Parazoa no true tissues Eumetazoa Multicellularity RadiataBilateria

QUIZ (CHAMPACA) 1. True or False : Jellyfishes have no nervous system. 2. What are the 2 stages of the life cycle of jellyfishes ? 3. What is the term used to describe the two - tissue layer that Cnidarians possess ? 4. Give one class under this Phylum 5. Give ecological significance of Cnidarians.

Gr. “ nettle ” cnidocytes with nematocysts previously “ Coelenterata ” with the Ctenophora ( coel + enteron ) sp. PHYLUM CNIDARIA STINGING ANIMALS

FORM AND FUNCTION DIMORPHIC BODY PLAN radially - symmetric diploblastic 2- layered body wall ( epidermis + gastrodermis ) gelatinous mesoglea gastrovascular cavity ( GVC ) incomplete gut digestive sac with only one opening /17987/polypdiagram.gifhttp:// /17987/polypdiagram.gif, GHG4p2wPVPs/TenLrQE0cyI/AAAAAAAAA_s/YZiq _lfYItM/s1600/10a.JPG, GHG4p2wPVPs/TenLrQE0cyI/AAAAAAAAA_s/YZiq _lfYItM/s1600/10a.JPG

FORM AND FUNCTION: FEEDING predatory extracellular digestion in GVC  intracellular within cells of gastrodermis circulation through diffusion

FORM AND FUNCTION: RESPONSE

FORM AND FUNCTION: MOVEMENT Polyps : hydrostatic skeleton Contractile fibers ( not true muscle tissues ) + H 2 O in GVC Medusas : jet propulsion Fibers contract  medusa closes  H 2 O forced out  forward movement

FORM AND FUNCTION: REPRODUCTION ASEXUAL THROUGH BUDDING SEXUAL THROUGH SYNCHRONIZED RELEASE OF GAMETES

Phylum Cnidaria Hydrozoa conspicuous polyp stage Hydra Physalia Praya Anthozoa polyp stage only Sea anemone Coral animals Scyphozoa cup shaped medusa stage Aurelia Mastigia Cyanea Cubozoa umbrella shaped medusa stage Chironex a3.jpghttp:// a3.jpg, 4/17/14/-Sea-Anemone.jpg, mages4/braw3.jpg, m/images/2475/large/box- jellyfish-24M jpg 4/17/14/-Sea-Anemone.jpg mages4/braw3.jpg m/images/2475/large/box- jellyfish-24M jpg

ECOLOGY Coral reefs budding produces new polyps, new polyps lay down new limestone  growth rate,  lifespan 1a/e040701a.html

IMPORTANCE Coral reefs symbiotic relationships with other plantlike protists animal habitat protects land from wave action tourism medical research

IMPORTANCE Distribution of corals determined by: temperature water depth light intensity Problems of corals: Human activity Coral bleaching