Giant grouper (Alfred Diem / CC BY)

Groupers (Epinephelinae) have stout bodies, large heads, and mouths with jutting lower jaws. They have strong tooth plates that are well adapted for crushing prey. Most grouper species carry spines along the front part of their dorsal fins. Some species (giant grouper, potato grouper) reach 2 meters (6.5 feet) in length. Groupers are usually not aggressive. However, at places where divers regularly feed fish, larger grouper species have been reported to bite.

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This supplemental online resource accompanies the book Scuba Diving Hand Signals by Lars Behnke, available on Amazon.