Mussel therapy?

[Lokipsl]

So it seems I have a pretty decent size mussel that hitchhiked his way on this zoa rock. It’s pretty active and I’m pretty sure it was going through some kind of reproduction phase last night as it was shooting small uniform bits out of its opening. I put the white lights on to get a good shot of it but it closed up pretty fast. Any info on this thing? Should I let him hang out for the time being or frag Zoas of the shell and chuck this guy? Any thoughts would be appreciated

 

[Lokipsl]

Shot of it opened.

 

[Maritimer]

Mussels aren't harmful ... they're plankton feeders. The bits you saw coming out may have been poop - if it'd been spawn, it probably would have just looked cloudy. These guys don't often live terribly long in our tanks, as it seems difficult to keep the suspended foods they need in the water column without nitrates going through the roof.

If it dies - your fish get a snack, and your zoanthids live on an empty shell.

~B.

 

[Staghorn]

I got one of those like 18 years ago on some live rock. It lived for like a year, at that point I was feeding everything I could find because I had a crocea clam that everyone told me I had to constantly feed. I also had a goniopra stokesi in that aquarium that lived for years before I crashed the tank eventually.