Arctic char vs Brook trout
How to tell them apart, and what follows from getting it right.
Why they get confused
Both are char rather than trout, both carry pale spots on a dark ground and white-edged orange fins, and both are stocked and introduced well outside their native ranges — so the two now share water in places neither reached naturally. In spawning condition they converge further, because both turn orange-red underneath.
Arctic char
Salvelinus alpinus — Salmonidae
Brook trout
Salvelinus fontinalis — Salmonidae
The differences
Each difference is marked with how far it can be trusted on its own. A single diagnostic character settles the identification; suggestive ones only narrow it.
| Character | Arctic char | Brook trout | Reliability |
|---|---|---|---|
| Markings on the back and dorsal finIdentification | Back plainly coloured; the dorsal fin carries no worm-like pattern. | Back and dorsal fin carry pale vermiculation — wavy, worm-like markings rather than round spots. | Diagnostic on its own |
| Shape of the spots on the flankIdentification | Round pale spots, cream to pink, sometimes with a red centre and no blue surround. | Round pale spots plus scattered red spots each ringed with a distinct blue halo. | Diagnostic on its own |
| Tail shapeIdentification | Caudal fin distinctly forked, more so in sea-run and lake fish. | Caudal fin square or very slightly notched — the square tail is where the American name squaretail comes from. | Supporting — use with others |
| Belly colour in spawning conditionIdentification | Orange to deep red, brilliant in spawning fish and absent in silver sea-run or deep-lake fish. | Orange to red, with the white-and-black fin edges standing out more sharply against it. | Suggestive only — varies |
| Where the fish is likely to have come fromRange | Circumpolar; the northernmost freshwater fish, with isolated relict populations in deep cold lakes further south. | Native to eastern North America, and introduced very widely to cold streams and lakes elsewhere. | Supporting — use with others |
Why it matters
Chiefly because of what an Arctic char may be. Southern char populations are glacial relicts confined to single deep lakes, genetically distinct, of high conservation concern and in several cases legally protected — while brook trout in the same country are frequently an introduced species that managers would rather have removed. Getting the pair the wrong way round can mean killing an irreplaceable fish and returning an unwanted one.
The full records
This page compares two species. Each of them has a complete record covering biology, behaviour, handling and the evidence behind all of it.
More about arctic char
Where it lives, how it is caught, and what else it is confused with.
Similar and related fish
What these connections rest on (1)
Scientific evidence — 1 connection
Supported by peer-reviewed research or fisheries science. The sources are listed and can be checked.
Brook trout
An identification comparison naming both binomials: Salvelinus alpinus and Salvelinus fontinalis.
- FishBase: a global information system on fishes — Froese, R. and D. Pauly, eds. — FishBase Consortium (Scientific institute)Relied on for: Morphological and distributional data for Salvelinus alpinus and for Salvelinus fontinalis.States this directlyPassage read and verified
- The IUCN Red List of Threatened Species — International Union for Conservation of Nature (Conservation authority)Relied on for: Separate assessments treating Salvelinus alpinus and Salvelinus fontinalis as distinct species.States this directlyCitation checked — the work exists and is described correctly
How it is caught
- SpinningFlies, small spoons and trolled lures, fished deep in summer and shallow at the margins of the season.
- Stillwater fly fishingFlies, small spoons and trolled lures, fished deep in summer and shallow at the margins of the season.
- TrollingFlies, small spoons and trolled lures, fished deep in summer and shallow at the margins of the season.
What these connections rest on (3)
Practitioner consensus — 3 connections
Widely and independently recommended by experienced anglers and specialist sources. This is real angling knowledge, not proof: controlled evidence for it is limited, and FishingHQ records it as convention rather than as a demonstrated effect.
Spinning
A practitioner claim about how Salvelinus alpinus is commonly fished, following from where and how it feeds.
- General angling website restatements of established technique — Various (Credible secondary source)Relied on for: Widely restated practitioner accounts of fishing for arctic char.Citation checked — the work exists and is described correctly
- Sea Angler — Bauer Media (Specialist angling publication)Relied on for: Practitioner treatment of the methods used for arctic char and comparable species.Citation checked — the work exists and is described correctly
Stillwater fly fishing
A practitioner claim about how Salvelinus alpinus is commonly fished, following from where and how it feeds.
- General angling website restatements of established technique — Various (Credible secondary source)Relied on for: Widely restated practitioner accounts of fishing for arctic char.Citation checked — the work exists and is described correctly
- Sea Angler — Bauer Media (Specialist angling publication)Relied on for: Practitioner treatment of the methods used for arctic char and comparable species.Citation checked — the work exists and is described correctly
Trolling
A practitioner claim about how Salvelinus alpinus is commonly fished, following from where and how it feeds.
