There are over 340 known varieties of sharks in the world today. Scientists classify these into eight distinct groups:

• Squatiniformes (flat body, mouth at front, no anal fin) - angelsharks, monkfish
• Pristiophoriformes (long snout, mouth underneath, no anal fin) - sawsharks
• Squaliformes (short snout, mouth underneath, no anal fin) - dogfish and cookiecutter sharks
• Carcharhiniformes (anal fin, 5 gill slits, 2 dorsal fins, no fin spines, mouth behind the eyes, nictitating eyelids) - ground sharks, including catsharks, swellsharks, shysharks, houndsharks, weasel sharks, requiem and hammerhead sharks
• Lamniformes (anal fin, 5 gill slits, 2 dorsal fins, no fin spines, mouth behind the eyes, no nictitating eyelids) - mackerel sharks, including the basking, goblin, megamouth, great white, crocodile shark, thresher, porbeagles, mackerel sharks, sandtiger, and mako sharks
• Orectolobiformes (anal fin, 5 gill slits, 2 dorsal fins, no fin spines, mouth in front of the eyes) - carpet sharks including the wobbegong, nurse, bamboosharks, blind, zebra, and whale shark
• Heterodontiformes (anal fin, 5 gill slits, 2 dorsal fins, dorsal fin spines) - bullhead, horn sharks
• Hexanchiformes (anal fin, 6-7 gills, 1 dorsal fin) - frilled and cow sharks - having six or seven gills on each side of the head.