2019 saw the largest turnout in a decade for fishing in the USA, with over 50 million Americans casting their lines. One of the most popular freshwater catches is bass, particularly the largemouth and smallmouth bass, and is now a multi-billion dollar industry. The smallmouth and largemouth appear similar, so how can you tell them apart?
Differences between Smallmouth bass vs. Largemouth can be explained by the larger size of the largemouth, its larger mouth, and its vertical patterned flanks. The largemouth also has a divided dorsal and has more varied habitats than smallmouths, including swamps, ponds, and backwaters.
These two firm fishing favorites have crossover habitats and similar physical characteristics, making them hard to tell apart from the untrained eye. However, the “largie” (largemouth) and “brown bass” or “smallie” (smallmouth) have fundamental differences. Here, we list some of the behaviors and characteristics that will help you tell your smallies from your largies.
Why Are Smallmouth and Bigmouth Bass So Popular?
According to US wildlife statistics, over 43% of freshwater anglers fish for bass, and there are many reasons for these two species of bass’s popularity. These two bass species can be caught in multiple ways and are creatures of habit, making it easier for anglers to locate.
They also follow precise seasonal movements and can be found in certain areas seasonally. For example, fallen logs or boat docks are prime Largemouth catching areas, and creek channels submerged brush piles, and drop-offs are large bass meccas.
Bass also put up a fight when caught and are a challenge to land, however easy they may seem to hook. The larger the bass, the more challenging it becomes for an angler to reel in their prey (and often, the bass wins).
You may find largemouth bass almost anywhere where there is a body of water, making them a versatile fishing option for many locations in the USA. Bass can also accommodate a variety of fishing skill levels due to their curious nature and tendency to go for a variety of lures. Biologist Fred Cross has found eels, snakes, and baby ducks in bass stomachs, reflecting just how opportunistic bass are in their meal choices!
Bass is also a popular fish for eating. People favor Smallmouth bass for their sweeter, more clean tasting flesh, but many Americans love the fishier and meatier texture of a largemouth dinner on the coals.
According to statistics, a professional bass fisherman may make up to $350,382 a year, which shows just how lucrative bass fishing has become. The industry surrounding largemouth bass fishing has given rise to several new and specialized fishing gear, including:
- Electronic depth finders
- Location instruments
- Drift boats
- Float tubes
- Specialized bass fishing boats
People have introduced bass across the world, and there is now competitive bass fishing in countries as remote as:
- South Africa
Largemouths have been introduced widely as a recreational ﬁsh species throughout the world. As a result, competitive bass ﬁshing has now spread to Japan, Korea, Italy, Australia, and South Africa.
The Smallmouth bass or Micropterus dolomieu is often also called a “brown bass” or “smallie” and is a freshwater type of fish from the Sunfish family or (Centrarchidae) of the order Perciformes. The Smallmouth bass is native to the Mississippi River basin and the Saint Lawrence River Lakes system into the Hudson Bay basin. The largest smallmouth ever caught was in Kentucky and weighed in at over 11lbs (4.98kgs).
The Largemouth bass or Micropterus salmoides is a freshwater gamefish of the Centrarchidae family and, like the smallmouth bass, are part of the black bass species. The largemouth bass is native to:
- Eastern and Central North America
- United States
- Northern Mexico
However, the species has spread to other parts of the world.
An Angler caught The largest reported Largemouth bass in Montgomery Lake, Georgia, in 1932 10.1kgs (22lbs).
The most apparent distinction between the large and smallmouth bass beyond the jaw is the size. The largemouth grows substantially larger than its ‘smallie’ cousins. Largemouth bass grow 4 to 6 inches (10 to 15 cm) in their first and reach their 16inch mature length of 40cm at three years old.
Smallmouth bass is also between 12 and 16 inches (30.5 cm to 40.6 cm) but is typically much lighter with an average of 6.61lbs (3kg) compared to the largemouth average at around (5.5kg) or 12lbs.
The most apparent difference between the two kinds of bass is their mouth sizes, hence their names. The largemouth bass has a large and slightly sloping mouth, which extends far beyond its eye’s rear margin. The smallmouth bass’s upper jaw does not extend from beyond the center of its eye when viewed in profile.
Smallmouth bass is often brown but may appear black or green because they adapt their color to suit the water conditions. They have red or brown eyes with darkened vertical bands down their sides. On the other hand, largemouth bass tend to be olive green to green/grey and have distinctive dark blotches that form a horizontal stripe along their sides.
