Phylum Porifera

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Phylum Porifera

• AKA Sponges

and no not this loser! ?
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Porifera ? General Characteristics

• Literally means pore-bearers
• They are covered in pores
• How are they animals?
• Multicellular
• Hetertrophic
• No cell walls
• A few specialized cells
• Adults are sessile

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Porifera ? Body Plan

• Asymmetrical shape
• Only animals that are so
• No mouth or gut
• No tissues or organs

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Body Plan Cells Structures

• Pores
• Openings thru the body into the central cavity
• Osculum
• Opening from body cavity into open water
• Choanocytes
• collar cells
• Use flagella to create water currents

• Archaeocytes
• Multi-function cells
• Make spicules and are involved in digestion and
  reproduction
• Spicules
• CaCO3 or silica skeleton
• Spongin
• Flexible skeleton fibers

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Porifera Drawing
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Essential Functions

• Feeding
• Filter feeders
• Remove organic matter from the water
• Digestion is intracellular
• Food is trapped
• Digestion started by choanocytes
• Finished transported by archaeocytes

• Respiration
• Circulation
• Excretion
• All are accomplished by diffusion and water
  movement

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yet more Functions

• Response
• No nervous system
• no response
• Some produce toxins
• Unpalatable
• or
• Poisonous

• Movement
• No nervous system
• no movement
• Adults are sessile
• Only larva move

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and finally
Reproduction!

• Some reproduction is asexual
• Budding part breaks off and grows new adult
• Gemmules archaeocytes surrounded by spicules
• Produced during difficult environment conditions
• Some reproduction is sexual
• Individuals can produce both sperm and egg cells
• However, they are produced at different times

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Sexual Reproduction

• Internal fertilization
• Sperm is released into water
• They enter pores of other sponges
• Archaeocytes carry sperm to egg
• Zygote forms a motile larva

SpermEgg
Zygote
Larva
Adult Sponge
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Humor Break
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Sponges Are Also Important to the Environment.

• They fill many ecological roles.

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Role as Habitat

• Sponges can be home to many organisms.
• Snails, sea stars, sea cucumbers, brittle stars,
  shrimp, fish, eels

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Symbiotic roles

• In addition to larger organisms
• sponges provide habitats for many bacteria and
  algae.
• especially photosynthetic organisms
• Some actually live inside the sponge body.
• Spicules focus and reflect the light internally

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Role as cleaner

• Sponges keep the water clear for sunlight to pass
  through.
• accomplished as a filter-feeder
• This allows photosynthesis to take place.
• 2 inch diameter sponge ? filters 4 gal./hour