Presentation on theme: "1 Phylum Cnidaria BIO 2215 Oklahoma City Community College Dennis Anderson."— Presentation transcript:
1 Phylum Cnidaria BIO 2215 Oklahoma City Community College Dennis Anderson
2 Phylum Cnidaria Radial symmetry Mouth at oral end surrounded by tentacles. One opening into and out of gastrovascular cavity. Cnidocytes that discharge pneumatocysts Two body forms –Polyp –Medusa Two germ layers Nerve net
10 Nervous System Nerve cells, arranged in a nerve net.
11 Class Hydrozoa Freshwater & marine. Cnidocytes present only on epidermis. Medusa (if present) with a muscular velum. Mesoglea without ameboid cells. Asexual reproduction by budding. Sexual reproduction via gametes produced by epidermis & released into water.
12 Class Hydrozoa Hydra Obelia Gonionemus Physalia
13 Class Hydrozoa HydraSpermariesSpermaries OvariesOvaries EncapsulatedembryoEncapsulatedembryo Sexual cycle Asexual cycle BuddingBudding
14 GastrovascularcavityGastrovascularcavity EpidermisEpidermis MesogleaMesoglea GastrodermisGastrodermis Hydra Body Wall
27 Aurelia Mouth Oral arm Gastric pouch Tentacles
28 Class Cubozoa Medusa dominant & cuboid Tentacles arise at four corners from blade-like pendalium. All marine Strong swimmers which prey primarily on fish Stings of some may be fatal within minutes to humans.
29 Class Cubozoa GonadGonad TentacleTentacle PedaliumPedalium
31 Class Anthozoa Medusa stage absent Solitary or colonial Some produce protective skeletons Gastrovascular cavity subdivided by at least 8 mesenteries Cnidocytes on mesenteries Mesoglea contains ameboid cells All Marine
43 Coral Reefs Formed over thousands of years from successive layers of coral skeleton deposits (calcium carbonate forms underwater mountains of coral animal skeletons) The underwater equivalent of the amazon jungle- very high species diversity and biomass Reefs contain sponges, colonial hydrozoans, anemones, many varieties of coral, fish, many types of worms we’ve not discussed, not to mention bryozoans, ctenophores, protists, bacteria, etc etc..