BIOL 2003 Lecture Notes - Lecture 5: Chironex Fleckeri, Gastrovascular Cavity, Octocorallia
8 Jan 2018
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Document Summary
Class anthozoa: polyps only "flower animal, 6000+ species, anemones, corals, tubular body and pharynx, large gastrovascular cavity. Subclass hexacorallia: 6 axes of symmetry, anemones. Stony/true/hard corals: mini seas anemones in calcareous cups. Subclass octocorallia: 8-part symmetry, gorgonian corals: proteinaceous, fleshy bodies, calcareous spicules only in mesoglea. Soft corals, seas pansies, sea pens, sea fans. Class hydrozoa: disparate (too different to compare) group, most are colonial and exhibit polymorphism (different forms in life cycle and colony) Includes the freshwater cnidarians (hydra): no medusa, can bud off new hydra: ex obelia. Class scyphozoa (true jellies: 200-400 species, small or big, dioecious (separate sexes) Square-shaped bells: tentacles at the corner: rhopalia (eyes): some eyes are image forming, chironex fleckeri sea wasp that is fatal. Ecological importance of anthozoa: photosynthetic dinoflagellates (zooxanthellae): important for food for coral, coral bleaching, coral reefs in general: biodiversity hot spots, habitats, 25% of marine life, deep sea ecosystems, mutualism with anemones: mucus on fish skin, crabs.