- General angling website restatements of established technique — Various (Credible secondary source)Relied on for: Widely restated practitioner accounts of fishing for arctic char.Citation checked — the work exists and is described correctly
- Sea Angler — Bauer Media (Specialist angling publication)Relied on for: Practitioner treatment of the methods used for arctic char and comparable species.Citation checked — the work exists and is described correctly
Gear for this fish
- SpoonsChar in the sub-Arctic lakes and rivers are taken principally on small spoons and spinners, and the flash carries in the clear, low-light water they occupy.
- StreamersSea-run and lake char take a stripped streamer readily, particularly where they are feeding on small fish before or after a run.
What these connections rest on (2)
Practitioner consensus — 2 connections
Widely and independently recommended by experienced anglers and specialist sources. This is real angling knowledge, not proof: controlled evidence for it is limited, and FishingHQ records it as convention rather than as a demonstrated effect.
Spoons
A practitioner claim about which lure family answers this species' feeding or holding behaviour.
- General angling website restatements of established technique — Various (Credible secondary source)Relied on for: Widely restated North American lure practice for this species.Background and mechanism onlyCitation checked — the work exists and is described correctly
- IGFA International Angling Rules and World Record Requirements — International Game Fish Association (Angling or fisheries organisation)Relied on for: Recognition of the species as an established sport fish taken on artificial lures, and the tackle conventions used for it.States this directlyPassage read and verified
Streamers
A practitioner claim about which lure family answers this species' feeding or holding behaviour.
- Trout & Salmon — Bauer Media (Specialist angling publication)Relied on for: Fly categories and their application to salmonids in running and still water.States this directlyCitation checked — the work exists and is described correctly
- Still Water Fly-Fishing — Andre Deutsch, 1952 (Specialist angling publication)Relied on for: Still-water fly categories, and the feeding observations they are chosen from.Background and mechanism onlyCitation checked — the work exists and is described correctly
Where it lives
- Deep cold lakesThe most cold-adapted freshwater fish of the northern hemisphere. Southern populations survive only in deep lakes where a cold bottom layer persists through summer, and are relicts isolated since the last glaciation.
- Lowland stillwatersHolds in deep cold lakes and runs to sea from northern rivers.
- Upland lakes and hill lochsRelict populations isolated in deep, cold upland and glacial lakes since the last glaciation, and of considerable conservation interest.
What these connections rest on (3)
Scientific evidence — 3 connections
Supported by peer-reviewed research or fisheries science. The sources are listed and can be checked.
Deep cold lakes
A claim that the species depends on the cold layer below the summer thermocline, which is a thermal-tolerance claim about the animal rather than an angling observation, and rests on the reference literature accordingly.
- Freshwater Fishes of the British Isles — HarperCollins (New Naturalist 75), 1992 (Reference work)Relied on for: Distribution, habitat association, thermal requirements and life history of the freshwater fishes of the British Isles and north-west Europe.States this directlyCitation checked — the work exists and is described correctly
- FishBase: a global information system on fishes — Froese, R. and D. Pauly, eds. — FishBase Consortium (Scientific institute)Relied on for: Recorded depth range, temperature tolerance and habitat association for the species.States this directlyPassage read and verified
Lowland stillwaters
A habitat association for Salvelinus alpinus taken from the environment and distribution data on its FishBase summary.
- FishBase: a global information system on fishes — Froese, R. and D. Pauly, eds. — FishBase Consortium (Scientific institute)Relied on for: The environment, depth range and habitat description recorded for Salvelinus alpinus.States this directlyPassage read and verified
Upland lakes and hill lochs
Habitat association recorded for the species, in an environment the catalogue could not express until Sprint 30 modelled it.
- Freshwater Fishes of the British Isles — HarperCollins (New Naturalist 75), 1992 (Reference work)Relied on for: Habitat association and distribution of European freshwater fishes, including occurrence in artificial and modified waters.States this directlyCitation checked — the work exists and is described correctly
- FishBase: a global information system on fishes — Froese, R. and D. Pauly, eds. — FishBase Consortium (Scientific institute)Relied on for: Habitat association, depth range and water-type tolerance recorded for the species.States this directlyPassage read and verified
Reviewed 2026-08-13. FishingHQ does not state what any rule is or where any rule applies. Where this page says the two species are managed differently, that is a reason to check the authority for the water you are on — not a statement of what it requires.