Rainbow trout (Oncorhynchus mykiss)

Scientific name: Oncorhynchus mykiss Walbaum, 1792

The Rainbow trout (Oncorhynchus mykiss) is a freshwater fish of the family Salmonidae. In the aquarium it needs water at 10–24°C (50–75°F).

Rainbow trout care at a glance

Temperature: 10–24°C (50–75°F)

Biology

Inhabits cold headwaters, creeks, small to large rivers, and lakes. Anadromous in coastal streams. Stocked in almost all water bodies as lakes, rivers and streams, usually not stocked in water reaching summer temperatures above 25?C or ponds with very low oxygen concentrations. Feeds on a variety of aquatic and terrestrial invertebrates and small fishes. At the sea, preys on fish and cephalopods. Undertakes short spawning migrations. Anadromous and lake forms may migrate long distances to spawning streams. Utilized fresh, smoked, canned, and frozen; eaten steamed, fried, broiled, boiled, microwaved and baked. Cultured in many countries and is often hatched and stocked into rivers and lakes especially to attract recreational fishers.

Source: FishBase, licensed CC BY-NC 4.0.

Species facts

Scientific name: Oncorhynchus mykiss
Family: Salmonidae (Salmonids)
Order: Salmoniformes (Salmons)
Class: Actinopterygii (Ray-finned fishes)
Maximum length: 120
Common length: 60.0
Depth range: 0–200 m (0–656 ft)
Environment: Marine; freshwater; brackish; benthopelagic; anadromous; depth range 0 - 200 m
Climate: Subtropical
Distribution: Native to Pacific Slope from Kuskokwim River, Alaska to (at least) Rio Santa Domingo, Baja California, Mexico; upper Mackenzie River drainage (Arctic basin), Alberta and British Columbia in Canada; endorheic basins of southern Oregon, USA. Widely introduced in cold waters elsewhere in North America and rest of the world. Eastern Pacific: Kamchatkan Peninsula and have been recorded from the Commander Islands east of Kamchatka and sporadically in the Sea of Okhotsk as far south as the mouth of the Amur River along the mainland. The records outside Kamchatka probably represent migrating or straying Kamchatkan steelhead (penshinensis) rather than the established native population (Reg. 50080). Several countries report adverse ecological impact after introduction.
Conservation status (IUCN): Not Evaluated
Threat to humans: Potential pest
Uses: Fisheries: highly commercial; aquaculture: commercial; gamefish: yes
Resilience: Medium, minimum population doubling time 1.4 - 4.4 years (K=0.38-0.46; tm=2-5; tmax=11; Fec=200)

Sources

Taxonomy, distribution and biology data: FishBase (Froese, R. and D. Pauly, eds.), licensed CC BY-NC 4.0.

Last updated 27 September 2026