Dolphins are highly intelligent marine mammals and are part of the family of toothed whales that includes orcas and pilot whales. They are found worldwide, mostly in shallow seas of the continental shelves, and are carnivores, mostly eating fish and squid. Dolphin coloration varies, but they are generally gray in color with darker backs than the rest of their bodies. Dolphins consume a variety of prey including fish, squid and crustaceans. It is difficult to estimate population numbers since there are many different species spanning a large geographic area. Most species live in shallow areas of tropical and temperate oceans throughout the world. Five species live in the world’s rivers. Dolphins are well known for their agility and playful behavior, making them a favorite of wildlife watchers. Many species will leap out of the water, spy-hop (rise vertically out of the water to view their surroundings) and follow ships, often synchronizing their movements with one another. Scientists believe that dolphins conserve energy by swimming alongside ships, a practice known as bow-riding. Dolphins live in social groups of five to several hundred. They use echolocation to find prey and often hunt together by surrounding a school of fish, trapping them and taking turns swimming through the school and catching fish. Dolphins will also follow seabirds, other whales and fishing boats to feed opportunistically on the fish they scare up or discard. The familiar bottlenose dolphin is around 8 feet (2.5m) long and weighs between 440–660 lbs (200–300kg). Because the forty species of dolphins are so diverse, they range in size. The smallest of the dolphin species, Maui’s Dolphin, is around 4 feet (1.2m) long and weighs around 90 lbs (40 kg). The largest dolphin species is the orca, or killer whale. Male orcas grow to about 25 feet in length and weigh about 19,000 pounds.
1) Dolphins are odontocete cetaceans. The order Cetacea includes a group of mammals fully adapted to life in the ocean.
2) The closest relatives of dolphins are whales and porpoises. All are members of the order Cetacea.
3) Dolphins are mammals; warm-blooded animals which give birth to live offspring and feed them with breast milk from the mother.
4) They do not have hair on the skin. Only a small accumulation of thin hair near the spiracle and in some other places. Only the Boto (Amazon River Dolphin) has a small amount of hair that they keep as an adult.
5) Like whales, manatees, seals, walruses and porpoises, they are mammals that live permanently in an aquatic environment.
6) Apparently, dolphins sleep resting one side of the brain at a time. Thanks to its bone structure and its ability to hold air in the lungs for a long time, dolphins can rest underwater. However, they need to breathe regularly. Therefore, some degree of awareness is necessary, and one side of the brain remain active, while the other part rests.
7) Dolphins can communicate with each other by emitting a variety of sounds.
8) Dolphins do not have a good sense of smell.
9) Dolphins can swim at a speed of up to 25 miles per hour for a long time. This is about three times faster than the fastest humans in the world.
10) Dolphins inhabit all seas of the world.
11) Most species live in salt water, but some dwell in fresh or brackish waters.
12) All dolphins are carnivores.
13) There are about 100 teeth in the mouth of a dolphin, but the amount varies among species. However, they use the teeth to grab their prey, but they don’t chew it. All food is swallowed whole.
14) Dolphins can hear a frequency range ten times broader than that of a human being.
15) Dolphins are mostly larger than porpoises. However, some species of dolphins are the smallest cetaceans.
16) Mothers breastfeed calves for 2 or 3 years.
17) The lower limbs of dolphins are vestigial legs because millions of years ago they could walk on land.
18) There are about 43 species of dolphins. But the number keeps changing because of new discoveries and new taxonomic classifications.
19) There have been cases of attacks on humans, but they are very rare. Even though dolphins are usually very mild tempered, they can be aggressive.
20) At birth, calves weigh approximately 10 kilos and measure around one meter. This weight increases up to 7 times during the first year of life.
21) Many individuals have been seen making jumps in front of the ships and following the bow waves.
22) The teeth of dolphins work as a kind of antenna to pick up the sounds bounced back during echolocation.
23) Dolphins enjoy socializing and playing. They have been seen playing with small objects and with other dolphins. They play with seaweed or with other members of the pod. Sometimes, they will tease other living creatures in the water.
24) They are social animals and can live in groups called pods that can have hundreds of members or even join with other groups creating superpods with thousands of individuals.
25) The favorite foods of many species of dolphins are fish, octopus, and squid.
26) The gestation period in most species lasts between 10 and 12 months.
27) Dolphins detect prey and objects using their echolocation, that is, by interpreting the echo of sound waves bounced back by the target.
I love dolphins…
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