ID please, (you're amazing if you know what it is)

[dempseyjosh]

ok, so i just noticed this tucked into a crevice a rock. for about a week i thought it was a shell stuck in the rock, but then i saw it close suddenly. i haven't seen anything come out if it, but if i move too quickly when i'm close to the tank, or a crab gets to close, it quickly closes. any idea what it might be without actually seeing something come out of it?

 

[reefforbrains]

Burrowing clam.
Do I get a prize?

 

[cranberry]

+1
I'm just runner up amazing

 

[dempseyjosh]

well i guess it wasn't that hard. i've seen clam shells stuck in rock before, but not a live one. i was expecting something to come out of that but couldn't imagine what it could possibly be.

 

[mr.clownfish]

well what do they win?

 

[dempseyjosh]

it doesn't say you win a prize if you know what it is, it says you are amazing.
but.... how about a cookie?

 

[katsafados]

Got milk?

 

[mr.clownfish]

awww i want some now!!