noun, plural (especially collectively) pi·lot·fish, (especially referring to two or more kinds or species) pi·lot·fish·es.
Examples from the Web for pilot-fish
There are other curious things about these pilot-fish that naturalists cannot explain.
He was made to stick to the skipper as though he were of some use—as the pilot-fish, they say, is to the whale.End of the Tether|Joseph Conrad
The law which doomed him to be the humble attendant of stronger spirits resembled the law which binds the pilot-fish to the shark.Critical and Historical Essays, Volume III (of 3)|Thomas Babington Macaulay
One paper likened him to the pilot-fish, which guides the shark to his prey.Andersonville, Volume 2|John McElroy
Still, you know Moggridge has taken care that the bait carefully conceals the snare within, and the pilot-fish are none the wiser.The White Squall|John Conroy Hutcheson