Inconnu (Sheefish)

Overview

The inconnu, or sheefish, is a large predatory whitefish of the far north, nicknamed the "tarpon of the north" for its silvery leaps and hard runs. A prized game fish on remote Alaskan and Canadian rivers, it is the giant of the whitefish family.

Identification

Sheefish are big and silvery with a large mouth, a projecting lower jaw, and the deeply forked tail of a whitefish. They look like an oversized, predatory whitefish and can top thirty pounds.

Naming note: the inconnu of Alaska and northwestern Canada is the nelma, Stenodus nelma, which is now often treated as a species of its own; in the strict sense Stenodus leucichthys, the name long used for it, covers only a whitefish of the Caspian Sea basin (Wikipedia).

Range & Habitat

They live in the large rivers, lakes and deltas of Arctic Alaska and northwestern Canada, some running between fresh and brackish water on long migrations.

Behavior & Diet

Unlike most whitefish, sheefish are aggressive predators that chase and eat other fish, striking lures hard and leaping when hooked. They gather at river mouths and rapids on their runs.

Best Seasons

Best fishing is the short northern open-water season of summer, and again as fish stage for fall spawning, with strong ice fishing where accessible.

How to Catch Them

Cast and retrieve large spoons, jigs and swimbaits through river runs and holes; their fish-eating habits make lure fishing productive.

Tackle & Rigs

Medium-heavy spinning gear, 12-20 lb line, big spoons, jigs and swimbaits for a hard-pulling predator.

Landing, Handling & Release

Fight them off the drag and handle wet; many are released to protect slow-growing northern stocks.

Table Quality

Sheefish is excellent - white, flaky and mild, a staple food fish of the north.

What Costs Anglers Bites

Fishing too light for a big, hard-running predator and missing the short northern season.

Regulations & Conservation

Managed with northern area limits, often on Indigenous lands requiring permits. Always confirm the current regulations before fishing. We do not give legal advice.

FAQ

What lure works for sheefish? Adult sheefish feed almost only on other fish, so the Alaska Department of Fish and Game suggests a brightly coloured or shiny lure that looks like a small fish in distress. Under the ice near Kotzebue in winter and spring their stomachs are full of herring, and after break-up they feed heavily on smelt in the Yukon and Kuskokwim estuaries before moving upriver to the mouths of tributaries. Anything over 13.6 kg (30 lb) counts as a trophy, and the record sport-caught sheefish from northwestern Alaska weighed 24 kg (53 lb) (ADF&G).

Are sheefish good to eat? In rural Alaska they are a valued subsistence fish: usually the first fish seen after the river ice breaks up, and a source of fresh fish before the salmon runs. There is no directed commercial fishery for them in Alaska, and ADF&G suggests cooking them like halibut (ADF&G).

Why 'tarpon of the north'? For its size, silvery leaps and hard fight.

Is it really a whitefish? Yes - a large, predatory member of the whitefish family.