Smallmouth Vs Largemouth Bass

Both one of America’s favorite freshwater game fish, it seems strange that for many anglers confusion between identifying the smallmouth bass and largemouth bass still exists. Even for a more experienced angler like myself, mistaking the two, especially when they’re at the small end of the weight scale, still happens from time to time.

For those new to bass fishing, however, this problem can prove all too familiar. Sometimes the really inexperienced might even fail to recognize the existence of two different species in the “largie” (largemouth) and “brown bass” (smallmouth).
To help solve that problem, and in the hope of better developing your understanding of each species’ behavioral habits (possibility resulting in a greater catch rate), we’ll take a look at some of the key differences.

A Common Case of Misidentification

Due to the huge size and scale of the bass fishing industry, there’s a ton of information out there when it comes to specific tips and tricks to employ when on the hunt for either smallmouth or largemouth bass.

Thanks to their appearance, however, which is oftentimes hard to tell apart, particular gear or angling strategies could prove mismatched when it comes to making the first cast into uncharted waters.

Largemouth Bass

This is one of the major pain points in the problem of confused identification. Although both species can look overwhelmingly similar, a tournament referee or pro angler will certainly know the difference.

Their edge could prove your downfall (especially if you’re fishing in a species-dependent tournament) in possible competition or recreational match-ups.

What may commonly confuse novice or beginner anglers is the fact that both species are the same shape, often a similar size, and even inhabit the same waters.

Knowing that, you might begin to appreciate just how difficult a task telling a smallmouth from a largemouth (and vice versa) can be. Even more so if you’ve never actually fished for bass before.


That’s why it’s important to break things down by starting at the top. By discussing what each species actually looks like.



One of the main points of differentiation when it comes to matching the two species up is considering what size they can potentially grow to. Largemouth tend to have an advantage in this area, generally growing a lot bigger than the smallmouth.

Largemouth tend to max out around 12 lbs and smallmouth around 8 lbs, though there are obvious exceptions if you find yourself looking at state and national records.

Largemouth bass, for that matter, have been caught at over double the size of the biggest smallmouth for hundreds of years. Armed with a larger mouth to swallow and catch food, it’s no real surprise that they’d have a physiological reason to grow larger.

Increased size also means increased dominance in the ecosystem, meaning they’re better adapted to outcompete other fish for the same food sources too.


Coming back again to their main differentiator (that’s also in the name), the best way to tell them apart is by drawing your focus to the mouth and its positioning in relation to other features.

The largemouth has an upper jaw that reaches past its eye while the smallmouth’s jaw is usually in-line or falling short of the eye.

Turning the bass carefully on its side after removing the hook is a quick way of doing this, but is not exactly precise.

Credit Jonathunder CC BY-SA 3.0


Another easy method is to look at the dorsal fin (the fin along the top of the fish that runs along its spine). A largemouth usually has a break or gap separating the fin whereas the smallmouth doesn’t.


Color-wise it’s also possible to better distinguish between the two. As previously mentioned, smallmouth are commonly called “brown bass” for this reason, whereas largies take the nickname “green bass”.

Relying on this system has its pitfalls, however, as oftentimes these colors don’t match up, particularly when taking into consideration age, location and other factors.

Body and Scales

The bass’ body and scales can be a giveaway too; with largemouth having horizontal dark lines and smallmouth having straight vertical lines marking its sides. This is not 100% reliable, but can help in identification


Catching a few of each will obviously lead to easier differentiation, but be aware that there’s something of a debate when it comes to describing a bass’ appearance with anglers preferring certain descriptions over others (largemouth having “blotches” rather than “stripes” for example).

By far the best way to learn identification is to simply ask a more experienced fisherman. If you don’t know someone personally, take a picture and try the subreddit what is this fish.

Location and Habitat

The location of each bass species and the types of waters it lives in is something important to keep in mind if encountering either for the first time.


The largemouth, although native to eastern and central US and parts of Mexico, can be found all over thanks to introduction schemes. Because of that, it’s often called different names regionally too (like widemouth, green trout, and bucketmouth).

The state fish of Georgia, Florida, Alabama and Mississippi, the largemouth is hugely common in these regions but you’ll also find the smallmouth too.

Habitat-wise, the largemouth prefer warmer water with lots of cover and look to nest and hunt in areas around rocks, grass, weed piles, and stumps. Murky water is also a preference largemouth tend to have.


Smallmouths are native to the river basins of the Mississippi, Hudson and the Great Lakes. They’re also, thanks to stocking and illegal introduction, common in waters in the north of the US and parts of Canada. Like the largemouth they’re also identified by regional names; “bronzeback,” “brownie,” “smallie,” and “bareback” all examples.

Although they might live in the same waters something that can make it a little easier to tell the species apart is that they usually reside in different parts of the same waters.

Smallmouth , like largemouth, also like cover but usually don’t enter it and prefer instead to hunt and spawn around it. They also tend to prefer clearer water over murky.