The Largemouth bass has a distinctive dorsal fin with a clear separation between the first and second dorsal, with the front fin bearing 9-11 spies and the back 12-14 rays. The smallmouth has a more continuous dorsal fin structure with three spines in the anal fin and 9-11 soft rays in the dorsal fin.
The smallmouth bass is generally brown, sometimes appearing as green or almost black with red or brown eyes. Smallmouth show dark brown vertical bands rather than a horizontal band along the flanks. There are typically 13-15 rays in the dorsal fin.
Here are some great visuals for telling the physical difference between the two bass species:
Largemouth bass can live in a much more diverse range of habitat than the Smallmouth bass, which is why they can be found more extensively in the continental United States. They can occupy almost any large body of water from ponds and creeks to swamps, lakes, flowages, and backwaters.
Largemouth bass can also tolerate warmer temperatures than their smallmouth cousins and often use thick and shallow vegetation for cover. They also prefer spawning areas with a firm substrate of mud gravel and sand.
Adult largemouths use submerged vegetation to ambush their prey, and younger bass use aquatic weeds and submerged tree limbs and logs to protect themselves from predators. Dissolved oxygen is essential in the largemouth’s habitat choice.
Adult largemouth bass utilizes aquatic vegetation as camouflage to surprise their prey, and younger largemouth use weedy areas and sunken tree limbs to hide from their predators. Enough oxygen dissolved in the water is also essential to largemouth bass habitat.
You will often find largemouth bass in weedy oxbows and clear floodplain lakes and prefer warmer water between 81-86°F (27.2°-30°C). Because of its warmth preference, you will generally not find largemouth below 18.8 feet. In winter, the largemouth bass moves to deeper waters, and in spring, they migrate to the warmer bays.
During the day, the largemouth generally cruises above the aquatic vegetation at depths between 3 and 10 feet or uses lily pads or the shade of overhanging trees, piers, or brush. They return to deeper water at night, resting on the bottom of the water under logs or submerged trees.
Smallmouth are rarely found in water 25 feet deep and generally prefer water with current flow. Their chosen temperatures are between 67° to 71°F (19.4 to 21.6°C).
Smallmouths tend to move to shallower waters in the summer months and move back to the shallows in the fall, where fishermen may hook them anywhere from the bank up to 20 feet deep.
Unlike largemouth bass, smallmouth bass prefer clear waters with cooler streams and rivers with a rocky substrate. Like largemouths, they seek outcroppings of rocks or trees or pier posts to avoid predation but typically choose clear running water of rivers and streams with relatively swift currents.
Smallmouth bass is suited to rivers’ transitional areas between rocky tumbling streams of hills and the slower flowing central regions of rivers. These fish also prefer high visibility for prey and are not often found in stiller backwaters or dark, silty waters of ponds as their larger largemouth cousins.
Smallmouth bass are more agile and prone to jumping and enjoy feeding and hunting in waters with hard currents. In big waters, anglers often use electronics with mapping equipment to isolate extensive flats, rocky points and reefs, and shoals that smallmouths favor.
Juvenile largemouth eat small baitfish, shrimp, and insects, while adults consume smaller fish, shad, worms, crawfish, frogs, and snakes. They are also known to eat small water birds, baby turtles, and alligator hatchlings. Large largemouths may consume prey as large as 50% of its body length or even larger.
Smallmouth bass have similar feeding habits. Juvenile smallmouths favor zooplankton, and insect larvae and adults prey on crayfish, amphibians, insects, and other fish (smallmouths often cannibalize the young of their same species). The main difference between the two bass is their feeding habits.
While smallmouths often venture out and around cover to feed, largemouths tend to remain in cover when feeding. Largemouth look for current breaks to rest and use cover to ambush their prey, and you won’t often find them in the stiffer water movements. Smallmouths are the opposite and tend to favor fast water over water breaks. They are also not afraid to head to open water without cover when their preferred prey is plentiful.
Ways of Catching Them
Weather often comes into play when choosing which bass to target according to the time of day. Largemouths tend to take cover on sunny days, so it’s a good idea to target thick vegetation and shaded areas of piers and boat docks. Smallmouth cover in humps and rock piles in sunny weather, so it’s best to seek them there.
Windy and rainy weather tends to make both species roam around weed openings and the rocky banks. Topwater poppers and walking baits are great for both bass in overcast and rainy weather.
In the summertime, largemouths are easy to find and tend to seek cover in creeks and bays. Smallmouth tends to move out to deeper waters in summer and are less plentiful in shallow areas. Here they are as deep as 45 feet as they move offshore to avoid the heat.
