Rainbow Trout vs. Brown Trout: A Tale of Two Species

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Rainbow trout swim in pure river.

If you’ve ever been trout fishing, chances are you fished for rainbow or brown trout. For a seasoned angler, identifying the two is very easy. But for a first-timer, knowing the difference between a “bow” and a “brownie” can be challenging. In fact, I used to carry pictures of trout to see the difference! 

Rainbow trout have a silver or green body with a distinct pink stripe. Brown trout have yellow and brown bodies with black and red spots along their side and back. But their differences do not end there. Though both are well-known, their origins, behavior, and temperament differ. 

Physical Differences: Which Gets Bigger? 

Compared to rainbow trout, brown trout tend to get bigger. Rainbow trout live in freshwater streams, rivers, and lakes and do not migrate. If you compare a river’s brown trout to its rainbows, you will find that the browns have a larger average size. 

The typical size of your quarry depends on your fishery and genetics. For example, in my neck of the woods, average browns are 11-14 inches long. But if you were to fish out west, a stream might yield brown trout that average 14-18 inches. 

Any inland trout over 20 inches is worth a humble brag and a celebratory drink. Nonetheless, brown trout grow larger and longer compared to rainbow trout.

Differences Fishing For Rainbows or Browns 

You will likely use the same tactics and gear while fishing for rainbows and browns. But that doesn’t mean catching rainbow and brown trout will be equal in effort. Due to temperament and behavior, one is more challenging to catch than the other.

Are Brown Trout Harder To Catch Than Rainbow Trout?

Generally speaking, brown trout are more challenging to catch than rainbows. First, brown trout are picky. The perfect fly or lure can be meaningless since browns have limited feeding hours. You’ll often find browns that are lock-jawed. They just aren’t eating. 

Second, brown trout are less prevalent than rainbow trout. You will find rainbow trout in reservoirs, stocked ponds, lakes, and rivers, which makes catching them a numbers game. There is more access to rainbows than browns. 

Third, stocked rainbow trout will eat anything that looks like a pellet. So, if you’re in an area with stocked rainbows, your chances of catching one are high. 

But remember, there’s a reason they call it fishing and not catching. When approaching a rainbow trout fishery, bring an open mind and a humble heart. Plenty of times, both browns and rainbows gave me a run for my fishin’ money. 

Are Brown Trout More Aggressive Than Rainbow Trout? 

Some studies show rainbows are more aggressive compared to brown trout. Rainbow trout also tend to have longer feeding windows due to their insect-heavy diet. Between their belligerence and plain appetite, they would appear more aggressive to anyone looking to hook a fish.

In contrast, brown trout prefer to eat smaller trout, crayfish, minnows, and worms. This leads to a shorter and pickier feeding window. As a result, brown trout can be wary and prefer low-light conditions. 

I recommend finding a vantage point and observing a group of brown trout when possible. Take half an hour to sit at the bank and watch their behavior. Some swipe side to side and upward to feed, while others float in the current. Throughout that half hour, you can learn which nymphs or baits elicit their response. 

David watching brown trout feeding in Western Wisconsin. If this video is low-quality, we can delete it

Which Ones Fight Harder? 

The better question might be, how do they fight? When comparing rainbow to brown trout, one fights with brawn and the other with brain. 

Rainbow trout tend to go on strong runs and provide acrobatic displays. These runs are powerful but short. Seeing their leaps through the air is a kick for any angler, especially the first-timer. 

Meanwhile, brown trout will fight hard but in a systematic manner. While rainbows go on powerful runs, browns look for logs, undercuts, or any cover to get unhooked. If you’re fishing near cover, take it from me: have a game plan to steer a potential lifetime fish away from snags. 

If there is a log for your line to get wrapped around, I guarantee a brown will find it. And I guarantee the results will be disappointing. So, learn to steer brown trout by keeping a tight line with appropriate drag. 

Related Questions

Can Rainbow Trout Breed With Brown Trout? 

Rainbow trout and brown trout do not breed with each other. They each have crossbreeds, but not with each other. 

Brown trout will breed with brook trout to create the elusive and sterile tiger trout. Though these are not big fish, tiger trout are rare and warrant a celebratory cheer from the riverbank. My wife and I are lucky enough to have caught a few tiger trout. And yes, we cheered. Loudly.

David with a tiger trout caught in Western Wisconsin’s Driftless Area.
David with a tiger trout caught in Western Wisconsin’s Driftless Area

Rainbow trout will spawn with cutthroat trout to create a cutbow. These are common throughout the western states and can grow to sizable proportions (16-20 inches). Identifying a cutbow can be difficult, as their pink cheek or red underjaw can be faint.

My first time catching a cutbow, I had to ask a nearby fisherman what I had caught. So, don’t hesitate to ask questions. We’ve all been there!

Which Tastes Better? 

Well, which taste do you prefer? Rainbow trout are known for their nut-like flavor, while browns have a robust fishy flavor. Large brown trout can turn many people away, as their taste is much fishier than the mild flavor of rainbow trout. 

Where Do Rainbow Trout and Brown Trout Come From? 

Of North America’s four major trout, only brown trout is a non-native species. Brown trout originated from Germany and were introduced to the U.S. in the 1880s. As a result, you might hear people refer to brown trout as the “German brown.” 

On the other hand, rainbow trout are native to the U.S. They originate from the Pacific Northwest but spread worldwide since the 1880s. They’re so prevalent today that you’ll find them in every U.S. state.

Final Thoughts

If you go trout fishing, you’re likely catching rainbows or brown trout. Rainbows have a gray-green body featuring a pink stripe, while brown trout are, well… brown. 

Both are a blast to catch, but rainbows will give you powerful, short bursts of energy. Meanwhile, brown trout will outsmart you by finding any cover or snags to get free. 

No matter what you’re fishing for, rainbow and brown trout can provide fun, challenging, grip n’ grin moments that will last a lifetime.

David with a beautiful brown caught in the city limits of his western Wisconsin town.
David with a beautiful brown caught in the city limits of his western Wisconsin town
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