classes of sponges and sponge anatomy notes

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classes of sponges and sponge anatomy notes

• HW

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Classes of Sponges

• There are three different classes of sponges
• Calcarea
• Hexactinellida (Glass Sponges)
• Demospongia

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Canal Systems

• Canal systems refer to method of water flow
  throughout the sponge.
• There are three different types of canal system
• Simple (asconoid)
• Water enters spongocoel by incurrent openings of
  the pore cells. Cells lining the spongocoel
  absorb the nutrients and oxygen and left over
  water is expelled through the osculum.
• Advanced (Syconoid)
• The body wall is folded, accomodating more pores
  without increasing the size of the sponge.
• Complex (Leuconoid)
• This canal system is extensively branched, and
  thus more complex.

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Calcarerous Sponges

• Sponges of the class Calcaera are known as
  calcareous sponges.
• Their specific characteristics include
• are usually small (4 in height).
• Found in shallow waters
• Skeletons are made up of separate spicules of
  calcium carbonate.

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Calcaerous Sponges

• There are two different varieties
• Leucosolenia
• These are the simplest sponges that have a simple
  canal system.
• Scypha
• These contain an advanced canal system.
• There are also calcareous sponges that have a
  complex canal system.

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Class Hexactinellida

• This class is commonly known as glass sponges.
• Their specific characteristics include
• Skeleton consists of six-pointed spicules fused
  in a geometric pattern.
• Found in deep, tropical waters.
• Possess an advanced canal system.

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Class Demospongia

• This class contains that largest number of
  sponges.
• They are also the most marketable sponges, often
  used as cleaning products.
• Their specific characteristics include
• Skeleton consisting of elastic (spongin) fibers,
  silicon dioxide, or a combination of the two.
• It is the elastic nature of the skeleton that
  makes them spongy.
• They possess a complex canal system.

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Sponge Anatomy

• Sponges have the following types of cells
• Epidermal cells line the outside of the sponge.
• Pore Cells Which extend through the body wall
  of the sponge to allow water in.
• Gelatinous Layer The middle layer of the body
  wall that is jelly-like and contains mobile
  amoeboid cells.
• Amoeboid Cells mobile cells that move around
  the sponge, secrete spicules, and are responsible
  for digestion.
• Spicules are the calcium carbonate structures
  that are imbedded in the body wall of the sponge
  to support it.
• Collar Cells Line the internal cavity
  (spongocoel), and have flagella used to catch
  food particles.