Clam pest or predator?

[Faciosity]

I noticed that one of my Maximas wasn't open as big as it should be so I looked at it very closely and noticed 6 or 7 tiny long spiral white snails sitting very closely under the mantle. I then checked the other clam and found about the same amount even though there was no symptoms on the second clam. What are they? I got rid of every tiny one I could find. Here is a couple pics of them in a bowl. I know the pictures suck, but it gives reference to the size and shape.

 

[Faciosity]

Opened fully after removal of the snails. Could it be more of a nuisance irritation rather than a real danger? They didn't seem to even be touching or harming the mantle, just chillin' under it for some shade.

 

[returnofsid]

Pyramallid snails. They're more than a nuisance and can become a real danger, but you've found them quick. Check both clams, and you'll be busy inspecting daily, or every other day. They've likely laid egg clusters which are tiny and easy to miss. You'll need to inspect and remove, as the snails grow. Use a toothbrush to clean the shell really well. Magnifying glass helps also. These snails are very tiny and easy to miss.

 

[Faciosity]

Just found about ten more for a total of about 20+. Will check frequently and do my best to remove them. If I keep them off of the clams will they die off and go away, or just live somewhere else and reappear once I stop checking daily? The clams are both attached to the same medium sized rock, after I'm sure they don't have any more snails on them, should I move the rock?

Pyramallid snails. They're more than a nuisance and can become a real danger, but you've found them quick. Check both clams, and you'll be busy inspecting daily, or every other day. They've likely laid egg clusters which are tiny and easy to miss. You'll need to inspect and remove, as the snails grow. Use a toothbrush to clean the shell really well. Magnifying glass helps also. These snails are very tiny and easy to miss.

 

[returnofsid]

Moving the rock won't do any good. Any of the snails that are in your tank, will be on your clams. Here's some really good reading about them.
http://reefkeeping.com/issues/2008-02/nftt/index.php
http://www.wetwebmedia.com/pestsnailfaqs.htm

 

[Reefreak]

A six line wrasse will help at cleaning them up as well.

 

[saltwaterfishes]

I had these pyramid snails attacked my astrea snails. Didn't know why my astrea snails kept on dying, then found a bunch pyramid snails underneath. Removed as much of the pyramid snails that I can see, bought a leopard wrasse....haven't seen any pyramid snails ever since.