Adults usually prefer hard sandy substrate where they can burrow; can exploit a broad range of lower and mid-estuary habitats including salt marsh creeks and seagrass beds, which usually have muddy or silty substrates , as well as sand flats (Ref. 26621). Occur in bays, lagoons and shallow coastal waters. Utilized fresh and frozen; can be steamed, fried, boiled, microwaved and baked (Ref. 9988). Exported fresh to Japan for sashimi.

P. dentatus is one member of a large family of distinctive benthic flatfishes that inhabit continental shore waters in the tropical and temperate zones of the Atlantic, Pacific and Indian oceans. Flatfishes such as the flounders are unlike most other fishes in that they begin life as bilateral animals, having equal right and left side, and swim as do other fishes. However, toward the end of the larval period, flatfishes settle to the benthos and take up a cryptic, somewhat sedentary lifestyle, lying on one side of the body, and swimming laterally to the substratum. Metamorphosis to the juvenile stage involves complex modification of the skeletal structure of the head, and rearrangement of the nervous system and muscle tissues. Additionally, the eye on the side that faces the substratum (termed the blind-side eye) begins to migrate to the upper side of the body. P. dentatus is a left-eye flounder, thus it lies on its right side, and at metamorphosis, the right eye migrates to the left side of the head. Lefteye flounders sometimes exhibit sexual dimorphism, with females having eyes that are closer together than in males, and males having somewhat longer pectoral fins (Rogers and Van Den Avyle 1983).

Northwest Atlantic: Maine (rarely Nova Scotia, Canada) to northern Florida, USA.

Paralichthys dentatus is found from the southern Gulf of Maine to South Carolina and occasionally around Florida (Bigelow and Schroeder 2002).

Maine (rarely Nova Scotia) to northern Florida

Gulf of Maine, North West Atlantic

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Recorded range for this species is from Maine to Cape Canaveral, Florida (Powell and Henley 1995). P. dentatus can be common throughout the Indian River Lagoon, however, it is most common north of Cape Canaveral.

Western North Atlantic: off eastern U.S.A.

Continental waters from Maine to South Carolina, possibly to Florida; chiefly south of Cape Cod.

Maximum size: 940 mm TL

94.0 cm TL (male/unsexed; (Ref. 7251)); max. published weight: 12.0 kg (Ref. 7251); max. reported age: 9 years (Ref. 52684)

Powell (1974) showed that the annual growth cycle in P. dentatus begins in the spring and ends in the fall as the water temperature reached approximately 7 °C threshold. Flounder in North Carolina were 111 - 219 mm (4.4 - 8.6 inches) TL at the end of their first season. Maximum sizes of males collected from New York were about 600 mm (23.6 inches) TL and 2200 g (5.9 pounds), while females reached 800 mm (31.5 inches) and 5500 g (14.7 pounds) (Powell 1974).Summer flounder may live about 10 years (Rogers and Van Den Avyle 1983).Growth rates published for flounder collected outside the South Atlantic Bight were summarized by Smith et al. (1981).

to 94 cm TL (male/unsexed); max. weight 12 kg.

demersal; oceanodromous; marine; depth range 10 - 183 m (Ref. 5951), usually ? - 37 m (Ref. 5951)

Habitat and Ecology

Systems

• Marine

benthic

Found to depths of 10 m, prefer hard sandy bottoms in which they can burrow.

Depth range based on 7705 specimens in 1 taxon.
Water temperature and chemistry ranges based on 4275 samples.

Environmental ranges
  Depth range (m): 0 - 366
  Temperature range (°C): 4.628 - 25.874
  Nitrate (umol/L): 0.289 - 22.089
  Salinity (PPS): 32.163 - 36.748
  Oxygen (ml/l): 3.424 - 6.849
  Phosphate (umol/l): 0.092 - 1.564
  Silicate (umol/l): 0.756 - 16.288

Graphical representation

Depth range (m): 0 - 366

Temperature range (°C): 4.628 - 25.874

Nitrate (umol/L): 0.289 - 22.089

Salinity (PPS): 32.163 - 36.748

Oxygen (ml/l): 3.424 - 6.849

Phosphate (umol/l): 0.092 - 1.564

Silicate (umol/l): 0.756 - 16.288
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

Habitat Type: Marine

Demersal; marine; depth range to 10 m. Hard sandy, sandy, and silty substrates; estuary habitats including salt marsh creeks and seagrass beds and sand flats. Occurs in bays, lagoons and shallow coastal waters.

