Jellyfish or jellies are the major non-polyp form of individuals of the phylum Cnidaria. They are typified as free-swimming marine animals consisting of a gelatinous umbrella-shaped bell and trailing tentacles. The bell can pulsate for locomotion, while stinging tentacles can be used to capture prey. Jellyfish are found in every ocean, from the surface to the deep sea. A few jellyfish inhabit freshwater. Large, often colorful, jellyfish are common in coastal zones worldwide. Jellyfish have roamed the seas for at least 500 million years, and possibly 700 million years or more, making them the oldest multi-organ animal.
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DOCUMENTARY: The World Of Snakes
Snakes are elongated, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales. Many species of snakes have skulls with many more joints than their lizard ancestors, enabling them to swallow prey much larger than their heads with their highly mobile jaws. To accommodate their narrow bodies, snakes’ paired organs (such as kidneys) appear one in front of the other instead of side by side, and most have only one functional lung. Some species retain a pelvic girdle with a pair of vestigial claws on either side of the cloaca.
DOCUMENTARY: Reptiles and Amphibians
Reptilians survive from the age of the Saurians, but if many look Ancient that’s because their early and sometimes relatively recent adaptations to widely varied conditions worldwide still work admirably. Examples include lizards like the giant Komodo dragon, still top-dog on his Indonesian island, the feared crocodilian hunters, color-changing chameleons and snake species fitted for most (warm) ecosystems. The same goes for amphibians, including numerous specialized (tree) frogs and toads. Both groups are cold-blooded, hence vulnerable while warming up.
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