Smallmouth bass photographed in side profile

Brett Billings / USFWS · Public domain

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Species guide

Smallmouth Bass

Micropterus dolomieu

A bronze-toned bass strongly associated with clear water, rock and current, though appearance changes with habitat and age.

Global status
Least Concern · global
Assessment
IUCN assessment: March 1, 2012
Published
August 26, 2026
Last reviewed
August 30, 2026

Habitat

Clear, cooler lakes and rocky or gravel-bottom rivers, runs and pools.

Habitat supports a shortlist; it does not prove an identity. Water bodies change seasonally, and introduced populations may occur outside the best-known native setting.

Range

Native to the St. Lawrence–Great Lakes, Hudson Bay and Mississippi systems; introduced in many regions.

Check a current state, provincial or national fisheries record before making a high-confidence range claim. Drainage boundaries are more informative than political borders.

Compare carefully

Use several structures together. A reddish eye or bronze color can support an identification but should never decide it alone.

When a decisive structure is hidden, record the observation as probable or unresolved. An honest uncertainty is more useful than a precise label built from incomplete evidence.

Responsible observation

Include the jaw-to-eye relationship, dorsal-fin connection and several vertical flank marks in one sharp frame.

For a live fish, prepare the camera first, use wet hands when handling is unavoidable, support the body and return it promptly according to local rules.

Photograph, creator and usage status ↗Taxonomy and global status record ↗USFWS species directory ↗