Grouper

Groupers are large fish of the perch type. They are genera in the subfamily Epinephelinae.
Groupers and the sea basses are in the family Serranidae. Most groupers are in one of two large genera: "Epinephelus" and "Mycteroperca". Also, species in the small genera "Anyperidon", "Cromileptes", "Dermatolepis", "Gracila", "Saloptia", and "Triso" are also called groupers. Fish in the genus "Plectropomus" are referred to as coral groupers. These genera are all in the subfamily Epiphelinae. 
Sometimes other fish have common names with the word "grouper". Nonetheless, "grouper" on its own is usually taken to mean the subfamily Epinephelinae.
Groupers and octopuses often work together to catch prey on coral reefs.