Identify Green Things - Please

[sharkbite]

My 10 gal tank is about a month old with about 7 lbs of live rock. About two weeks ago I spotted the green thing in the picture slowly moving around the rocks. I am concerned about the proliferation as there are now 7 that I can see. I do not know what they are or if they are good or bad.
Help Please !!!

 

[sharkbite]

Here is another pic.

 

[attml]

A little tough to tell from the pictures but possibly a Keyhole Limpet? Does it look like this? If so exercise caution they occasionally snack on corals!

 

[sharkbite]

They do look like that. Thanks I will do some more studying on Limpets. I don't have any coral. Any other suggestions on containment or should I not be concerned?

 

[*bta*]

Lift one up! look at its inside because it could very well be the offspring of your snails, mine reproduced they have the same shells as your first post and on the other side they have the snail body..

 

[sharkbite]

From reading other threads it seems they aren't too bad. I will let them alone for a while.
Thanks everyone.