Animals are multicellular, eukaryotic organisms of the kingdom Animalia (also called Metazoa). The animal kingdom emerged as a clade within Apoikozoa as the sister group to the choanoflagellates. Animals are motile, meaning they can move spontaneously and independently at some point in their lives. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later in their lives. All animals are heterotrophs: they must ingest other organisms or their products for sustenance.

Most known animal phyla appeared in the fossil record as marine species during the Cambrian explosion, about 542 million years ago. Animals can be divided broadly into vertebrates and invertebrates. Vertebrates have a backbone or spine (vertebral column), and amount to less than five percent of all described animal species. They include fish, amphibians, reptiles, birds and mammals. The remaining animals are the invertebrates, which lack a backbone.

These include molluscs (clams, oysters, octopuses, squid, snails); arthropods (millipedes, centipedes, insects, spiders, scorpions, crabs, lobsters, shrimp); annelids (earthworms, leeches), nematodes (filarial worms, hookworms), flatworms (tapeworms, liver flukes), cnidarians (jellyfish, sea anemones, corals), ctenophores (comb jellies), and sponges. The study of animals is called zoology.

Animals Are Not Trophies

Animal Planet is outraged and heartbroken by the recent killing of Cecil the lion. The network strongly opposes the deplorable practice of trophy hunting and poaching, asserting that they devastate conservation efforts, reduce wildlife populations and weaken the populations' gene pools.

How You Can Help, Sign a petition. Donate to a cause. Get the word out.The Humane Society: Help Save the African Lion from Extinction by getting the African lion listed as threatened under the Endangered Species Act.takepart: Lions Like Cecil Aren't Trophies. Petition for legislation to ban importation of African lion trophies.WildCRU: Cecil and the Conservation of Lions. Help raise funds for the group who was studying Cecil and other lions in his coalition.

More About Animal Conservation, Reach Out. Act. Respond (R.O.A.R.) - Explore the work of our partners who are striving to improve conservation of animal species both wild and domesticated. David Shepherd Wildlife Foundation - Projects include protecting species including the Elephant, Rhino, Tiger, Lion, Leopard and more, as well as raising awareness about poaching and wildlife crime. World Wildlife Fund: Wildlife Conservation - Find out what this renowned organization is doing to empower people to protect wildlife, stop wildlife crime, use technology and elevate wildlife's worth to protect species. International Fund for Animal Welfare - Protecting animals from illegal wildlife trade is one of their many projects, which also include efforts to prevent animal cruelty and rescue individual animals.

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