Mycteroperca bonaci, the black grouper, black rockfish or marbled rockfish, is a species of marine ray-finned fish, a grouper from the subfamily Epinephelinae which is part of the family Serranidae, which also includes the anthias and sea basses. Other fish are sometimes called the black grouper including the similar gag grouper (Mycteroperca microlepis), the misty grouper (Hyporthodus mystacinus), and the critically endangered Warsaw grouper (Epinephelus nigritus). This species is found in the western Atlantic Ocean from the northeastern United States to Brazil.