Oceanodromous. Migrating within oceans typically between spawning and different feeding areas, as tunas do. Migrations should be cyclical and predictable and cover more than 100 km.

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

Adult P. dentatus are visual feeders that are adept at feeding on the bottom or in the water column (Olla et al. 1972). They are generally regarded as top or near-top predators. Though the feeding ecology of this species is not fully documented, larvae and postlarvae are thought to initially feed on zooplankton. In a Pamlico Sound study, juveniles longer than 80 mm were found to initially consume mysid shrimp. As they grew, they fed on progressively larger prey items, shifting their diets from mysids to small fish and other crustaceans. As these fish reached adulthood, the diet was again shifted toward larger fish (Rogers and Van Den Avyle 1983). Data from the South Atlantic Bight indicate that adults in estuaries and shelf waters north of Cape Hatteras feed primarily on fish and large invertebrates (Rogers and Van Den Avyle 1983).Burke (1995), based on differences in morphology and behavior between summer flounder and southern flounder in North Carolina, compared prey distribution and feeding ecology between the 2 species following metamorphosis to the juvenile stage. Summer flounder juveniles have generally smaller mouths, smaller, teeth, and lighter, more numerous gill rakers than do southern flounder. Feeding in the summer flounder was always preceded by active searching behavior (Burke 1995), while southern flounder tended to remain still on the bottom and wait for prey to come within striking distance (Minello et al. 1987; Burke 1995). In this study, summer flounder 20 - 60 mm SL consumed spionid polychaete worms, followed by clam siphons, mysid shrimp, calanoid copepods, the blue crab, Callinectes sapidus, and small fishes. In contrast, southern flounder primarily consumed amphipods and mysid shrimp, followed by copepods, insects, fish and invertebrate parts. Burke concluded that post-settlement differences in feeding habits developed between the 2 species, with southern flounder shifting to more mobile prey which could be attacked from below, while summer flounder continued to feed upon benthic prey organisms.Habitats: Adult summer flounder spend the warmer months in nearshore shelf waters and coastal embayments (Rogers and Van Den Avyle 1983). Summer flounder eggs and larvae from wild populations develop in offshore waters, with late stage, premetamorphic larvae (stage 4b to 5), likely returning to estuarine habitats via passive transport on nearshore and tidal currents. Once returned to estuaries, larvae settle to the substratum and metamorphose into juveniles.In a comparative study, Burke et al. (1991) reported that larvae of both summer flounder and southern flounder recruit into estuaries during the same period, and for a time, show considerable overlap in distribution within an estuary (Burke 1995). However, segregation occurs quickly (Burke et al. 1991; Burke 1995). Premetamorphic larvae of southern flounder tend to concentrate on tidal flats in the upper reaches of estuaries where salinity ranges from 9 - 25 ?, and the substratum consists of 4 - 45 % sand. Premetamorphic larvae from summer flounder generally move into the silt and mudflat areas in the lower and middle reaches of estuaries where salinity ranges from 24 - 35? and the substratum consists of 50 - 95 % sand (Burke et al. 1991). Burke et al. (1991) concluded that settlement in P. dentatus is most likely influenced by substratum type, while that of P. lethostigma is influenced by salinity. Capture data following segregation of the 2 species within the Newport River Estuary, North Carolina showed that summer flounder were most common on sand flats vs. mudflats in the lower estuary, while there was little difference in capture rates among southern flounder in sandy vs. muddy substrates in the upper reaches of the estuary. Data from Rogers and Van Den Avyle 1983 are in agreement with Burke et al. (1991) study, showing that juvenile summer flounder occur more frequently over sandy substrata than mud or silt bottoms in Pamlico Sound, North Carolina. They further reported that during daylight hours, summer flounder tended to occupy areas in estuaries that have submerged vegetation.Activity Time: Laboratory studies and field collections indicate that summer flounder are active primarily during daylight hours (Rogers and Van Den Avyle 1983).

