Download - Phylum Porifera - Sponges
Phylum Porifera- Sponges
Among the most ancient animals
Mostly marine but some fresh water
Porifera- literally means “pore bearer”, which is appropriate because they have tiny openings all over their body
Once thought to be plants because they are sessile
What are Sponges? Multicellular, heterotrophic animals They are very different from other
animals Scientist believe that the
evolutionary line that lead to sponges is a dead end and produced no other animals
Phylum Porifera – Internal Structures
Porocytes = pore cellsChoanocyte = collar cellSpongocoel = central cavityMesohyl = jelly-like inner layer
1. Body Symmetry
Asymetrical (no symmetry)
2. Level of body organization
Cellular- assemblage of specialized cells
No tissues No organs
3. Body Cavities/ Coeloms
Nothing that resembles a mouth or gut
Feeding Filter feeders – microscopic particles
stick to collar cells and engulfed by endocytosis
Then passed on to amebocytes where it is digested and moved on to other parts of the cell
Respiration Water that flows through the sponge allows it to absorb oxygen and release CO2 into the water
Internal Transport
Mostly done by the water that is filtered through sponges
Amebocytes
Excretion
Metabolic waste is also carried away by the water that is moved through the sponge
Response
No nerve system Do not respond to stimuli
Movement
Sessile Attached to the
substrate
Reproduction
Reproduce asexually and sexually Formation of gemmules
Asexual Reproduce by budding (really it is
fragmentation) - part of the sponge simply falls off the parent and grows into a new sponge
Gemmule Formation When faced with cold
winters gemmules are formed
Sphere shaped collections of amebocytes surrounded by a tough layer of spicules that can survive cold temperatures and drought
Reform into a sponge when conditions are favourable
Sexual Sperm are released into the water
via the osculum Amebocytes collect the incoming sperm
and deliver it to the eggs in the body wall Creates a zygote Develops into a larvae that swims
and is carried away by water Later settle down and create a new
sponge
Boring Sponges
Clean up the ocean floor
Symbiotic relationships
Blue-green algae
Plant like protists
Provide oxygen to the sponge and clean up waste
Human Use Cleaned dried sponges
can be used for bathing A compound in a
Caribbean sponge may be useful against leukemia and the herpes virus
May be the answer to powerful antibiotics
Can possibly fight against certain forms of arthritis