lake trout, Arctic char, and white-spotted char (of Asia). Of these species, bull trout are most closely related to white-spotted char.

  • Average Size

    The size of bull trout depends on life-history strategy. Resident bull trout tend to be small, averaging 8 inches in length and rarely exceeding 12 inches. Adults that migrate to larger downstream rivers average about l6 inches, and often exceed 24 inches. Maximum sizes of bull trout are reached in large lakes where adults grow over 27 inches in length and 22 pounds in weight.

  • Life History

    There are three life history forms: 1) a resident form that lives in small headwater streams; 2) a fluvial form that resides as an adult in large rivers but spawns in small tributaries; and 3) an adfluvial form that lives as an adult in lakes and spawns in tributaries. The resident form reaches sexual maturity at a young age and remains small. The fluvial and adfluvial forms mature later and get large. Different forms can occur together.

  • Diet

    Small bull trout eat terrestrial and aquatic insects but shift to preying on other fish as they grow larger. Large bull trout are primarily fish predators. Bull trout evolved with whitefish,
    sculpins and other trout and use all of them as food sources.

  • Habitat

    Habitat needs depend on the life-history form. River habitat requires cold, clean water; lots of deep pools associated with instream and overstream cover. Streams should be complex, and the presence of large woody debris is important. So are groundwater upwellings. Bull trout are sometimes called the grizzly bear of the fish world because of their need for unaltered, pristine habitat.

  • Status

    Bull trout are designated a threatened species under the Endangered Species Act. In the Columbia Basin, bull trout now occur in less than half of their historic range. They have declined due to habitat degra-dation and fragmentation, block-age of migratory corridors, poor water quality, past fisheries management, and the introduc-tion of non-native species such as brown, lake and brook trout.

  • Other Facts

    Bull trout were so abundant in the rivers and streams of western Montana that many Salish-Pend d' Oreille place names refer to these fish. For example, the confluence of the Blackfoot and Clark's Fork Rivers was called Nʔaycčstm, meaning "Place of the Large Bull Trout", in apparent reference to the fluvial or adfluvial form of the species.

The Salmonids (Trout)

Salmonids, sometimes called trout, include bull trout, westslope cutthroat trout, and mountain whitefish. Salmonids are usually found in cool, clear streams and lakes.

My Image

Juvenile

My Image

Adult

Click on a topic to learn more

  • Other Names

    Salish Name
    The Salish call large bull trout aay and small bull trout ɫʔay

    Scientific Name
    Salvelinus confluentus

    Common Names
    It was once thought bull trout and dolly varden were the same species, and until 1978, bull trout were called dolly varden in Montana. But genetic research has shown that the two are different species. The only name used now is bull trout.

  • Classification

    Bull trout are members of the char subgroup of the salmon family (Salmonidae), which also includes brook trout, dolly varden, lake trout, Arctic char, and white-spotted char (of Asia). Of these species, bull trout are most closely related to white-spotted char.

  • Average Size

    The size of bull trout depends on life-history strategy. Resident bull trout tend to be small, averaging 8 inches in length and rarely exceeding 12 inches. Adults that migrate to larger downstream rivers average about l6 inches, and often exceed 24 inches. Maximum sizes of bull trout are reached in large lakes where adults grow over 27 inches in length and 22 pounds in weight.

  • Life History

    There are three life history forms: 1) a resident form that lives in small headwater streams; 2) a fluvial form that resides as an adult in large rivers but spawns in small tributaries; and 3) an adfluvial form that lives as an adult in lakes and spawns in tributaries. The resident form reaches sexual maturity at a young age and remains small. The fluvial and adfluvial forms mature later and get large. Different forms can occur together.

  • Diet

    Small bull trout eat terrestrial and aquatic insects but shift to preying on other fish as they grow larger. Large bull trout are primarily fish predators. Bull trout evolved with whitefish,
    sculpins and other trout and use all of them as food sources.

  • Habitat

    Habitat needs depend on the life-history form. River habitat requires cold, clean water; lots of deep pools associated with instream and overstream cover. Streams should be complex, and the presence of large woody debris is important. So are groundwater upwellings. Bull trout are sometimes called the grizzly bear of the fish world because of their need for unaltered, pristine habitat.

  • Status

    Bull trout are designated a threatened species under the Endangered Species Act. In the Columbia Basin, bull trout now occur in less than half of their historic range. They have declined due to habitat degra-dation and fragmentation, block-age of migratory corridors, poor water quality, past fisheries management, and the introduc-tion of non-native species such as brown, lake and brook trout.

  • Other Facts

    Bull trout were so abundant in the rivers and streams of western Montana that many Salish-Pend d' Oreille place names refer to these fish. For example, the confluence of the Blackfoot and Clark's Fork Rivers was called Nʔaycčstm, meaning "Place of the Large Bull Trout", in apparent reference to the fluvial or adfluvial form of the species.

The Salmonids (Trout)

Salmonids, sometimes called trout, include bull trout, westslope cutthroat trout, and mountain whitefish. Salmonids are usually found in cool, clear streams and lakes.

My Image

Juvenile

My Image

Adult

Click on a topic to learn more

  • Other Names

    Salish Name
    The Salish call large bull trout aay and small bull trout ɫʔay

    Scientific Name
    Salvelinus confluentus

    Common Names
    It was once thought bull trout and dolly varden were the same species, and until 1978, bull trout were called dolly varden in Montana. But genetic research has shown that the two are different species. The only name used now is bull trout.

  • Classification

    Bull trout are members of the char subgroup of the salmon family (Salmonidae), which also includes brook trout, dolly varden, lake trout, Arctic char, and white-spotted char (of Asia). Of these species, bull trout are most closely related to white-spotted char.

  • Average Size

    The size of bull trout depends on life-history strategy. Resident bull trout tend to be small, averaging 8 inches in length and rarely exceeding 12 inches. Adults that migrate to larger downstream rivers average about l6 inches, and often exceed 24 inches. Maximum sizes of bull trout are reached in large lakes where adults grow over 27 inches in length and 22 pounds in weight.

  • Life History

    There are three life history forms: 1) a resident form that lives in small headwater streams; 2) a fluvial form that resides as an adult in large rivers but spawns in small tributaries; and 3) an adfluvial form that lives as an adult in lakes and spawns in tributaries. The resident form reaches sexual maturity at a young age and remains small. The fluvial and adfluvial forms mature later and get large. Different forms can occur together.

  • Diet

    Small bull trout eat terrestrial and aquatic insects but shift to preying on other fish as they grow larger. Large bull trout are primarily fish predators. Bull trout evolved with whitefish,
    sculpins and other trout and use all of them as food sources.

  • Habitat

    Habitat needs depend on the life-history form. River habitat requires cold, clean water; lots of deep pools associated with instream and overstream cover. Streams should be complex, and the presence of large woody debris is important. So are groundwater upwellings. Bull trout are sometimes called the grizzly bear of the fish world because of their need for unaltered, pristine habitat.

  • Status

    Bull trout are designated a threatened species under the Endangered Species Act. In the Columbia Basin, bull trout now occur in less than half of their historic range. They have declined due to habitat degra-dation and fragmentation, block-age of migratory corridors, poor water quality, past fisheries management, and the introduc-tion of non-native species such as brown, lake and brook trout.

  • Other Facts

    Bull trout were so abundant in the rivers and streams of western Montana that many Salish-Pend d' Oreille place names refer to these fish. For example, the confluence of the Blackfoot and Clark's Fork Rivers was called Nʔaycčstm, meaning "Place of the Large Bull Trout", in apparent reference to the fluvial or adfluvial form of the species.