Bull Trout Care

bull trout

Last updated on August 31st, 2022 at 04:04 am

There is a fish in the Missouri River called bull trout. This type of trout can be found throughout Montana, and it has been designated as threatened by the United States Fish and Wildlife Service under Endangered Species Act.

They are typically smaller than most other types of salmonids, but they have a high reproductive rate – which means that soon they will be populous again.

The bull trout is an important fish in Montana’s ecosystem. The connection between these smaller types of salmonids and the larger type, which are found living downstream from where they live, shows that they have a symbiotic relationship with one another.

This means that when there were more bull trout available for predators to prey on like pike minnows, the number of pike minnows would decrease. This is because more of them means that there are fewer small fish for predators to prey on in a given area – which benefits everyone involved as it prevents predation from becoming unsustainable.

Bull Trout are one of the most threatened fish species in the Columbia River Basin. They have been declining since 1970s, and they now occupy less than half their historic range.

They require cold water with good flow to survive; if a reservoir becomes too warm or shallow due to dam construction, bull trout will disappear from it. And while they have been declining for decades, the decline has accelerated in recent years.

Origin of bull trout

bull trout

The bull trout (Salvelinus confluentus) is a member of the family Salmonidae, or salmon fish. It inhabits streams and lakes in North America’s Rocky Mountains, where it has been recreated after being hunted to extinction by settlers. The species was also introduced into parts of Europe through Norwegian immigrants at the turn of the 20th century.

The bull trout’s name comes from its large size and a propensity for fighting when hooked, related to “bulldogging.” The fish is also known as wolverine trout or black-back salmon. It can grow up to three feet long and weigh more than 35 pounds.

Bull trout are classified as a “threatened” species due to habitat loss, pollution and overfishing.

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The bull trout is the only native fish in 12 states that inhabit streams and lakes of North America’s Rocky Mountains such as Colorado, Utah, Wyoming, and Idaho.

The name “bull trout” comes from its large size and fighting when hooked which is related to bulldogging. The fish may grow up to three feet long and weigh more than 35 pounds. Bull trout are classified as a “threatened” species due to habitat loss, pollution, and overfishing.

Species profile


bull trout

The bull trout, also called the mountain trout or speckle-back, is a freshwater fish that lives in cold water streams and lakes. It can be found in areas where humans have introduced non-native predatory species such as brown and rainbow trout. The name “bull” was given to this type of trout because it has large canine teeth.

The bull trout is considered a threatened species because of logging, mining, and agriculture. It may also be in danger from climate change. Many states have taken steps to protect the Bull Trout by listing it as endangered or threatened under their state laws. The National Marine Fisheries Service has listed this species as Threatened under the Endangered Species Act.

Color and appearance

The bull trout is olive to brown in color. The body becomes darker with age, while the caudal fin remains silver.

Male fish are typically more brightly colored than females and have a green or blue back. Females may be grayish due to their drab colors making them less visible when spawning near gravel stream bottoms.

Habitat and Range

The bull trout will make its home in lakes, tributaries and rivers. It is a cold water fish but can also live at temperatures of 20°C – 25°C for short periods. If the temperature exceeds 26°C it needs to be relocated as soon as possible because they cannot survive there long-term.

In order to survive in these warmer temperatures, it needs access to cool water.

The bull trout can be found all throughout the world except for Antarctica and Australia. They are native to North America but have been introduced into other parts of the world including Scotland, Scandinavia, Russia, and Japan.

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Their range has also increased since they were first discovered due to their popularity with anglers.

Bull trout have a preference for living in fast-moving water and they can be found in riffles, shallows or eddies. They also prefer the slower sections of streams where there is more vegetation present to provide them with cover from predators. Bull trout will use logs and other obstacles as hiding places along the banks of the stream.

Bull trout are preyed upon by a variety of predators including birds, mammals, other fish, and amphibians. Due to this they often rely on camouflage to avoid going hungry.

Bull trout have also been known to use their large fins as protection from these potential predators in case of an attack. They will swim away if the predator gets too close.


