Phylum – Porifera
The Sponges
General
Information
About 9000
different species.
The most simple
of all animals.
Thought to be
the first animals
ever. Many found
in the fossil
record.
Evolution?
• Thought to be
related to
protozoans called
choanoflagellates.
• Sponges have
cells called “collar
cells” that look just
like them.
Choanocytes of a Sponge
• Choanocytes (collar
cells) line inside of
body cavity
(spongocoel)
• Have flagella that
spins to pull in water
& food
• Collar traps plankton
(food) from water
Collar
Characteristics
o All are aquatic. Most are
marine
o Saltwater sponges are
brightly colored
o Freshwater sponges are
small and dull green color
o Asymmetrical
o Sessile as adults (attach
to rocks)
Size – about ½ inch to 6 feet.
Characteristics
o Porifera means porebearing
o Water enters through
pores (ostia) bringing in
food and oxygen
o Filter feeders on stuff
like plankton
o Osculum – large opening
at the top where excess
water leaves
•Choanocytes line the gastrovascular cavity &
capture food
•Amebocytes digest & distribute food
Sponge Body Structure
o Inside body cavity of sponge is a
hollow space alled the Spongocoel.
o Have 2 cell layers with Jelly-like
material between cell layers called
mesoglea.
o The inside is lined with “collar cells”
that have flagella that move the
water into/out of the sponge body.
WATER OUT
Water Flow
Through the
Sponge
WATER IN
Osculum
Water Flow Through Sponge
Skeletal Structure of the Sponge
• Skeleton made of network of
protein fibers called Spongin
• Spicules are hard spear or starshaped structures
• Spicules made of CaCO3 (like sea
shells) or silica (glass)
Sponge Skeletons
Silica Spicules
Limestone Spicules
SPONGIN
Sponge Reproduction
o Sponges can
regenerate (regrow)
lost body parts
through mitotic cell
division (asexual)
o Sponges also
reproduce asexually
by budding
Sponge Reproduction
o Sponges are
hermaphrodites (produce
both eggs & sperm)
o Sponges reproduce
Sexually by releasing
eggs & sperm into the
water from the Osculum
o Cross-fertilize each
other’s eggs
Sponge
releasing eggs &
sperm
Surviving Harsh Conditions
o Gemmules are specialized buds made
to survive harsh weather (hot or
cold)
o Become adult sponge conditions
become favorable
Some animals use the sponge for
camouflage or as a hiding place or home
the venus flower basket is the strongest
“glass” structure known. it is so sturdy that it
is being investigated by material scientists
for the source of its strength.
Branching Tube Sponge
Stove Pipe Sponge
Vase Sponges
Barrel Sponges
Ball Sponges
Rope
Sponges
Bath sponges…