Invertebrates and small fishes.

Paralichthys dentatus (Summer flounder) is prey of:
Gadidae
Hemitripterus americanus
Leucoraja erinacea
Leucoraja ocellata
Amblyraja radiata
Pleuronectes americanus
Mustelus canis
Squalus acanthias
Lophius americanus
Pomatomus saltatrix
Chondrichthyes
Homo sapiens

Based on studies in:
USA, Northeastern US contintental shelf (Coastal)

This list may not be complete but is based on published studies.

Paralichthys dentatus (Summer flounder) preys on:
Ctenophora
Crangon
Mysidae
Pandalidae
Decapoda
Gammaridae
Hyperiidae
Caprellidae
Isopoda
Stomatopoda
Porifera
Cancer
Brachyura
Hydrozoa
Polychaeta
Bivalvia
Ammodytes marinus
Actinonaias ellipsiformis
Tridonta arctica
Merluccius bilinearis
Urophycis regia
Urophycis tenuis
Urophycis chuss
Macrozoarces americanus
Brosme brosme
Triglidae
Hippoglossina oblonga

Based on studies in:
USA, Northeastern US contintental shelf (Coastal)

This list may not be complete but is based on published studies.

Epitheliocystis. Bacterial diseases

P. dentatus is one of the largest and most commercially valuable flounders in the western North Atlantic (Burke et al. 1991).

Adults migrate to offshore spawning grounds during the fall and winter, though some remain in estuaries year-round. Summer flounder begin a spawning migration as they near peak gonadal development. Often the oldest, largest fish migrate first each year (Morse 1981). P. dentatus spawns during late fall, winter, or early spring on or near the bottom in shelf waters ranging from 30 - 200 m deep (Rogers and Van Den Avyle 1983). Evidence indicates that P. dentatus is a serial spawner, continuously releasing mature eggs throughout the spawning season (Morse 1981; Rogers and Van Den Avyle 1983). Evidence from Wilk et al. (1980) shows that summer flounder from Middle Atlantic stocks tend to use the same spawning grounds and wintering areas each year. This pattern has not been proven for stocks in the South Atlantic Bight.In the Middle Atlantic Bight, the spawning cycle is strongly correlated with the cooling of coastal waters throughout fall and winter. Thus, spawning along the Atlantic coast begins along a North-South gradient, with summer flounder in the northernmost region beginning to spawn in September, and those in the southern region spawning in early spring. In the area between Virginia and North Carolina, the major spawning period for P. dentatus is from November to late January and early February (Smith 1973). From Cape Hatteras through Florida, P. dentatus begin spawning in late November to early December, and are spent by early spring.

Probable late autumn, winter, and early spring spawner.

Larvae spawned offshore make their return to estuarine habitats by passive transport on nearshore and tidal currents from November through April in North Carolina, with a peak in recruitment occurring in February (Burke et al. 1991).

The following is a representative barcode sequence, the centroid of all available sequences for this species.


No available public DNA sequences.

