Smallmouth VS Largemouth Bass: Physical and Behavioral Differences

The difference between smallmouth vs largemouth bass eludes many anglers. At least, it’s a difficult situation for beginners and many intermediate fishermen. That’s because they’re both some of the hardest-fighting bass in the world and while the names seem to paint the perfect picture, both of them tend to look extremely similar in person.

So, how do you tell them apart? How do you know you have a record-sized smallmouth or an average largemouth?

Well, it’s not too difficult, but you have to look at the details. To help with that, the team at BassForecast is here to help.

Let’s get started.

Why Does it Matter?

If you’re a really raw rookie, you might be wondering why this matters at all. A bass is a bass, right? Well, there are some key differences that make a huge impact on whether the weight of the fish is good or not, and of course, if you want target records, you have to know how to differentiate between fish.

For example, it’s very abnormal for a smallie to weigh 10 pounds. In comparison, a largemouth can weigh up to 21 pounds, and most decent bass anglers pick up 10-pounders fairly regularly. It’s not an everyday occurrence, but it certainly happens often.

So, if you want to target records, truly understand the impressive nature of your catch, or even get bragging rights with a degree of accuracy, you need to tell the difference. Not to mention, it’s part of the sport.

Comparing Smallmouth VS Largemouth Bass

Now, we’re ready to start doing a one-to-one comparison of the two main freshwater bass species. We’re going to cover each tiny detail in-depth, and by the end, you should know exactly what is dangling from the end of your line.

The Mouth Differences:

First, we need to look at the mouth. After all, that’s the part that both names use to help anglers differentiate. Unfortunately, it’s not the easiest thing to notice, but it’s the main difference in terms of physical traits.

Largemouth Mouth Trait:

The largemouth is the top game fish in the United States. So, it’s where we’re going to start.

The mouth of a largemouth bass opens much wider. That’s because the jaw joint is placed far behind the eye of the bass. This allows it to hinge itself open more, and it creates the “bucket” that many fishermen love to lip when they catch a big bass.

This is the primary way to tell the difference. Just take a look at the fish’s eye. If the round joint notch is behind its eye, it’s a largemouth regardless of how wide its mouth looks or any specific markings it has.

Smallmouth Mouth Trait:

With smallmouth, the positioning of the jaw notch is noticeably different. Instead of being a bit behind the eye like a largemouth, a smallmouth’s jaw aligns with its eye. That prevents its mouth from opening as wide as you’d expect if you’re used to catching largemouth.

Dorsal Fin Trait:

Unless the fish is breached, you won’t notice what the mouth looks like. However, you might notice the fin first.

Largemouth Dorsal Fin:

A largemouth’s dorsal fin is split almost halfway through. That means it stops, a new fin starts, and you have a smaller fin.

If the bass has its dorsal fin expanded when you get it to the surface, you can tell that it’s a largemouth if it looks like there are two fins. That's not always possible, because bass have their fins collapsed sometimes, and there’s a lot of action going on that can make you miss those small details.

Just keep an eye out.

Smallmouth Dorsal Fin:

A smallmouth’s dorsal fin isn’t split. It looks like one continuous fin. So, if the fin is expanded, you can see what it is before you get close to it.

Again, this isn’t always possible. So, don’t get used to differentiating them this way.

Color of the Bass

There is a very slight color difference between the two bass.

Largemouth Color:

Largemouth are known as “green bass”. They tend to have a lighter green color, and while they can get quite dark, there is greener in their coloring than brown.

This is the main visual way you’ll spot them in the water. Their colors can overlap due to water conditions, size ratios, and more, but in general, there’s a distinct difference.

Of course, you’ll likely be able to tell much sooner due to other factors once you spend a while catching both species.

Behavior of Bass

Largemouth and smallmouth bass both behave in dramatically different fashions. They are both hard fighters, and they both do the same thing to an extent, but they do behave differently.

The Surface Breach:

This is the part of a bass fight that makes anglers lose their minds. Both species breach the water explosively.

However, smallmouth bass are far more acrobatic. You will see more smallmouth jumps, and they look more graceful when they do it.

Largemouth are the opposite. Most of the fight is submerged in a variety of situations. A largemouth will fight extremely hard, but the most you’ll usually see is the tail slapping the water. On the other hand, when they do breach, you get one of the coolest sights possible in freshwater. 

When a largemouth jumps, it tends to violently flair its gills. It ends up looking a lot like something off Jurassic Park instead of a simple North American game fish that poses no real threat to humans.

The Underwater Fight:

Expect smallmouth bass to be jerkier, more sporadic, fish to fight. They’re feisty despite being small in general. However, unless you hook into a big boy, they don’t pack too much strength.

On the other hand, largemouth bass tend to attack in waves. They’ll thrash wildly from side to side, then they’ll pause and tug, and then they’ll thrash again. The thrashes are harder, and when a big largemouth tugs, it can feel like you’re tugging on a pile of cinder blocks.

