1. CNIDARIANS & WORMS CNIDARIANS HAVE DIFFERENT BODY SYSTEMS –Cnidarians are invertebrates (jelly fish, coral,hydras, sea anenome) Most feed on plankton, fish,& clams. –Cnidarians have tentacles with specialized stinging cells to capture prey. Stinging cell has a nematocyst (like a spring loaded dart that shoots out & releases poison). ANIMALS HAVE DIFFERENT BODY PLANS MOST WORMS HAVE COMPLEX BODY SYSTEMS

2. CNIDARIANS Made of layers of tissues (central opening to take in food & remove waste); have a simple nervous system to respond to their environment. Reproduce asexually by buds released in the water; Sexual reproduction by sperm carried to egg in female  releases free swimming larva

4. Animals: different body plans Most cnidarians have radial symmetry (organized around a central point) Radial plan lets sessile organism to capture food from any direction. Most animals have bilateral symmetry (only 1 way to divide into 2 equal halves) Animals head at forward end where mouth is. Animals moves forward, head first in search for food. Food enters one end, nutrients absorbed and waste released at other end; works well for mobile organisms. Jellyfish larva  settle on ocean floor & grow to sessile polyps  release buds (medusas-adult jelly)

5. WORMS Some worms have simple bodies, others have well- developed bodies. Worms have tube shaped body with bilateral symmetry. Take in oxygen dissolved in water through their skin! Must live in moist environments; many live in water

6. SEGMENTED WORMS Segmented worms have bodies divided into compartments. Called annelids (ringed animal). Earthworms(type of annelid) pass soil through digestive system to digest pieces of plant & animal matter from soil & excrete leftover waste. This adds nutrients and oxygen to the soil. Earthworm also has nervous(sense light & vibrations in soil) & circulatory system (several hearts). Some annelids are asexual. But Earthworms have male & female organs; 2worms exchange sperm, fertilize & release eggs which hatch into larva

8. FLATWORM & ROUNDWORMS Flatworms are the simplest worms; they absorb nutrients directly thru their skin. Many flatworms live as parasites, feeding off other organisms (tapeworm lives in digestive tract of humans/animals to absorb their nutrients, doesn’t need a digestive tract of its own) Roundworms found everywhere on Earth Roundworms are more complex, have muscles to move with, Nervous system & Digestive system. Some roundworms are important decomposers on land and in water.