2 clam like object on this rock

[atraperegrinus]

picked up this rock at the lfs today.

i noticed when i got home, theres 2 shapes of what i thought was just rock, but they open and close when the rock is disturbed, are they some kind of clam or something?

i cant really get a better picture its the larger black open spot, and the larger white rock looking spot in the pics amisdt the yellow polyps.

small resized

high res picture
https://dl.dropboxusercontent.com/u/70013956/2015-08-25%2015.49.18.jpg

 

[Stevenliu9]

If you wave your hand over the rock, do you see any movement? most clams (even oysters) are sensitive to light and will shut their shells when the surrounding changes.

 

[atraperegrinus]

If you wave your hand over the rock, do you see any movement? most clams (even oysters) are sensitive to light and will shut their shells when the surrounding changes.

I havn't tried after putting in tank, but when I took them out of my acclimation container, Iseen them snap shut. I'll see if I can get diff pics tomorrow.

If it is, do I need to do anything special for them?

 

[atraperegrinus]

well i now know for sure they open and close.

i went to take a picture of the black one this morning, and it snapped shut when the light for the flash turned on.

u can see in this pic he was still slightly open
https://dl.dropboxusercontent.com/u/70013956/2015-08-26%2011.11.54.jpg


i cant get a decent pic of the white shell one.

excuse all the worms, they have been eating up all the dead stuff on the new rock lol

 

[Stevenliu9]

hard to tell, definitely doesn't look like any of the tridacnid clams that I have known, there is a slight chance it's a hippopus, or perhaps more like an oyster or mussel of some sort.

 

[Bent]

Am I blind? I don't see squat except some barnacles. Is that what you are talking about?

 

[atraperegrinus]

Am I blind? I don't see squat except some barnacles. Is that what you are talking about?

i have no idea what it is, that's why I'm asking, all i know is they are about 1" roughly in diameter, and open and close when u wave your hand by them or shine light on them.

they open up about 1/4 of an inch, maybe slightly more.

here, i circled them in red in this picture.

https://dl.dropboxusercontent.com/u/70013956/circleinred.jpg

its hard to see in the pictures, but in person, they clearly have a hinged edge, and a round edge the rest of the way around that they open.

 

[figuerres]

Looks like some oysters to me...

 

[Giovanni]

looks like some oysters to me...

+1

 

[Coralreefer1]

Small oysters and clam species often come accompanied on live rock as hitchhikers. They provide beneficial filtration by feeding on nitrates in your water.