Dolphin
A dolphin is an aquatic mammal of the order Cetacea, which also includes the whales and porpoises.
Dusky Dolphins
The word is used in a few different ways. It can mean:
- Family Delphinidae (oceanic dolphins),
- Both Delphinidae and Platanistoidae (oceanic and river dolphins),
- Or all of suborder Odontoceti (toothed whales).
There are almost 40 species of true dolphin in 17 genera. They vary in size from 1.2 metres and 40 kg (Heaviside's Dolphin), up to 7 metres and 4.5 tonnes (the Killer Whale which, despite the name, is a dolphin). Most species weigh between about 50 and about 200 kg. They are found worldwide, mostly in the shallower seas of the continental shelves, and all are carnivores, mostly taking fish and squid.
The dolphin family is the largest in the Cetacea, and relatively recent: dolphins evolved about 10 million years ago, during the Miocene.
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Delphinidae Oceanic Dolphins
The Dolphin Brain is similar in size to the human brain (slightly larger in some, up to 5 times larger in others, like the Orca, but their brain to body ratio is slightly lower than humans on average. Their brain consists of two hemispheres divided into four lobes—very different from the human brain. It is unknown why dolphins evolved this structure. Some hypothesize that the dolphin brain is shaped this way to allow for more acute conscious perception of three dimensions, thus allowing it to use its highly developed powers of echolocation. Others have gone as far as to say that dolphins perceive higher dimensions of reality than humans do. It appears that dolphins are an example of highly evolved oceanic intelligence. It has been long-theorised that they have a complex language, which may consist of visual symbols as interpretations of high frequency sound waves.
See also military dolphin.
List of dolphins
Platanistoidae River Dolphins
Six toothed whales are in the family Delphinidae, and are therefore strictly speaking dolphins. They are sometimes called "blackfish": Dolphin Intelligence
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Dolphin (or more properly, dolphinfish) is also used to describe a species
of fish, Coryphaena hippurus, which is unrelated to the mammal.
The name is being used less frequently than in times past, and has generally
been replaced with its Polynesian name, mahi-mahi, to avoid confusion with the mammal, especially since the fish is commonly eaten. In Spanish, this fish is also referred to as a dorado.
Dolphin was the code name for the Nintendo Gamecube before it was released.
Dauphin was a title adopted by many French kings and aristocrats, received originally from Humbert II
