Write 5 pages thesis on the topic marine dolphins.  .The major types of marine dolphins are pacific bottlenose, rough-toothed, spotted dolphin and spinner dolphin. The bottlenose dolphins are the most famous of all cetacean species. The scientific name for bottlenose dolphin is Tursiops truncatus. Rough-toothed dolphin has vertical grooves that run from the gum line to the tip. The scientific name for rough-toothed dolphin is Steno bredanensis. Spotted dolphins are of a smaller size than rough-toothed or bottlenose dolphins. They have a dark cape that extends from their forehead to the dorsal fin. The scientific name for spotted dolphin is Stenella attenuata. Spinner dolphins are smaller than the spotted dolphins. The spinner dolphins got their name from their spinning behaviour. Their scientific name is Stenella longirostris (Shirihai 77).
Like other marine animals, dolphins have become adapted to sea life. Anatomically, the bodies of the dolphins are streamlined to enable them to move more efficiently in the aquatic environment. The streamlined body ensures fast movement of the dolphins as it reduces the resistance of water when the dolphin is moving.  .The hind limbs of the dolphins have disappeared, and front limbs are developed into flippers (Gordon 26). This helps the dolphin in steering balance and changing direction. The dolphins have a powerful tail, which helps in propulsion. The speed under which the dolphins move at is closely related to the feeding habit of the dolphin. Research has shown that those dolphins that feed on slow-moving prey do not exceed a speed of 10 mph.Other dolphins that feed on fast-moving fish species usually attain a speed of up to 15 mph. Also, dolphins have smooth skin. Thedolphin’s skin is thick, hairless and lacks glands. It is kept smooth by the constant slough and replacements. For example, the bottlenose dolphin replaces its outermost skin layer after every two hours. This smooth skin of the dolphin increases the speed at which the dolphin moves. Like other marine mammals, the dolphins have a thick layer of fat below their skin. This layer of fat is important since it insulates the dolphins against heat loss. The dolphins rely on their sense of hearing to detect any danger around them. The sense of hearing in dolphin is a very complicated behaviour referred to as echolocation. Echolocation is where a dolphin emits a series of split clicks by its blowhole focusing the sound to the melon and the melon directs the sound pulses in a directional beam.