Paralichthys albiguttata, better known by its common name, the Gulf Flounder, is one of the most prolific fish along the gulf coast.
Species of flounder can be found up and down America’s shores, and the gulf flounder, in particular, is one of the most fascinating.
The gulf flounder is an impressive fish characterized by its distinctive appearance, incredible camouflage, and adept hunting sense.
Read on to learn everything you need to know about these clever fish, from their appearance and physical characteristics to their lifespan, habitat, diet, and much more.
Characteristics & Appearance
The Gulf flounder is one of the most peculiar species in the ocean from an appearance perspective. Read on as we take a closer look at their size, color, and characteristics.
Weight & Length
The gulf flounder is the smallest species within the genus Paralichthys. What these clever fish lack in size, they make up for with their cunning nature and astute hunting ability.
The average gulf flounder weighs somewhere between 1-3 pounds, and they’re typically 12-14” long.
While most fish fall into this size range, it’s common for gulf flounder to get as large as 6-pounds.
Physical Characteristics & Color
When it comes to their physical characteristics, gulf flounder are among the most interesting creatures in the ocean.
Gulf flounder are both predator and prey, and their unique physical makeup allows them to hunt and attack efficiently while also protecting from larger predators.
Gulf flounder are flatfish, which means they spend most of their time lying on their bellies, and they swim with their belly parallel to the seafloor. Their underbelly is solid white, while the top of the fish has shades of brown, green, and grey.
Gulf flounder are characterized by three “eyes” on their body. One “eye” sits along the lateral line towards the tail, while two additional eyes are positioned above and below the lateral line.
This unique coloration provides deep camouflage, allowing the flounder to blend into their surroundings to protect them from predators effectively. A flounder can also change its color to match the seafloor it’s lying on more closely.
Gulf flounder are born with an eye on either side of their heads. As the fish matures, the eye on the right side of the fish migrates toward the center.
It looks a bit odd, but this adaptation allows the fish to effectively view its surroundings while it’s nestled into the sand or mud of the seafloor. These fish have big mouths with sharp, canine-like teeth.
Lifespan & Reproduction
While the reproduction and migratory habits of gulf flounder were once shrouded in mystery, scientists have managed to develop a fairly complete picture of these fish’s lifecycle and reproductive patterns.
Female specimens tend to grow larger and faster than their male counterparts, and they have a lifespan of around seven years.
Female fish reach maturity at approximately one year. Male flounder take a bit longer to mature, and they have a longer lifespan of about 8-11 years.
Most mature adults spend their time inhibiting bays and estuaries, while juveniles spend most of their time in high salinity seagrass beds until they reach maturity.
Adult flounder migrate offshore to deeper and colder waters during the fall and winter, where they spawn before returning to coastal waters in the summer.
Flounder are among the most prolific species of saltwater fish, and they can be found up and down the eastern and Gulf coasts of the U.S.
These fish can live in a variety of different habitats. They’re known to migrate throughout the year to the most suitable habitat at the time.
These fish tend to prefer waters with high salinity, and they don’t do well in brackish or low-salinity environments.
Gulf flounder can be found throughout the southeastern coast of the United States, ranging from Texas, Louisiana, and Florida on the gulf side and traveling up into the Carolinas on the ocean side.
Where Do Gulf Flounder Live?
Virtually all flounder species, including gulf flounder tend to spend most of their time on seafloors with a sandy bottom.
A sandy or muddy bottom allows the fish to burrow under the surface, providing excellent camouflage so they can ambush prey while also protecting themselves from predators.
Juvenile flounder spend most of their time inshore along seagrass beds. Mature fish tend to inhabit flat areas with a hard, sandy bottom.
In the colder months, adult flounder migrate offshore to spawn before returning to the shallows in the warmer months.
Food & Diet
Gulf flounder are opportunistic feeders, and they’re happy to make a meal of most things that cross their path.
This fish is an ambush predator, and they lie in wait on the seafloor before striking at their prey. Gulf flounder are carnivores, and their diet consists almost exclusively of other fish and crustaceans.
What Do Gulf Flounder Eat?
Gulf flounder are mostly opportunistic feeders, and they’re happy to make a meal of virtually anything that crosses their path.
For newborn and juvenile flounder, the diet consists primarily of zooplankton. From there, they move onto amphipods and tiny crustaceans.
Once gulf flounder reach full maturity, most of their diet consists of baitfish such as bunker, pinfish, croakers, and mullet.
While fish compose most of the mature flounder’s diet, they’re also big fans of shrimp and other small crustaceans.
While most predatory fish will progress to larger prey as they grow, gulf flounder are unique in the sense they don’t gravitate towards larger meals as they reach maturity. Instead, large flounder eat a greater quantity of small fish and crustaceans.
During the day, flounder spend most of their time in deeper waters, along drop-offs, and on ledges. Flounder will eat any prey that presents itself during the daytime.
As the sun sets, flounder will make their way to warmer inshore waters where small baitfish and shrimp are even more plentiful.
Threats & Predators
While gulf flounder are voracious predators in their own right, they also face several threats from humans, other predators, and outside sources.
Recreational anglers and commercial fishing represent the greatest overall threat to gulf flounder.
Each year, thousands of summer flounder are brought to the dock by anglers, as these hard-fighting fish are prized for their delicious white filets. Even more summer flounder are caught as bycatch in the nets of commercial fishers.
Climate Change & Global Warming
Climate change and global warming pose additional threats to gulf flounder populations. Rising water temperatures cause the flounder habitat to shrink, while the warmer water encourages new predators that aren’t common in the Gulf to enter the area.
Another threat that gulf flounder face is the destruction of seagrass in their habitats. Seagrass is integral for young flounder, as they spend much of their time in relative safety with an abundance of small creatures to eat.
While seagrass levels have been holding steady for decades, massive die-offs in the 80s and 90s dramatically affected the gulf flounder population.
Overall, the gulf flounder population is healthy, and the species has the designation of Least Concern from the IUCN.
While several different threats have affected the population over the years, the outlook for the species is good, and the population is holding firm.
Fun Facts About Gulf Flounder
Still want to learn more about the gulf flounder? Check out these fun facts about this unique and fascinating species.
- There are over 30 species of flounder, and the gulf flounder is among the smallest
- The largest recorded gulf flounder was over 6 pounds, but most specimens are in the 2-3 pound range
- Gulf flounder can be found throughout the southeast coast at depths from 1-200 feet
- Can change colors to better blend in with the seafloor
- Flounder are born with eyes on either side of their head, but the right eye migrates to the center of their head as they mature