Flounder
Flounder (Paralichthys spp.) is a saltwater species. The first thing to check: both eyes on one side of the head — on summer and southern flounder, the left side when the fish faces you belly-down. The look-alike to rule out is Winter Flounder: winter flounder are right-eyed with a small, almost toothless mouth.
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| Scientific name | Paralichthys spp. |
|---|---|
| Also called | fluke, summer flounder, southern flounder, doormat |
| Water | Saltwater |
| Group | Flatfish |
| Temperature | Moves inshore in spring as water passes the high 50s and runs back offshore in autumn as it falls below the low 60s. |
How to identify a Flounder
- Both eyes on one side of the head — on summer and southern flounder, the left side when the fish faces you belly-down.
- A large mouth reaching back past the eye, with sharp teeth. Right-eyed flatfish such as winter flounder have small mouths.
- Ocellated spots or blotches on the eyed side, and a plain white blind side.
Photograph the fish and the app will name it, though it returns this species as Gulf Flounder and Southern Flounder rather than Flounder — the same fish under the label the app uses.
Fish it is mistaken for
| Species | How to tell them apart |
|---|---|
| Winter Flounder | Winter flounder are right-eyed with a small, almost toothless mouth. |
| Gulf Flounder | Gulf flounder carry three prominent dark ocellated spots in a triangle; summer flounder have more numerous, less organised spots. |
Where it lives
Atlantic and Gulf coasts. Buries in sand and mud beside structure — channel edges, inlet mouths, sandbars, drop-offs and dock shadows — and ambushes upward.
Temperature
Moves inshore in spring as water passes the high 50s and runs back offshore in autumn as it falls below the low 60s.
The conditions that matter
Flounder are an ambush predator lying on the bottom facing into the current, so tide direction determines which side of a structure they will be on. The autumn run out of an inlet is triggered by falling water temperature. Tide stage and water temperature per catch make the inlet run predictable year to year.
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 flounder 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.