PHYLUM PORIFERA
The Sponges
General characteristics of phylum
Porifera
1. Asymmetrical
2. Multicellular, with no tissues or organs
3. Produces skeleton-like structure
4. All aquatic, mostly marine
5. Sessile adults, free swimming larvae
6. Asexual and sexual reproduction
Random facts
• There are roughly 5,000
living species of sponges
• Sponges have lived on this
planet for approximately 540
million years
• What does this tell us about
their adaptability?
• Some sponges can live at
depths of 900 m (3000 ft)
• Giant Barrel Sponges can
be more than 1 meter in
height and diameter
Classes of sponges
• Calcarea
• Hexactinellida
• Demospongae
The Sponge Skeleton
• Made of microscopic needles called spicules or spongin,
a fibrous protein
Body structure of sponges
• Open chamber in the
middle
• Open at the top- Osculum
• Specialized cells
• Porocytes: control water flow
into the sponge
• Archaeocytes: Move around in
the walls; distribute nutrients,
produce spicules/spongin
Body structure of sponges
• Specialized cells
• Choanocytes: line the inner
chamber of the sponge
• Have a flagella that creates water
currents
• Have collar of microvilli to trap
food particles
Archaeocyte
The life of a sponge
• Feeding
• Circulation
• Excretion
• Respiration
• Reproduction
• Movement
• Response
How Sponges Eat
• Filter feeders: eat bacteria, algae, protists and other
organic matter
• Some deep water sponges are carnivores
How Sponges Eat
• Flagella create current and pull water in
• Choanocytes trap and digest the food- intracellular digestion
• How do the nutrients get to the cells? (circulation)
• Archaeocytes
Respiration and Excretion
• Oxygen comes in with water current
• Individual cells release waste into the water
• Leaves out the osculum
Video
• Wonderful world of sponges- BBC Wildlife
http://www.youtube.com/watch?v=BW05vMziy2o
• Harp Sponge
• http://www.youtube.com/watch?v=VC3tAtXdaik
• Sponge filtering with dye
• http://www.youtube.com/watch?v=8ueKlShb9Ls
The life of a sponge
• Feeding
• Circulation
• Excretion
• Respiration
• Reproduction
• Movement
• Response
Sponge Reproduction
• Asexual Reproduction
• 1. Budding, where part breaks off and grows
Sponge Reproduction
• Asexual Reproduction
• 2. Gemmules are formed
• Similar to a seed- made of archaeocytes and spicules
• Gemmules will open and grow into a new sponge
Sponge Reproduction
• Sexual reproduction
• Sponges are monecious
• One individual can produce both sperm and eggs
• Sperm are released into the water
• Carried by currents into the pores of another sponge
• Fertilization produces a larvae which floats on the
currents then settles and develops into an adult
Video
• Sponge reproduction
• http://www.youtube.com/watch?v=5K0gRrowTyA
Response
• No nerves or brain
• Cells can detect touch, water flow or other chemical
signals
Sponge Ecology
• Sponges contain toxic or distasteful chemicals – reduces
predation
• Some fish, turtles, sea slugs eat them,
• Provide habitat for fish, worms, shrimp, symbiotic algae,
• Camouflage for others
• Molluscs or arthropods
Humans and sponges
• Used for scrubbing
• Sponge chemicals can be useful as drugs
• antitumor
• antibiotic
• anti-inflamatory