It is easy to confuse a halibut with a flounder, given their similar odd appearance. Nevertheless, there are many ways to differentiate these flatfish species from each other.
Halibut are typically larger, with elongated, diamond-shaped bodies suited to deep, cold oceanic environments. Meanwhile, flounders are smaller, have rounded shapes, and are more adaptable to diverse habitats. The halibut texture is firm and meaty, whereas flounders have softer, flaky consistencies.
These fishes have more differences besides appearance, habitat, and meat texture, given that they come from different species. If you want to know more about them, stick around, as this guide has more to offer!
Summary of Halibut vs. Flounder
| Halibut | Flounder |
|---|---|
 |  |
| Appearance: – Generally large, diamond-shaped flatfish; – More streamlined appearance; – Eyes are on the right side of the body after metamorphosis. | Appearance: – Smaller, oval-to-round body shape; – Depending on the species, their eyes can be on either the left or right side after metamorphosis. |
| Color: – Typically mottled gray to dark brown on the top side; – White underbelly | Color: – Vary in color but often have a brown or dull green top side; – White underbelly, sometimes exhibiting a pattern of spots or camouflage-like mottling. |
| Size: Up to 108 in (9 ft) | Size: 20–35 in (1.7–3ft) |
| Weight: Up to 800 lbs (363 kg) | Weight: 6–20 lbs (3–9 kg) |
| Habitat: North Pacific and North Atlantic, preferring deep offshore bottoms | Habitat: More adaptable and found in coastal and deep-sea waters, including estuaries and bays |
| Distribution: Northern parts of the Atlantic and Pacific Oceans | Distribution: Distributed more widely and found in oceans worldwide and various marine environments |
| Taste: – Firm and lean with a mild, sweet flavor; – Often considered a delicacy | Taste: – Tender, flaky, and mild, with a fine texture; – Slightly sweeter taste than halibut |
| Price: $15–$30 per pound | Price: $10–$20 per pound |
Key Differences Between Halibut and Flounder
Although quite identical in appearance, there are key traits that set halibut apart from flounders. Their classification, physical appearance, habitat preference, and culinary values are quite distinct.
Classification
Halibut and flounders share the same order but belong to different families. Both are part of the order Pleuronectiformes, which includes all flatfish species. This group of fish is characterized by a flat, sideways body and swims on their side.
Halibut species fall under the family Pleuronectidae. True halibut species belong to the genus Hippoglossus and are known for the eye placement on the right side of the body.
The two known true halibut species are the Atlantic Halibut (Hippoglossus hippoglossus), revered as the largest flatfish, and the Pacific Halibut (Hippoglossus stenolepis), a popular catch in the North Pacific.
On the other hand, flounder is a common name that encompasses several species across various families within the same order, including Bothidae and Pleuronectidae.
Flounder species can have eyes on either the left or right side, depending on the type. They’re generally smaller and more diverse than halibut.
Noteworthy species include the Summer Flounder (Paralichthys dentatus), commonly found in the Atlantic off the East Coast of the United States, and the European Flounder (Platichthys flesus), native to waters around Europe.
The Witch Flounder (Glyptocephalus cynoglossus) is another species prized for its taste, dwelling in the North Atlantic.
Meanwhile, the Southern Flounder (Paralichthys lethostigma) prefers the warmer coastal waters of the Southern United States, and the Windowpane Flounder (Scophthalmus aquosus) is known for its thin, translucent body.
Fun Fact: The California Halibut (Paralichthys californicus), despite its common name, is not a true halibut but a large-tooth flounder species. The same is true with the Greenland Halibut or Turbot (Reinhardtius hippoglossoides), a flatfish under the Reinhardtius genus.
Appearance and Color
(Image credit)
When distinguishing between halibut and flounder, their appearance is a key factor.
Halibut species are characterized by a more elongated, diamond-shaped body, which is quite robust compared to flounders. They are also right-eyed species, meaning their eyes migrate to their right side.
Flounders, in contrast, exhibit a range of body shapes but are generally more rounded. They have a flatter appearance, and while they share the unique feature of having both eyes on one side of their head, their overall physique is less imposing than that of the halibut.
Unlike halibut species, flounders are not always right-eyed. Some migrate their eyes to their left side when they mature.
The coloration of these fish also serves as a distinguishing feature. Halibut species typically have a dark brown or greenish top side, designed to blend seamlessly with the ocean floor.
Watch this video to witness the amazing camouflage ability of halibut:
Flounders, although also camouflaged, tend to display a greater variation in colors and patterns, which can include lighter shades and more pronounced spots or mottling.
This variety in coloration among flounder species reflects their diverse habitats and ecological roles.
The tails of these fish species are also giveaway traits. Halibuts have forked or concave tails, while flounders have more rounded or fan-shaped tails.
These differences in body shape, color, and appearance are caused by their adaptations to different environments and lifestyles within the ocean.
Size and Weight
The size difference between halibut and flounders is also one of their defining characteristics. Most halibut species are heavier than flounders.
Halibut, particularly the Pacific Halibut, can reach remarkable lengths of up to 108 inches (9 feet). This makes them one of the largest representatives of the flatfish family.
In terms of weight, halibut species are real heavyweights, with some weighing up to 800 pounds.
In contrast, flounder species, such as the Summer Flounder or the European Flounder, are generally smaller. They typically measure between 20 and 35 inches (1.7–3 feet) in length.
