Southern flounder
Fish · Last reviewed 2026-10-09
The left-eyed flounder of Gulf and south-east US bays, taken on light tackle and by wading with a lantern and gig at night.
Catching Southern flounder
Everything here on fishing for it. Each entry opens the page behind it.
- Ground
The southern flounder is the flounder of the Texas bays, and according to Texas Parks and Wildlife it accounts for more than ninety-five per cent of the flounder harvested in the state. It is a left-eyed flatfish: both eyes of an adult are on the upper, pigmented side, and that side changes shade to match the bottom.
Its year is a migration between the bays and the Gulf. Adults leave the bays in the autumn to spawn in the Gulf of Mexico, in fifty to a hundred feet of water, and come back in the spring. The autumn movement is concentrated and the spring return is gradual, which is why the best catches of the year are made in the autumn in the channels and passes leading to the Gulf. Not every fish leaves: some spend the winter in the bays.
It is an ambush feeder. Adults move into very shallow water at night and lie on the bottom, often partly buried, waiting for prey; the depression a flounder leaves behind is called a bed. That habit is the basis of the method the fish is best known for: wading the shallows at night with a lantern and a gig.
FishBase records a maximum of 83 cm and 9.3 kg and an age of eight years, and the IUCN lists the species as Near Threatened.
Catching it
How it is caught
The fish
Identification
No photograph of Southern flounder has passed identity review yet, so none is shown. A photograph is published only once somebody has checked the animal in it against the diagnostic features described on this page.
- Scientific name
- Paralichthys lethostigma
- Family
- Paralichthyidae
- Water
- Saltwater, Brackish
- Conservation status
- Near Threatened
- Regions
- North America, Caribbean
- A left-eyed flatfish: both eyes of the adult are on the upper side, and the fish lies left side up.
- The upper side changes its pigmentation to match the surrounding bottom, so colour is not a reliable mark.
- Often found partly buried in very shallow water at night; the empty depression it leaves is known as a bed.
- By far the commonest flounder in Texas bays, making up more than ninety-five per cent of the state's flounder harvest.
Size
- Typical
- Not given as a figure by the sources read
Exceptional: FishBase records a maximum of 83 cm, 9.3 kg and an age of 8 years
Lifecycle and reproduction
Larvae hatch from buoyant eggs and swim upright with an eye on each side. As the fish grows the right eye moves to the left side of the head, a change complete at about half an inch long. Young fish of that size enter the bays in late winter and early spring and seek shallow grassy areas near the Gulf passes; some move further into the bays and some into coastal rivers and bayous.
Adults leave the bays in the autumn and spawn in the Gulf of Mexico through the winter, at depths of fifty to a hundred feet, spawning for the first time at two years old. The eggs are buoyant. Most adults make the journey, though some remain in the bays over winter.
Feeding and senses
Juveniles feed mainly on crustaceans and take more fish as they grow. Adults are ambush feeders that enter shallow water at night and lie on the bottom, often partly buried, waiting for prey. They prefer live to dead bait, and live shrimp or killifish worked slowly along the bottom are the baits Texas Parks and Wildlife names.
The page read does not describe the flounder's senses directly. It describes the adaptations that make its ambush work: both eyes on the upper side, an upper surface that changes colour to match the bottom, and no swim bladder, which helps it hold position on the bottom.
Through the year
Autumn: a concentrated movement out of the bays to the Gulf, when the best catches are made in the channels and passes. Winter: spawning in the Gulf, with some fish remaining in the bays. Spring: a gradual return, when wading anglers work the edges of channels such as the Intracoastal Waterway.
Distribution
Western Atlantic: Virginia to Texas in USA, northern Mexico, south to Trinidad and Tobago
This is a biological range — where the species occurs, not a prediction that you will catch one. To browse the fishing geography FishingHQ holds, start at fishing places.
Why anglers care
Highly prized as food and as a sport fish on the Texas coast. It is taken by rod and reel on light tackle, with weighted soft plastic worms over bare bottom and shallow-running spoons in vegetation, or live shrimp and killifish, and by gigging: wading the shallows at night with a lantern. Shorelines with cord grass and a slightly silty or muddy bottom are described as better ground than hard sand.
Handling and returning
The page read gives no handling instructions. Two things on it bear on what is kept: the species is listed as Near Threatened, and the autumn run concentrates the adult fish in a few channels and passes on their way to spawn, which is when they are easiest to catch in number.
Safety and rules
More
Where to go next
Where it lives
- EstuaryThe bays, with coastal rivers and bayous, between an autumn run to the Gulf and a spring return.
- Seagrass bedsYoung fish seek shallow grassy areas near the Gulf passes.
More fish
Not related to this page — just the rest of the section. There is little else joined to this subject yet, and a short page should still lead somewhere.
Sources and evidence
- FishBase: a global information system on fishes — Froese, R. and D. Pauly, eds. — FishBase Consortium (Scientific institute)Relied on for: Family, maximum size, depth range, environment, distribution and the IUCN assessment for Paralichthys lethostigma.States this directlyPassage read and verified
- The IUCN Red List of Threatened Species — International Union for Conservation of Nature (Conservation authority)Relied on for: The Near Threatened assessment for Paralichthys lethostigma, assessed 12 June 2015.States this directlyCitation checked — the work exists and is described correctly
- Texas Parks and Wildlife: southern flounder — Texas Parks and Wildlife Department (Government fisheries body)Relied on for: The southern flounder's eye migration and camouflage, its autumn spawning migration to the Gulf and spring return, its night-time ambush feeding in the shallows, its share of the Texas flounder harvest, and how it is caught by rod and reel and by gigging.States this directlyPassage read and verified
Why the 4 connections on this page are here, and the sources
How it is caught
Official guidance — 2 connections
Stated by a fisheries authority, scientific institute or recognised angling body. Authoritative, but summarising rather than demonstrating.
Gigging
Texas Parks and Wildlife describes gigging, wading quietly along the shallows at night with a lantern, as the method that offers the best challenge for this species.
- Texas Parks and Wildlife: southern flounder — Texas Parks and Wildlife Department (Government fisheries body)Relied on for: That southern flounder are taken by gig as well as by rod and reel, by anglers wading the shallows at night with lanterns.States this directlyPassage read and verified
Spinning
Texas Parks and Wildlife names weighted plastic worms and shallow-running spoons, fished on light tackle, as effective lures for flounder.
- Texas Parks and Wildlife: southern flounder — Texas Parks and Wildlife Department (Government fisheries body)Relied on for: That light rod-and-reel tackle with artificial lures is used for flounder: leaded plastic worms over barren bottoms and shallow-running spoons in heavily vegetated areas.States this directlyPassage read and verified
Where it lives
Official guidance — 2 connections
Stated by a fisheries authority, scientific institute or recognised angling body. Authoritative, but summarising rather than demonstrating.
Estuary
Texas Parks and Wildlife describes the bays as where the fish lives for most of the year, entering them as half-inch juveniles and returning to them each spring.
- Texas Parks and Wildlife: southern flounder — Texas Parks and Wildlife Department (Government fisheries body)Relied on for: That southern flounder live in the bays, with some entering coastal rivers and bayous, leaving for the Gulf in the fall and returning in spring.States this directlyPassage read and verified
Seagrass beds
Texas Parks and Wildlife says the young fish seek shallow grassy areas near the passes when they enter the bays.
- Texas Parks and Wildlife: southern flounder — Texas Parks and Wildlife Department (Government fisheries body)Relied on for: That young southern flounder entering the bays seek shallow grassy areas near the Gulf passes.States this directlyPassage read and verified
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