Brook trout
Salvelinus fontinalis
Also known asSquaretail · Brookie
Water parameters
Minimum tank: 300 L per individual at harvest size.
Feed and growth
- Feed protein
- 45% target
- Daily feed (warm)
- 1.20% of body weight
- Daily feed (cool)
- 0.80% of body weight
- Max density
- 30 g per litre
A 500 g adult eats about 6.0 g of feed per day at optimum. 10 fish at adult size: ~60 g daily.
Legality
Rules vary by jurisdiction and change over time. Verify with your local fisheries or wildlife authority before stocking.
| Jurisdiction | Status | Notes |
|---|---|---|
| California | permit required | verified 2026-05-13 |
| European Union (bloc) | restricted | Restricted in several EU member states due to native trout conservation concerns verified 2026-05-13 |
Unlisted jurisdictions default to "check local regulations".
Origin and habitat
Native to cold freshwater streams, rivers, and lakes across eastern North America, from Georgia and the southern Appalachians north through New England and across eastern Canada. The species (Salvelinus fontinalis) is a char, not a true trout, closely related to arctic char and lake trout. Brook trout require the coldest water of any commonly cultured salmonid: optimal temperature is 10–16°C, with stress above 20°C and mortality above 25°C. Wild populations are an indicator species for water quality; they're among the first fish to disappear from degraded streams. The flesh is white to pink with a delicate, sweet flavor. Brook trout are a traditional food and sport fish in Appalachia and New England, with significant cultural importance. Commercially farmed primarily in the northeastern US and Canada.
Climate and outdoor ponds
- Climate
- cold-water (cool water required, dies in heat)
- USDA zones
- 2–6 (winter low around -46°C or warmer)
- Heating needed
- no
- Cooling needed
- yes, if summer water exceeds upper tolerance
Care notes
A cold-water aquaponics species for systems maintaining 10–16°C year-round. Brook trout are more temperature-sensitive than rainbow trout: they stress above 18°C and die above 22–25°C, which limits them to colder climates or well-chilled systems. Growth is moderate: 200–400 g in 12-18 months on salmonid pellet (40-45% protein). FCR is 1.2-1.6, acceptable but slightly less efficient than rainbow trout. Stocking density should be lower than rainbow trout (15-25 g/L) because brook trout are more aggressive and territorial. Males develop hooked jaws (kype) and intensely colored spawning dress in autumn, with bright red-orange bellies and blue-haloed red spots. Dissolved oxygen must stay above 7 mg/L; brook trout are the most oxygen-demanding commonly cultured salmonid. Ammonia tolerance is lower than rainbow trout: keep TAN below 0.5 mg/L. Fingerlings are widely available from state hatcheries and private trout farms across the eastern US and Canada. Legal in most jurisdictions. The flesh commands a premium in local markets, especially in the northeastern US where it's a heritage product. Brook trout are best suited for spring-fed aquaponics systems in Appalachia, New England, or eastern Canada where cold water is naturally available year-round.