Phylum Porifera
Phylum Porifera
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Sponges are the simplest animals
Radially symmetrical
Acoelomate
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Body resembles a perforated sac.
Has inner cavity called spongocoel
Has large opening called osculum
Lining body are cells flagellated cells called
choanocytes
These cells beat to produce a flow of H20 into the
sponge through pores in through the body wall, and
out through the osculum.
Body wall is composed of many elements
Mesohyl - gelatenous material
Amoebocytes
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Motile cells which perform many functions
Capture, digest and transport food
Create tough structural fibers of the body wall
called spicules.
A Typical Sponge
Sponges