CNIDARIANS

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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

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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

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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)

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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

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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

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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, doesnt 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.