Blue catfish

Quick facts

Adult size

80 cm, 4000 g typical harvest weight

Days to harvest

540 to 900 days from fingerling

Lifespan (max)

up to 20 years

Diet

omnivore

Temperature class

warm-water

Difficulty

intermediate

Water parameters

Temperature range

10–32°C (optimum 27°C)

pH

6.5 to 8.5

Hardness

4 to 20 dGH

Minimum tank

1000 L per individual at harvest size

Feed and growth

Feed protein

32% target

Daily feed (warm water)

2.50% of body weight per day

Daily feed (cool water)

1.00% of body weight per day

Max stocking density

50 g per litre of system water

A 4000g adult eats about 100.0 g of feed per day at optimum temperature. For a roster of 10 fish at adult size, that's around 1000 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 Mississippi, Missouri, and Ohio River basins and Gulf Coast drainages from Texas to Guatemala. The species (Ictalurus furcatus) is the largest catfish species in North America, with wild specimens exceeding 60 kg (the IGFA all-tackle record is 64.8 kg from Kerr Reservoir, Virginia). Found in large rivers with moderate to strong current, preferring deeper, faster-moving water than channel catfish. Blue catfish are predatory omnivores: adults feed primarily on other fish (shad, herring), crayfish, and freshwater mussels, while juveniles consume insects and invertebrates. The flesh is white, firm, and noticeably milder than channel catfish, making it a premium commercial product. The species has been introduced outside its native range for sport fishing and has become highly invasive in Chesapeake Bay tributaries, where exploding populations threaten native blue crabs, shad, and other species.

Climate and outdoor ponds

Climate classification

temperate (handles seasonal swings)

Outdoor pond zones (USDA)

5 to 11 (winter low around -29°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 large-bodied catfish option for aquaponics operators with substantial tank volume (500 L minimum, 1000+ preferred for grow-out). Blue catfish grow larger and are more predatory than channel catfish, creating both opportunities (bigger fillets, premium mild flesh, higher per-fish value) and management challenges (cannibalism, larger system requirements, greater aggression). Growth rate is comparable to channel catfish: 500–1 g in 12-24 months on commercial catfish pellet (32-36% protein), though blue catfish continue growing well beyond 2 kg given time and feed. FCR is 1.5-2.0, similar to channel catfish. Temperature tolerance is broad (5–32°C), with optimal growth at 24–28°C. Dissolved oxygen tolerance is good but not as extreme as channel catfish; keep above 3 mg/L. Stocking density: 10-20 g/L, lower than channel catfish because blue catfish are more aggressive. Cannibalism is a real concern with mixed size classes; maintain tight size grading and never combine fish differing by more than 30% in length. Fingerlings are available from catfish hatcheries in the southeastern US. Legal in most states without special permits.

Further reading

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