Freshwater Flounder

Freshwater Flounder: The Ultimate Care Guide

Freshwater flounder, belonging to the Solidae family, are native to the Gulf of Mexico and can be a stunning addition to your aquarium. With their unique flattened and laterally compressed bodies, they are a spectacle to behold.

Despite their name, freshwater flounders thrive best in brackish water conditions. They are relatively easy to care for and can live for up to five years with optimal tank conditions. Adding freshwater flounders to your aquarium can bring a touch of exotic beauty.


The freshwater flounder, belonging to the Solidae family, is native to the Gulf of Mexico. With a unique appearance and flattened bodies, they make a captivating addition to any aquarium. These fish thrive in brackish water and can live up to five years with proper tank conditions.

Introduction To Freshwater Flounder

Freshwater Flounder, also known as Hogchoker, is a fascinating species of fish that can be a great addition to your aquarium. Native to the Gulf of Mexico, this unique-looking fish has distinct characteristics that set it apart from other freshwater species.

We will explore the appearance, characteristics, and benefits of keeping Freshwater Flounder in an aquarium.

Unique Appearance And Characteristics

  • Freshwater Flounder has a flat and oval-shaped body, resembling a traditional flounder.
  • They have both eyes located on one side of their body, which allows them to camouflage with the sandy bottoms of rivers and lakes.
  • These fish have a brown or greenish-brown color, helping them blend in with their environment.
  • Freshwater Flounders are relatively small, growing up to 6 inches in length.
  • They have a thin and flexible body, making them agile swimmers.
  • Their mouth is located on the bottom side of their body, enabling them to search for food in the sand.

Benefits Of Keeping Freshwater Flounder In An Aquarium

  • Freshwater Flounder can be an interesting and unique addition to your aquarium due to their distinctive appearance.
  • They are relatively hardy and adaptable, making them suitable for both beginner and experienced fish keepers.
  • These fish are peaceful and can coexist with a variety of other freshwater species.
  • Freshwater Flounder can help control the population of small invertebrates and insects in your aquarium, contributing to the overall balance of the ecosystem.
  • They have an intriguing feeding behavior, burying themselves in the sand and using their mouth to trap small prey.
  • Watching Freshwater Flounder swim and hunt can be an entertaining and educational experience for aquarium enthusiasts.

Freshwater Flounder is an intriguing species that offers a unique visual and behavioral experience in an aquarium setting. With their distinctive appearance and peaceful nature, they can be a great addition to your aquatic community. Their ability to control small invertebrate populations also adds to their value as an integral part of the ecosystem.

Consider adding Freshwater Flounder to your aquarium and enjoy the fascinating world they bring to your aquatic habitat.

Tank Setup And Maintenance

Found in the Gulf of Mexico, freshwater flounders are unique fish with laterally compressed bodies. They thrive in brackish water and can make a stunning addition to your aquarium. Care for them properly, and they can live up to five years.

Discover more about their care, breeding, and diet in our comprehensive guide.

Found in freshwater environments such as rivers, ponds, and lakes. If you’re interested in keeping freshwater flounder as a pet, it’s important to set up a suitable tank environment for them. In this section, we will discuss the tank size and requirements, water parameters, filtration and water circulation, substrate choices, decorations and hiding spots, as well as proper cleaning and maintenance routines.

Tank Size And Requirements:

  • A tank with a capacity of at least 30 gallons is recommended for a single freshwater flounder.
  • If you plan to keep multiple flounders, make sure to provide an additional 10 gallons for each additional fish.
  • Flounders are bottom-dwelling fish, so it’s essential to provide enough horizontal space for them to swim and explore.
  • Consider providing a tank with a length of at least 3 feet to accommodate their natural behavior.

Water Parameters For Freshwater Flounder:

  • The water temperature should be maintained between 72°F and 78°F (22°C – 26°C).
  • A pH level ranging from 6.5 to 7.5 is suitable for freshwater flounder.
  • Flounders prefer soft to moderately hard water, so aim for a water hardness level of 5 to 15 dGH.
  • Regular monitoring of ammonia, nitrite, and nitrate levels is crucial to ensure a healthy environment.

Filtration And Water Circulation:

  • A high-quality filtration system is essential to maintain clean and healthy water for freshwater flounders.
  • Consider using a combination of mechanical, biological, and chemical filtration methods.
  • Ensure proper water circulation in the tank to prevent stagnant areas and promote oxygenation.

