Sponges, Cnidarians, Flatworms and Roundworms

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Sponges, Cnidarians, Flatworms and Roundworms

• Chapter 26
• Biology
• Auburn High School
• p. 712 737

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26.1 Sponges

• p. 713 717

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Characteristics of Sponges

• Phylum Porifera
• Meaning porus pore fera bearer
• Habitat
• Most live in ocean but some live in freshwater
• Locomotion
• Adults are sessile
• Larvae have the ability to swim
• Feeding
• Filter feeder

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Characteristics of Sponges

• Reproduction
• Asexually
• Fragment break-off from parent and form new
  sponges
• Or external buds form
• Sexually
• Most are hermaphrodites
• Some have separate sexes
• Either external fertilization ( eggs and sperm
  are released into the water) or internal
  fertilization ( eggs remain and sperm are carried
  by the flow of water through the sponge)
• Refer to Figure 26.3 - p. 716

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Characteristics of Sponges

• Body plan
• Asymmetrical

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26.2 Cnidarians

• p. 718 725

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Characteristics of Cnidarians

• Phylum Cnidarian
• Meaning knide needle
• Habitat
• Marine invertebrate
• Locomotion
• Polyp stage is sessile
• Medusa stage is motile via tentacles

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Characteristics of Cnidarians

• Feeding
• Use nematocyst (sticky or barbed capsule) to
  sting prey
• Prey is taken into the body to be digested
• predator

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Characteristics of Cnidarians

• Reproduction
• Sexual
• Occurs in the medusa stage
• Male releases sperm and female release eggs into
  the water
• Zygote becomes a larvae and grows into a polyp
• Asexual
• Occurs in polyp stage
• budding

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Characteristics of Cnidarians

• Body plan
• Radial symmetry
• Significance
• Provide homes for other sea creatures
• Examples
• Jellyfish
• Sea anemones
• Hydra
• corals

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26.3 Flatworms

• p. 726 730

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Characteristics of Flatworms

• Phylum Platyhelminthel
• Acolemates with thin solid bodies
• Habitat
• Moist habitats on land
• Marine and freshwater
• Locomotion
• Through the use of cilia or muscle contractions

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Characteristics of Flatworms

• Feeding
• Parasites
• Release enzymes to begin food digestion outside
  the body, then suck it into the gastrovascular
  cavity
• Reproduction
• Most are hermaphrodites
• both sexually and asexually
• Sexually they exchange sperm eggs are
  fertilized internally
• Asexually by regeneration

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Characteristics of Flatworms

• Significance
• Cause diseases
• Examples
• Tapeworms
• Planarians
• Flukes

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26.4 Roundworms

• p. 731 733

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Characteristics of Roundworms

• Phylum Nematoda
• Pseudocoelomate, cylindrical worms w/ length wise
  muscles, relatively complex digestive systems,
  and 2 body opening
• Habitat
• Soil, animals, freshwater and saltwater
• Locomotion
• thrashing

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Characteristics of Roundworms

• Feeding
• Half are parasitic
• Significance
• Can infect and kill people,
  animals and plants

• Examples
• Ascaris
• Hookworms
• Pinworms
• Trichinella
• Heart worms (dogs)