Powan

• It has several distinct morphs adapted to lake or anadromous habitats within the same species.
• It lives mainly in deep, cold lakes, especially in the Alps and Great Britain.
• It has been maturing earlier over recent decades as water temperatures rise.

Skeleton type

Vertebrate - internal bony skeleton (fish)

Habitat & environment

Deep, cold lakes of Europe, especially in the Alps and Great Britain, with some anadromous populations in the Baltic

Birth weight

Egg laid in gravel; a tiny larva on hatching

Size at birth

A tiny larva on hatching, after winter spawning in shallow gravel

Sexual maturity

Male: 1 year (in managed breeding populations) | Female: 2 years (in the wild, 2-5 years depending on the region)

Gestation / incubation

The egg develops through the winter months into spring

Litter / clutch size

3,600 eggs per female at a first spawning; up to 8,000 at later ones

Sources consulted: Aquatic Living Resources (Baltic Sea maturity study); ResearchGate (Lake Gaładuś brood stock study); FishBase; AdriaticNature; Grokipedia

Best time: From November to January, during spawning, when it gathers over shallow gravel bottoms in Alpine and northern European lakes.