Shared & Unique Characteristics
No definite symmetry.
Simplest animals- Multicellular body, few tissues, no
No true body cavity.
All are sessile.
Reproduce sexually or asexually.
Has no nervous system.
Lives in aquatic environments, mostly marine.
All are filter feeders.
Skeleton composed of spongin and spicules.
Able to repair damages to their bodies.
Sponges are sessile (non-moving)
Sponges are multicellular and their cells are organized
to be beneficial to each other
They lack true tissues, or groups of cells that act as a
funtional unit and are separated from other tissues by
They do contain different types of cells
Classes of Porifera
They are split based on the type
of spicules they have.
They have spicules composed of calcium carbonate that
form rays and circles as they come out.
They have simple shapes: either purse, vase, or cylinder
First appeared during the Lower Cambrian Period.
Like the Hexatinellida and the Demospongia, they were
most diverse during the Cretaceous.
Most surfaces are pastel colored, tan, or black.
There are over 100 genuses of calcareous sponges
They have the greatest diversity in the tropics.
Mostly found in shallow waters.
Characterized by their six pointed siliceous spicules.
They are very uncommon and found at great depths.
Most of these animals are cupped shaped with
sturdy internal skeletons and fused spicules.
They were the first sponges developed and the
earliest known Hexactinellidas are from the earliest
Cambrian or late Neoproterozoic
Electric recievers on the spicules that can conduct
Largest, commonest and most widely distributed
group with a skeleton made of siliceous spicules.
They are members of the Leucon grade, which
means that they have many canals inside their
body and their shape can change throughout the
day to take in more water.
They are sometimes brightly coloured.
They are the only group that has freshwater
When they decompose, their spicules can easily
Sclerosponges were first proposed as a class
of porifera, but then Vacelet found out that
sclerosponges occurred in different classes
of porifera. ( which means they are not a
closely related group)
They have a soft body with a skeleton
constructed from calcium carbonate,
argonite or calcite.
They are similar to coral reefs, which is why
they are also named coralline sponges.
• Porocytes-Water enters the sponge through porocytes
• Spongocoel-Water goes from the porocytes into the
spongocoel. The spogocoel is the central cavity of the
sponge where digestion takes place.
• Choanocytes-Have beating flagella which move water
through the sponge. These are the “feeding” cells. Food is
engulfed and digested or transferred to amoebocytes.
• Amoebocytes-Transport nutrients to other cells of the
sponge. Produce materials for spicules.
• Spicules-Skeletal support structures
• Osculum-Large opening on top of the sponge where
water and waste is expelled.
Basic Structure (continued)
Multicellular, but not yet real tissue
Structure of Sponges Helps with
The whole structure of a sponge is built around the
flow of water through the sponge.
There are pores to intake water and an osculum to
expel the water
Interesting Facts! YAY!
• Inside a sponge, there are no organs. Special cells carry out all the
• When sponges are strained through a piece of cloth, they come back
together into a new shape on the other side of the cloth.
• If part of a sponge breaks off, then it becomes an entirely new sponge.
• Near Florida and in other areas, sponges live on the backs of hermit
crabs and act as a type of shell.
• Chemicals from sponges are being used to find a cure for cancer and
• Within a sponge, it is possible to find 16,000 other animals!
• In the Caribbean Sea, sponges can filter all of the water in one day.
• The largest sponge ever measured was about 10 feet wide. It was a
Choanocyte: also known as collar cells. Flagellated
cells that line up the internal chambers.
Atrium: where water and food particles flow into
Osculum: excretory structure in a sponge
Spicules: skeletal structure that provides structural
Spongin: collagen protein that forms the fibrous
Parenchymello: larval form of Demospongiae
Gemmules: internal buds found in freshwater sponges