What Kind of Fish is Flounder? (The Little Mermaid)

Over time fans came up with many theories for the species of Ariel’s yellow fish friend. But what kind of fish is Flounder from The Little Mermaid really?

Your first thought might be that he is a flounder – why else would he have that name? But looks pretty much like the exact opposite of a real flounder. So I did a bit of research to find out which species he really belongs to:

Flounder from The Little Mermaid is a sergeant major as it was verified by the 2023 live-action movie: he has a yellow-blueish color and vertical stripes. Contrary to popular belief, Flounder is not a real flounder and also not a guppy.

So let’s have a closer look at the sergeant major and other similar fishes as well examine the reasons why Flounder definitely is not a flounder or guppy.

Flounder is a Sergeant Major

Disney did not specify what kind of fish flounder is. Up until now, we couldn’t even be sure if Flounder was even based on a real fish species. But the new live-action movie shows him as that: a sergeant major.

In this image, you can see that Flounder has five black vertical stripes, a yellow back and a blueish tint in the new live-action movie. Those are the same features that sergeant major fishes have:

The sergeant major even has the same body shape and size as well as the same kind of fins. It seems that Flounder really was inspired by a fish species that is actually out there.

Sergent majors live in the Atlantic Ocean but have also been spotted in the Mediterranean Sea, where The Little Mermaid takes place.

They owe their names to their stripes (known as bars) as they look similar to the insignia of a military sergeant major.

These cute fish can get up to 9 inches long (22.9 cm).

But why do some people still think that Flounder is a guppy, a flounder or some other tropical fish? Let me explain.


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Why do people think that Flounder is a Guppy?

Guppy does not look like flounder
Guppies look very different compared to Flounder – and they are tiny.

Some people do however think that Flounder is a guppy. But is that even possible?

Flounder is not a guppy because he is not that small and he has stripes, which guppies do not have. Guppies are tiny fish, they only grow 0.6–2.4 inches long (1.5–6 cm). If Flounder was the size of a guppy he would be as small as Ariel’s pinky or even smaller!

The idea that Flounder might be a guppy probably came up because Ariel calls him a guppy in the movie. When she sneaks to the sunken ship on the ground of the ocean to see if she can find some human treasures, she takes Flounder with her.

But he is scared and tells Ariel there might be sharks around. Ariel replies saying “Flounder, don’t be such a guppy“.

You can click on the video to watch that scene (at 0:18 min).


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Flounder replies “I’m not a guppy!”. Why would he say that if he were a guppy? I mean, you wouldn’t say “I’m not a human” either would you (unless you’re a mermaid)?

The word “guppy” seems to be more of a metaphorical word for someone who is scared. Basically like the underwater version of a “scaredy-cat”. Because of how tiny guppies are, it might also refer to small baby fish, which would result in a meaning similar to “don’t be such a baby“.

Guppies are tiny fish, that are often held as pets. They are also called millionfish or rainbow fish and live in tropical regions all over the world. Since they are so tiny and are quick to hide, Disney might have made that meaning up.

Why Flounder is Definitely Not a Flounder

A real flounder is pretty much the opposite of Flounder.

Real flounders are a flatfish species that have evolved to live at the bottom of oceans and sometimes even rivers. There they camouflage themselves with their brown muddy color that looks just like the ocean floor.

As you can see, they have a completely different appearance compared to Ariel’s friend Flounder. Most importantly, they are not colorful.

Their eyes are also different than in most other fish. They are both on one side of their face – the side that faces upwards, so they can see what is happening above them.

Why is Flounder called Flounder if he is not a flounder?

There is only one explanation for how Flounder got his name: it doesn’t have anything to do with his biological fish family but with his character.

The word to flounder” means to be clumsy in the water (or mud) or to move awkwardly as well as to be in a difficult situation or struggle with something as if you lost your balance for a while.

You can literally say “Flounder floundered around in the water” which would basically mean that Flounder is a pretty clumsy fish, even in the water.

This name actually fits his anxious character quite well. He gets scared easily. For example in the scene where he and Ariel sneak into the shipwreck, he is very worried that there might be a shark around.

Furthermore, he is very clumsy indeed! In the same scene, he gets stuck in the ship’s bull’s-eye, then he gets scared by a skeleton and jumps against the walls of the ship making the wood fall down. When the shark is after him, he then bumps his head on a pole.

You can watch the video again to see what I mean. He is basically a cute fish in a china shop. So his name actually makes a lot of sense after all.

Which other fish look similar to Flounder?

There are a few more fish species that look similar to the original Flounder from the cartoon version. Flounder is a round, bright yellow fish with blue stripes and fins. Intense colors like that can generally be found in tropical fish.

Some examples are certain tangs and angelfish. Let’s have a look at them as well.

The Hawaiian Tang and Convict Tang

Flounder’s most prominent features are his bright yellow color and his stripes. These features can be found in the yellow and the convict tang.

The yellow Hawaiian tang has an intense yellow color like Flounder.

The yellow Hawaiian tang has one of the prettiest yellow colors in the ocean, which looks very much like Flounder’s color.

They can reach about 8 inches (20,3 cm) in length.

The only problem is that the yellow tangs don’t have any blue strips like Flounder.

The convict tang is a relative of the yellow tang and they actually have stripes – just like a convict’s clothes:

The stripes do in fact look very similar to Flounder’s because they are vertical and they start at the top and don’t reach all the way down to their bellies.

They can grow up to about 8 inches long (20,3 cm).

The only thing that doesn’t really fit is the distribution of the stripes over the body. The fins and face shape look different too when you compare them to Flounder from the live-action movie.

The Royal Angelfish and Emperor Angelfish

Another kind of tropical fish that looks very similar to Flounder is the angelfish. There are two species in particular, that might just be his siblings – two very royal siblings that is: the royal angelfish and the emperor angelfish.

The royal angelfish is yellow with blue stripes – just like Flounder.

The royal angelfish (also called regal angelfish) looks strikingly similar to Flounder. They have an intense yellow color with blue and gray vertical stripes.

They can grow up to 10 inches (25,4 cm) long.

If they had fewer and no gray stripes and all fins were blue, they would be pretty much indistinguishable. At least color and pattern-wise.

But what about the body and face shape? The before-mentioned fish all don’t quite capture the cute expression that Flounder has. But there is one fish that has just that: the emperor angelfish.

The emperor angelfish has a similar body and head shape as Flounder.

The emperor angelfish has the same cute baby face as Flounder. It also has the same yellow color as the yellow tang and the royal angelfish, but it has horizontal instead of vertical stripes. Flounder’s stripes are vertical though.

They can get quite big, the adults are about 15 inches (38,1 cm) in length. So size-wise this species might be a bit too big in comparison to Ariel. But we know that Flounder is actually still a child in the first movie because in the second The Little Mermaid movie he is much bigger. So, who knows.


As explained, Flounder seems to be a sergeant major. But there are also some other colorful tropical fish that share similarities with Ariels’ cute friend as well. He is definitely not a flounder or a guppy though.

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