Bull trout can grow up to 24 inches in length and weigh as much as 15 pounds. They are also called silver or gray trout, depending on what region they live in.

Life cycle

The bull trout is a freshwater fish, generally found in the cold water tributaries of lakes and streams. They are closely related to steelhead trout; both have similar habitats and behaviors. The spawning behavior between these two species differs: Bull trout migrate upstream during winter months for breeding while steelhead most often spawns in headwater areas of large water bodies.

Bull trout can often be found in streams and lakes as long as they have cold-water sources, but cannot live in warm habitats without access to cold tributaries or springs.

The bull trout’s life cycle begins with the adult female laying eggs on a gravel bed during spawning season (generally between late autumn and early spring). The eggs hatch into tiny, inch-long fish called alevin. Once hatched from the egg, these young bull trout need live food to survive for several weeks before becoming free-swimming.

The life cycle of this species is about three years long and ends with death or release in water habitat as an adult fish either during spawning or migration.

The bull trout population has been declining in recent decades due to overfishing and habitat destruction but is still found across the United States and Canada.

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Are they peaceful or aggressive?

Bull trout are considered to be semi-aggressive. They can become aggressive if they feel threatened or cornered, but the true aggression is not as high as other species like brown and brook trout.

General care information


bull trout

What they eat

Bull trout primarily feed on algae, insects, and other small invertebrates. They also eat some fish eggs and very rarely may consume larvae of salmonid fishes.


They are generally kept in freshwater tanks as they need a lot of water and a big tank. Bull trout can live up to 11 years or more, but may not make it past their fourth year due to the quality of water in ponds near them. They also have very specific needs for filtration which will only work with certain models of aquariums.

A bull trout’s diet depends on the water condition in which it lives. Bull trout are opportunistic piscivores, meaning they will eat whatever prey is available to them and live around aquatic vegetation such as submerged logs or roots that provide cover for their prey.

In lakes with high levels of nutrients (eutrophic), bull trout have been observed to feed primarily on insects. In lakes with low levels of nutrients (oligotrophic), the trout eat mostly small fish, such as minnows and whitefish.

Water condition

They thrive in cold, clean water with a pH of under 7. The species can live in lakes and streams but prefers cooler temperatures. Bull trout are less tolerant to thermal pollution than brown or cutthroat trout because they require colder waters for spawning success.

They’re also more sensitive to siltation due to their preference for cold water.


Bull trout are semelparous, which means they typically only spawn once. Fishing pressure can affect their breeding success and the timing of their spawning migration from freshwater to saltwater.

They are considered an attractive sport fish with a reputation for challenging anglers in fresh or saltwater. They will eat almost anything that is within reach, including smaller fish.

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They usually reach sexual maturity when they are three to four years old. The fish mainly spawn in late summer or fall but have been known to do so into the winter months as well.

Spawning takes place on gravels near riffles of tributaries that are clear and flowing at a high speed during periods of heavy rainfall. The eggs and milt will float downstream to sandy or gravelly areas where the next generation of trout will hatch.

The time it takes for bull trout to spawn from egg to fry may take up to eleven months, but generally averages around six months.


They usually live six to seven years in the wild.

Parasites and diseases

bull trout

One of the causes for bull trout population decline is parasites and diseases. A parasite called ichthyophthirius multifiliis can cause a fish to become sluggish, which makes it vulnerable to predators.

In addition, bacteria such as columnaris or viruses like salmonid herpes virus can also be deadly.

Some of the other causes for the decline in their population include habitat loss. For example, when humans cause streams to become polluted and silt-filled, it can be difficult for fish populations to thrive there.


Bull trout are preyed upon by a variety of different predators. They include pike, lake trout, brown and rainbow trout, kingfishers, gulls, ospreys, eagles, and raccoons.

Does it make good pets?

Bull trout are not the best fish to keep as pets. They need a lot of room in order for them to grow and thrive, so they’re better suited for aquariums or large outdoor ponds rather than small bowls or tanks.

One thing that bull trout enjoy is catching their own food by chasing down prey with their mouths open wide! Fish with this type of diet needs to be fed live food like minnows, worms, or bloodworms.