When it comes to weight, flounders are much lighter compared to halibut, with their weight usually ranging between 6 and 20 pounds.
Habitat and Distribution
Halibut and flounder are flatfish found in various parts of the world’s oceans, but they have different preferences for where they call home.
Halibut, such as the Pacific Halibut and the Atlantic Halibut, are typically found in the cold waters of the North Pacific and North Atlantic Oceans.
They prefer deep, chilly ocean bottoms and are often found on the continental shelf or slope where the water depth ranges from 20 to 1,000 meters.
Flounders, on the other hand, inhabit a broader range of environments. Species like the American Plaice or the Southern Flounder are versatile and inhabit coastal areas and estuaries and also venture into deeper waters.
They are widespread and found in both the Northern and Southern Hemispheres, adapting to varying salinity and temperatures of different marine habitats.
The halibut distribution is more concentrated in the northern hemisphere, making them less globally widespread than flounders.
Taste and Texture
Regarding taste and texture, halibut and flounder offer distinct experiences. Both fish are lean protein sources, but their different textures suit different cooking methods.
Halibut are known for their firm, white flesh that holds together well when cooked, making them a versatile choice for cooking. Their flavor is mild and slightly sweet, often described as clean-tasting.
Flounders, by contrast, present a delicate texture that’s light and flaky, perfect for those who enjoy a fish that gently falls apart with a fork.
The taste of flounder is subtle and mildly sweet, with a less pronounced flavor compared to halibut. This makes it an excellent base for various seasonings and sauces, absorbing flavors beautifully.
What I do when I can’t decide whether to buy a halibut or a flounder is consider what type of dish I would like to prepare.
For grilling and searing, I use halibut since its meat is firm. But if I want a dish that is steamed, stuffed, or sautéed, I go for flounder meat that offers a flaky consistency.
Here is an informative video of how a halibut is prepared in Japanese cuisine:
Price
Halibut typically command a higher price than flounders. This is partially due to their larger sizes, which yield more meat, and their reputation as a premium fish with a firm texture and rich flavor.
Typically, halibut can cost anywhere from $15 to $30 per pound retail, depending on the cut and whether it’s fresh or frozen.
Halibut’s cost also reflects their commercial fishing regulations, which can be stricter due to conservation efforts, contributing to their higher market value.
Flounders, being smaller and more abundant with border distribution, are generally more affordable, ranging between $10 and $20 per pound. Their lower price makes them a popular choice for daily consumption.
While flounders’ delicate taste and texture are prized, their abundance helps keep prices down, making them a budget-friendly option for many consumers.
Nevertheless, exact price ranges for these fishes can vary widely depending on factors such as geographic location, season, and market demand.
Other Differences
Beyond the primary differences already noted, halibut and flounders differ in their life span and reproductive habits as well.
Halibut can live for several decades, some reaching up to 50 years, and they tend to migrate long distances for spawning.
Flounder, in comparison, generally have a shorter life span, often living up to 15 years.
They usually stay within a more localized area throughout their lives and have different spawning behaviors, often associated with the changing seasons.
Common Misconceptions About Halibut and Flounder
When it comes to halibut and flounders, many people hold onto mistaken beliefs that can lead to confusion in both ecological understanding and culinary contexts.
Here are some common misconceptions about halibut and flounders:
- Halibuts are just big flounders. It’s often believed that halibut are simply larger flounders. While they look similar, halibut and flounder are from different families and have distinct biological traits.
- Flounders are always found on the ocean floor. While flounders are bottom-dwellers, some species can be found in midwater levels.
- Halibut species are always dark on top. Halibut can vary in color, sometimes lighter or with mottled patterns, depending on their environment.
- Flounder cannot be eaten raw. Flounder, especially when fresh and properly handled, can be served as sashimi.
- Halibut species are not found in southern waters. While they prefer cold waters, some halibut species live in the Southern Hemisphere.
- Flounders are not commercially valuable. Flounder are widely fished and valued, especially in Asian and American cuisines.
- All flounders have both eyes on the left side. It’s mistakenly thought that all flounders have left-side eye placement. Eye placement in flounder varies, with some species having right-side placement, which is a significant taxonomical feature.
Whether for academic study or culinary exploration, understanding the true nature of halibut and flounder is key to respecting their place in our ecosystems.
Frequently Asked Questions
Are Halibut and Flounder Related?
Halibut and flounder are related. They are part of the Pleuronectiformes order, commonly known as flatfish. This group is characterized by a unique adaptation with both eyes on one side of the head.
Despite this shared family trait, they come from different families within this order, which leads to their varied physical and behavioral characteristics.
Why Is Halibut Fish So Expensive?
Halibut is expensive due to its high demand and relatively limited supply. It’s a large fish that offers thick, meaty fillets with a mild, clean flavor that’s highly prized.
Overfishing concerns have also led to stricter fishing regulations, which limit the number of halibut that can be caught, contributing to its premium price.
Is Flounder Better Than Halibut?
Whether flounder is better than halibut depends on personal preference and intended use.
Flounders are delicate with a fine texture, ideal for subtle flavors and lighter meals. Halibut, with its firmer texture and larger fillets, is better suited for hearty dishes and holds up well to various cooking methods.
The difference between halibut and flounder is clear, and choosing between the two ultimately boils down to your preference. Which one do you think you prefer more? Let us know in the comments!
