weird thing in LR

[erg59541]

I found this thing in my boyfriends tank and it pokes out of the live rock about a half of an inch and when you look at it closely it seems to get scared and hide quickly. the top part or what you can see when the thing is tuked inside its hole is kindove almond shaped and when it comes out the pointy end opens up with a V shaped opening.
Anyone know what this might be?

 

[iwantacans]

boring clam of some sort?

 

[erg59541]

hmmm never thought of that.....do clams close up really quickly when they get scared?

 

[iwantacans]

yup

 

[erg59541]

cool, well i think i might still take it to the fish store and see what they have to say about it.