One key difference is that smallmouth bass enjoy feeding and hunting for prey in waters with hard currents. Armed with that knowledge it’s often easier to pick smallmouth out by casting into fast-moving water and avoiding dropping lures into deep cover.



Behavior is another possible way to tell smallmouth and largemouth bass apart. Smallmouth are more agile and prone to jumping out of the water, many anglers prefer the thrill of the more unpredictable fight that smallies offer. For that reason, they’re often favored in big tournament fishing as they could be considered a “more difficult” catch.


In respect of feeding and spawning patterns, both species have a wide and varied diet. Feeding off similar food sources like scuds, shrimp, salamanders and shad, the largemouth is able to prey on larger fish, however, due to its size.

Juvenile and adult fish of both species vary somewhat in what they eat too; with the young of both developing on algae before graduating to other fish or insects.


Adult largemouth bass, considered the apex predators in their environment, can often be quite invasive if occupying waters with little to no cover. This means their prey can easily be spotted and caught, leading to them quickly wiping out populations of open-water baitfish.

Smallmouth, on the other hand, may be considered less invasive due to their migration patterns and periods of semi-hibernation.


Sexual maturity in largemouth bass occurs around one year of age while spawning happens in springtime as water temperatures rise. This period, usually prolonged in the southern states, means that the south is largely responsible for bigger and larger populations than the north as a general trend. The males often opt for sand, gravel or mud bottoms as their nesting sites too.

Smallmouth males also guard nests while the female lays eggs. Despite this similar behavior though, smallmouth are much less tolerant of polluted water than the largemouth. Avoiding or refusing to spawn in waters that are disturbed or of too high a temperature, smallmouth behavior is a little more finicky in comparison to the largemouth.

Best Season to Fish

Having shed some light on either species behavioral patterns then, perhaps it’s a good time to discuss the best seasons to fish both species of bass. Given that both species spawn in the spring, the months between April and June are the most obvious recommendations for catching either type of fish.

Anglers preferring to fishing all year round, however, might want to target the largemouth in other seasons and both species in the spring and summer. Because of the smallmouth’s tendency to migrate to deeper pools and enter semi-hibernation when the water temperature drops, it can prove difficult to catch them in winter and autumn months.

Something to also consider is the water and location you’re choosing to fish. Experienced anglers will understand that each body of water and region has differing peak seasons for certain fish populations. With a small amount of research, it can become easier to target where’s best to fish for either species based off meteorological and seasonal reports (as well as the advice of local fishermen who frequent the waters).

Besides seasonal change, there are some general principles anglers should keep in mind if looking to better their catch rates.

Largemouth bass, for example, often spend the warmest months in shallows that have access to plenty of cover. This enables them the comfort of cooling down while hunting effectively.

Largemouth anglers differ somewhat in their recommendations as to the best conditions to make a catch. Arguing that factors like cloud cover, wind and drizzly days often make for the best conditions, others still have plenty of success in conditions other than the norm.

Unlike largemouth, smallmouth opt for the deep rather than the shallows when temperatures get hot. For that reason, they’re often hard to pull out the water in the summer but easier in the fall and spring when they retreat back to the shallows.

Given these factors; catch a bass in summer and the chances are that it’s likely to be a largemouth. That’s one key indicator for a beginner struggling to tell the species apart on appearance alone.

Gear Selection: Smallmouth Vs Largemouth

After breaking down some of the key differences and similarities between both species let’s get down to discussing gear.

Knowing what to use and why when tailoring an approach to either species of bass is simply the best way to improve your catch rate. When it comes to largemouth versus smallmouth, however, you can’t use a “one-size-fits-all” remedy.


Considering the largemouth’s tendency to occupy areas of heavy cover it makes the most sense to take a firmer approach in your gear set-up.

That might mean baitcasting rods rather than spinning rods due to added power that helps plow through underwater obstacles and increased control when it comes to the cast. A middle of the road medium action rod should do the trick.

In terms of lures, it’s probably best to attach something like a jig or crankbait to a braided or fluorocarbon line so you can hit the bottom and bump across the water to create ample distraction to draw in the fish.


Both baitcasters and spinning rods with medium action will work well with smallies.

A couple of changes you might want to consider switching out when it comes to targeting smallmouth bass is the fact you’ll probably be chasing fast-moving water and a current. That means you’ll want a strong enough line to withstand being carried across the surface downwater but a lure that doesn’t seek to deep that it actually sits lower than the bass themselves.

Dressing a lure might be approached in a similar way fishing for both species given their comparable diets.

One good piece of advice is to check what’s in the water (and thus what the bass are actually feeding on) first before rigging up.


Fishing for smallmouth and largemouth bass, in many ways, is a fairly comparable experience. Compared to other species of fish they behave, look and breed much in the same way. Telling them apart, although tricky, not only helps widen your experience and knowledge as a keen sports angler, however. It also helps you gather information and insight into what works in waters where either species is dominating.