The Blacktip Reef shark (Carcharhinus melanopterus), found in Hawaii's coral reefs, isn't native to Hawai'i. It can be easily spotted because of its black-tipped dorsal fin. The backtip shark eats reef fish, mainly surgeon fish and mullet, and can grow up to six feet long. It has been seen hunting in small groups during the day, but it generally eats alone. Its teeth are long and thin. It can be dangerous to waders and divers, but it is not very aggressive. It can be found in shallow waters.