Original: The pilot fish congregates around sharks, rays, and sea turtles, where it eats ectoparasites on and leftovers around the host species; younger pilot fish are usually associated with jellyfish and drifting seaweeds.
Simplified: Pilot fish usually gather around sharks (as well as rays and sea turtles). When pilot fish are young, they gather around jellyfish and drifting seaweeds.