Phylum Porifera

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Phylum Porifera

• The Sponges

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Phylum Porifera Overview

• Most primitive of the multicellular animals
• There is some debate if sponges are complex
  colonial protozoans and not metazoans.
• Sponges
• Over 7,000 species, approximately 40 species that
  occur in local waters
• 2 of all sponges are freshwater, none are
  terrestrial

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Evolution

• Evolved from Edicarian fauna in Precambrian 600
  mybp
• Presently 15,000 species, in which 150 occur in
  freshwater.

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Phylum Porifera
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Characteristics

• No true tissues or organs
• No symmetry
• No nerves or muscles
• Sessile
• Reproduce sexually and asexually
• Skeletons composed of CaCO3 or SiO2 spicules or
  spongin
• Filter feeders

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Phylum Porifera
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Sponge Body Shapes Types
Asconoid
Syconoid
Leuconoid
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Porifera Anatomy

• No true tissues
• Consists of organized cells supported by a
  skeleton of
• spongin fibers
• calcareous spicules
• silica spicules
• a combination of these, or perhaps no skeletal
  structure at all

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Phylum Porifrea
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Porifera Anatomy
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Phylum Porifrea
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Collar Cells

• Choanocytes (collar cells) act as a pump to
  bring water into the sponge

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Phylum Porifrea
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Sponge Support

• Collagen is found between the inner canals and
  chambers
• Mesohyl
• Ameboid cells located in the mesohyl, have
  different roles
• Archeocytes
• Sclerocytes

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Phylum Porifrea
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Spicules

• Collagen is stiffened by adding microscopic
  mineral accretions or additional protein fibers
  (spongin) or both.
• Spicules skeleton structures, made of calcium
  carbonate (CaCO3) or silicon dioxide (SiO2).

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Phylum Porifrea
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Asconoid Diagram
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Phylum Porifrea
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Porifera Classification

• Phylum Porifera
• Class Calcarea
• Class Demospongiae
• Class Hexactinellida
• Sclerospongiae is no longer considered a class

Taxonomic Detail
All other classes
Desmospongia
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Phylum Porifrea
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Class Calcarea

• CaCO3 spicules
• Mostly small in size (lt15 cm.), and form
  irregular masses
• Contains all asconoid forms
• Most syconoids
• Never contain spongin, restricted to shallow
  water, and strictly marine

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Class Desmospongia

• Most marine sponges (90)
• All freshwater sponges
• Leuconoid
• Spongin and SiO2 spicules

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Phylum Porifrea
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Class Hexactinellidae

• Usually found in deep water on soft substrates in
  the tropics 200-1,000m.
• Glass-like lattice work
• SiO2 spicules
• Spicules are six pointed and have a lattice-like
  structure
• Cup, vase or urn shape

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Phylum Porifrea
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Porifera Reproduction

• Asexual budding
• Regeneration can regenerate from broken pieces
• Sexual Usually hermaphroditic with male and
  female cells scattered throughout the connective
  tissue.

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Phylum Porifrea
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Porifera Larvae

• Neighboring sponges are fertilized by sperm
  entering through the ostia
• Ciliated mouth less larvae (parenchymella) is
  released.

parenchymella
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Phylum Porifrea
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Feeding

• Filter feeding plankton and organic matter.
• Most of this material is trapped by the
  choanocytes
• Amoebocytes gather food from choanocyte, digests
  it, and delivers nutrients to cells. Also forms
  skeletal fibers and gametes and removes CO2 and
  waste.

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Predators

• A few species of fish
• seaslugs
• hawks bill and loggerhead turtles
• Can use toxins to ward off predators

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Refuge

• Sponges provide habitat for wide variety of
  animals.
• As many as 16,000 different species of animals
  have been found in one loggerhead sponge.

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Hawaiian Sponges
Phylum Porifera Class Desmospongiae Gelliodes
fibrosa
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Hawaiian Sponges
Phylum Porifera Class Desmospongiae Haliclona
caerulea
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Hawaiian Sponges
Phylum Porifera Class Desmospongiae Suberites
zeteki
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Hawaiian Sponges
Phylum Porifera Class Desmospongiae Mycale
parishii
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Hawaiian Sponges
Phylum Porifera Class Desmospongiae Mycale armata