Adaptations, Characteristics & Behaviors of Dolphins

Dolphins are a type of water mammal that are famously intelligent, agile and playful. They can be found in ocean waters worldwide eating fish, squid and crustaceans. Most species of dolphins average about 8 feet long though there is some variation among species. For instance, the maui dolphin is only about 4 feet in length while the orca whale grows to 25 feet. Dolphins evolved with numerous adaptations to thrive in their oceanic environment and exhibit several distinct characteristics and behaviors that make truly unique animals.

  1. Types of Dolphin

    • The orca is a large type of dolphin.

      More than 40 different species of dolphins exist around the world including the Atlantic whiteside dolphin, long-beaked common dolphin, spinner dolphin, striped dolphin and the hourglass dolphin. The most familiar dolphin is the bottlenose dolphin, which is an especially friendly subspecies of dolphin, particularly to humans. The orca, or killer whale, is actually a large variety of dolphin even though they have a distinctive black and white coloring.

    Adaptations

    • Dolphins exhale and inhale through a blowhole on their heads.

      As dolphins evolved, they developed several adaptations to live and thrive in the ocean full time. Dolphins have a specially developed larynx and throat enabling them to make extremely high-pitched sounds for eco-location and lower pitched sounds for day-to-day communication with dolphin-pod members. Dolphins have a blowhole at the top of their head to take in air when they surface. They can exhale and inhale in under half a second before diving back beneath the surface. Dolphins can hold their breath for approximately 15 minutes. To conserve oxygen while diving, dolphins adapted the way blood flows through their bodies. As they dive, oxygen moves away from other parts of the body and is redirected to the heart, brain and lungs, and the heart rate slows down.

    Physical Characteristics

    • All dolphin species have a dorsal fin on their backs.

      While dolphins can come in various colors and sizes, they have several distinct physical characteristics that make them unique as a species. The fin on their backs, or the dorsal fin, is often seen cutting through the water's surface. It is used to keep them steady and balanced while swimming. In addition, all dolphins have two rear tail flukes that move up and down to keep them in motion. Dolphin skin does not have any hair or sweat glands and is rubbery in texture for swimming efficiency. Dolphin males are heavier and longer than dolphin females.

    Social Group

    • Dolphins enjoy jumping out of the water and landing on their sides of backs.

      Dolphins are deeply social and intelligent mammals. They live in a cooperative group called a pod, the structure of which is based largely on the age and sex of the animals. The size of these pods varies, but generally gets bigger with increases in water depth and habitat openness. The pods work together to hunt for food, protect one another, play together and often form very strong social bonds.

    Behavior

    • Dolphins are frequently observed riding at the stern wakes of boats, playing in the waves. Other play-behaviors include chasing one another around, tossing seaweed and carrying objects around. A common behavior that dolphins share is jumping. Dolphins have the capacity to jump very high out of the water and land on their sides or backs. These animals also help injured, drowning or ill dolphins get air, and have been known to rescue humans in danger. Despite their generally friendly nature, dolphins can be aggressive when they sense danger or when establishing a pod leader.