Observation

Delicious Fun Facts from the Sea: About Clams

In this "Let’s Look" section, we will learn about clams. What kind of creature is a clam? Let's find out with Kahaku Expert.

What You’ll Learn in “Let's Look”

What are clams' relatives?
About the clam's body

Today's theme is "clams."

Hmm...

You don't seem very interested... Well then, how about we start with a simple quiz?

A quiz? Alright, I'm in.

Great.
Before we start the quiz, I have a question for you. Did you know clams are part of a group of shellfish that live in the sea?

Of course, I know that.

Right, of course you do...
Well then, out of all these sea shells, which ones are related to clams?

That's a piece of cake! This one and this one!

Hmm, but are those really clams?

Good question, you're thinking carefully! These shells look a little different from clams, but since they have two shells, they belong to the same group called “bivalves” as clams do.

So, you count the number of shells?

The shells we saw earlier can be divided into two groups: "bivalves" with two shells, and "gastropods" with a spiral shell.

I see.

Are you starting to get a little interested now?
Did you know clams have a front and a back?

No way. I've never heard of that before. They don't have faces, so I don't get it.

Well, let me show you how to find the front and back. Here's the key point.

This part isn't the face, right?

No, no! This raised part is called the “umbo,” and the front and back are decided based on it. Look at this diagram.

The side where the shell is shorter from the umbo is the front, and the longer side is the back.

Interesting.

And there's also a belly and a back. It might be easier to imagine because the belly side is where the shell opens.

Yeah, I see.

Once you know the front and back, and the belly and back, you can distinguish the right and left shell halves.

I had no idea!

Even many adults don't know this!

Next, let's take a look at the clam's body. Have you ever seen inside a shell before?

When I drank clam miso soup, I saw some whitish lumps, but I didn't really look closely. I think I remember seeing two little black things that looked like eyes.

Those whitish lumps are the clam's body. Are the two black things its eyes? Let's find out together.

Okay!

This is a canned clam. It's a clam with the shell removed.

Yeah, I've seen these before.

Are these two black parts the "eyes" we were talking about earlier?

That's it.

Actually, these parts are where the clam takes in and pushes out seawater. The side where seawater comes in is called the "inhalant siphon," and the side where it goes out is called the "exhalant siphon."

So it wasn't an eye after all!

Nope, clams (bivalves) don't have eyes.

Oh, they don't have eyes!

The clam sticks these two siphons outside the shell to take in plankton food along with seawater, and to push out waste outside the shell.

Interesting.

Now, it's time for the "Let’s Think" section. Here comes a quiz about shells!

Okay!

What You Learned in "Let's Look"

Clams belong to the “bivalve” group.
Clams have a front and back, and a right and left side.
Clams don't have eyes.
They take in food through their siphons.