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Sponges and Cnidarians. Life Science. Review the Animal Kingdom. 4 Major Characteristics? Multicellular Eukaryotic Heterotrophs Cells lack cell walls. Feeding Respiration Circulation Excretion. Response Movement Reproduction. 7 Essential Functions?. Hard Shells. Fur & Milk Glands.
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Sponges and Cnidarians Life Science
Review the Animal Kingdom • 4 Major Characteristics? • Multicellular • Eukaryotic • Heterotrophs • Cells lack cell walls
Feeding Respiration Circulation Excretion Response Movement Reproduction 7 Essential Functions?
Hard Shells Fur & Milk Glands Amniotic Egg Lungs Bony Skeleton jaws Brain Encased Skull
Phylum Porifera “Pore-Bearers”
Sponges are the simplest of all animals. They are multicellular, heterotrophic, have no cell walls, and have specialized cells.
Sheet sponge Carnivorous- eat small crustaceans
Adult sponges are sessile. CAN”T MOVE They live attached to a single spot.
Sponges are asymmetrical filter feeders Feed on : bacteria, unicellular algae, and protists through filter feeding.
IV. 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 cells • B. Protection: skeleton of spicules (glass-like material) or spongin (soft)
Asymmetrical? • Have no front or back ends, no left and right sides • A large, cylindrical water pump • The body forms a wall around a large central cavity through which water flows continually
Protection- Silica (cells of glass offer protection and support
C. 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 spicules 3. Pore cells – Cells thru which water flows into the body of a sponge
Major Body Functions • D. 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 cells 2. Carbondioxide and other wastes, diffuse into the water and are carried away
Major Body Functions • E. Response/Movement- no nervous system, do produce toxins, adults don’t move (sessile), larva swim • F. Reproduction- sexually with internal fertilization between two different sponges or asexually by budding or fragmentation
Osculum • A large hole at the top of the sponge, through which water exits • The movement of water provides a simple mechanism for feeding, respiration, circulation and excretion
The Anatomy of a Sponge Water flow Osculum Collar Cell Central cavity Pores Spicule Pore cell Pore Epidermal cell Archaeocyte
Ecology of Sponges • Ideal habitats for marine animals such as snails, sea stars, sea cucumbers, and shrimp • Mutually beneficial relationships with bacteria, algae and plant-like protists
Sponge Life Cycle (Sexual Reproduction)Sponges are hermaphrodites. MEIOSIS Adult sponge releases sperm into the water Haploid (N) Diploid (2N) New sponge Sperm (N) Mature sponge (2N) Egg (N) Larva attaches to a hard surface Larva (2N) The zygote develops into a free swimming larva Sperm fertilize eggs inside the body of another sponge FERTILIZATION
Review Questions • Answer the 4 questions on your own.
Asexual Reproduction-Budding A new polyp genetically identical to the parent is formed.
Some have eyes! Box Jelly
Found off the coast of Australia Deadly within 3 minutes! Over 100 deaths in the last 25 years Chironex fleckeri
Orange Cup Coral Red Sea Fan
Sea Pen Feathery Hydroid
Giant Sea Fan Mushroom Coral
Solid Table Coral Staghorn Coral
Phylum Cnidaria –more complex than sponges • A. Carnivorous animals with stinging tentacles around their mouths • B. Simplest animals to exhibit symmetry – cnidarians have radial symmetry • C. Simplest animals to have true tissues including nerves
Cnidarians have two body forms Polyp - stationary, vase-shaped Medusa - swimming, cup-shaped Examples: hydra, coral, sea anemone Examples: jellyfish, portuguese man of war
Examples: hydras, jellyfishes, sea anemones, and corals • A. Hydrozoans: Most of life as polyp ex. hydra • B. Scyphozoans: Most of life as medusa ex. jellyfish • C. Anthozoans: Only polyp stage in the life cycle ex. corals and sea anemones
Simplest animal with true tissues. • soft bodied, have tentacles, radial symmetry, • 1. Gut – gastrovascular cavity with one opening • 2. Nerve net- detects stimuli • 3. Hydrostatic Skeleton- movement and support with the use of muscles
The Polyp and Medusa Stages 1. Polyp - Stationary, Examples: Hydra, Coral, and Sea Anemone 2. Medusa- Swimming, Cup Shaped. Examples: Jelly Fish and Man O War
The Polyp and Medusa Stages Tentacles Bell gut Mouth/anus Mouth/anus Gut Tentacles 3 tissue layers Epidermis Mesoglea Gastroderm Medusa Polyp
1. 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.