Windowpane FlounderorWinter Flounder
Two fish anglers mix up. Here is what separates them, and what each one’s rules are in your state.
How to tell them apart
Windowpane Flounder
So thin it's translucent held to the sun; nearly round, left-facing, finely freckled.
Windowpane flounder, next to winter flounder: thin enough to see through.
Winter Flounder
RIGHT-facing thick flatfish with a small mouth and straight lateral line; muddy black-brown.
Winter flounder, next to windowpane flounder: thick, right-facing.
Side by side
| Windowpane Flounder | Winter Flounder | |
|---|---|---|
| Scientific name | Scophthalmus aquosus | Pseudopleuronectes americanus |
| Also called | Sand dab | Blackback, Lemon sole (big ones) |
| Waters | Inshore | Inshore |
| Heaviest state record | 0 lb 11.2 oz · Connecticut (2020) | 8 lb 2 oz · Massachusetts (1996) |
| On the table | Too thin to fillet — release. | Excellent — the sweetest flounder. |
| Rules of its own in | 5 states | 8 states |
Rules for
Every state, both fish
The two fish are regulated differently in 8 of 8 states with a rule for either. In Connecticut, windowpane flounder is —, No retention and winter flounder is 12" minimum, 2 per angler. Call the fish wrong and you keep a short one or throw back a legal one.
| State | Windowpane Flounder: size · bag · season | Winter Flounder: size · bag · season |
|---|---|---|
| Connecticut | —No retentionProhibitedPut it backFederal rule (New England federal waters)NOAA GARFO 2026 · checked | 12" minimum2 per anglerApr 1 - Dec 31OpenCT DEEP 2026 · checked |
| Delaware | Not specifically regulated; the state’s default for unlisted species applies. | 12 in min2 per dayFeb 11 - Apr 10ClosedDE DNREC 2026 · checked |
| Maine | —No retentionProhibitedPut it backFederal rule (New England federal waters)NOAA GARFO 2026 · checked | 12" min8 per dayOpen year-roundOpenME DMR 2026 · checked |
| Massachusetts | —No retentionProhibitedPut it backFederal rule (New England federal waters)NOAA GARFO 2026 · checked | 12 in total length8 per dayOpen year-roundOpenMA DMF 2026 · checked |
| New Hampshire | Possession prohibitedPossession prohibitedClosed year-roundPut it backNH F&G 2026 · checked | 12 in TL min8 fish/dayOpen year-roundOpenNH F&G 2026 · checked |
| New Jersey | Not specifically regulated; the state’s default for unlisted species applies. | 12 in min2Mar 1 - Dec 31OpenNJ DEP 2026 · checked |
| New York | Not specifically regulated; the state’s default for unlisted species applies. | 12"2Apr 1 - May 30ClosedNY DEC 2026 · checked |
| Rhode Island | —No retentionProhibitedPut it backFederal rule (New England federal waters)NOAA GARFO 2026 · checked | 12" min2/person/dayMar 1 - Dec 31OpenRI DEM 2026 · checked |
In the app
Point the camera at the fish and Chum names it before you take the picture, windowpane flounder or winter flounder, with the right rules for the water you’re standing in. No signal needed.
Get the appQuestions anglers ask
How do you tell windowpane flounder from winter flounder?
Windowpane Flounder: So thin it's translucent held to the sun; nearly round, left-facing, finely freckled. Winter Flounder: RIGHT-facing thick flatfish with a small mouth and straight lateral line; muddy black-brown. Winter flounder, next to windowpane flounder: thick, right-facing. Windowpane flounder, next to winter flounder: thin enough to see through.
Which gets bigger, windowpane flounder or winter flounder?
Winter Flounder. The heaviest state record we hold is 8 lb 2 oz in Massachusetts; the heaviest windowpane flounder record is 0 lb 11.2 oz in Connecticut.
Which is better to eat, windowpane flounder or winter flounder?
Windowpane Flounder: Too thin to fillet — release. Winter Flounder: Excellent — the sweetest flounder.
Do windowpane flounder and winter flounder have the same limits?
Not everywhere. They differ in 8 state rulebooks. Connecticut: windowpane flounder —, No retention, winter flounder 12" minimum, 2 per angler; Maine: windowpane flounder —, No retention, winter flounder 12" min, 8 per day; Massachusetts: windowpane flounder —, No retention, winter flounder 12 in total length, 8 per day; New Hampshire: windowpane flounder Possession prohibited, Possession prohibited, winter flounder 12 in TL min, 8 fish/day; Rhode Island: windowpane flounder —, No retention, winter flounder 12" min, 2/person/day; and more in the table on this page.