Download Slide 1 - River Mill Academy

Marine Science
Phylum Porifera
“The Sponges”
Characteristics of sponges:
1) All sponges are multicellular organisms.
2) They cycle water using a system of external pores and internal canals.
3) Internal canals are lined with cells named choanocytes. The function of
choanocytes are to generate water currents which cycle water throughout
the sponge.
4) They have a large exterior opening called an osculum.
5) The biodiversity of sponges is immense since they appear in a variety of
shapes and sizes.
6) The “skeletal system” of sponges are composed of tiny particles or fibers
known as spicules.
Characteristics of sponges continued ….
7) There are three types of spicules:
(1) calcareous spicules (CaCO2),
(2) siliceous spicules (Si),
(3) spongin fibers
8) They are classified based on the level of complexity of their body plan:
(1) asconoid sponges,
(2) syconoid sponges,
(3) leuconoid sponges.
9) Sponges have NO internal organ systems!
10) The processes of excretion and respiration occur via. diffusion across the
cell membrane.
11) Adult sponges are sessile. The larval stage of sponges (planula larva) are
motile and are part of the meroplankton.
The Anatomy of a Typical Sponge
Note the flagella present on each of the
choanocytes lining the inner canal of a sponge.
The cells have been stained for better clarity.
Water
Circulation
Sponges
circulate water
through a series
of external pores
connected by
internal canals.
The large inner
chamber is
called the
spongocoel.
Syconoid Sponges
Asconoid Sponges
Leuconoid Sponges
The 3 Body Types of Sponges
The least
complex
form of a
sponge is an
asconoid.
The most
complex
form of a
sponge is a
leuconoid.
“Skeletal Support”
(calcareous and siliceous spicules & spongin fibers)
3 Types of Spicules
(calcareous, siliceous & spongin fibers)
Siliceous spicules resemble glass
fragments.
Calcareous spicules resemble
small three-pointed stars.
Spongin fibers more closely
resemble pieces of sewing thread
than other spicules.
Sponges release sperm and eggs into the water through a
process called broadcast spawning. This form of sexual
reproduction is necessary because adult sponges are sessile.
Planula
larva
The Biodiversity of Sponges
Sponge Biodiversity
Sponges come in a variety of shapes, sizes and colors.
Because of its simplicity Leucosolenia
is one form of an asconoid sponge.
Grantia is an example of
a syconoid sponge.
Note the osculum
present at the top
end of the organism.
The spicules give this
small sponge a fuzzy
appearance.
The common bath sponge is an
example of a leuconoid sponge
This syconoid sponge has been stained so that
you can view its level of cellular complexity.
The world of sponges beneath the sea!
Vase Sponges
Branching vase sponge
Isodictya palmata, Palmate sponge
The glass sponge usually has a small symbiotic shrimp that lives
within its spongocoel. The sponge receives a free cleaning from
it’s symbiont and the shrimp gets a free meal. This is a
good example of commensalism.
Euplectella aspergillum, Glass Sponge
Finger Sponge
Predation!!!
In this picture the sponge has fallen as prey to
its predator, a sea star!
These are not real sponges!
The loofa sponge actually comes from a
plant called a gourd! It is sold as a health
and beauty aid supply and is commonly
used to exfoliate dead skin cells.
Artificial sponges are chemically
created and sold for their abilility
to absorb water. They are often
used to wash cars.
Loofa Gourd
The role of the sponge in Rome in the early first century was that
of cleanliness. Sponges were used in place of toilet paper!
The sponge-on-a-stick was rinsed in
the channel of running water at
your feet. Ewwww!
The End