ABSTRACT
Mutualism is also known in marine environments. Two encrusting sponges (Suberites rubrus and Suberites luridus) protect the queen scallop (Chlamys opercularis) from predation by a starfish, the common crossfish (Asterias rubens) (Pond 1992). They probably do so by making it difficult for the common crossfish to grip the scallop with their tube-like feet, and by excluding other organisms settling on the scallop, so hindering its mobility. The sponge benefits from the association by being afforded protection from the shell-less nudibranchgastropod predator Archidoris pseudoargus, and more generally by being carried to favourable locations.
