Technically, Dolly Varden and Bull Trout are both species of char from the salmonid family.
They were once believed to be the same species and some recent studies say they have the ability to interbreed, perhaps one reason why they sometimes get mixed up.
Dolly Varden is the smaller of the two, distinguished by its polka dot markings – it is said to be named after the character in Charles Dickens’ Barnaby Rudge who wore a printed gown.
Some Dollies in the Skeena drainage spawn in fresh water and run to the sea for part of their life like salmon do.
The sea-run fish are shades of blue and silver, while the freshwater ones are shades of dusky white to olive or brown.
Bull Trout differ in that they can get much bigger than Dollies and have larger, broader, flatter heads. They aren’t known to go to the sea.