Hermit crab at work

[Palinurus]

If a hermit crab spies a snail´s shell mostly it tests, if the new one may be better than the recent one. But this hermit has discovered, that the shell is covered with delicious algae. And so it´s turning the shell with his legs, scraping algae with his smaller claw, than looses and had to lean out considerably to get it again. Than clasps it again, heaves it up, continues scraping until a neighbour disturbes it.
When you observe the hermit crab scraping, it seems, it gets nothing, but it always puts something into his mouth, later you can see the traces of its work

[tyrano34]

Thank you for this topic, you know the name of the species?