Looking inside the darkness of the grotto one may find there various sea gherkins, for example, Holothuria sanctori, that differs from the Holothuria forskalii (I wrote last year about) by papula lacking white ends and absence of habit defending itself by ejecting adhesive tubules of Cuvier.
An orange leave at the background could not be identified yet, though there is a suspicion, that it might be some kind of Turbellaria.