Inshore & surf · Saltwater
Summer flounder
Paralichthys dentatus
Western Atlantic native, Nova Scotia to the east coast of Florida; the U.S. fishery is concentrated from Cape Cod, Massachusetts to Cape Hatteras, North Carolina.
Also called Fluke, Northern fluke, Flounder.
- Inshore
- Nearshore
- Surf
- Regulated context
- 4 of 4 overlays reviewed
- Reviewed 2026-08-27
Before you target this fish
Regulated context — check the rules for the exact water
Where this applies U.S. Atlantic coast, Nova Scotia to Florida, under joint MAFMC/ASMFC management with state-by-state recreational implementation via conservation equivalency.
The reviewed context, unedited
Jointly managed by the Mid-Atlantic Fishery Management Council (federal waters) and the Atlantic States Marine Fisheries Commission (state waters). Recreational size, season and bag limits are set through 'conservation equivalency' - anglers follow the rules of the state where they land their catch rather than one coastwide rule, and those rules are revisited annually, so verify current limits before keeping fish. The 2025 assessment found the stock not overfished and not subject to overfishing.
Rules for this fish change at a state line and sometimes inside one. Check the ones that apply to the exact water you are standing on before you act on anything here — this record is biology, not permission.
Take this somewhere
This page is the record. The reading is what happens when you add water, a season and a temperature to it — that is where the families below get ranked against each other instead of just listed.
Those three links carry the fish and nothing else. No conditions were declared on this page, so none travel, and the link says so rather than sending an empty reading.
The half nobody publishes
What this record does not know
Everything else on this page comes from a named agency or peer-reviewed source. This is the other side of that: the questions a reviewer went looking for an answer to and came back without, and the fields the record leaves empty because filling them would mean guessing.
It is here rather than at the bottom because a page that only shows what it knows is easy to read as a page that knows everything. For Summer flounder there are 12 of them.
Named by a reviewer
8Somebody looked for this and wrote down that they did not find it.
- Behaviour
Territoriality/aggression, cold-front response, water-level response, flow-change response, clarity response and angling-pressure response were not sourced.
Diel tendency is thinly sourced (two general daylight/dawn mentions) and may not hold across the full range.
- Identification
A single continent-wide maximum weight/length figure was not found in the agency sources reviewed.
Sexual dimorphism beyond size-at-age (females grow larger and older) was not sourced.
Juvenile appearance and spawning coloration were not specifically sourced beyond general adult coloration.
- Forage
A clean season-by-season diet breakdown (rather than a size-class breakdown) was not found.
Forage substitution across regions was not sourced.
- Season
Nobody has sourced:
- early_spring, early_summer, late_summer and late_fall were not separately distinguishable in the sources reviewed and were folded into the adjacent season.
Absent from the record
4No reviewer wrote a gap here. The field is simply empty, which is its own answer.
- Water temperature
No agency or peer-reviewed temperature band for Summer flounder was found that a review would accept. The reading runs without one rather than borrowing a number from a related fish.
- Identification
No reviewed image. A photograph is only in this catalog when an agency or a named creator labelled the subject, and nobody has cleared one for this species yet.
- Presentation
No species-specific weighting rule is reviewed for Summer flounder. Its ranking comes from the shared model — season, temperature, water type, holding and forage — with nothing added for this fish in particular.
- Population context
No regional population profile is registered. The species-level reading stands on its own; it does not silently become a local one.
Where the record puts it
Water and range
Inshore
4 reviewed holding classes- Grass flat
- Sand hole
- Tidal creek
- Channel edge
Nearshore
3 reviewed holding classes- Inlet mouth
- Nearshore reef
- Pier structure
Surf
2 reviewed holding classes- Jetty wash
- Beach cut
DepthBottom-oriented ambush predator on sand, mud, and shell-hash substrate. Adults use lower-to-middle estuary reaches and shallow coastal water in warm months and move to the outer continental shelf (to roughly 500 ft) in winter. Juveniles settle in shallow marsh creeks, seagrass beds, mudflats and open bays and move to progressively deeper water as they grow. South Carolina DNR's species account, already cited above, separately states summer flounder are found 'also around inlets, jetties, beaches and nearshore reefs' in addition to the estuarine and shelf habitat described above, and ASMFC's species page confirms anglers catch them 'from the shore, piers, and boats' - both agency statements support surf and nearshore presence as an ambush predator on adjacent sand bottom, not a claim that it uses the jetty or pier structure itself the way a structure-oriented fish would.
Moving waterNot sourced as a general tide-stage relationship for adults. The one tide-specific finding available is a New Jersey marsh-creek study of young-of-year moving into creeks at night on a flooding tide and out on the ebb; that single regional, single-life-stage study is not generalized here to adults or other regions.
