Home Fishing Tips & Advice Difference Between Fluke and Flounder

Difference Between Fluke and Flounder

Flounder? I never lost her! Just kidding. The urge to make fluke and flounder puns was overwhelming, but I promise not to indulge too much. If you’ve ever hauled one of these doormats or placemats into the boat, you might not have known whether you had a fluke or a flounder or what to do with it. Neither one is likely to win a beauty contest anytime soon, but they are great to bring to the kitchen table. They’re surprisingly easy to filet and have a nice, mild flavor. You can even eat them raw. But first, you have to identify your fish. So, let’s get started!

Young Fluke and Flounder

It must be a hard life for these fish. Imagine going through life the way you are now, with both eyes facing forward. But then, let’s say you spend more and more time in bed. Eventually, your eyes start to migrate to the side. Finally, you end up looking out of one side of your head. It’s a great way of adapting to life on the ocean floor, but I bet having your eyes move around takes some getting used to.

That’s what happens with both fluke and flounder. They start life in much the same way other fish do. These fish hatch from tiny eggs as larvae that feed on plankton. After a month or two, they settle to the bottom and start to change. At this stage, the fish is only about a half-inch long. Much more than just the eyes change. Their whole skeleton, their muscles, and their nerves all shift around until their bodies flatten out and they swim on their sides. Finally, their skin color starts to change so they can blend into their surroundings. All of this dramatic change happens in the space of just two to three weeks. And you thought puberty was bad.

Fluke and Flounder Family

In answer to the important question here, what’s the difference between these two fish? The answer is both simple and complex. Put simply, a fluke is just a type of flounder. The fluke’s other names are Summer Flounder and Paralichthys dentatus. Flounder is a large grouping of loosely-related fish. 

What makes things more complicated is that there are over 500 different flatfish species in the world. Five of them are commonly called “flounder.” That includes our fluke. If you’re in the Western Atlantic, near New York, Virginia, and Florida, you’re likely to encounter four of these species: Gulf flounder, Summer flounder, Winter flounder, and Southern flounder. In Europe, you’ll encounter the aptly-named European flounder and the Witch flounder. In the North Pacific, we have Halibut and Olive flounder.

Generally, a fluke differs from most flounder in the way its eyes are positioned. When those eyes migrate, they shift over to the left side of the fish’s head. Many flounders have their eyes on the opposite – the right – side of their heads. Color is another clue. Most flatfish have lighter colors on the down-facing side and darker colors on the up-facing side. Between fluke and flounder, the fluke often has the lighter up-facing color of the two. But, since this coloration is meant to help hide the fish, where they live will make a big difference in what they look like.

Fluke and Flounder Facts

Here are a couple of interesting facts about fluke and flounder. If nothing else, they can be good conversation starters for when you’re heading back after a long day of fishing.

Winter Flounder are found from Canada to West Virginia. Summer Flounder (fluke) territory overlaps with the Winter Flounder’s but extends further south to Georgia. Southern Flounder overlaps Summer Flounder from the Carolinas on but goes further south to cover the Gulf and Florida too.

These fish are so wide and flat that the big ones are sometimes called “doormats.” The smaller versions are often called “placemats.”

The vast majority of Fluke are caught in just four states: North Carolina, Virginia, Rhode Island, and New Jersey. Landings of Fluke have decreased nationally every year since 2012.

The Japanese like Fluke so much, that they have this fish shipped live all the way from the mid-Atlantic. There, it’s called Hirame and it’s eaten raw as sashimi.

Fish that hang around on the seafloor, the way Flounder do, are called demersal fish. This term, which describes their behavior, comes from the Latin word “demergere” which means to sink.

Most of the Fluke that are caught by inshore anglers are female since the male Fluke spend most of their time offshore.

Eating Fluke and Flounder

At the top of this article, I mentioned just a little about the edibility of these fish. Let me go a little further into the tasty world of flatfish. Summer Flounder (fluke) not only have nice, mild meat, but they also have edible skin. That’s one less preparation step! You can get them already fileted if you want or pick one up whole if you haven’t caught it yourself. The flesh of this flounder is very delicate and flakey.

Eating Summer Flounder will give you some Omega-3s, a ton of protein, and a fair amount of sodium and cholesterol. The seafood site Fish Choice recommends eating fluke only once a month and not serving it to kids under five. Both fluke and flounder are relatively free from some of the nasty parasites that infect other types of fish but can be affected by environmental contaminants. The main one is PCBs. Although PCBs were banned back in the ’70s, this chemical sticks around for a long time, especially at the bottoms of lakes, rivers, and coastlines. They’re bad for anyone to consume, but especially for young children. You can still enjoy eating this delicious fish, just try to keep it to a serving a month.

Whether you broil them in lemon butter, fry them with potatoes, or bake them with parmesan, flounder are delicious. So, next time you pull one into the boat, consider inviting it to dinner!

Continue reading: Difference Between Largemouth and Smallmouth Bass