Substrate Choices For The Tank:

  • Choose a fine-grained substrate like sand or smooth gravel to mimic the flounder’s natural habitat and prevent damage to their delicate bodies.
  • Avoid using rough or sharp-edged substrates that may harm their skin or fins.

Decorations And Hiding Spots:

  • Provide a variety of hiding spots and structures in the tank to mimic a natural environment.
  • Use driftwood, rocks, and plants to create suitable hiding places for freshwater flounders.
  • Create caves and crevices where they can retreat and feel secure.

Proper Cleaning And Maintenance Routine:

  • Regular water changes of 25% should be performed every two weeks to maintain water quality and remove accumulated waste.
  • Use a siphon to clean the substrate, removing any uneaten food or debris.
  • Monitor the filter, ensuring it remains clean and functioning correctly.
  • Remember to dechlorinate new water added to the tank during water changes.

Remember, a well-maintained tank with the right setup and environment is crucial for the health and well-being of your freshwater flounder. By following these guidelines, you can provide a suitable home for your flounder and enjoy observing their unique behavior in your aquarium.

Feeding And Nutrition

Freshwater Flounder, a unique fish belonging to the Solidae family, can be a captivating addition to your aquarium. With their flattened, laterally compressed bodies, these fish create a stunning spectacle. Native to the Gulf of Mexico, they thrive in brackish water and are easy to care for, living up to five years in optimal tank conditions.

Natural Diet Of Freshwater Flounder:

  • Freshwater Flounder in its natural habitat primarily feed on small invertebrates like insects, crustaceans, and worms.
  • They also consume aquatic plants and algae as a part of their diet.

Choosing The Right Food For Them:

  • A well-balanced diet is essential for the health of Freshwater Flounder.
  • Opt for high-quality fish pellets or flakes specifically formulated for flounders.
  • Look for a diet that contains a mix of protein, carbohydrates, vitamins, and minerals.
  • Consider feeding them freeze-dried or freeze-frozen foods occasionally for added variety.

Frequency And Portion Size For Feeding:

  • Freshwater Flounder should be fed small meals multiple times a day.
  • Aim for 3-4 feedings per day, providing only as much food as they can consume within 2-3 minutes.
  • Pay attention to their appetite and adjust the portion size accordingly to prevent overfeeding.

Supplementing With Live Or Frozen Food:

  • Freshwater Flounder can greatly benefit from the inclusion of live or frozen foods in their diet.
  • Offer them small live organisms like bloodworms, brine shrimp, or daphnia.
  • Frozen foods such as plankton, mysis shrimp, or blackworms are also excellent options.
  • These foods provide essential nutrients and mimic their natural feeding behavior.

Monitoring Their Feeding Behavior:

  • Observe the feeding behavior of Freshwater Flounder to ensure they are healthy and getting enough food.
  • Watch for any signs of overeating, such as bloating or sluggishness.
  • If there are any uneaten food particles, remove them promptly to maintain good water quality.
  • Adjust the feeding schedule or portion sizes if necessary based on their growth and activity level.

Remember to always provide a balanced diet and closely monitor the feeding behavior of Freshwater Flounder to promote their overall health and well-being.

Compatibility And Tank Mates

The freshwater flounder, belonging to the Solidae family, is native to the Gulf of Mexico and can thrive in brackish water. With their unique appearance and laterally compressed bodies, they make a captivating addition to any aquarium. Care for these fish is relatively easy, and they can live up to five years with optimal tank conditions.

Ideal Tank Mates For Freshwater Flounder:

  • Discus: These peaceful and colorful fish are a great choice as tank mates for freshwater flounders.
  • Neon Tetra: These small schooling fish create a beautiful contrast with the flounders and add movement to the aquarium.
  • Guppy: These active and colorful fish are compatible with freshwater flounders and provide a lively display.
  • Zebrafish: These hardy and active fish are a popular choice for community tanks and can coexist well with freshwater flounders.
  • Cherry Barb: These peaceful and colorful fish are a great addition to an aquarium with freshwater flounders.
  • White Cloud Mountain Minnow: These small and peaceful fish are known for their tolerance of various water conditions, making them a good match for freshwater flounders.

Fish Species To Avoid Keeping Together:

  • Scatophagus argus: These brackish water fish have different water requirements and may not thrive in the same aquarium as freshwater flounders.
  • Sailfin Molly: These livebearers prefer brackish water conditions and may not be compatible with freshwater flounders.
  • Green Chromide: These fish are also known as “pearl spot” and are commonly found in brackish water environments.
  • Catfish: Some catfish species can be territorial or aggressive, which may lead to conflicts with freshwater flounders.
  • Siamese Tigerfish: These predatory fish can pose a threat to freshwater flounders due to their aggressive nature.
  • Largemouth Bass: These large and aggressive fish are not suitable tank mates for freshwater flounders.

