Echinoderms use pheromones to communicate with each other, and ascothoracican barnacles attach to echinoderms or corals. Given these facts, corals use what to communicate with each other among the following options:
- Energy
 - pheromones
 - kinetic energy
 - produce light
 - heat produced
 - heat energy
 - Chemical energy
 - sound


 

  pheromones       