Porifera
common name:
Sponges
Domain: Eukarya
Kingdom: Animalia
Phylum: Porifera
The organisms in the phylum Porifera can
be further divided into four ‘classes’
• Calcerous sponges
• Horn sponges
• Tropical reef sponges
• Glass sponges
Phylum Porifera
There are more than 900 (mostly
marine) species in this phylum.
Below are several examples.
Yellow sponge
Tube sponge
Vase sponge
Giant barrel sponges
can grow large enough
to fit a person inside!
Kingdom:
Animalia
Phylum:
Porifera
Class:
Demospongiae
Order:
Haplosclerida
Family:
Petrosiidae
Genus:
Xestospongia
Species:
X. testudinari
Barrel Sponge
Body Plan/Key Characteristics of Sponges
 multicellular with few specialized cells
 no mouths, tissues, or organ systems
 asymmetrical- no front/back or left/right
sides
 often have a wall around a large central
cavity
 simple skeleton:
 In harder sponges the skeleton is made
of spiny spicules
 In softer sponges the skeleton is made
of spongin, a network of flexible
protein fibers. These are the sponges
that are harvested and used as natural
bath sponges.
7
Essential Functions
Feeding
Sponges are filter
feeders, sifting
microscopic food
particles from the
water.
Fundamental question: How do choanocytes help sponges feed?
Choanocytes are specialized cells that use their
flagella to move a steady current of water (and
food!) through the sponge.
Respiration, Circulation, Excretion
As water moves through
the body cavity, oxygen
dissolved in the water
diffuses into the cells of
the sponge.
At the same time, waste
such as carbon dioxide
and ammonia diffuse
into the water and are
carried away.
Response (nervous system)
 Sponges do not have a nervous
system.
 Many sponges protect
themselves by producing toxins
that make them poisonous to
potential predators.
Reproduction
Sexual reproduction
Most sponges are hermaphrodites: a single sponge will
produce both egg and sperm, but at different times.
Asexual reproduction
Some sponges can reproduce by a process called budding.
Movement
Only able to move during the
larva stage
Sessile as adults
Ecology
SPONGES…
 provide habitat for marine animals - snails, sea stars
and shrimp
 are a food source for many organisms such as sea
stars, turtles and fishes.
 provide a protected place for bacteria, algae and
plantlike protists to grow. These photosynthetic
organisms provide food and oxygen to the sponge.
Endangered species: Cloud Sponge
- They are extremely
fragile… bodies are
composed of silica (glass)
- Bottom trawling (dragging
nets along sea floor to
catch bottom fish) breaks
their bodies – threatening
the survival of the
population
Resources
Miller, Kenneth and Levine, Joseph. Biology. Upper Saddle
River: Prentice Hall, 2004.
"Marine Mysteries - Could Solving These Mysteries Save The Oceans?"
Marine Mysteries. World Wildlife Federation, n.d. Web. 11 June 2012.
<http://www.marinemysteries.ca/>.
"Treasures of the Sea Exhibit." Treasures of the Sea. Delaware Technical
Community College, n.d. Web. 11 June 2012.
<http://www.treasuresofthesea.org/>.