10Adult sponges are sessile. CAN”T MOVEThey live attached to a single spot.
11Sponges are asymmetrical filter feeders Feed on : bacteria, unicellular algae, and protists through filter feeding.
12IV. Phylum- Porifera (“pore bear”) –sponges – simplest of all animals A. Body Plan – asymmetrical, pores all over body with large hole on top called osculum where water is pumped through, Have no mouth or gut, Have no tissues or organ systems, Simple functions are carried out by a few specialized cellsB. Protection: skeleton of spicules (glass-like material) or spongin (soft)
13Asymmetrical? Have no front or back ends, no left and right sides A large, cylindrical water pumpThe body forms a wall around a large central cavity through which water flows continually
14Protection- Silica (cells of glass offer protection and support
15C. Feeding – filter feeders, trap microorganisms in water flow. 1. Collar cells - specialized cells that use flagella to move a steady current of water thru the sponge. Each collar cell digests its own food.2. Archaeocytes - specialized cells that make spicules3. Pore cells – Cells thru which water flows into the body of a sponge
16Major Body FunctionsD. Respiration/ Circulation/ Excretion – water flow carries out all body functions (osmosis and diffusion)As water moves through the cavity:Oxygen dissolved in the water diffuses into the surrounding cells2. Carbon dioxide and other wastes, diffuse into the water and are carried away
17Major Body FunctionsE. Response/Movement- no nervous system, do produce toxins, adults don’t move (sessile), larva swimF. Reproduction- sexually with internal fertilization between two different sponges or asexually by budding or fragmentation
18OsculumA large hole at the top of the sponge, through which water exitsThe movement of water provides a simple mechanism for feeding, respiration, circulation and excretion
19The Anatomy of a Sponge Water flow Osculum Collar Cell Central cavity PoresSpiculePore cellPoreEpidermal cellArchaeocyte
20Ecology of SpongesIdeal habitats for marine animals such as snails, sea stars, sea cucumbers, and shrimpMutually beneficial relationships with bacteria, algae and plant-like protists
21Sponge Life Cycle (Sexual Reproduction) Sponges are hermaphrodites. MEIOSISHaploid (N)Diploid (2N)Adult sponge releases sperm into the waterNew spongeSperm (N)Maturesponge (2N)Egg (N)Larva attachesto a hard surfaceLarva(2N)The zygote develops into a free swimming larvaSperm fertilize eggs inside the body of another spongeFERTILIZATION
22Review QuestionsAnswer the 4 questions on your own.
44Phylum Cnidaria –more complex than sponges A. Carnivorous animals with stinging tentacles around their mouthsB. Simplest animals to exhibit symmetry – cnidarians have radial symmetryC. Simplest animals to have true tissues including nerves
45Cnidarians have two body forms Polyp - stationary, vase-shapedMedusa - swimming, cup-shapedExamples: hydra, coral, sea anemoneExamples: jellyfish, portuguese man of war
46Examples: hydras, jellyfishes, sea anemones, and corals A. Hydrozoans: Most of life as polyp ex. hydraB. Scyphozoans: Most of life as medusa ex. jellyfishC. Anthozoans: Only polyp stage in the life cycle ex. corals and sea anemones
47Simplest animal with true tissues. soft bodied, have tentacles, radial symmetry,1. Gut – gastrovascular cavity with one opening2. Nerve net- detects stimuli3. Hydrostatic Skeleton- movement and support with the use of muscles
48 The Polyp and Medusa Stages 1. Polyp - Stationary, Examples: Hydra, Coral, and Sea Anemone2. Medusa- Swimming, Cup Shaped. Examples: Jelly Fish and Man O War
49 The Polyp and Medusa Stages 3 tissue layersEpidermisMesogleaGastrodermTentaclesMouth/anusGutBellgutMouth/anusTentaclesMedusaPolyp
501. Feeding- kill small prey with stinging cells in tentacles, digest in gut, food in and waste out of one opening.2. Respiration/Circulation/Excretion- all by diffusion (no true organs)3. Response- have specialized sensory cells and nerve net to gather info and react to stimuli.
51b. Ocelli: eyespots made of cells that detect light Responsea. Statocysts: groups of sensory cells that help determine the direction of gravityb. Ocelli: eyespots made of cells that detect light
534. Movement- propel themselves with water using hydrostatic skeleton 5. Reproduction- asexually by budding, sexually by external fertilization, sperm and egg are released and meet in water
54IX. Ecology of Cnidarians A. Source of new drugs/chemicals sunscreen 855B. Provide habitats for marine organismsC. Source of food for other organisms (like sea turtles)D. Symbiotic relationships with other organisms
55Jellyfish Life Cycle (Sexual Reproduction) Female medusa (2N)MEIOSISFertilization occurs in the open water, producing many diploid zygotes.Egg (N)Adult medusas reproduce sexually by releasing gametes into the water.FERTILIZATIONSperm (N)Each zygote grows into a ciliated larva. The larva eventually attaches to a hard surface and develops into a polyp.Zygote (2N)Male medusa (2N)Young medusaSwimming larvaPolypThe polyp buds to release young medusas.HaploidDiploidBudding polyp