Thanks for sharing .While many of the smaller hermit species are found intertidally, rocky shores and sand flats, the reefs do have a number of hermit crab species of different sizes.
The one most encountered by reef hobbyists for cleaning up algae is the relatively small 'Scarlet Reef Hermit Crab' (Paguristes cadenati). As the name suggests, it is found on coral reefs in the Caribbean.
I was led to believe for years that hermit crabs were not from reefs themselves but close by .
Interesting to know that was not 100% true