This paper summarizes research done as part of the Grouper Moon Project to understand sound made by several species of grouper. Many fishes produce calls during spawning that aid in species and mate recognition. When multiple sound-producing species inhabit an area, the detection range may decrease and limit call function. Acoustic partitioning, the separation of calls in time, space, or spectral frequency, can minimize interference among species and provide information about fish behavior and ecology, including possible response to increasing anthropogenic noise. The authors investigated acoustic partitioning among 4 sound-producing epinephelids, Nassau Grouper Red Hind, Black Grouper, and Yellowfin Grouper, using passive acoustic data collected at the mass spawning aggregation site on the west end of Little Cayman in the Cayman Islands during the spawning seasons of 2015 to 2017. Results indicate separation in space and time between species calls, which aids in acoustic partitioning. When this separation did not occur, unique call structures were present, which may aid in effective intraspecies communication.