| Whales and dolphins |
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Since thousands of years men have been fascinated by whales and dolphins. It's not surprising that they became part of myths and legends. This fascination is unbanned till today and the success of "Flipper" and the "Free Willy"-movies or dolphinariums proove that. |
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Dolphins are whales. Together they make up the biological order of the cetaceans. It has got 13 different families and is divided into two suborders: odontoceti (toothed whales) and mysticeti (baleen whales). The characteristic of the odontoceti is that they have theeth while the mysticeti have horny plates, the baleens. With these they filter their food from the water. The Cetaceans contain of approximately 80 different species. The exact number differes between 76 and 81. Especially modern research methods such as DNA-analysis single species could be identified, which had been related with another species before. Today it is thought that there are more then 80 species. The majority of Cetaceans are Odontoceti. Dolphins are odontoceti as well.
Despite their marine living and their fishlike bodies whales are mammals. Due to the findings of fossils and skeletons it is likely that the Cetaceans descend from terrestrial animals of the tertiary. The oldest prooven ancestor is likely to be a doglike-looking relative of the Mesonyx, who lived 55 million years ago. These were primitive, hooved mammals who lived in the regions of todays Northern America, Europe and Asia. The animals possibly lived near rivers, coasts and swamps and lived partly amphibic. Rudimentary parts of the pelvis of recent baleen whales and the phelange-bones still show the origin of the cetaceans lays on land.
Whales and dolphins have no natural enemies except men. Today the animals are endangered because of commerical whaling and pollution of the water. This includes species which just began to recover from the extreme hunting of the last centuries. Another big problem is the overfishing of the oceans because on one side it lowers the amount of their food and on the other they die due to bycatch.
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Nevertheless dolphins fascinate thousands of people in dolphinariums. There are different opinions towards those but they show the high popularity of the whales. The good social feeling of dolphins also provide a big success with dolphintherapy as well. |
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