December 10 2020
Dolphin is a fairly common name of marine mammals in the family Cetacea, which includes all cetaceans. The word dolphin generally refers to the extinct families Delphinidae, Platanista, Iniidae and Pontopuriidae; however, there are several extinct subfamilies and genera in the Delphinoidea; all of these have been called dolphins.
The fossil record of these extinct genera provides evidence of their existence in the seas of the Triassic period. The early ancestors of the dolphin family were small, probably weighing about twenty pounds. They had a short trunk, long forelimbs, short hind legs and relatively short tail. A short crest was present on the snout, and their eyes were almond in shape and large, giving them an otherwise blind appearance. Their nostrils were short, giving a deep voice.
The modern-day dolphin is roughly one to two meters in length, with a body plan much more similar to that of the whale. Their dorsal fins and pectoral fins were used for swimming, as well as tail flukes for flapping, which could be very powerful. Male dolphins are larger, weighing between three hundred and five hundred kilograms, while female dolphin can weigh up to one hundred twenty-two kilograms. The bottlenose dolphin is only slightly larger, at a weight of two hundred seventy-five kilograms. To know more about dolphins click here.
Dolphins use their sense of smell to find food. They usually locate food by smell alone, although other means may be employed as well, including the use of sight.
Dolphins also use their vision to hunt, as with humans, but they have no eyes. In order to hunt, a dolphin will search for its prey by swimming and waving its flippers and mouth in front of its face. A dolphin may take an object of particular interest from the surface of the water and then dive and follow the object.
The nose of a dolphin is located at the top of the head and is curved forward, allowing the animal to detect small objects with great accuracy and speed. It is used mostly to detect a food source.
The dolphin's brain is very complex, consisting of two hemispheres, a temporal lobe, and a central area, which is where memory, speech, and language processing are located. The dolphin's olfactory lobe is responsible for detecting and distinguishing smells, including food, which are then used to communicate with other dolphins or to locate their food sources.
The dolphin's lifespan is around thirty years, although some are known to live up to seventy years. Various diseases which may affect dolphins include liver failure, liver tumours, and cardiac arrhythmia. However, all of these are usually non-fatal if caught early enough. If a dolphin is exposed to any of these conditions, it should be seen by a doctor immediately.