LightSourced only as a diel feeding pattern, not a light-intensity preference: one source describes increased feeding activity near sunrise, another describes general daylight foraging. No low-light or night-feeding claim beyond the single flood-tide creek-entry study above was found.
Thermal band
Temperature
No reviewed temperature band
Nobody publishes a preferred or active temperature range for Summer flounder that a review would accept. Borrowing one from a related fish would look like knowledge and behave like a guess, so the reading runs without it and says which parts of the answer that weakens.
How it uses water
Behaviour
Sourced as an individual ambush predator lying on the bottom; no schooling behavior was reported. Not resolved by life stage beyond the general adult/juvenile habitat separation described under habitat.
Primary mode is bottom ambush: the flounder lies partly buried and coloration-matched to the substrate and takes prey passing close by. One source also describes flounder pursuing schools of small baitfish to the surface, occasionally breaking it - recorded here as a documented but secondary pursuit behavior, not the default feeding mode.
One source reports increased feeding activity near sunrise; another describes general daylight foraging. No sourced night-feeding pattern beyond the single flood-tide, nighttime creek-entry study noted under habitat.
Seasonal activityAdults move inshore in late spring/early summer and offshore to the outer continental shelf in fall as part of a spawning migration; fall spawning itself is conservation context, not a targeting cue.
Depth movementSeasonal rather than diel: shallow estuarine and coastal water in warm months, progressively deeper water on the shelf (to roughly 500 ft) in winter. Juveniles move from very shallow nursery habitat to deeper water as they grow.
Facing the currentNot sourced as a general current-facing behavior for adults. The one tide-specific finding available is young-of-year moving into marsh creeks at night on a flooding tide and out on the ebb - a single regional study, not generalized here to adults.
CoverNot associated with hard structure in the sources reviewed. It uses soft substrate (sand, mud, shell hash) and vegetated bottom (eelgrass, marsh grass) rather than reef, wreck or rock cover.
Predator avoidanceCamouflage against the substrate is the primary sourced predator-avoidance behavior; the species changes color and pattern to match the bottom.
Spawning (conservation context)A fall/winter serial (batch) spawner during the offshore migration to wintering grounds, peaking October-November per NOAA within a broader September-March window. Females are highly fecund (460,000 to over 4 million eggs). Any spawning concentration or migration corridor is excluded from targeting in this catalog.
Where the general rule stops
- Both eyes migrate to the left side of the body during larval development; this record assumes a normally left-eyed fish and does not cover the rare reversed individual.
- This record does not include coordinates or named passes, reefs, inlets or wrecks, and we never give them.
- The thermal figure above is an occurrence range drawn from larval collections (a distribution range, not a controlled preference study). A narrower young-of-year marsh-creek range of about 72-77F was reported in one New Jersey study and a fall spawning-migration range of about 54-66F was reported separately; neither should be read as the species' preferred temperature.
- Surf and nearshore holding classes above are sourced to SCDNR's and ASMFC's descriptions of summer flounder around inlets, jetties, piers, beaches and nearshore reefs; the fish itself remains a soft-bottom ambush predator using the sand adjacent to that structure, not the structure directly.
What it can eat
Forage
- Small forage fish
- Larger prey fish
- Crustaceans
- Mollusks
- Worms / annelids
- Zooplankton
Fish make up the majority of the adult diet by weight (over 61% in one diet study, with sand lance especially important at 26 cm and longer); shrimp, crabs and other crustaceans dominate for smaller fish (under 21 cm, 43.3% of diet). Adults also take squid, bivalve mollusks and worms. This is diet capacity across sizes, not a current bait event.
- Feeding style
- Opportunistic
- Feeding zone
- Benthic
Through the year
- Summer
- Peak inshore residency; opportunistic feeding on available crustaceans and small fish in estuarine and coastal habitat.
- Fall
- Offshore migration begins; fall is conservation context (spawning), not a documented diet shift.
By life stage
- Juvenile
- Crustacean-dominated (mysids and decapods, 43.3% of diet by weight in fish under 21 cm).
- Adult
- Fish-dominated (over 61% by weight overall; sand lance important at 26 cm+), with squid, crabs, shrimp, bivalve mollusks and worms also documented.
Prey sizeDiet shifts from crustacean-dominated (small fish) to fish-dominated (large fish) around a 21-26 cm size threshold in the sources reviewed; cephalopods (squid) become important around 31 cm.
Ontogenetic shiftLarvae feed on copepods and copepodites (zooplankton); juveniles shift to crustaceans; adults shift toward a majority-fish diet.
Diet capacity documented here is not proof of a current bait event. Observed current forage still comes from a user observation or Hatch Match.
Through the year
Season
Spring
- Where they sit
- Estuarine and coastal waters as adults move inshore from offshore wintering grounds.
