Starry Flounder
A North Pacific flatfish built for soft-bottom estuaries and coastal bays, the starry flounder ranges from the Bering Sea south along the Pacific coast to central California.
What sets it apart from other flatfish is its rough, star-shaped scales — run your hand across one and you'll understand the nickname 'grindstone' — and its boldly barred dorsal and anal fins.
Winter is prime time, when fish push out of deeper water and into bays, river mouths, and even freshwater reaches to spawn.
Also known as Grindstone, Emery wheel, Long-nosed flounder
- Bold alternating dark and white-to-orange bars on the dorsal and anal fins make this flounder easy to distinguish from other Pacific flatfish at a glance.
- Eyed side runs olive to dark brown or nearly black; blind side is white or creamy — typical flatfish coloration, but the rough skin is not.
- Skin on both sides is covered with tiny star-shaped tubercles (modified scales) that feel like sandpaper and will dull a fillet knife fast.
- Most fish run 12–18 inches and 1–3 lbs in recreational catches; the species can reach 36 inches and 20 lbs, though fish over 5 lbs are noteworthy.
What to know
Habitat Distribution
- Native to the North Pacific, from the Bering Sea and Aleutian Islands south along the North American coast to central California, and west across to Japan and Korea.
- A highly adaptable species that moves freely between full-strength ocean water, estuaries, and freshwater — young fish have been found more than 100 km inland in coastal river systems.
- Catadromous by nature: adults migrate from freshwater and estuarine habitats out to sea to spawn, then return inshore.
- Most common in water shallower than 150 meters, resting on mud, sand, or gravel bottoms.
Specific Spots
- River mouths and creek inflows into bays concentrate starry flounder, especially in winter — the mixing zone of fresh and salt water draws both baitfish and invertebrates that flounder key on.
- Flat, soft-bottom areas in estuaries and sloughs hold fish year-round; they lie motionless on the substrate waiting for prey to pass within range.
- Pier pilings and dock edges over muddy or sandy bottoms are reliable in winter when fish move into protected bays to spawn.
Starry Flounder FAQ
Answers from onWater's species guide.
What are the best lures and bait for Starry Flounder?
Natural baits fished on the bottom are the standard approach: shrimp (fresh or brined), worms, clams, squid, and cut herring or sardine all work, reflecting the species's invertebrate-heavy diet.
What do Starry Flounder eat?
Bottom-dwelling invertebrates make up the bulk of the diet, worms, crabs, clams, sand dollars, and brittle stars, which is why bait fished hard on the bottom consistently outperforms lures.
Where do Starry Flounder live?
Native to the North Pacific, from the Bering Sea and Aleutian Islands south along the North American coast to central California, and west across to Japan and Korea.
See it in the app
Most maps show you water.
onWater shows you Starry Flounder.
- 01 · Species map filter
Map every Starry Flounder water
Pick Starry Flounder and the map zeroes in on the waters they call home. No more guessing which lake holds them.
- 02 · Waterbody species
Tap any water. See what lives there.
Species, behavior and seasonal patterns for every lake, river and pond, before you leave the driveway.
- 03 · Angler Intelligence
Ask how to catch Starry Flounder
Tactics, gear and timing from onWater's AI fishing guide, tuned to the species and the water you're on.
Stop guessing where Starry Flounder are.
Open the map, filter by Starry Flounder, and head to water that holds them. Download onWater and plan your next trip in minutes.
- Species map filter
- Angler Intelligence
- Fishing journal
Explore other species
Trout, bass, salmon, panfish and everything in between. Each guide unpacks the behavior, seasons, and tactics that put fish in the net.
No species information available.
Smarter Fishing Starts in the App.
onWater Fish gives you everything you need to plan smarter, fish better, and own every trip from first cast to last.