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You can change your ad preferences anytime. A cnidaria. Upcoming SlideShare. Like this presentation? Why not share! Embed Size px. Start on. Show related SlideShares at end. WordPress Shortcode. Full Name Comment goes here.
Are you sure you want to Yes No. No Downloads. Views Total views. Actions Shares. Embeds 0 No embeds. No notes for slide. A cnidaria 1. Phylum CnidariaExamples? Body StructureA. Medusa 4. Polyp sea anemone 6. Polyp Hydra 7. Discharged nematocyst Level of OrganizationA.
No organs SymmetryRadial Compass jellyfish Aquatic 1. Most Marine 2. Few fresh-water Process of feeding 1.
Tentacles sting prey with nematocysts 2. Tentacles grab prey 3. Prey pulled into mouth Process of feeding4. GVC makes enzymes, extra- cellular digestion6. Internal TransportVia diffusion No cephalization or nervous systemB.
Nerve net around mouth Sensory cells 1. Chemoreceptors chemicals 2. Thigmoreceptors touch 3. Photoreceptors light Ocelli eyespots 4. Statocysts balance Medusa motile, free-swimmingB. Polyps sessile Exceptions: 1. Hydra tumbles on tentacles 2. Sea anemones glide on pedal disc Asexual budding from polyps or medusae2.
Sexual a. Larvae free-swimming Ecological RoleA. Predators and preyB. Neurotoxins in medical researchC. Coral — jewelry, building, reefs surfing! Coral reefs - habitat for many -great biodiversity - protect coastlineE. Symbiosis with other organisms Class Anthozoa: Sea Anemones Sea Anemones with sea urchins Sea Anemones Clown fish with sea anemone Clown fish with sea anemone Giant Sea Anemone Rosy Sea Anemone Class Anthozoa: Corals Brain Coral Coral Colt Coral Elkhorn Coral Cabbage Coral Flower Coral Feather Coral Gorgonian Fan Coral Lamellina Coral Sun Coral Subergorgia Coral Soft Coral Sea Pen Sea Fan Sea Plume Class Hydrozoa: Green Hydra Hydra Brown Hydra with buds Brown Hydra eating Class Scyphozoa: True JellyfishFried egg jelly Jellyfish JellyfishRed-eyed medusa Upside down Jelly fish Sea Nettle Jelly and diver Giant Jelly off Coast of Japan Beached Jelly fish
Introduction to Cnidaria
Cnidarians are incredibly diverse in form, as evidenced by colonial siphonophores , massive medusae and corals , feathery hydroids , and box jellies with complex eyes. Yet, these diverse animals are all armed with stinging cells called nematocysts. Cnidarians are united based on the presumption that their nematocysts have been inherited from a single common ancestor. The name Cnidaria comes from the Greek word "cnidos," which means stinging nettle. Casually touching many cnidarians will make it clear how they got their name when their nematocysts eject barbed threads tipped with poison.
Their distinguishing feature is cnidocytes , specialized cells that they use mainly for capturing prey. Their bodies consist of mesoglea , a non-living jelly-like substance, sandwiched between two layers of epithelium that are mostly one cell thick. They have two basic body forms: swimming medusae and sessile polyps , both of which are radially symmetrical with mouths surrounded by tentacles that bear cnidocytes. Both forms have a single orifice and body cavity that are used for digestion and respiration. Many cnidarian species produce colonies that are single organisms composed of medusa-like or polyp -like zooids, or both hence they are trimorphic. Cnidarians' activities are coordinated by a decentralized nerve net and simple receptors.