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The Kingdom Animalia • The movers and shakers • Part I: Introduction to animals and the phyla Porifera and Cnidaria. Gulo gulo What are animals? • Animials are multicellular, eukaryotic heterotrophs. • Animals are very responsive to their environment. • All animals are capable of locomotion at some point in their lifecycle. Falco peregrinis How do they move? • All animals, at least during some point in their lifecycle possess contractile fibers. • In higher animals, these contractile fibers are called muscles. • All muscles are capable of doing is shortening and then relaxing. The phyla of the Kingdom Animalia • There are nine phyla in the Kingdom Animalia. • Each phyla contains animals which share many characteristics with each other. • 8 of the phyla are considered invertebrates (this means that a they lack a backbone. • The 9th phylum are animals with a backbone. The nine phyla of Kingdom Animalia • 1. Porifera • 2. Cnidaria • 3. Platyhelminthes • 4. Nematoda • 5. Annelida • 6. Arthropoda • 7. Mollusca • 8. Echinodermata • 9. Chordata Phylum Porifera • Members of this phylum are commonly referred to as the sponges. • Over 5,000 species, mostly marine but some live in fresh water. • The very simplest of animals. • As adults they are sessile, asymetrical filter-feeders I thought all animals moved? • Adult sponges don’t move, but as larvae they do. • The larvae can swim around. • Eventually they attach themselves to the ocean bottom and metamorphose into their adult form. Reproduction • Sponges are capable of sexual and asexual reproduction. • In sexual reproduction a sperm cells swims to an egg cell and produces a motile larvae. • Sponges can also reproduce by budding, when a piece of a sponge breaks off and skips the larval stage all together. Cell layers • Sponges only have two layers of cells (germ layers). • Food is taken in by each individual cell. • This limitation puts a size restraint on a sponge. Feeding in Porifera • Porifera feed by pumping water through it’s body and filtering out nutrients. • The water is pumped by means of flagella which line the interior of the sponge. • Oxygen is absorbed and wastes excreted during this process. Phylum Cnidaria • The second phylum are represented by such animals as Jellyfish and corals. The Cnidarians • Over 9,000 species, all of them are aquatic. • Jellyfish are found in all of the worlds seas from the equator to the poles. • Corals live in warm shallow waters only. • Sea anenomies are marine predators which have stings like jellyfish. • Hydra are small fresh water cnidarians. Cnidarian body plan • Cnidarians display radial symmetry. • They have a central mouth surrounded by numerous tentacles that extend outward from the body. • The simple digestive cavity is a two- way tract. • Any materials which cannot be digested are passed out of the body through the mouth. Jellyfish stings • A characteristic of jellyfish that allows them to subdue and kill their prey are called nematocysts. • Each nematocyst contains a small vesicle filled with toxins, an inner filament and an external sensory hair. • When the hair is touched, it mechanically triggers the cell explosion, a harpoon-like structure which attaches to organisms that trigger it, and injects a dose of poison in the flesh of the aggressor or prey Dangerous Jellies • While most jellyfish stings are painful, only a few are considered life-threatening. • Box Jellies and Irukanji, both found in Austrailian waters are the most dangerous. • http://video.google.com/videosearch?cli ent=safari&rls=en-us&q=jellyfish&oe=UTF- 8um=1&ie=UTF-8&sa=N&hl=en&tab=wv Jellyfish types • There are several different families of Jellyfish. • Some, like the portugese man-o-war do not swim, but float by means of a bladder that acts like a sail. • Other jellyfish actively swim through the oceans. Corals • Corals reproduce sexually as both sperm and eggs are released into the surrounding water. • Larval corals are free swimming organisms. • They attach themselves to rock on the ocean bottom and metamorphose into adults. Marine ecosystems • Corals play a very important role in maintaining biodiversity. • Coral reefs support some of the most diverse communities of plants and animals on earth. • Rising water temperatures have a negative impact on coral reefs.
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