Mollusk?

[Jimbo Bucket]

I found this critter on the bottom of a large frag plug/plate. I popped it off, took the picture and through it back in. It's now on the sand bed. That frag had been in the tank for 2.5yrs so if can't be that bad can it (famous last words)?

 

[tupes]

I would put it back in where you can see it good. Have you ever seen it open? Probably a mussel and filter feeder. Itll filter the water through it.

 

[tupes]

Here is an example.

 

[mtfish]

Could be a flat tree oyster. Whatever it is looks like a harmless bivalve.

 

[Jimbo Bucket]

I would put it back in where you can see it good. Have you ever seen it open? Probably a mussel and filter feeder. Itll filter the water through it.

I only saw it that one day. Now its been blown out of sight. But it wasn't open while I was able to see it.

 

[saltyfilmfolks]

Mussel. I have several that look very similar. Mine are black or dark blue like the tips on yours and the largest got to 6+inches had it about 7!years. The smalles one at 1in and mostly kinda clear.