Yellowstone cutthroat trout
A native trout with a red-orange slash under its jaw, the fish that fed the whole web of life around Yellowstone Lake for thousands of years.
Yellowstone cutthroat trout at a glance
Oncorhynchus clarkii bouvieri KUT-throat TROWT; Oncorhynchus clarkii bouvieri is ong-koh-RING-kus KLAR-kee-eye boo-vee-AIR-eye
- Type
- Fish · trout
- Diet
- Carnivore
- Size
- Most are about 12 to 18 inches long, roughly the length of a kid's forearm, though lake fish can grow bigger.
- Lifespan
- Around 5 to 11 years.
- Conservation
- Least concern (IUCN); a native fish of concern, but not listed under the U.S. Endangered Species Act
Eats water insects, flying insects, tiny water animals, small fish
It feeds mostly on insects, both the young ones drifting in the current and the adults that land on the water. It waits in a good spot and darts up to grab food as it floats past.
Should you worry?
This trout is harmless. The only care it needs is from us. In Yellowstone, all native cutthroat trout must be released, so if you fish with an adult and catch one, keep it wet, handle it gently and briefly, and slip it right back. Never move a fish from one water to another, because that is how harmful outsiders like lake trout got into Yellowstone Lake.
The mark that names the Yellowstone cutthroat is a bright red-orange slash under its lower jaw, a splash of color that looks a little like a cut. The fish itself is a foot to a foot and a half long, about a kid’s forearm, and it feeds on insects, the young ones drifting underwater and the grown ones that land on the surface, waiting in a good spot and darting up to take food as it floats by. For thousands of years it was the only trout in Yellowstone Lake, and that one fact made it one of the most important animals in the park.
When a single fish is the only trout in a huge lake, everything that eats trout comes to depend on it. Bears, otters, ospreys, eagles, and pelicans all built their year around the cutthroat, especially when the fish crowded up the streams to spawn. So when the cutthroat began to drop, the loss did not stay in the water. It climbed the food web to every animal that had counted on the fish being there.
The drop had a cause: non-native lake trout, first found in Yellowstone Lake in 1994, which stay deep, out of reach of the birds and bears, and eat cutthroat by the dozen. To fight back, the park has pulled millions of lake trout out of the lake to give the natives room to recover. That is why the rule for a cutthroat you catch is simple: keep it wet, handle it briefly, let it go. And it is why you never move a fish from one water to another.
Did you know?
- Its name comes from the bright red-orange slash under its lower jaw, which looks a little like a cut, though it is only a splash of color.
- For thousands of years the Yellowstone cutthroat was the only trout in Yellowstone Lake, so bears, otters, ospreys, eagles, and pelicans all came to depend on it. When the cutthroat dropped, all those animals felt it.
- Non-native lake trout, discovered in the lake in 1994, eat huge numbers of cutthroat. A single big lake trout can eat dozens of cutthroat in a year, so the park has removed millions of lake trout to help the natives recover.
Common questions
Why is it called a "cutthroat" trout?
Because of the bright red-orange slash of color under its lower jaw. It looks like a little cut, but it is just a marking.
Why do so many animals depend on this fish?
For thousands of years it was the only trout in Yellowstone Lake, so bears, ospreys, eagles, otters, and pelicans all learned to eat it. Its ups and downs ripple through the whole area.
Can I keep a cutthroat trout I catch in Yellowstone?
No. Native cutthroat must be released. Keep the fish wet, handle it gently and quickly, and let it swim away.
What is hurting the cutthroat trout?
Non-native lake trout that eat them, plus warmer water and habitat loss. Yellowstone has removed millions of lake trout to give the natives a chance.