Rainbow Trout
Oncorhynchus mykiss
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A North American Pacific fish, stocked into fisheries here and almost never breeding wild.
A streamlined salmonid with a broad pink-magenta stripe along the flank, dense black spotting over the back, flanks and — crucially — the tail fin, which brown trout lack. Rainbow trout are native to the Pacific drainages of North America and were introduced to Britain in the nineteenth century. Around Dumfries they occur mainly where they have been stocked into fisheries and lochs.
Behaviour
Rainbows feed on insects, crustaceans and small fish, and rise freely to surface flies, which is why they are so widely stocked. Unlike brown trout they very rarely establish self-sustaining breeding populations in Britain — most fish encountered are stocked, and escapees do not usually persist. Where they do compete with wild brown trout and salmon parr, they are considered undesirable.
When to see it
Quick facts
- Family
- Salmon and trout (Salmonidae)
- Size
- Commonly 25–50 cm in stocked fisheries
- UK status
- Non-native; stocked, and rarely self-sustaining in the wild
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