largemouth bass out of water.

The largemouth and small-mouth bass fish are two of the most popular freshwater species in America. As such, it comes as no surprise that Bass fishing has become a multi-million-dollar industry over the years.

Because of their popularity and appeal, a plethora of tournaments and events are held every year. These involve anglers trying to trap species like the supersized smallmouth and even the Lunker Largemouth.

Differentiating between the two fish subspecies, particularly when the largemouth is on the smaller end of the spectrum, can prove tricky, even for experienced anglers. Here are all the facts we could find in relation to the smallmouth vs. largemouth.

Lifespan: Smallmouth Vs. Largemouth Bass.

Studies have shown that the average lifespan of a smallmouth fish is 12 years; in some cases, some individuals have been known to live up to 20-years. In comparison, the largemouth bass fish is known to live up to 16 years.

Physical Features: Small-mouth Vs. Largemouth Bass.

Although these two species are members of the same family, several slight differences can be observed. Here is how you can differentiate between the Small-mouth Vs. Largemouth Bass.

Size and weight.

Size is one of the main factors when it comes to telling the large and small-mouth apart. First, most people can tell that largemouth fish are significantly larger, just as their name suggests. Studies show that they can weigh as much as 25 pounds. In contrast, the small-mouth bass usually only grows to weigh around 12 pounds.

A small mouth bass being measured
The Smallmouth bass is much smaller in terms of size. (Image source:

We should also point out that size may sometimes prove problematic, particularly when the fish’s age has to be considered. A larger size and mouth usually mean more dominance, which improves the fish’s chances of survival. A much older smallmouth may also weigh just as much as a younger largemouth.

Lastly, experts also say that several other factors may adversely affect their size. These include the type of habitat, for instance.

A largemouth bass being measured
A largemouth bass (Image source:

Jaws and Mouth.

As was the case with their size, we can also spot a clear difference in the appearance of these species’ (smallmouth vs. largemouth) mouths and jaws. A close examination of the Largemouth Bass’ upper jaw reveals that it extends above the eye.

Thus, the largemouths’ mouth can open up to 120 degrees, which is one of the qualities that give it its name. On the other hand, the smallmouths’ upper jaw lines up level with its eye, giving it a 90-degree opening.

Dorsal Fins.

Another way to differentiate between the large and smallmouth is by closely examining their dorsal fins, which are located along their upper body.

The Largemouth’s dorsal fin is deeply notched and separated, while in comparison, the smallmouth’s dorsal fins have no breaks or gaps between them.

Additionally, the smallmouth also has tiny scales at the base of its dorsal and anal fins. In contrast, the largemouth bass’ fins are scale-less.


Another method of identification would require you to hold up the bass fish and examine its tongue. Upon close observation, you’ll find that the smallmouth bass has a tongue plagued with a rough patch, while largemouth fish tend to have smooth tongues with no patches. However, we should mention that discoloration may be mistaken for a rough patch if not observed closely.

Colour of their Scales and Appearance.

Another easy way to distinguish between the two fish is through the color of their scales. The smallmouth bass has scales that are much smaller than the largemouths.

A smallmouth bass out of water
A smallmouth bass (Image source:

Smallmouth fish typically have dark vertical bars, are also black green, and boast red eyes. Additionally, their bodies can range from white-yellow, brown to green.

In some instances, they can even be black, depending on the water clarity or the diet they observe. A closer look at a largemouth reveals various shades of green, overlayed with a dark lateral streak on its side.

Location and habitat.

Talking habitat, Anglers are in agreement that smallmouths prefer cool, clear, and current-driven waters. They also like to swim around boulders and weeds. In addition, smallmouth fish can be found across the Great Lakes, Hudson, and the Mississippi.

They like hunting in strong current waters, so it’s much easier to trap them by casting nets into these aforementioned strong currents.

When it comes to habitation, Largemouth fish prefer warm and murky waters. Other than that, they also like to nest and hunt in areas around grass, rocks, stumps, and weeds.

This is a key factor in differentiating between the two species as the smallmouth bass keeps to clear water streams and rivers. They can also be found at the bottom of lakes, nestled in the sand, or around rocky cover.

Largemouth bass prefer the areas around grass
(Image source:


The behavior patterns of these two fish (smallmouth vs. largemouth) can also serve as a defining factor in differentiating between these two species. Behavior in this instant can refer to feeding, movement, and seasonal habits.

First of all, Smallmouth fish like to feed on nocturnal foliage such as crayfish, insects, shad, perch, and minnows. In the summer, smallmouth fish tend to move inshore, away from the shallows, to avoid the rising temperatures. During winter, when cooler temperatures run rampant, these fish can be found along shallow waters.

Another key character trait can be observed while fishing. When hooked, smallmouth fish tend to swim around erratically and jump out of the water, a behavior that makes them less challenging when it comes to fishing for the thrill of the hunt. Smallmouths also tend to spawn in warm, clear waters with sufficient sunlight.

In contrast, largemouth fish usually feed on larger creatures such as frogs and even small aquatic birds. When it comes to feeding, their aggressive and opportunistic nature places them much higher in the food chain than smallmouth fish.

A largemouth bass attempting to eat a frog
(Image source:

They spawn once a year during spring when temperatures get to 60-degrees. Ideally, they prefer to deposit their eggs on gravel, clay, and even submerged grassroots with a thin layer of mud for cover. When caught in an angler’s hook, the largemouth fish while attempt to dive deeper and fight harder than the smallmouth fish ever could.

Best time to fish.

Since the smallmouth fish tends to be more active in cold waters, they are best trapped during the early spring, in the morning, and late afternoon.

On the other hand, the largemouth fish can be better trapped during the summer. Experts say that this is because they drift towards shallow bays and creeks, making them much easier to spot. In addition to this, a portion of the angler community insists that cloudy, drizzly days make for the best time to go fishing for the largemouth bass.

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