- Depth
- Shoaling from continental-shelf depth into estuaries and shallow coastal water.
- Movement
- Inshore migration.
What that changesStructure pitch and tidal drift bait become viable as fish reoccupy estuarine feeding grounds.
What would count against it
- treating spring as a fixed calendar date rather than a migration in progress
Summer
- Where they sit
- Shallow estuarine bays, marsh creeks, seagrass beds, mudflats and lower-to-middle estuary reaches over sand, mud or shell-hash bottom.
- Depth
- Shallow; juveniles progressively move to deeper water as they grow.
- Feeding
- Bottom ambush on crustaceans and small fish.
What that changesLive/natural bait suspension and tidal drift bait presented near bottom over open sand/mud edges.
What would count against it
- fishing it like a structure species - it is a soft-bottom ambush predator, not a reef fish
Fall
- Where they sit
- Departing estuarine and coastal water for the outer continental shelf.
- Movement
- Offshore spawning migration.
- Temperature
- Migration and spawning occur as water cools; NOAA reports a fall spawning peak in October-November.
What that changesInshore presentations lose fish as the population thins toward the coast; this record does not extend guidance to the offshore wintering water type.
What would count against it
- treating a thinning fall bite as a location problem rather than the stock leaving the water type this record covers
Fall is the spawning migration. Spawning concentrations and the migration corridor are excluded from targeting in this catalog.
Winter
- Where they sit
- Outer continental shelf (to roughly 500 ft), outside the water type reviewed in this record.
An overwintering and spawning population; not covered by this record's inshore-only presentation guidance.
Spawning · Fall, Late fall, Winter
Offshore fall/winter spawner during the seaward migration. NOAA gives a September-March window with an October-November peak tied to autumn plankton production. A highly fecund serial spawner (460,000 to over 4 million eggs per female depending on size). Any spawning concentration or migration corridor is excluded from targeting in this catalog.
Recorded as conservation context. No spawning site, staging concentration or migration bottleneck is named anywhere in this catalog, because naming one is how a population gets fished out.
Telling it apart
Identification
What to look at
- Left-eyed: both eyes on the left side of the body when the dorsal fin faces up (the right eye migrates across the head during larval development).
- At least five prominent ocellated (eye-like, ringed) spots on the posterior body, classically described as forming the five-side-of-a-die pattern.
- 13 or more long, thin gill rakers - the trait that separates it from the very similar southern flounder (8-11 short, stubby rakers) and gulf flounder (9-12 short, stubby rakers), both also left-eyed.
- Dorsal fin origin near the front of the eye.
- Upper-side coloration is variable brown, gray or drab and changes to match the substrate.
- Average adult length
- Commonly cited around 14-15 in for the average recreational catch; males rarely exceed 2 ft, females reach up to 3 ft.
- Common angling size
- Roughly 14-18 in for most recreational catches, further constrained by state minimum-size rules.
- Typical weight
- About 1.5 lb at the average recreational catch length.
- Maximum documented
- Females to about 3 ft. A South Carolina state-record fish weighed 3 lb 8 oz - modest next to the larger individuals reported further north, where a single continent-wide maximum was not found in the sources reviewed.
- Longevity
- To about 12-14 years theoretically; realized maximum age in the heavily fished South Atlantic is much lower (3-4 years) than the theoretical female maximum (12-20 years).
What it gets confused with
- Southern flounder (Paralichthys lethostigma)
- Also left-eyed and easily confused. Southern flounder has 8-11 short, stubby gill rakers and non-ocellated (plain) spots, versus summer flounder's 13+ long, thin gill rakers and ringed ocellated spots.
- Gulf flounder (Paralichthys albigutta)
- Left-eyed with 9-12 short, stubby gill rakers and three prominent eye-spots in a triangle, versus summer flounder's five-spot ocellated pattern and long thin gill rakers.
- Winter flounder (Pseudopleuronectes americanus)
- Right-eyed, with an oval, thick body and coloration ranging from muddy brown to olive to nearly black; lacks the ocellated spot pattern.
- Windowpane flounder (Scophthalmus aquosus)
- Also left-eyed but has a nearly circular, thin, almost translucent body, and the tips of the first 10-12 dorsal rays are free of membrane, giving a fringed look; summer flounder's body is more elongated with fully webbed fins.
What follows from all of that
Presentation families
Inshore
Structure pitch
Put a bait tight against hard structure and get it out again before the tide sweeps it into the barnacles.
- accurate short casts
- immediate contact
- lead them out
- expect abrasion
What it asks of the tackle
- Depth control
- Moderate
- Sensitivity
- High
- Casting distance
- Short
- Weight range
- 1/8–3/4 oz
- Cover resistance
- High
- Line visibility
- Secondary
- Retie frequency
- Very high
Tidal drift bait
Let a natural bait travel at the speed of the tide along an edge fish are feeding on.
