Groupers (Serranidae is the family) are predators that eat invertebrates and other fish, generally hunting in the daytime.  These fish can grow quite large (hundreds of pounds) and can live for several decades.  Groupers are also highly prized for food and are caught on a hook and line, by spearfishing or using fishpots. They can  be grown for food using mariculture techniques, especially in SE Asia but do not reproduce in captivity which means the juveniles must be captured.  Groupers take their common name from the fact that they "group" together in large numbers to reproduce!  Unfortunately this aggregation means that they are easy prey for fishermen and so their numbers can easily be depleted.  They have been heavily overfished in many places including Bermuda.  Two species of groupers, the jewfish and the Nassau Grouper, are now candidates for the U.S. Endangered Species list.  This particular individual is a Spotted Grouper.