KINGDOM ANIMALIA
Phylum Porifera
Sponge History
Evidence suggests that sponges
diverged early in the evolution
of animals.
555 mya
580 mya
Are sponges really animals?
Like other animals, they
– are multicellular.
– are heterotrophic.
– reproduce sexually.
Unlike most other animals, they
– do not have a mouth or gut
– are sessile as adults.
– are not organized beyond the cellular
level.
Question #1
Which of the following
characteristics makes sponges
unique among other animals?
A.
B.
C.
D.
They are multicellular.
They are heterotrophic.
They do not have a mouth or gut.
They are capable of reproducing
sexually.
Sponge Organization
A sponge is organized around its
canal system, through which
flagellated cells called choanocytes
pump water.
The body is supported by an
endoskeleton of spongin (a form of
collagen) and/or tiny spicules (made
of calcium or silica).
Question #2
What type of cellular structure
does a choanocyte use to help
create the current inside a
sponge?
A.
B.
C.
D.
cilium
flagellum
spongellium
pseudopodium
Question #3
The skeleton of a sponge
includes tiny crystal-like
structures that are called
A.
B.
C.
D.
spongin
spicules
collagen
choanocytes
Canal Systems
Three major types:
1. Asconoid-the simplest type of
organization. Small and tube
shaped, water enters the
sponge through dermal pores
and flows into the interior.
Asconoid
Canal Systems
Syconoid-larger versions of
asconoids, still having just a
single osculum. However, the
body wall is generally thicker
and more complex with
incurrent canals rather than
simple pores.
Syconoid
Canal Systems
Leuconoid-the most complex in
design in that not all the chambers
are flagellated.
Water flowing in through
incurrent canals is pumped
through the chambers and
expelled via one of a series of
oscula.
Best adapted to increase size.
Leuconoid
Question #4
Which of the following sponge
body types would you expect
to find in this sponge from the
video?
A. Asconoid
B. Syconoid
C. Leuconoid
How do sponges eat?
Sponges are suspension feeders.
Water brings in food that is
trapped by the choanocytes and
transferred to the rest of the
sponge by cells called
amoebocytes.
How do sponges eat?
choanocytes
amebocytes
Classification
There are four classes of sponges:
1. Calcarea-three- or four-rayed
calcareous spicules (calcium
carbonate); all three body forms
Classification
2. Hexactinellida-six-rayed
siliceous spicules (silica);
generally syconoid
Classification
3. Demospongiae-siliceous
spicules (silica) that are not
six-rayed, if any; all leuconoid
Classification
4. Sclerospongiae-not recognized by
all taxonomists. These sponges
have siliceous spicules and a
massive basal skeleton of calcium
carbonate; all leuconoid
Question #5
Which of the four classes of
sponges includes sponges with
both silica and calcium
carbonate in their skeletons?
A.
B.
C.
D.
Calcarea
Hexactinellida
Demospongiae
Sclerospongiae
Reproduction
Asexual Reproduction
– Asexual budding and regeneration
can produce new sponges.
Sexual Reproduction
– Most sponges are hermaphroditic
and can internally fertilize
themselves.