Phylum Porifera & Cnidaria PDF

1 2 3 Phylum Porifera and Cnidaria Numerical Distribution of the Animal Kingdom 4 PHYLUM PORIFERA Sponges are - simplest invertebrate animal (without vertebrae) - mostly marine, some freshwater - bodies contain pores - thus the name...

1 2 3 Phylum Porifera and Cnidaria Numerical Distribution of the Animal Kingdom 4 PHYLUM PORIFERA Sponges are - simplest invertebrate animal (without vertebrae) - mostly marine, some freshwater - bodies contain pores - thus the name “Porifera”. 5 They are multicellular but organized at the cellular level only - without tissues or organs. Beating flagella pump water through the pores bringing food and oxygen. Sponges can pump volumes of water up to 20,000 times their own volume. This cleans the oceans as the sponges feed on bacteria and plankton. Digestion occurs in the amebocytes. Sponges are a habitat for many marine organisms. 6 Reproduction may be sexual or asexual. Asexual is by external buds or internal gemmules. Sexual is by broadcasting gametes into the water. The meroplanktonic larvae settle into sessile adults. 7 8 9 Three types of sponges have different supporting structures: 1. Calcareous – with supporting spicules 2. Glass sponges – with silica spicules; typically found in great depth NOAA 10 3. Demosponges –with elastic fibers called spongin; used as commercial sponges (The kitchen-style “sponges” were never living animals.) 11  Jellyfish, Anemones and Corals Marine Biology and Oceanography© by Carol Matthews 12 13  PHYLUM CNIDARIA ex: (jellyfish, anemones, corals) - two tissue layers - an outer epidermis and inner gastrodermis - nerve net with stinging capsules called nematocysts radial symmetry with 2 body types: 1. polyp 2. medusa Sea Anemone Portuguese man-of-war a colonial Cnidarian 14 The coral animal may live as a free-floating polyp or build colonies into reefs, but not all corals build reefs. 1. stony coral - hermatypic or reef builders. The polyp grows in multiple parts to form a body of calcium carbonate ex: brain, staghorn, golf ball 15 The Siphonophora (Man of War) has a gas filled float and individuals that function like specialized organs. NOAA Some are carnivores with digestion in food vacuoles. 16 17 2. soft coral - polyps with tentacles While part of the reef, they do not build reefs because their bodies are a soft keratin. ex. sea fans, gorgonians 3. hydrocoral - false corals resemble the anemone and contain powerful neumatocysts that cause skin irritation ex: fire coral NOAA 18 19 20  NOAA The Australian box jellyfish is the most venomous marine organism. Poison vs Venom?? 21