Often smallmouths move shallower after dark and feed on nocturnal forage such as crawfish. Rocky banks are an excellent place to find them, and areas with deep water access and channel breaks. Smallmouth bass uses deep water as cover, much like largemouths use weed beds.
In the fall, both species tend to move towards the shallows. While the largemouth favors logs, stumps, and standing timber, the smallmouth prefers rocks and boulders and transition areas where chunk rock turns to pea gravel. You will find the largemouth as shallow as 1-2 feet while the smallmouths opt for deeper water between 5-10 feet.
The best bait for bass is a much-contested choice, with even the professionals swearing by anything from plastic jerkbaits to spinnerbaits and football jigs. Here are a few essential tips in fishing for these two kinds of bass.
Largemouth bass like to lurk under cover and an excellent way to hook them is by flipping and pitching into the vegetation where they lurk. Females may often ignore lures when they are on their bed, and large plastics and jigs are a good option.
Bass have powerful tails and excellent vision and vibration sensitivity and can maneuver underwater with agility. Largemouths are not tailored to long pursuits, especially away from covered structures. The chances of the bass chasing a lure over a distance is negligible.
The largemouth method of feeding is to hide and wait until the quarry passes close by and uses powerful suction to pull its prey towards its mouth. Largemouths feed primarily by sound (vibration) and sight and have an acutely sensitive lateral line that pinpoints prey through detecting vibrations.
Their vibration sensitivity makes them keen hunters in lower light conditions, which is why a bass can hit a black plastic worm in deep water on a dark night. The four main lures used for Largemouth bass are:
- Soft plastic lures such as worms are an excellent largemouth attraction, especially at temperatures over 55℉ (12.7°C).
- Spinnerbait is an excellent search bait with a safety pin design that prevents snagging.
- Crankbaits lure like spinnerbaits and are great for covering water fast.
- Jigs are an excellent largemouth lure and are often fished by flipping and pitching rather than casting.
Smallies will go for pretty much any lure, and they are quick on the uptake when they are bedding. One thing to avoid is a heavy line because the smallmouth has better vision than the largemouth bass, especially when the sun is out.
Smallmouth lures don’t have to be as weedless as the largemouth cousins, and you may often throw bait with an open hook like a tube on rocky bottoms without worrying about snagging on weeds. Smallmouth lures are also typically smaller than largemouth lures meaning lighter tackle.
Spinning reels are popular when smallmouth fishing because it handles light bait and lines much better than baitcasting gear. Lighter lines are a must for smallmouths’ superior vision. Older and larger smallmouths tend to become savvier, so finesse lures are a great option. Otherwise, you may choose from the following options:
- Blade baits are excellent for catching smallmouth in cold water. The trick is to let the bait sink to the bottom and let it sit. Fish react slower in colder water.
- Small soft plastics, specifically finesse lures, work well by dragging and hopping along the bottom. These include Ned Rig, Shaky Head, Tubes, and Grubs.
- Jigs are one of the most popular smallmouth bass lures, particularly the standard rubber skirted bass jig and bucktail jigs.
- Jerkbaits are great for targeting smallmouths in the cooler waters of early spring and are great for reaction strikes.
- Crankbait and spinnerbaits are excellent for catching smallmouth along with rock piles and weed edges from 6 to 30 feet and more.
- Topwater lures are useful in the early morning or late afternoon or cloudy conditions with a light chop on the water ‘walk the dog’ style lures are popular choices.
Here is an excellent clip with tips for choosing lures for bass fishing:
Largemouth and smallmouth bass will continue to be prized and sought after catches, with their beauty and sheer tenacity in equal measures. Understanding their differences in their physiology and behaviors makes it easier to target your preferred catch. Telling the two apart and where to find them might make ‘smallies’ and ‘largies’ easier to hook, but there is no guarantee of landing them.
- Statistica: Recreational Fishing in the US – statistics & facts
- Wikipedia: Perciformes
- Wikipedia: Centrarchidae
- Fish and Aquatic Conservation: Largemouth Bass
- Fish and Aquatic Conservation: Smallmouth Bass
- Animal Diversity: Micropterus Dolomieu
- Animal Diversity: Micropterus Salmoides
- Florida Museum: Micropterus Salmoides
- Bass Fishing and Catching: Largemouth Bass Lure?
- Wikipedia: Largemouth Bass
- Wikipedia: Smallmouth Bass