- match weight to the run
- stay in the seam
- let it swing at the end
- reset up-tide
What it asks of the tackle
- Depth control
- Moderate
- Sensitivity
- High
- Casting distance
- Short to moderate
- Weight range
- 1/8–1 oz
- Cover resistance
- Moderate
- Line visibility
- Low
- Retie frequency
- High
Live / natural bait suspension
Present a natural food form with enough life or scent to hold in a station without looking mechanical.
- keep it alive or fresh
- match the holding depth
- minimize hardware bulk
- detect without pulling it away
What it asks of the tackle
- Depth control
- High
- Sensitivity
- High
- Casting distance
- Short to moderate
- Weight range
- As light as conditions allow
- Cover resistance
- Moderate
- Line visibility
- Low
- Retie frequency
- High
Nearshore
Bottom contact
Keep a bait on or just above the substrate along a break, flat, or inside a weed edge.
- feel bottom
- drag or hop
- pause on the break
- stay in contact
What it asks of the tackle
- Depth control
- High
- Sensitivity
- High
- Casting distance
- Moderate
- Weight range
- 1/8–1/2 oz
- Cover resistance
- High
- Line visibility
- Low
- Retie frequency
- High
Live / natural bait suspension
Present a natural food form with enough life or scent to hold in a station without looking mechanical.
- keep it alive or fresh
- match the holding depth
- minimize hardware bulk
- detect without pulling it away
What it asks of the tackle
- Depth control
- High
- Sensitivity
- High
- Casting distance
- Short to moderate
- Weight range
- As light as conditions allow
- Cover resistance
- Moderate
- Line visibility
- Low
- Retie frequency
- High
Surf
Surf bait soak
Hold a natural bait still on the bottom of a trough or cut and let moving water bring fish to it.
- enough lead to hold
- read the trough
- let the rod load
- reset as the tide moves the bar
What it asks of the tackle
- Depth control
- Low
- Sensitivity
- Moderate
- Casting distance
- Long
- Weight range
- 2–8 oz of lead
- Cover resistance
- Moderate
- Line visibility
- Secondary
- Retie frequency
- High
What moves them for this fish
No species-specific rule is reviewed for Summer flounder. Its ranking comes from the shared model — season, temperature, water type, holding water, forage — with nothing added for this fish in particular. That is a gap, not a claim that nothing is special about it.
Where every sentence came from
Sources
Agency
NOAA Fisheries - Summer Flounder species page
Used for habitat, thermal band and presentation families; identification; behaviour; forage; season. Read 2026-08-30, next check 2026-11-27.
Agency
Atlantic States Marine Fisheries Commission - Summer Flounder species page
Used for habitat, thermal band and presentation families; identification; behaviour; forage; season. Read 2026-08-30, next check 2026-11-27.
Agency
NOAA Technical Memorandum NMFS-NE-151, Essential Fish Habitat Source Document: Summer Flounder
Used for habitat, thermal band and presentation families; identification; behaviour; forage; season. Read 2026-08-30, next check 2026-11-27.
Agency
Mid-Atlantic Fishery Management Council, Summer Flounder Essential Fish Habitat profile
Used for habitat, thermal band and presentation families; identification; behaviour; forage; season. Read 2026-08-30, next check 2026-11-27.
Agency
South Carolina Department of Natural Resources - Summer Flounder species account
Used for habitat, thermal band and presentation families; identification; behaviour; forage; season. Read 2026-08-30, next check 2026-11-27.
Agency
NOAA NEFSC Northeast Climate Vulnerability Assessment - Summer Flounder
Used for habitat, thermal band and presentation families; identification; behaviour; forage; season. Read 2026-08-30, next check 2026-11-27.
Agency
NOAA Fisheries - Windowpane Flounder species page
Used for habitat, thermal band and presentation families; identification; behaviour; forage; season. Read 2026-08-30, next check 2026-11-27.
Agency
NOAA Fisheries - Winter Flounder species page
Used for habitat, thermal band and presentation families; identification; behaviour; forage; season. Read 2026-08-30, next check 2026-11-27.
Agency
Used for habitat, thermal band and presentation families; identification; behaviour; forage; season. Read 2026-08-30, next check 2026-11-27.
Synthesis
Buzzards Bay Coalition summer flounder fact sheet (synthesis of primary literature)
Used for habitat, thermal band and presentation families; identification; behaviour; forage; season. Read 2026-08-30, next check 2026-11-27.
A source with no link predates the rule that one has to carry a URL. It is still a real citation and still checkable; it just takes a search rather than a click, and that is worth knowing before you rely on it.