Creating A Harmonious Community Tank:

  • Research and choose fish species that have similar water parameter requirements and temperaments.
  • Provide ample hiding places and territory boundaries in the aquarium to minimize aggression and territorial disputes.
  • Maintain a suitable number of fish in relation to the tank size to prevent overcrowding and stress.
  • Introduce new tank mates gradually to allow the fish to acclimate and establish their territories.
  • Regularly monitor the behavior of the fish and address any signs of aggression promptly to maintain harmony in the community tank.

Dealing With Aggression And Territorial Behavior:

  • If aggression becomes an issue, consider rearranging the tank decorations and adding new hiding spots to create new territories.
  • Add fish species that can help divert aggression, such as dither fish that can attract the attention of territorial fish.
  • Separate incompatible fish if aggression persists, providing each species with their own tank to ensure their well-being.
  • Avoid keeping fish species known for aggressive behavior together with freshwater flounders to prevent conflicts.
  • Ensure proper nutrition and a well-maintained aquarium environment to minimize stress, which can trigger aggression in fish.

Breeding Freshwater Flounder

Freshwater Flounder, also known as Brachirus selheimi, are unique fish native to the Gulf of Mexico. With their flattened bodies, they make a stunning addition to any aquarium. Learn about their care, breeding, and diet to provide optimal conditions for these fascinating creatures.

To freshwater habitats and can be found in various regions around the world. Breeding freshwater flounder can be a rewarding and fascinating process. In this section, we will explore the natural breeding behavior and requirements, setting up a breeding tank, conditioning the breeding pair, the spawning process and identification of eggs, as well as caring for the fry and raising them to maturity.

Natural Breeding Behavior And Requirements:

Breeding freshwater flounder can be a complex process, but understanding their natural breeding behavior and requirements is essential. Here are some important points to consider:

  • Flounder are generally solitary fish, so it’s crucial to provide each breeding pair with individual tanks to reduce stress and aggression.
  • Flounder require specific water conditions for successful breeding, including a pH level between 6.5 and 7.5 and a water temperature of 70-75°F.
  • Creating a natural habitat in the breeding tank is vital. Sand substrate and the presence of hides such as rocks or caves will mimic their natural environment.

Setting Up A Breeding Tank:

Setting up a suitable breeding tank is crucial for the successful breeding of freshwater flounder. Here are some key steps to consider:

  • Select a tank size of at least 20 gallons to provide enough space for the breeding pair.
  • Use a sponge filter or a gentle air-driven filter to maintain water quality without causing excessive water movement or disruption to the flounder.
  • Ensure the tank is adequately heated and maintained at a stable temperature suitable for breeding.
  • Provide appropriate lighting, mimicking their natural day and night cycle.

Conditioning The Breeding Pair:

Preparing the breeding pair for successful reproduction requires careful conditioning. Here’s what you should take into account:

  • Separate the male and female flounder and condition them separately for a few weeks.
  • Offer a varied and nutritious diet, including live and frozen foods, to ensure their optimum health and reproductive readiness.
  • Gradually increase the feeding frequency to mimic the abundance of food in their natural environment.

Spawning Process And Identification Of Eggs:

Once the breeding pair is conditioned and ready, the flounder will initiate the spawning process. Here’s what you need to know:

  • Provide suitable spawning surfaces such as rocks or slate in the breeding tank for the flounder to lay their eggs on.
  • During spawning, the female flounder will release eggs, while the male fertilizes them externally.
  • The fertilized eggs are adhesive and will attach to the chosen spawning surface.
  • It’s essential to closely monitor the tank during this time and remove any unfertilized eggs to prevent fungus growth.

Caring For The Fry And Raising Them To Maturity:

Caring for the fry requires attention to detail and proper nutrition. Here are some key aspects to consider:

  • Once the eggs hatch, the fry will absorb their yolk sacs for nourishment. After this stage, offer them small live or frozen foods such as brine shrimp or micro worms.
  • Maintain excellent water quality by performing regular water changes and monitoring ammonia and nitrite levels.
  • Gradually introduce commercial fry food as the fry grow and their nutritional needs change.
  • Monitor the fry’s growth and separate any aggressive individuals to prevent cannibalism.

Breeding freshwater flounder can be a challenging but rewarding experience. By understanding their natural behavior, providing suitable breeding conditions, and ensuring proper care for the fry, you can increase your chances of successfully breeding and raising these fascinating fish.

