Rainbow Trout
Rainbow Trout (Oncorhynchus mykiss) is a freshwater species. The first thing to check: a pink to red lateral stripe running from the gill cover to the tail, brightest on stream fish and spawning males. The look-alike to rule out is Cutthroat Trout: cutthroat carry a red-orange slash under each side of the lower jaw and heavier spotting towards the tail.
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| Scientific name | Oncorhynchus mykiss |
|---|---|
| Also called | redband trout, bow |
| Water | Freshwater |
| Group | Trout |
| Temperature | Optimal from 55 to 65 °F; stressed above about 70 °F. |
How to identify a Rainbow Trout
- A pink to red lateral stripe running from the gill cover to the tail, brightest on stream fish and spawning males.
- Small black spots scattered over the back, the dorsal fin and the whole tail fin.
- A white mouth and gums, where a cutthroat shows a red or orange slash under the jaw.
If you would rather not work through a key on a wet deck, photograph the fish and let the app name it — you get the common and the scientific name back, and the record is filed before you release.
Fish it is mistaken for
| Species | How to tell them apart |
|---|---|
| Cutthroat Trout | Cutthroat carry a red-orange slash under each side of the lower jaw and heavier spotting towards the tail. |
| Steelhead | Same species. A steelhead is the sea-run form: chrome-bright, heavier-shouldered, and far less coloured than a resident rainbow. |
Side-by-side comparisons
Read the full entry for Cutthroat Trout and Steelhead.
Where it lives
Native to Pacific drainages and now the most widely stocked trout on earth — rivers, tailwaters, mountain lakes and put-and-take fisheries across every region.
Temperature
Optimal from 55 to 65 °F; stressed above about 70 °F.
The conditions that matter
Rainbows in moving water are governed by flow and by hatch timing, both of which track water temperature. In tailwaters, generation schedules effectively set the feeding window. Barometric pressure has far less influence here than temperature and flow.
Global Fishing League records 18 weather and water readings against every catch automatically — tide stage, barometric pressure, water temperature, salinity, dissolved oxygen, chlorophyll, swell, current, moon phase and more, taken at your GPS position at the moment you log the fish. Over a season that turns a hunch about rainbow trout into a pattern you can read.
See every reading recorded with a catch, or the guides to what each reading means.
Size limits, bag limits and seasons
Size limits, bag limits, slot limits and seasons are set by your state wildlife agency — and for many offshore and migratory species by federal regulators — and on many waters they differ from the statewide rule. They also change between seasons. Check the current regulations for the exact water you are fishing before you keep a fish — we do not republish limits here, because a number that is a season out of date is worse than no number.
What the app does do is make your side of it accurate: every catch carries a length measured from the photograph, a GPS position and a timestamp, exportable if you ever need to show your work for a tournament or a record claim. It is also what a Global Fishing League entry is built from — a record that verifies itself, without publishing where you caught the fish.