How do clams move about if they have no arms, no legs and no fins?

We've been very busy going back to school and then going on a short holiday, so we've got a bit behind with our questions. We have a bit of a list so I'll be posting them over the next few days.

Today, it's all about clams.

In Spain we eat a lot of clams and a lot of mussels. My younger cousin Inés (who doesn't live in Spain anymore but in Edinburgh, absolutely loves mussels). So I have had a lot of time to look at this type of seafood and wonder about things. 

The first question for my blog I thought of was Do clams have eyes? but then, immediately after, I came up with a better one:

How do clams swim or move about in the water if they have no arms or fins?

I think the second question is more interesting because the answer is more incredible, but we did look up the answer to the first and we discovered that, as we had thought, clams have no eyes. They do have light sensors though, and react to changes in light, so I suppose that's kind of like seeing a bit. 

When we thought about the second question about how clams moved around, we came up with a few different ideas. My mother said maybe they used the air from opening up and closing, opening and closing, to move about by propulsion. So every time they let the air out and caused bubbles, they moved a tiny bit. My father said the tides were probably the main force that made clams move. I thought they might both be right. But when we went to have a look and discover whether we were right or not, we found out something amazing! Clams and mussels have feet! Well, a 'foot', that looks more like a tongue really. Would you like to see a clam moving about with its foot? 

Take a look: 

   

We also found this other video of a clam using its foot to bury itself and protect itself from a ray:

Isn't that fascinating?