Download FASTA File

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 7
Specimens with Barcodes: 23
Species With Barcodes: 1

United States

Rounded National Status Rank: NNR - Unranked

Rounded Global Status Rank: GNR - Not Yet Ranked

Population

Population Trend

Least Concern (LC)

Major Threats

Conservation Actions

fisheries: commercial; gamefish: yes

Fisheries.Fisheries Importance:COMMERCIAL FISHERY: P. dentatus is an important commercial and recreational fish along much of the Atlantic seaboard, but the commercial fishery is not substantial in the southernmost extent of its range (between Cape Hatteras, North Carolina and Florida). The estuaries of Pamlico Sound, North Carolina are believed to be a major nursery ground for juvenile summer flounder from the Middle Atlantic Bight (Cape Hatteras northward to Cape Cod) and South Atlantic stocks, but this is uncertain because dispersal patterns are not well understood (Rogers and Van Den Avyle 1983).In 1982 the Atlantic States Marine Fisheries Commission prepared a Fishery Management Plan for summer flounder which included recommendations for the best management practices for this species. Beneficial practices included regulating the annual catch and setting size limits for harvest; regulating commercial gear types; maintaining and protecting wetland habitat areas; controlling sedimentation; and controlling sources of thermal, chemical and physical pollution (Rogers and Van Den Avyle 1983). Among the adverse management practices cited in this plan were draining wetlands, marshes, ponds and lakes; dredging; wastewater assimilation and disposal; flow withdrawal of water supply; shoreline development; and construction of migration barriers (Atlantic States Marine Fisheries Commission 1987). Flounders of all species are harvested annually from waters in and around the Indian River Lagoon, and are especially prized by recreational anglers. However, the commercial fishery is not of particularly high value. For the years 1987 - 2001, 1.7 million pounds of flounders were harvested, with a dollar value of over 3.1 million reported in the 5 county area encompassing the IRL (Volusia, Brevard, Indian River, St. Lucie and Martin Counties).This ranks flounders nineteenth in commercial value within the IRL, and twenty-ninth in pounds harvested.Figure 1 below shows the dollar value of the flounder fishery to IRL counties by year. Note that all species of flounders were combined in the data presented. As shown, commercial catch ranged from a low of $77,149 in 1987 to a high of over $350,927 in 1999. Volusia County annually accounts for the largest percentage of the flounder catch with 83% in total (Figure 2), followed distantly by Brevard County, which accounts for 8% of the total. Indian River, St. Lucie and Martin Counties account for 3%, 4% and 2% of the total respectively. Note that the fishery's value brings in $125,000 - $300,000 annually to Volusia County businesses, while in all other IRL counties, the dollar value is typically less than $25,000. RECREATIONAL FISHERY: The recreational flounder fishery in Florida accounts for 65 - 70% of the annual state-wide harvest (Florida Fish and Wildlife Conservation Commission 2004). Landings on the Gulf coast of Florida are somewhat lower than those on the East coast, averaging approximately 198,015 pounds per year. On the Atlantic coast, landings have averaged less than 300,000 pounds per year since 2001. However, catch rates on both coasts are apparently stable, and have remained so since the early 1990s.The recreational fishery was first regulated beginning in 1996, when a 10-fish bag limit and 12-inch minimum size limit was implemented. Based on angler survey data provided by the national Marine Fisheries Service, summer flounder are not of particular importance as a fishery within the Indian River Lagoon, with most fishes harvested in nearshore and offshore waters (Figure 4). Since 1997, the recreational harvest in the 5-county area encompassing the Indian River Lagoon has remained fairly insignificant in inland waters and the IRL, with the bulk of the catch (80.4%) being taken from nearshore waters to 3 miles offshore, and in offshore waters to 200 miles. Inland waters other than the IRL accounted for nearly 19% of the catch, while the IRL itself accounted for only 0.8% of the harvest. The entire catch of summer flounder within waters of the IRL was only 360 fishes, all of which were taken in 1999. The total catch of summer flounder between 1997 - 2004 was 43,001 fishes. Of note is that much of the total harvest in eastern Florida was taken in 2 anomalous years: 1998 and 2001. The 1998 catch accounts for 37% of the total harvest, with over 16,000 fishes captured in nearshore waters to 3 miles. In 2001, the bulk of the catch, 9,800 fishes, was taken in offshore waters to 200 miles. The lowest harvest was recorded in 2002, when just 352 summer flounder were reported captured. The highest harvest occurred in 1998 when 22,114 summer flounder were taken.No data were available for 2004.