Something on live rock

[Guynamedfish]

I was wondering what this is it looks like a little clam I don’t know here’s the picture

 

[Nate Chalk]

Cyano bacteria

 

[Nate Chalk]

Green algae

 

[Nate Chalk]

Diatoms

 

[ISpeakForTheSeas]

If you're meaning the spiny thing on the underside of the rock, my guess would be for a thorny oyster (Spondylus genus - assuming your live rock is from the US east coast, possibly Spondylus americanus).

 

[Goaway]

If you're meaning the spiny thing on the underside of the rock, my guess would be for a thorny oyster (Spondylus genus - assuming your live rock is from the US east coast, possibly Spondylus americanus).

This. Or ball sponge. Yes, they can throw out them spikes.