The dolphin brain is large and highly complex and is different in structure from that of most land mammals. Unlike most mammals, dolphins do not have hair, except for a few hairs around the tip of their rostrum, which they lose shortly before or after birth. The only exception to this is the Boto river dolphin, which has persistent small hairs on the rostrum. Males have two slits, one concealing the penis and one further behind for the anus.
The female has one genital slit, housing the vagina and the anus. A recent study at the US National Marine Mammal Foundation revealed that dolphins are the only animals other than humans that develop a natural form of Type 2 Diabetes, which may lead to a better understanding of the disease and new treatments for both humans and dolphins.
Overall the scientific study of dolphins has greatly expanded our knowledge of the species, these creatures that are still considered a modern marvel to this day, they continue to astound and baffle scientists with riveting new facts that in essence not only teaches us about the dolphins but also gives us possible insight unto our own existences, for the dolphin even scientifically is not that far off from the average human, they behave like us, they mimic us in many social and emotional ways, and like us they fall ill to all the same illnesses and diseases, and if we can see how they cure and deal with these dilemmas maybe it will further provide a hint as to how we may solve our own.
Classification of a Dolphin Let us start with the family Delphinade which is the largest in the Cetacean order, and relatively recent: dolphins evolved about ten million years ago, during the Miocene.
Cetacean Order More importantly than the origin we need to understand the actual scientific classifications of each dolphin. Each eye moves independently of the other, so dolphins can see ahead, to the side, and behind them.
They can also see very well both underwater and above water. Dolphins use clicking sounds for echolocation, and many use whistles to communicate with other members of their pod, or group. In addition to clicks and whistles, researchers have described dolphin sounds as screams, calls, moans, trills, grunts, squeaks, and even a creaky door sound. Bottlenose dolphin researchers think that slow clicks and high-pitched whistles are signs of contentment, while harsh, low squawks express annoyance.
Their ear holes are tiny, about the size of a crayon point, but dolphins probably have the best hearing in the Animal Kingdom. They receive sounds through their jawbone and head, and the vibrations pass into the tiny bones of their inner ear. All dolphins make sounds that travel underwater, bounce off something, and then return to the dolphins as echoes.
This sophisticated echolocation allows dolphins to find food or avoid predators, even in dark or murky water. Dolphins that live in rivers have excellent echolocation for fishing in muddy waters.
They are the most agile and speedy of all marine mammals. They are known to travel with ships, leaping in front of the bow and swimming in the wake. Dolphins are found in all the oceans of the world. Some live mainly along coastlines, but others live far out at sea. Within these categories, there are various subcategories too, just to complicate things more. Marine mammals all share the characteristics of mammals, but they have adapted to a life in the ocean.
Both species are in the Kingdom animalia, because they are animals, Phylum chordate because they have backbones, class Mammalia because they are mammals give birth to live young and have hair , and in the order Cetacea, which includes whales, dolphins and porpoises. Cetaceans , as they are collectively called, are completely aquatic and have two front flippers, and a tail with two horizontal extensions called flukes.
However, spotted dolphins are in the Family Delphinidae while porpoises are in the Family Phocoenidae. Harbor porpoise next to a diver for size comparison. Photo credit: Wiki Commons. Really, the difference comes down to their faces. Porpoises have spade-shaped teeth, stubby faces, and triangular dorsal fins.
Of the two families, dolphins have greater diversity. Orcinus: pictures 6. Genus Peponocephala melon-headed whale. Genus Pseudorca false killer whale. Pseudorca: pictures 6. Genus Sotalia tucuxi. Genus Sousa humpbacked dolphins. Sousa: pictures 1. Genus Stenella spinner dolphins, spotted dolphins, and striped dolphins. Stenella: pictures Genus Steno rough-toothed dolphin.
Genus Tursiops bottlenose dolphin. Tursiops: information 1 Tursiops: pictures Read more Classification Kingdom Animalia animals Animalia: information 1 Animalia: pictures Animalia: specimens Animalia: sounds Animalia: maps Related Taxa Species Cephalorhynchus commersonii Commerson's dolphin Cephalorhynchus commersonii: information 1 Cephalorhynchus commersonii: pictures 2.
Cephalorhynchus eutropia: information 1. Cephalorhynchus heavisidii: information 1. Cephalorhynchus hectori: information 1.
Delphinus delphis: information 1 Delphinus delphis: pictures 2. Feresa attenuata: information 1. Globicephala macrorhynchus: information 1 Globicephala macrorhynchus: pictures 5. Globicephala melas: information 1. Grampus griseus: information 1 Grampus griseus: pictures 3. Lagenodelphis hosei: information 1. Lagenorhynchus acutus: information 1 Lagenorhynchus acutus: pictures 3. Lagenorhynchus albirostris: information 1.
Lagenorhynchus australis: information 1. Lagenorhynchus cruciger: information 1. Lagenorhynchus obliquidens: information 1 Lagenorhynchus obliquidens: pictures 2.
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