Smallmouth bass (Micropterus)
The smallmouth bass has a thick but elongated body, red eyes, and a broad and slightly forked tail. Its pelvic fins are situated near the front of the body below the pectoral fins. A single spine is found on each pelvic fin and on the front of the anal fin. The two dorsal fins are merged with the front one spiny and the second one featuring one spine followed by several soft rays.
Coloring will vary from brown and golden brown to olive green on the back, which fades to gold on the sides and white on the belly, although the dominant colors will often extend all the way down the belly. Young smallmouth have more distinct vertical bars or rows of spots on their sides, and the tail fin is often orange at the base with black and white outer edges.
The smallmouth is easily distinguished from its cousin, the largemouth, by its jaw bone, which extends to about the middle of the eye. The largemouths jaw will extend well beyond the eye. The coloration is also different, as smallmouth are more brownish in color, while the largemouth is predominantly green.
Young smallmouth bass feed mainly on plankton and switch to larger prey like water insects, amphibians, crayfish, and other fish as they grow.
Adult smallmouth bass are opportunistic predators and will eat whatever prey is available in their environment. Though they consume both aquatic and terrestrial insects, the majority of their diet is made up of crayfish and several prey fish species. Crayfish are the preferred meal where available, but smallmouth will also feed heavily on shad, perch, minnows, panfish and even small bass.
Smallmouth will feed at whatever depths they inhabit at a given time. At times, they may move to shallow water specifically for feeding, and can often be found chasing schools of baitfish or insects at the surface.
Smallmouth bass are native to only North America, their original habitat ranging from the Great Lakes and St. Lawrence River drainages in Canada south to northern Georgia, west to eastern Oklahoma, and north to Minnesota. It has since been widely introduced to waters within and beyond that range, across southern Canada west to British Columbia and east to the Maritimes, west to the Pacific coast states, and into the southwestern United States. It has also been introduced to Hawaii, Asia, Europe, and Africa.
Due to its specific habitat requirements, smallmouth bass do not adapt as well to many waters as largemouth bass, even within their native range. The largest smallmouth populations inhabit cool northern waters, but the largest fish are caught in the southern portion of their range.
Smallmouth bass prefer clear, calm waters and seek out areas with gravel, rubble, or rocky bottoms. They live in midsize, gentle streams that offer deep pools and plenty of shade, or in fairly deep, clear lakes and reservoirs with rocky bluffs, steep drop-offs and large shoals. They will also utilize weed beds and other vegetation, especially if found near some type of rock. Although they are fairly adaptable, they are rarely found in murky water. Smallmouth will inhabit rivers and streams with strong current but will spend most of their lives in areas that are sheltered from current.
Mature smallmouths prefer rocky, shallow areas of lakes and rivers and retreat to deeper waters as temperatures rise. They tend to seek cover and avoid bright sunlight. They hide in deep water, behind rocks and boulders, and around underwater debris and crevices, preferring water temperatures between 66 and 72 F.
Most bass do not travel great distances, and those in streams may spend the entire year in the same pool. As temperatures fall, they become less active and seek cover in dark, rocky areas.
- The largest smallmouth bass ever reported weighed 11 pounds, 15 ounces. It was caught in Dale Hollow Lake on the border between Tennessee and Kentucky in 1955.
- Smallmouth bass were harvested commercially in North America until the 1930s, a practice that stopped due to overfishing concerns.