Stupid cleaner shrimp...

[Delphinus]

I'm afraid I have to report I have witnessed my cleaners eating Stomatella snails. I long suspected that something was eating them because they are always WAY more numerous in my fugia or my sumps or in spaces inaccessible to larger creatures, but I did finally one day find a cleaner shrimp going nuts on something, and on closer inspection I realized what he was eating.

Those shrimp are literally just empty stomachs with an exoskeleton.

Stomatella reproduce fairly freely in aquaria though, so as long as you have a place where they can live out without being predated into psuedo-extinction in your tank then at least you can have THOSE areas kept clean by the snails (if not the other areas).