Some kind of bivalve? Spawning.

[mc-nuggs]

I've seen these filter feeders on some live rock from Florida, but I don't know exactly what they are. They have large shells with tiny holes, and I'm pretty sure they have two distinct shells. They are about the same size and shape as a walnut shell.

I noticed 2 of them squirting a stream of cloudy white stuff in my tank just now, immediately after I added marine vitamins to the tank.

All suggestions welcome.

 

[Timfish]

Maybe a jewel box clam? Those are pretty common on florida maricultured rock. They definitely will spawn in aquaria and providing filtration doesn't remove them (no skimmers, filter pads) the larva can survive and settle out and grow.

Creating your own bivalve bliss: Are you interested in keeping clams?

Since title of thread says bivalve here's a picture of a bivalve hitchhiker I've had for 4 years now, as well as my 1 and only Maxima.

www.reef2reef.com