What are these?

[Michaelrisucci]

Hey guys, I got a shipment from reef cleaners yesterday and a bunch of my Astrea and turbo snails have these mollusks attached to their shells. They seem to camouflage with each snail’s shell. My guess is limpets. Can anyone confirm?

 

[EricR]

First one looks to me like what people call hoof snail, which is similar to a limpet.
Last one looks more like an actual limpet to me.
***can't tell really well from the pictures but those are my guesses

 

[ISpeakForTheSeas]

Yeah, looks like either a Slipper Limpet (genus Crepidula) or a Hoof Snail (taxonomic family Hipponicidae) - both are harmless; slipper snails are filter feeders, and hoof snails feed by extending a long proboscis (think like an elephant's trunk) to eat either their host snail's waste or any food it can reach from its host's back.