2 Odyssey Expeditions - Sponges
Introduction
• Phylum Porifera “pore bearer”
• Aquatic and mostly marine• Sessile • Body can be stony,
rubbery, or gelatinous• Size range: few
millimeters to five meters • Radially symmetric or
asymmetrical
Jason Buchheim
Jason Buchheim
3 Odyssey Expeditions - Sponges
Structure
• Simplest form resembles a tube closed at the attached end and open at the other.
• Outer surface is called the pinacoderm (made up of pinacocyte cells)
• Pinacoderm has many porocytes (pores) which allow water to enter the sponge wall.
• The atrium opens to the outside through the osculum (large opening at top)
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Structure
• Beneath the pinacoderm is the mesohyl (gelatinous matrix that contains support structures and amoebocytes)
• Body supported by calcareous or siliceous spicules (needle, rod, star shaped) and/or spongin fibers
• Atrium wall consists of choanocytes which create a flow of water through the sponge by beating their flagella
• As water flows in the amoebocytes pick up and distributes nutrients to the sponge.
7 Odyssey Expeditions - Sponges
Feeding
• Water flow created by choanocytes
• Water enters porocyte
• Nutrients picked up by amoebocytes
• Waste products deposited in water flow
• Water enters atrium
• Flow carries waste materials and water out the osculum
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Reproduction
• Many can regenerate • Asexual and sexual reproduction• Asexual by fragmentation and
budding• Sexual: Hermaphroditic• Most fertilization is external• Larvae is free swimming and
attaches to a suitable hard surface after a few hours to several days later (two types)
• Changes into a sponge
Parenchymella Larvae
Amphiblastula Larvae
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Economic• Harvested for bath sponges
• Anticancer biochemicals
12 Odyssey Expeditions - Sponges
Body Types• Asconoid (simplest)• Syconoid• Leuconoid (most complex)• Body wall folding is the main difference between
body types• Body folding increases surface area:
– Increases choanocyte layer and reduces the amount of water needed to filter
– Increased turbulance puts more food in contact with amoebocytes
– Enables the sponge to grow large because of the added nutrition
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Asconoid
• Simplest in form
• Cylindrical in shape
• No body wall folding
14 Odyssey Expeditions - Sponges
Syconoid
• More complex than asconoid
• Mostly cylindrical in shape
• Some body wall folding
• Increase # of choanocytes
Flagellated chamber
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Leuconoid
• Most complex
• Varied in shape
• Extreme body wall folding
• Greatly increases # of choanocytes
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Sponge Classes
• Class Calcarea
• Class Hexactinellida
• Class Demospongiae
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Class Calcarea
• Spicules composed of calcium carbonate
• No spongin
• Entirely marine
• Usually found in shallow water
• All three body types
• Typically less than 10 cm in height
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Class Hexactinellida
• Called glass sponges• Siliceous spicules• Most symmetrical looking sponges• Cup, vase, or urn-like in shape• 10-30cm in height• Inhabit deep water: 200m to 1000m• Dominant sponge in the arctic• Leuconoid body type
21 Odyssey Expeditions - Sponges
Class Demospongiae
• Siliceous spicules and/or spongin fibers• Most are marine, FW sponges belong to
this class• 90% of sponges• Leuconoid body type• Inhabit shallow to deep water• Irregular in shape• Bath sponges belong in this class
24 Odyssey Expeditions - Sponges
Resources
• Barnes, Robert D. and Edward Ruppert. Invertebrate Zoology: Sixth Edition. Fort Worth: Saunders College Publishing, 1994
• BIODIDAC: A Bank of Digital Resources For Teaching Biology. 20 Dec. 2006. <http://biodidac.bio.uottawa.ca/>
• Kinsella, John, Drew Richardson and Bob Wohlers. Life on an Ocean Planet. California: Current Publishing Corp., 2006
• Taylor, Walter K. and Robert L. Wallace. Invertebrate Zoology: A Laboratory Manual Sixth Edition. New Jersey: Prentice Hall, 2002
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