is this a clam?

[excell007]

I saw this in a hole in the live rock this morning and put it on top, it looks like a clam. Last addition to the tank are 5 frags, but I dipped and inspect them for hitchhikers.
Sorry for the fuzzy picture, phone camera can't focus very well on it. Right now it's a little over haft an inch long and quarter inch thick.

 

[SHNICI]

it look like clam.
Have on mind, if the clams are closed during the dip, you can't do anything on them, they will be fine.

 

[vetteguy53081]

these are common on live rock and represents a clam but better known as bivalves which are closer to a scallop and filters the water for food and are short lived in captivity several months)

 

[excell007]

Thanks for the replies. I wonder where they came from, cause the tank and the rocks are more than 15 years old, this is the first time I saw one on this tank. I am glad it's not one of those bad hitchhikers.

 

[SHNICI]

Thanks for the replies. I wonder where they came from, cause the tank and the rocks are more than 15 years old, this is the first time I saw one on this tank. I am glad it's not one of those bad hitchhikers.

probably from frag or from LR, and probably it's been small and it grow in your system. You can introduce it easy from everywhere and notice it now (if it's been hiding like usually do till yet.