In fact, such is the level of trust between the animals that pilot fish are even known to enter their shark's mouth to nibble away food debris.
The bonds shared by those predators and their diminutive pilot fish posses has been a source of fascination for ages. A book about sailing published in 1832 even remarked about what appeared to be a sense of loyalty between them:
"The beautiful little fish called the pilot-fish, which always accompanies the shark, has been known to follow a ship for six weeks after the shark to which it belonged was taken!"
Chances are better than not that the fish weren't acting out of concern, however. Pilot fish are known to swim along with other things bigger than them, like manta rays, sea turtles, and even the occasional boat. But when it comes to making powerful friends, nothing beats a shark.