orange mollusk?

[yaksplat]

Anyone know what these are? I have 2 of them in my tank.
I don't know what they are, but they look pretty neat.

[scuba_steve]

those are cool think they need alot of food though

[reefrunner69]

How many siphons do they have? Could be a univalve probably a hitchiker bivalve. Clam more than likely.

[yaksplat]

i'm not sure if they're alive, there's no movement

[ImLookinForNemo]

See those little red roundish/oval things on the rock in the background of the pic? I have those on my rock too-what are they?