Brown Trout

• Some exceptional populations, known as ferox trout, switch to an entirely fish diet and grow far larger and live longer.
• It feeds on aquatic insects and their larvae, on crustaceans, and — in larger fish — on smaller fish.
• Some populations are anadromous, migrating between sea and river as sea trout.
• sentidosIt can detect subtle differences in the chemistry of its home river's water, which helps it navigate on spawning migrations.

Skeleton type

Vertebrate - internal bony skeleton (fish)

Habitat and environment

Cold, well-oxygenated rivers, streams and lakes of Europe and western Asia; some populations are anadromous (the sea trout)

Birth weight

A ~12 mm alevin at hatching, still carrying its yolk sac

Size at birth

12 mm long at hatching

Sexual maturity

2-4 years

Gestation / incubation

6-20 weeks depending on water temperature

Litter / clutch size

200 to 1,500 eggs per female (a usual reference of ~2,000 eggs per kg of body weight)

Life expectancy in captivity

Documented record of up to 25 years in some introduced populations

Sources consulted: ResearchGate (reproductive characteristics study); Wisconsin DNR; Animal Diversity Web; USGS NAS Species Profile; Bait Your Hook Blog; MDB Fish Fact Sheet; AnAge; JungleDragon; Woodland Trust; Fishing Planet Wiki; Grokipedia; FishBase; BioKIDS