One of the most common questions asked by novice anglers is, ‘what’s the difference between a wild and stocked trout?’

For those who are unfamiliar with these terms, a stocked fish is raised in captivity, also known as a hatchery, with hundreds of others alongside it. These fish are specifically bred to provide anglers with an opportunity to fish for fresh trout in waters that are not able to naturally support a healthy population of trout.

Wild trout are born naturally without any intervention from humans. People often get confused between wild and native fish—native fish are those that naturally occur in a certain water system.

Here’s all you need to know to differentiate between wild and stocked fish on your next guided fly fishing trip in Montana:

Color

One of the easiest ways to tell the difference between a wild and stocked fish is the color. While things have slowly been changing over time, stocked trout’s diet primarily consists of pellets. Wild fish can consume many different types and amounts of food such as freshwater shrimp and insect larvae, which contain many proteins and minerals that affect the fish’s pigmentation.

Stocked fish are also raised in a protected environment where their color gradient doesn’t play much of a role when it comes to survival.

Damaged skin or fins

Since stocked fish are raised alongside hundreds of others in rather confined spaces, it’s rather common to see trout with shredded tails or fins, or even large scrapes across their bodies. These scars are a result of spending almost an entire lifetime getting scraped against walls of cement or getting nipped by surrounding fish. While the skin and fins do grow back over time, some injuries can be identifiable forever.

Sometimes, their find might also get clipped on purpose to help identify them better. If you come across a fish that has a clipped adipose or dorsal fin, it’s probably a stocked fish.

Fat content

Due to their living conditions and diet, stocked trout have an extremely disproportionate fat distribution. They’re raised in ponds and are fed perfectly on time by humans, and don’t have to spend too much of their energy searching for food or swimming up currents like wild trout. Also, instead of getting a balanced diet of smaller fish and bugs, they’re raised on high-fat food pellets their whole lives.

If you see a seemingly juvenile trout that has a lot of fat near its stomach, there’s a high chance that it’s stocked.

A Yellowstone River guide can help

Top fly fishing guides in Montana at FishTales Outfitting can help you identify different kinds of fish on your Montana fly fishing vacation. Pick and choose from our wide variety of fly fishing packages to curate the perfect trip for yourself or your loved ones! We also have a list of recommended gear that you should have on hand.

Contact us to find out more!