Potential Diseases And Health Issues

Freshwater flounders, also known as Brachirus selheimi, are native to the Gulf of Mexico and can make a captivating addition to your aquarium. With their unique appearance and flattened bodies, these fish are easy to care for and can thrive in brackish water environments.

Learn more about their care, breeding, and diet in our comprehensive freshwater flounder care guide.

Mexico and the Western Atlantic Ocean, but can also be found in freshwater environments such as rivers and lakes. These unique fish have a flat, diamond-shaped body and are known for their ability to camouflage themselves by changing color to match their surroundings.

Common Diseases Affecting Freshwater Flounder:

  • Bacterial Infections: Bacterial infections can occur in freshwater flounder and can be caused by poor water quality or injuries. Symptoms may include loss of appetite, lethargy, fin rot, and open sores.
  • Fungal Infections: Fungal infections are common in freshwater flounder and can result from poor water conditions, injuries, or stress. Symptoms may include white or cottony growth on the body, fins, or gills.
  • Parasitic Infections: Freshwater flounder can be affected by various parasites, such as Ich (white spot disease), gill flukes, and skin flukes. Symptoms may include itching, flashing, loss of appetite, and visible parasites on the fish’s body.
  • Dropsy: Dropsy is a condition where the fish’s body swells and scales may become raised. It is often caused by poor water quality, bacterial infection, or internal organ failure.

Recognizing The Signs Of Illness:

  • Lethargy and loss of appetite: A sick freshwater flounder may become inactive and show little interest in food.
  • Changes in coloration: If the fish’s color becomes dull or there are abnormal spots or patches, it may indicate an underlying health issue.
  • Erratic swimming behavior: If the fish is swimming erratically, twitching, or tilting to one side, it could be a sign of illness.
  • Abnormal fin or scale growth: Look for ragged fins, discolored or damaged scales, or visible growths on the fish’s body.

Proper Quarantine And Treatment Methods:

  • Isolate sick fish: If you notice signs of illness in your freshwater flounder, it is essential to isolate them from healthy fish to prevent the spread of disease.
  • Consult a veterinarian: If you are unsure about the best course of action or need help diagnosing the illness, consult a veterinarian with experience in fish health.
  • Follow recommended treatment protocols: Treatments may include medicated baths, antibiotics, antifungals, or other medications specific to the diagnosed illness.
  • Monitor water quality: Regularly test and maintain optimal water conditions to promote healing and prevent further stress on the fish.

Maintaining Good Water Quality To Prevent Diseases:

  • Adequate filtration: Use appropriate filtration equipment to maintain clear water and remove harmful substances.
  • Regular water changes: Perform regular partial water changes to remove toxins and maintain stable water parameters.
  • Proper temperature and pH: Ensure the water temperature and pH are suitable for the freshwater flounder species you are keeping.
  • Avoid overfeeding: Overfeeding can lead to excess food waste, causing poor water quality and potential health issues.
  • Quarantine new fish: Quarantine any new fish before introducing them to your existing tank to prevent the introduction of diseases.

By understanding common diseases affecting freshwater flounder, recognizing the signs of illness, implementing proper quarantine and treatment methods, and maintaining good water quality, you can help keep your fish healthy and thriving.

Frequently Asked Questions For Freshwater Flounder

Are There Any Freshwater Flounder?

Yes, there are freshwater flounder. They belong to the Solidae family and are native to the Gulf of Mexico.

What Are Freshwater Flounder Called?

Freshwater flounder are called oddball tropical fish and belong to the Solidae family. They are native to the Gulf of Mexico.

Where Do Freshwater Flounder Live?

Freshwater flounders live in the Northern Gulf of Mexico to northern Argentina, and Florida. They thrive in brackish water.

Do Flatfish Live In Freshwater?

Yes, flatfish, also known as freshwater flounder, can live in freshwater environments.


The freshwater flounder is a fascinating fish native to the Gulf of Mexico. With its unusual appearance and laterally compressed, flattened body, it can make a captivating addition to any aquarium. Despite its name, the freshwater flounder thrives in brackish water and can live up to five years with proper care and tank conditions.

This fish belongs to the Solidae family and is known for its distinctive features. As a true freshwater flounder, it is quite rare and mainly found in the South American Uruguay and Parana Rivers. Overall, the freshwater flounder is a unique and intriguing species that can bring a touch of beauty to any aquatic environment.

So if you’re looking to add some variety to your aquarium, consider the freshwater flounder as an option.

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