Discussion in 'ID This!' started by Mr. Bill, Jan 27, 2013.
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Not advisable but have you tried touching the texture of it?
Actually, no. I have thought about it, but I'm afraid of injuring it. It's much, much smaller in real life, barely the size of a #2 pencil eraser.
Yup, it's a fissurellid, a member of the keyhole limpet family (not to be confused with a lot of other flat shells that are called limpets). It probably feeds on cryptic sponges and microorganisms on your rocks. It's not really flattening itself, that's an optical illusion. When it extends the mantle from under the shell, it makes it look different than when the animal is completely withdrawn and tucked down against the rock. I don't see a hole at the top, like most members of the family, but the first pic looks like it may have a small opening at the bottom front, which would make it an Emarginula species. Some of them have no openings at all, but they still pretty much behave the same (and are essentially harmless).
Thank you, Don. I greatly appreciate your expertise.
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