|Hairy hermit in Nerite shell|
The shell is one I bought in the aquarium supply store. It comes from a fresh- or brackish-water snail. I think this one is from Indonesia. New, it was deep red with black spots, but a year or so in the tank has leached out much of its colour.
Hermits occasionally decide to use the shell, but soon discard it in favour of one of the usual mud snail, periwinkle, or whelk shells. "Shop locally," is their motto.