I noticed after placing new shells into my tank that I had a few pregnant hermits. Their "soft" parts that they keep inside the shell were covered with tiny red eggs. It's now many months later and I have no baby hermits (okay, so if I do then they are WAY tiny and haven't emerged at all!). The eggs prolly became food for the rest of the tank.
Marlin: Okay, a mollusk walks up to this sea cucumber, well he doesn't actually walk, he's just there, and he turns to the sea cucumber, and... Well, wait, there's a mollusk and a sea cucumber and...
Chum: You know for a clown fish, he's not that funny.