Where Are Smallmouth and Largemouth Bass?

Beyond their appearance and their behavior, their locations differ, too. You can find both largemouth and smallmouth in the same ponds and lakes, but only where the temperature suits both species. If the temperature of the water is the opposite of the preferences we mention for each fish, the fish with the conflicting preference will be harder to find.

For example, smallmouth bass like to stick around colder waters that are toward the north of the country. So, in New York, you’ll find a lot of smallmouth bass, and largemouth will be difficult to find. However, largemouths like hotter temperatures, and they’re usually found in the lower half of the United States.

Both species tend to be in water along that long such as the Great Lakes.

Do You Use Different Techniques for Largemouth and Smallmouth?

Now that you know about their behavior and physical differences, it’s time to talk about what the actual catching experience is like for each.

Luckily, it’s not much different.

You’ll be using many of the same bass lures and rigs regardless of which one you target. Cranks, jigs, soft plastics, spoons, and spinners all work perfectly fine.

There are two differences, though.

First, the presentation you use is different. Typically, smallmouth bass tends to like jerkier, more sporadic presentations. They strike faster, and they usually like more active prey.

Largemouth are usually the opposite. You usually want to focus on natural presentations that mimic actual bait in the area, or you want to buzz your lure quickly in the middle or top of the column.

Then, you have to consider the size difference of the fish. Peak smallmouth are dramatically smaller than the largest largemouth. In general, smallmouth are half the size of largemouth of the same age. The lure you use has to reflect that.

If you’re using 7-inch Trick Worms to target largemouth bass, it’s usually better to use a 3-inch U-Tail. The same goes for any other type of lure. You want to scale down what you’re doing if you’re going after smallmouth.

Which Is Better? Largemouth or Smallmouth?

This is a largely debated question in the bass angler community. If largemouth and smallmouth bass are so similar, which one should you go after?

Well, there are a few factors to look at.

Yes, the two are extremely similar. However, there are some differences in the kit and technique. You also need to consider that smallmouth are more acrobatic and more likely to put on a show.

That doesn’t mean that one’s technically better than the other, though. They both offer slightly different experiences, and a good angler will gladly fish any lake either of them are available in.

There are two situations where one can be viewed as better than the other.

The first is in the record book. If you’re going for a state record, some states are more practical to break one fish's record than the other. For example, in New York, the largemouth record isn’t very substantial. Even though you’ll find fewer largemouth, each one that is above average can potentially break the record. In comparison, the smallmouth record is closer to the peak of the species. So, it’s hard to break. In that case, largemouth would be the better fish to target if you wanted to get in the record books.

The other situation is a tournament or similar competition.

With largemouth being the most popular game fish in America, the vast majority of bass fishing tournaments cater to largemouth fishermen. That means that you’ll have an easier time finding tournaments at your skill level without having to travel abroad. 

From the smallest local competitions to the largest pro circuits, largemouth bass dominate the sport side of bass fishing. So, if you have hopes to be a professional, it’s definitely better to focus on the bigger-mouthed varieties rather than smallies.

Other than those things, your best bet is to simply target whatever species is most dominant in the lake you’re fishing.

Which States Are Best for Which Bass?

If you’re in the States like the vast majority of our readers, there are a handful of states that stand out as the best for each bass species. If you’re in one or next to one, you can expect to have some great bass fishing available to you that stands out from other areas.

Luckily, these states are all spread out fairly well. So, you shouldn’t have to travel too far to get in on the action no matter where you live.

Which States are Known for Smallmouth?

Smallmouth are found all over the United States in most states, but they are most common in Arizona, Arkansas, Louisiana, Mississippi, and Utah. Those are the states where you’ll find the best records, the records are more complete, and even outside of record-breaking fish, there are more average and above-average fish than anywhere else.

Which States are Known for Largemouth Bass?

Largemouth are found in every state, but the best states to catch them are Alabama, California, Florida, Texas, and Michigan. Again, that stretches across the entire country, so the best bass fishing around is never further than a weekend vacation away for most anglers.

What are the Best Spots for Smallmouth and Largemouth Bass?

In each of the states we’ve mentioned, there are tons of ponds and lakes. Not all of them produce the same level of quality fish, though. In fact, some states are mostly known for one body of water. So, which lakes do you go to? Once you’re there, what are the best spots? Which lures work best for smallmouth vs largemouth bass?

BassForecast fishing app can help with all those questions. We provide top-notch maps for anglers across the United States, and each map comes with location-specific weather data including barometric pressure, wind direction and speed, spot-on solunar, and more.

Not only that, but we bring anglers together with a genuine community, and we have an extensive backlog of guides and articles to get you filled in with the latest tips, tricks, and historical bits.

Whether you’re targeting largemouth bass or smallmouth bass, download the BassForecast fishing app, today.