All Photos On This Article Were Taken By Myself, Apart From The Ones Where I'm In The Picture With The Dolphins. There are almost forty kinds of dolphin in seventeen genera. They vary in size from 1.2 meters (4 ft) and 40 kg (90 lb) (Maui's dolphin) to 9.5 m (30 ft) and 10 ton (9.8 LT, ST-11) (Orca or Killer Whale ). They are located worldwide, mostly in the more shallow oceans of the continental shelves, and are carnivores, mostly eating fish and squid. Family Delphinidae is the largest whale in the sequence, and relatively recent: dolphins evolved ten million years ago, during the Miocene. Dolphins are among the smartest animals and their often friendly appearance and seemingly playful approach made them popular in human culture.

Dolphins have hair as well - but not much! Dolphins belong to a group of mammals known as cetaceans. Cetaceans consist of all whales and dolphins. A number of cetaceans, like the blue whale, are baleen whales and contain horny plates hanging from their upper jaw that are used to strain food from the sea. Others, like dolphins, are "too thed whales." In the group of toothed whales, there are a number of subgroups:

Although they are equally toothed whales, they have different body shapes. Dolphins generally have a large forehead. The easiest way to tell them apart is by looking at their teeth. All dolphin teeth are round when you cut them in half. But all porpoise teeth are flat.

Dolphins lack any hind limbs. The dolphin's tail is called its flukes (each half is a fluke). There are no bones in a dolphin's flukes, just tough connective tissue. The dolphin uses its flukes for swimming and its flippers for steering. The majority of dolphins have a boneless dorsal fin in the middle of their back that works to some extent like the rudder on a boat. Similar to the flukes, the dorsal fin does not hold any bones.

Dolphin body color is extremely variable. Various, like the killer whale, are strikingly black and white. Other dolphins - like the pilot and false killer whales - are almost solid black. The bottlenose dolphin is generally some shade of gray, but it is a lot lighter on its belly than on its back. This type of coloring might help camouflage dolphins in the water. Looking down on them, the dark colors mix in with the deep-sea. And if you look up from underneath, the patches of light and dark skin blend in with the sunlight coming through the water.

No one really knows how fast most dolphins swim except bottlenose dolphins typically swim at 3 to 7 miles per hour. They can go over 20 miles per hour when they give their best. The body shape of a dolphin is what helps it swim fast. The dolphin's body is shaped like a tube that is pointed at both ends. This streamlining helps the water flow over the dolphin's body as it swims. It's difficult to say how deep oceanic dolphins can dive since most of the 32 species have not yet been studied. Bottlenose dolphins are shallow divers and usually don't go deeper than 150 feet. In the Indian River Lagoon the deepest waters are only 10 to 12 feet deep.

Although dolphins are warm-blooded, and their internal temperature is about 98 degrees, they need to preserve their body heat in colder water. Like most whales, dolphin's body is surrounded by a thick layer of fat (called blubber) just under the skin that helps keep the dolphin warm. Mostly Dolphins eat a variety of fish and squid, depending on what part of the ocean they live in. The bottlenose dolphins in the Indian River Lagoon eat mainly fish since there aren't many squid in the lagoon. A dolphin's cone-shaped teeth interlock to catch fish. Their teeth are not used to chew, so they swallow their food intact.

Just like dogs, cats, and other mammals they communicate by using sound, vision, touch, and taste. Dolphins don't have the facility to smell, on the other hand. Scientists do not think that dolphins have a language like humans. Each dolphin can make a unique signature whistle that may help individual dolphins recognize each other, but it may just help a dolphin know that some other dolphin is nearby. Scientists don't know for sure. We don't know exactly how intelligent they are for the simple only because no one has given them an intelligence test! Most scientists believe that dolphins are on a level with chimpanzees and dogs. Dolphins can learn to perform certain actions. They learn best when actions are broken into small steps and they are given food or other rewards

Echolocation is a way of using sound to find objects in the environment. Bats use it in the air and dolphins use it in the water. To echolocate, the dolphin generates a sound pulse (of clicks) in its forehead which is sent into the water. The sound bounces off objects, creating an echo that returns to the dolphins. We believe that dolphins hear the returning echoes by feeling the sound pulses against their jaws. Different objects (like different kinds of fish) give off different kinds of echoes. Dolphins can also judge how far away the object is by the amount of time it takes for the echo to return. People ask- are all dolphins endangered? No, all dolphins are not endangered. Neither the bottlenose dolphin nor the killer whales are endangered. On the other hand, several of the river dolphins are extremely endangered since humans have destroyed their habitat. If we humans don't take care of the earth, many more species of dolphins will become endangered in the future.