Don’t shoot the messenger just based on the headline—hear me out.
While the Flylords crew was chatting earlier this week, our own Wills Donaldson told us a story about something a renowned guide in Alberta once told him. This guide reckons brown trout should be considered a char instead of a trout.
The reasoning? Browns spawn in the fall, same as bull, brook, and lake trout. Rainbows, cutthroat, and goldens spawn in the spring. Is that just a genetic anomaly, or is there more to it?
To answer that, we need to revisit some high school biology. But don’t worry—this stuff is interesting!
Animal Family
All trout and char belong to the family Salmonidae. And if you remember back to biology class, “families” are one of the taxonomic classifications used to sort all animals on earth into different groups. A taxonomic family is a group of closely related genera, which is the plural for genus.
A taxonomic family is a fairly narrow classification, because right after family, animals are sorted by their genus, then species. You really can think of it like your own family—all related, but each with enough quirks and differences that you deserve your own spotlight.
So, within the Salmonidae family, you’ll find every trout, char, salmon, grayling, and whitefish, all getting together for 4th of July barbecues and Christmas parties.
On a serious note, that’s why there’s so much similar behavior and, to an extent, appearances, between trout, char, salmon, grayling, and whitefish. They’re all cousins.
Where Do Brown Trout Fit?
Within the animal families we just learned about, biologists will also group animals together into subfamilies and tribes. Subfamilies and tribes are tools to further define animals, while keeping them within their family.
A good example is to look at cats. Within that family (Felidae), you have the Pantherinae subfamily that includes your lions and tigers, and your Felinae subfamily that’s home to domestic cats.
Or, you could think of all this like your collection of fly rods. You probably have some that are trout-focused, some for saltwater, and then an old antique or hand-me-down bamboo rod that you never use much, but you keep it with your fly rods because that’s what it is.
Brown trout are in the subfamily Salmoninae. Within the Salmoninae family, there are two tribes: Salmonini and Oncorhynchini. Brown trout are in the Salmonini tribe, alongside the genus Salvelinus, which is the genus for char like brookies, lakers, and bull trout.
Rainbow, cutthroat, and golden trout are in the Oncorhynchini tribe, which also includes Pacific salmon.
Here’s a screenshot from Wikipedia that shows it all laid out in a way that might make more sense:
On the phylogeny chart on the right, you can clearly see how the Salmo and Salvelinus genera are connected in their own tribe, while the Oncorhynchus genus is on its own branch of the family tree (and interestingly enough, more closely related to taimen than brown trout).
So What?
The scientific name for brown trout is Salmo trutta. It’s the only fish considered a true “trout” that has its own genus. Rainbow trout are Oncorhynchus mykiss, cutthroat trout are Oncorhynchus virginalis, and king salmon are Oncorhynchus tshawytscha.
That means cutthroat trout and king salmon are more closely related, genetically, than cutthroat are with browns. And it gets all the more confusing because we call a brook, lake, or bull trout a “trout,” even though they’re technically a char.
If it sounds like I’m splitting hairs—I am. There’s a reason we refer to all these fish with the common name “trout.” Browns, rainbows, cutthroat, brookies, goldens, lakers, bulls, Arctic char, and dolly varden all share the same basic shape and feeding habits. I’ve caught dolly varden on an elk hair caddis on Kodiak Island, in Alaska—the same fly I use to catch cutthroat here in Wyoming.
I don’t mean to sound like a biologist (I’m not) and I’m certainly not questioning the long-established order of things. But the observation that brown trout have more in common with char than trout really is a fantastic way of looking at these fish.
On one hand, brown trout clearly belong in the “trout” group, instead of with the char, because of their coloration. The surefire method for differentiating char from trout is that char have dark bodies with light spots. Trout have light bodies with dark spots.
But brown trout spawn in the fall. They share a Linnean tribe with char and Atlantic salmon. Other than their coloration, brown trout seem to fit the bill as a char, instead of a true trout.
I bet you’re not thinking of that when you hook into one, though.