Bull trout have a large head that appears flattened and has a pronounced hook in the lower jaw when compared against other Charr members.

Bull Trout Distinguishing Features

The Bull Trout is olive green in appearance, but this can vary greatly depending on their habitat and food.

As with most fish, the top is darker in appearance to blend in with the rocky lake and river bottoms that it dwells in. At spawning, these dark areas can appear black.

The sides are pale and is populated with spots that appear red or orange. These spots are off white in colour towards the top.

The pectoral, pelvic and anal fins have off white painted along the edges.

The male Bull Trout changes colour when it spawns. The top back changes to dark olive/black and its belly becomes a bright orange. Deep red spots replace the normal spots along the sides and the fins off white becomes a deep fluorescent white almost as though they have been bleached.

Differentiating From The Brook Trout

Some confuse the Bull Trout with brook trout by the absence of vermiculations on their back. The Brook Trout also have red spots, but they are enveloped by a bright blue.

Where this gets confusing is when the Bull Trout and Brook Trout spawn together with the offspring having a mix of features from both species.

The Bull Trout is an endangered species and hybridization only makes matters wore as it further depletes the gene pool.

When the Bull Trout returns from the sea, it is silver in colour and does not have any spots.

All Tackle Record Bull Trout

Bull trout can reach very large sizes, especially in remote areas where they are no fished much.

The all-tackle record Bull Trout ever caught is 32 pounds/14.5 kilograms and it was a staggering 40.5 inches/103 centimetres long. It was caught at Lake Pend Orielle, Idaho, in 1949, but few even close to this size have been caught ever since.

Bull Trout and Dolly Varden Size Differences

To help clear up the mystery surrounding the differences between the Bull Trout and the Dolly Varden, it is important to understand how they differ in size.

The largest Dolly Varden ever caught was 20 pounds. The largest Bull Trout is 32 pounds/14.5 kilograms. As for the average Bull trout caught, it is around five pounds while the Dolly Varden is about two pounds.