Phylum Porifera

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Phylum Porifera
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General Characteristics

• SPONGES!
• Simplest of all animals
• _________________
• No true tissues or organs
• _________________________
• Marine and Freshwater
• Saltwater are colorful
• Freshwater are dull green color

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General Characteristics Cont.

• Sponges are sessile as adults
• Free swimming larval stage called dipleurula
• Porifera means pore-bearing
• Water enters through pores bringing in food and
  oxygen
• ____________________________
• Osculum- large opening at the top where excess
  water leaves

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Water Flow Through the Sponge
WATER OUT
WATER IN
Osculum
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3 Basic Cell Types

1. _______________
2. Mesenchyme Cells
3. Choanocytes

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3 Basic Cell Types

• 1. Pinacocytes- flat cells that line the outer
  surface of the sponge.
• May be slightly contractile
• ____________ a specialized type of pinacocyte
  are tube-like in shape contractile and can
  regulate water circulation.

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• 2. Mesenchyme Cells- move around in the mesohyl
  layer are specialized for reproduction,
  secreting the skeleton, transporting/storing
  food.
• ____________ jelly-like layer just underneath
  the pinacocyte layer.

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• 3. Choanocytes- flagellated cells that line the
  inner chamber of the sponge called collar cells.
• Flagellum flagella spins to create water
  currents to pull in water and food
• Collar __________________________ (plankton)
  from the water

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Choanocyte
Choanocyte
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__________________________

• Consists of either one or all of the following
• Spicule microscopic needle-like spikes that are
  made of Calcium carbonate (CaCO3) or silica
  (glass).
• Spongin a fibrous protein made of collagen

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Sponge Skeletons
Silica Spicules
Limestone Spicules
SPONGIN
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Sponge Body Types

• 3 Kinds-
• Ascon
• __________
• Leucon

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Ascon

• ____________________
• Are vase-like
• Least common type of sponge

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________________

• Sponge wall is folded into canals
• Choanocytes line the
• radial canals to
• move water

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Leucon

• Have an extensively branched canal system.
• ___________________________
• Multiple ostia
• for water to exit
• Increased surface
• area means more
• water can move
• through sponge

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Body Forms Summary
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Reproduction

• Sexual Reproduction- sponges are monoecious (male
  and female in the same body)
• Release sperm and eggs into the water from the
  Osculum
• Cross-Fertilization takes place in the ocean
• _____________________________

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Reproduction
Sponge Releasing Eggs Sperm
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Reproduction Cont

• Sponges can regenerate (regrow) lost body parts
  through mitotic cell division (asexual)
• Sponges also reproduce asexually by
  ________________

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Reproduction Contd
gemmule

• Asexual Reproduction- involves the formation of
  gemmules
• ______________ resistant capsules that sponges
  release to survive unfavorable conditions.
• When conditions become favorable, the gemmules
  sprout into sponges.

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_____________________

• Phylum Porifera
• 3 Classes
• Class Calcarea
• Class Hexactinellida
• Class Demospongiae

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Class Calcarea

• Spicules made of Calcium Carbonate
• Can have all three body forms
• __________________
• Ex. Grantia

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Class Hexactinellida

• ___________________________
• Can have syncon or leucon body forms
• Often fused into an intricate lattice
• Glass sponges

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Class Demospongiae

• Spicules made of silica, spongin, or both.
• ____________________
• Ex common bath sponge