How does a shark find and catch its prey? Great white sharks are apex predators, at the top of the ocean food chain. Many sharks are most active and feeding at dawn, dusk and night. A shark finds a meal with its nose, its ears, a flow sense along its body, an electric sense and its eyes, and then it uses its body and teeth to catch it.

The first tool is the nose. Sharks have a very good sense of smell and are sometimes called swimming noses. A Florida Atlantic University study looked at the nose responses of sharks and their relatives. The best detection was about one part of scent in a billion parts of water. That is remarkably keen, but no better than the sense of smell of typical bony fishes.

The next tool is hearing. Sharks hear with ears inside the head, one on each side. They are most sensitive to low-pitched sounds, like those made by a struggling fish.

Sharks can pick up the sounds of fish splashing. Splashing makes low sounds like a struggling fish, which sharks can hear and may come to investigate. Donald Nelson and Samuel Gruber made synthetic sounds that imitated a struggling fish. They played them from an underwater speaker developed by the Navy. In the first tests, 22 sharks came to investigate the fake fish sounds.

Two more senses work close to the prey. The lateral line is a system of pores and canals that lets a shark sense movement and pressure changes in the water nearby. It helps the shark sense nearby prey. Sharks also use jelly-filled organs called ampullae of Lorenzini to sense the weak electric fields that other animals give off.

Then there are the eyes. Sharks have sharp eyesight, and their pupils open and close to control the light, as ours do. Many sharks have a mirror-like layer behind the retina called the tapetum. It helps them see in low light at dusk and night. Its full name is the tapetum lucidum, and a cat's eye has one too.

Colors help a hunter hide. Many sharks are dark on top and light underneath. This pattern, called countershading, helps hide them. A great white shark has a white belly and a gray or brown back.

A shark also needs a body that moves well. Its skin is covered with tiny tooth-like scales called denticles. They point toward the tail and reduce friction from the water as the shark swims. A shark's pectoral fins, the pair near the front of its body, give it lift as it swims. Sharks have no heavy bone. A light cartilage skeleton and a large liver full of low-density oil help them stay afloat. Many sharks must keep swimming to breathe: water is driven in through the mouth and over the gills, called ram ventilation. Some less active sharks, such as nurse sharks, can rest without swimming because they pump water over their gills.

Teeth do the catching. A shark loses teeth all its life and grows new ones to replace them. Sharks have many rows of teeth that are constantly replaced. Some species can go through about 30,000 teeth in a lifetime. White shark teeth are broad, triangular and serrated. Some sharks have flat, strong teeth for crushing hard-shelled animals such as shellfish. Tiger sharks have strong jaws and serrated teeth that can crack the shells of sea turtles.

Some sharks do not catch prey with their teeth. A whale shark's teeth are tiny and play little part in feeding. A basking shark feeds on zooplankton by holding its huge mouth open so that seawater flows over its gills, which strain the tiny animals out. It is a filter feeder. A whale shark swims with its mouth open and filters tiny food out of the water. It eats very small sea animals called plankton.

What a shark catches depends on the shark. A baby white shark is about 4 feet long when it is born, and as of November 2026 a great white shark can grow to about 20 feet long. Young white sharks eat bottom fish, smaller sharks, rays and schooling fish before they move on to seals, and adult great whites mostly hunt seals and sea lions. Tiger sharks eat almost anything, including fish, turtles, birds and even garbage. Sharks feed on sick and dying animals too. Each shark finds its meal with its senses and catches it with the body and teeth it has.

Words to know

• lateral: along the side
• ampullae: jelly-filled organs
• tapetum: eye mirror layer
• countershading: hiding colors
• serrated: with jagged edges