Rec-Rec are fishlike plankton that feed on sound waves.

They absorb sound waves transmitted through water and use them as a form of nutrition. The sound waves that the Rec-Rec eat are then stored inside their bodies until they have been digested. Once the digestion process is complete, they play back the sounds in perfect four-second intervals. While these sounds are playfully emitted, wave patterns can be seen pulsating on their bodies. Rec-Rec always swim side by side in schools of four. When they swim at different speeds, the frequency with which they emit sounds also changes.