Bluegill

Water parameters

Minimum tank: 200 L per individual at harvest size.

Feed and growth

Feed protein

40% target

Daily feed (warm)

1.20% of body weight

Daily feed (cool)

0.60% of body weight

Max density

40 g per litre

A 300 g adult eats about 3.6 g of feed per day at optimum. 10 fish at adult size: ~36 g daily.

Legality

Rules vary by jurisdiction and change over time. Verify with your local fisheries or wildlife authority before stocking.

Unlisted jurisdictions default to "check local regulations".

Origin and habitat

Lepomis macrochirus is a North American sunfish of the family Centrarchidae, one of the most familiar panfish on the continent. It is native to the United States east of the Rockies, from coastal Virginia to Florida, west to Texas and northern Mexico, and north to Minnesota, New York, and southeastern Ontario, and it turns up in nearly every warm pond, lake, and reservoir across that range. Three subspecies are recognized, including the southern coppernose. The fish is chiefly carnivorous, taking aquatic insects, crustaceans, snails, and small fish, with some plant matter. For aquaponics it has a built-in edge: it is native and legal to raise in every US state without the permits tilapia often requires. The flesh is firm, white, and sweet, rated excellent table fare and, to many palates, as good as or better than tilapia. Bluegill grow to about 41 cm and 2 kg at the extreme, though pond fish are usually far smaller, and they live around eight to twelve years. The species has been widely introduced abroad and now sits on the European Union's list of invasive alien species.

Climate and outdoor ponds

Climate

temperate (handles seasonal swings)

USDA zones

3–10 (winter low around -40°C or warmer)

Heating needed

no

Cooling needed

no

Care notes

A legal, hardy stand-in for tilapia in US states that restrict tilapia stocking. Bluegill grow more slowly than tilapia, taking twelve to eighteen months to a modest 150–250 g, and stay smaller, but the fillets are excellent and the paperwork is simple. They tolerate a wide band, roughly 4–32°C, with best growth around 22–28°C, and they keep feeding down to about 10°C where tilapia would quit, which suits unheated greenhouse systems in temperate areas. Feed a floating pellet over about 32 percent protein; feed conversion runs from roughly 1.3 in well-managed tank systems up toward 2.5, less efficient than tilapia but fine for home use. Reproduction is seasonal rather than year-round: males sweep out saucer-shaped nests in shallow 'beds', often in colonies, and guard the eggs when water warms past about 20 C in late spring through summer. That seasonal habit is an advantage, since it sidesteps the constant overbreeding that crowds tilapia systems, and spawning is easily managed with the right substrate and broodstock handling. Fingerlings are easy to find from hatcheries, farm stores, and state stocking programs, and the fish is among the hardiest and most disease-resistant in North American culture. Keep stocking moderate, around 10 to 20 g/L.

Further reading

• Aquaponics permits: what you need before selling fish or produce
• Feed conversion ratio explained
• Raising trout in aquaponics: cold water systems