Cleaner wrasse are fish that eat parasites off the skin of other fish. Both parties benefit from this relationship: the cleaner wrasse get food and the other fish get cleaned of parasites. As these data show, the addition or removal of a relatively small number of cleaner wrasse has a large impact on the biodiversity of fish living on coral reefs.
This information indicates that cleaner wrasse are best described as
O filter feeders
O keystone mutualists
O apparent competitors
O foundation species