Biodiversity
Brain
EntomOLogy
Genetics
Marine BiOLogy
MicrobiOLogy
PaleontOLogy
ZoOLogy
AnthropOLogy
ArchaeOLogy
Astronomy
Climate Change
Earth
Physics
Water
Talking Underwater
Like bats, dolphins rely mainly on echolocation to navigate and find prey. Echolocation is the ability to use the echoes of sound waves to locate distant objects. Dolphins emit a series of clicks from their nasal cavities, just below their blowholes. These clicks are sent out through the melon, a fatty structure in the dolphin's forehead. The melon helps focus the sound waves into a beam, directing them forward. The sound waves bounce off objects in the ocean, such as fish, obstacles, and other dolphins. The returning echoes travel through a fat-filled cavity in the dolphin's lower jaw to the inner ear. Using echolocation, a dolphin can tell the size, distance, speed, and even the shape of distant objects. This ability is particularly helpful at night or in murky waters.
Size: up to eight feet long
Weight: 250 pounds
Habitat: tropical and temperate oceans around the world
Diet: fish and squid
Characteristics: sleek body, long snout, dark tail, flippers, and dorsal fin
Threats: fishing nets, pollution, hunting, human disturbance
Dolphin breathe through:
a blowhole at the top of its head
its mouth
gills
Correct!
A dolphin is a mammal, so it has lungs and breathes air. Dolphins must surface to get air. A dolphin breathes through a blowhole at the top of its head. When a dolphin dives under the water, it closes the blowhole to keep water out.
One of the best ways to tell a dolphin from a porpoise is by looking at its:
tail
color
teeth
Correct!
Dolphins have long, cone-shaped teeth, while porpoises have short, flat teeth. A dolphin uses its strong teeth to catch prey, not to chew. (Dolphins swallow their food whole.)
Dolphins tend to travel alone or in pairs.
Fiction
Dolphins are very social, swimming in large schools or "pods." Sometimes hundreds or even thousands of dolphins are found swimming together.
Dolphins are related to whales.
Fact
Dolphins and whales are cetaceans, a group of marine mammals. While whales have two blowholes, dolphins have only one.