Smallmouth Bass
Black bassMicropterus dolomieu · also called bronzeback, brown bass
The smallmouth is a river and clear-lake fish, and pound for pound the harder fighter. Its bronze colour and vertical barring make it look quite different from a largemouth once you have seen both, but the jaw test is what settles it.
Quick facts
- Appearance
- Bronze to brownish-gold with dark vertical bars on the flank and often three dark bars radiating back from the eye. The dorsal fin is shallowly notched and continuous.
- Typical size
- 1–5 lb
- Waters
- lake, river, reservoir
- Regulations
- Smallmouth frequently carry different limits from largemouth, and many rivers have catch-and-release or slot regulations specifically for them.
How to confirm it
- Upper jaw ends at or before the rear edge of the eye.
- Dark vertical bars rather than a horizontal stripe.
- Bronze or brown-gold cast, not green.
- Dorsal fin continuous, only shallowly notched.
- Red or orange eye in many populations.
What it is confused with
One check settles each of these.
The jaw. Past the eye means largemouth; at or before means smallmouth.
Spotted bass has spot rows below the lateral line and a tongue tooth patch; smallmouth has neither.
Why this matters beyond curiosity
- Look-alike species often carry different limits. Walleye and sauger, black and white crappie, pike and muskie, blue and channel catfish — each pair can have different sizes, seasons and daily limits in the same water.
- Check it before the fish goes in the livewell. Most of the tests on this site take seconds and are far easier on a fish you are still holding.
- If you cannot tell, release it. That is the answer that is never wrong, and it is the one a warden will not argue with.
- Regulations are set by your state or province and change annually. This site identifies fish; it does not tell you the rules. Check the current regulations for the water you are on.