Smallmouth bass

Quick facts

Adult size

35 cm, 800 g typical harvest weight

Days to harvest

540 to 1095 days from fingerling

Lifespan (max)

up to 15 years

Diet

carnivore

Temperature class

cool-water

Difficulty

intermediate

Water parameters

Temperature range

8–28°C (optimum 21°C)

pH

6.5 to 8.5

Hardness

5 to 25 dGH

Minimum tank

400 L per individual at harvest size

Feed and growth

Feed protein

40% target

Daily feed (warm water)

1.20% of body weight per day

Daily feed (cool water)

0.60% of body weight per day

Max stocking density

30 g per litre of system water

A 800g adult eats about 9.6 g of feed per day at optimum temperature. For a roster of 10 fish at adult size, that's around 96 g of feed daily.

Legality

Aquaculture and possession rules vary by jurisdiction and change over time. This table reflects regulations as of the verified date on each row. Verify with your local fisheries or wildlife authority before stocking.

Jurisdictions not listed here default to "check local regulations". A non-listing is not a green light; rules in your specific county or municipality may apply.

Habitat and origin

Native to the Great Lakes, upper Mississippi basin, and Ohio River system in central and eastern North America, with a range extending into southern Quebec and Ontario. The species (Micropterus dolomieu) inhabits clear, cool-water rivers and lakes with rocky substrate, preferring stronger current and cooler temperatures than largemouth bass. Adults reach 40–55 cm and 2–4 kg. Smallmouth bass are among the most popular freshwater sport fish in North America, prized for their aggressive strikes and strong fighting ability. The flesh is white, firm, and mild, comparable to largemouth bass but slightly more delicate. Smallmouth have been widely introduced outside their native range for sport fishing and are present in suitable waters across most of the US and parts of Europe.

Climate and outdoor ponds

Climate classification

temperate (handles seasonal swings)

Outdoor pond zones (USDA)

4 to 9 (winter low around -34°C or warmer)

Heating in a temperate climate

Not required (handles seasonal cool periods)

Cooling in a temperate climate

Not required

Zone bounds reflect year-round outdoor pond viability with no active heating. Anywhere outside the bounded zone, the species can still be kept in an indoor heated tank or a seasonally-managed system. Verify your specific microclimate, as a sheltered yard zone can run a half-zone warmer than the regional rating.

Care notes

A cool-water to warm-water predatory species with culture characteristics similar to largemouth bass but adapted to cooler, clearer water. Optimal temperature is 18–24°C (2–4°C cooler than largemouth), with tolerance from 5–30°C. Growth in culture: 300–600 g in 18-24 months on high-protein pellet (42-48% protein). FCR is approximately 1.5-2.0 for pellet-trained fish. Like largemouth bass, smallmouth must be trained to accept pellets as small fingerlings; older fish that have fed on live prey are extremely difficult to wean. Source pellet-trained fingerlings from hatcheries. Stocking density: 8-12 g/L (lower than largemouth because smallmouth are more active swimmers and more stressed by confinement). Cannibalism between size classes is a serious concern; maintain strict size grading. Dissolved oxygen above 5 mg/L; ammonia below 0.5 mg/L. Smallmouth bass require better water quality than largemouth bass, making them more suitable for well-managed aquaponics systems with good filtration. Fingerlings are available from bass hatcheries, though less widely than largemouth. Legal in most states with appropriate aquaculture permits. For cool-water aquaponics in the northern US, smallmouth bass is a premium option.

Further reading

• Aquaponics water chemistry: balancing pH for fish and plants
• Fish for aquaponics: tilapia vs everything else