Aren’t all bass the same? What’s the difference between a largemouth bass and smallmouth bass? Those are questions that I get a lot from many different people. One of the most important aspects of fishing, not just for bass but for all fish, is understanding your quarry. Both species of bass have their own unique physiology and behavior that, if you can understand, you can exploit to your advantage. These small things can sometimes mean the difference between a day with bass thumb or getting skunked.
Above: Not so much alike…. The most obvious difference between the two species is the mouth. There’s a reason why largemouth bass are called “largemouth” and smallmouth bass are called “smallmouth”. The jaw of the largemouth bass extends far past the eye, hence the name “largemouth”. The jaw of the smallmouth extends to the middle of the eye, hence the name “smallmouth”. In the warmer, more fertile waters that largemouth live in, they have a greater range of prey to swallow, and eat on larger, rounder or spinier prey, such as bluegill or catfish. Smallmouth, on the other hand, live in colder, less fertile waters, and have less diversity in their diets. They mostly eat smaller, thinner prey, such as shad, and don’t need as large of a mouth to swallow their prey.
The coloration and pattern of the two species is also different. Smallmouth tend to have spotted dark marks across their skin, while largemouth tend to have one solid dark pattern running down their body, but there are always variations. Largemouth also tend to be greenish in color, while smallmouth are usually brownish or a dark yellow.
Habitat is also a way to tell the two species apart. Smallmouth, as mentioned before, live in colder, infertile, faster flowing waters, such as the upper Potomac or the Great Lakes. Most clear, flowing creeks in the US will have a population of smallmouth. Largemouth live in fertile, slow moving, warmer water, such as most farm ponds and town lakes. Of course, there can be a little overlap, especially in larger reservoirs and rivers, with largemouth living in the shallower, calmer waters, and smallmouth living in the deeper or faster flowing sections.