Sizing Up Sharks,the Lords of the Sea

This slow-moving, filter-feeding shark is the largest known fish species alive.

A wide head helps these sharks scan for and pin down rays and other prey.

This legendary predator lives in coastal surface waters worldwide. Its serrated teeth may be a link to extinct ancestors.

Scientists suspect that this slow-growing Arctic species can live up to a hundred years.

This shark is named for its distinct black stripes, which fade in adulthood.

Sharks typically have five gills, but this primitive species has six. Most related species are extinct.

Due to high demand for shark fin soup, these large-finned sharks are in decline.

With flat bodies and broad pectoral fins, angel sharks resemble rays and skates.

Its long, toothy snout helps it sift sand for prey but can get snared in gill nets.

These bottom-feeders live in darkness, at depths greater than all other sharks.

This solitary shark uses its horned head to crack open mollusks and crustaceans.

Bioluminescent organs make these tiny sharks glow in the dark, attracting prey.

A seven-inch fossil tooth of this extinct shark was used to project the scale of its massive body, which would have included jaws more than six feet wide.