190 likes | 578 Views
Phylum Cnidaria. Jellyfish. hydra. Coral. Sea Anemone. “True Animals” – Have tissues ( ecto and endo ) & symmetry Most live in salt water; some in fresh water. Cnidaria. Polyp: Cylindrical, pine shaped animals that are usually attached to a rock Ex. Hydra, sea anemones, corals
E N D
Jellyfish hydra Coral Sea Anemone
“True Animals” – Have tissues (ecto and endo) & symmetry Most live in salt water; some in fresh water Cnidaria
Polyp: Cylindrical, pine shaped animals that are usually attached to a rock • Ex. Hydra, sea anemones, corals • Medusa: Bell shaped body; umbrella • Ex. Jellyfish Appearance
None! No mesoderm Body cavity?
Most have primitive muscle cells Coral have external skeletons of calcium carbonate Muscular-Skeletal
Sac with a digestive cavity- Gastrovascular Cavity Single opening that acts as a mouth/anus Digestion
Capturing Prey- Cnidarians are carnivores (eat meat) that use tentacles arranged in a ring around their mouth to capture prey When a trigger is stimulated on a stinging cell called the cnidocyte, a harpoon or nematocyst shoots out & injects poison into the prey Food is pushed into the gastrovascular cavity where digestion begins (extracellular digestion) Undigested remains leave through the mouth/anus Digestion
Cnidocyte and nematocyst at work! Jellyfish Video!
Nerve Net – Cnidarians do not have a brain but they have simple sensory receptors that detect & respond to stimuli Nervous Circulation • NONE! Respiration • Diffusion- Cnidarians absorb oxygen through their skin
Asexual – Budding: • Formation of outgrowths that pinch off from parent to live independently Reproduction
Sexual – Forms a zygote & free swimming planula that settles on ocean floor REPRODUCTION
One opening Mouth/Anus – release waste Excretion
Radial! Symmetry