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Are Mermaids Mammals Or Fish?

Are mermaids mammals or fish as one of the biggest questions you could ask. This question might seem a little silly on its surface, but once you dig in deep this question lets us take a closer look at some deep scientific problems.

As it turns out, mermaids can be both mammals and fish at the same time while also being neither. We’re going to get deep exploring the scientific realities of this mythological creature.

Keep in mind that there are a lot of different types of mermaid legends out there which range from ancient Syrian goddesses to contemporary cartoons.

This means that there are some mermaids that are definitely going to be fish and other mermaids that are definitely going to be mammals.

The fact that there are so many different types of mermaids out there only makes this question more interesting because it gives us a wider range of types of mermaids to consider.

The question of “are mermaids mammals or fish” blends together some of the most interesting parts of human mythology and scientific study.

We could test the limits of our understanding of the creatures we share the natural world with while also looking at myth making and how we make sense of the world. Let’s dive in by first looking at the case for mermaids being a mammal.

The Case For A Mermaid Being A Mammal!

Let’s start off with what could be the easy one and describe the ways in which a mermaid could probably be a mammal. Why is this one of the easiest options of the two?

Well, it all comes down to the surprising ways in which mermaids are depicted as being very similar to mammals—and even similar to humans in particular.

The fact that the most popular depictions of mermaids have them being essentially human with the lower body of a fish make some mammals and some of the most important ways.

In order for something to be classified as a mammal, it needs to meet a few specific criteria. These can include having hair or fur, being warm-blooded, giving birth to live young rather than eggs, and having mammary glands.

Most mammals share all of these traits or at the very least have a majority of them. It would seem that most mermaids also share all of these traits.

There are, of course, mammals that are exceptions to these rules. The platypus, the echidna, and a few others are types of mammals known as monotremes that lay eggs.

There’s a good chance that a mermaid could be a mammal in the same way that a platypus is a mammal. They share most of the qualities that make mammals mammals, but have their own unique exceptions that make them a little different.

The Case For Mermaids Being Fish!

We’re going to start off the same way we did when trying to consider mermaids as mammals. It’s actually just as easy to classify mermaids as fish as it was to classify them as being mammals.

They share a lot of the same similarity to fish as they do with all the types of animals. All mermaids are half humans, and humans are decidedly mammals, mermaids are also half fish which definitely aren’t mammals.

Let’s start off by talking about what makes a fish a fish.

There’s a few things that almost all species of fish share in common and these can include the presence of scales, fins, a backbone, fish typically live in the water for their entire life cycle, and fish also have gills at every stage in their life cycle.

We can also say all of these things are true about mermaids.

Every depiction of mermaids has scales, fins, a backbone, and they live in water. The presence of gills throughout their entire life cycle is one of the biggest questions we have about mermaids.

There are definitely depictions of mermaids out there that have gills, but there are also some that don’t. This means that mermaids fit most of the criteria for being a fish, but not all of them just like they fit most of the criteria for being a mammal, but not all of those either.

Are Mermaids Mammals Or Fish?

You might have been able to guess where the answer to this question was going, but mermaids can be both fish and mammals.

It all depends on what type of mermaid we are talking about and the scientific classifications were looking at to study those mermaids. Let’s elaborate on this answer a little bit by talking about the science of taxonomy.

Taxonomy is a science used to categorize all of the different types of animals on this Earth. This is how we make categories for mammals, fish, and everything else that’s out there.

It’s important to note that taxonomy isn’t an exact science, but more like a useful framework. Most mammals are similar to each other and that helps us make important understandings about the world around us by looking at mammals as a group together.

If mermaids were real, they would be an entirely different type of animal that we would have to classify in the same way we approached the platypus we mentioned earlier.

The mermaid is a mammal that’s also kind of a fish or a fish that’s also kind of a mammal. It’s also a good example of convergent evolution which is a type of evolution where one species winds up very similar to an unrelated species.

In this way, mermaids are similar to dolphins and whales which are mammals that then evolved to have bodies that are very similar to the bodies of fish.


We’ve gone deep into the big question “are mermaids mammals,” but there’s still a lot deeper into this question you could go! The question about whether or not mermaids are mammals might seem silly on the surface, but it actually helps us to understand complicated scientific ideas like taxonomy and convergent evolution. Now it’s your turn to reason through these arguments about how mermaids could be mammals, fish, or something new all together.