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
Salvelinus fontinalis is native to cold streams, rivers, and lakes of eastern North America, from the Great Lakes east to the Atlantic and down the Appalachians as far south as Georgia, where it holds on in high, cold headwaters. Despite the name it is a char, in the genus Salvelinus with arctic char and lake trout, rather than a true trout. It needs the coldest water of the commonly farmed salmonids: it does best around 12 to 16 C, is stressed above about 20 C, and cannot survive sustained temperatures past the mid 20s. Because it is so sensitive to warmth and pollution, it serves as an indicator species, among the first fish to vanish as a stream degrades. The flesh is white to pink, delicate, and sweet. Most stream fish run 15 to 30 cm and live three to five years, though fish in large lakes can reach two feet and several kilograms and live longer. A heritage food and sport fish in Appalachia and New England, it is farmed mainly in the northeastern US and eastern 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 species for systems that hold 10–16°C all year. Brook trout are fussier about heat than rainbow trout, stressed above about 18°C and killed by sustained warmth past the low-to-mid twenties, so they belong in cold climates or chilled systems. Growth is moderate, around 200–400 g in twelve to eighteen months on a high-protein salmonid pellet of 40 to 45 percent; feed conversion is roughly 1.2 to 1.6, a little behind rainbow trout. They need plenty of oxygen, among the more demanding trout, so keep dissolved oxygen high, above about 5 to 7 mg/L, and hold ammonia low. Stock somewhat lighter than rainbow trout, around 15 to 25 g/L, since brook trout are territorial. They spawn in autumn, with males coloring up. Fingerlings are easy to get from state hatcheries and private trout farms across the eastern US and Canada, and the fish is legal in most places, with permits or restrictions in some. The flesh fetches a premium in local northeastern markets as a heritage product, and the species fits best in spring-fed systems in Appalachia, New England, or eastern Canada where cold water runs year-round.