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Sponges (Chapter 26.2). Please set up your notebook for Cornell Notes. Phylum Porifera pore bearers Sponge characteristics Sessile spend entire adult life attached in a single place Multicellular with a few specialized cells Heterotrophic with no cell walls. Form and function - PowerPoint PPT Presentation
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Sponges (Chapter 26.2)Please set up your notebook for Cornell Notes
Phylum Porifera pore bearersSponge characteristics
Sessile spend entire adult life attached in a single placeMulticellular with a few specialized cellsHeterotrophic with no cell walls
Form and functionBody plan asymmetrical
Large central cavityChoanocytes cells that use flagella to move water through the spongeOsculum large opening at the top of sponge where water exits
This movement of water allows a sponge to feed, respire, excrete and circulate
Other cell structuresSpicule a spike shaped structure made of silica or calcium carbonate
Spicules are made by cells called archaeocytesSponges are filter feeders
Sift microscopic food from water and digest intracellularly
Sponges have no nervous tissue and cannot respond to changes in the environment
Some sponges do produce toxins to thwart predators
ReproductionSexual sperm is released into the water and drawn into other sponges by the choanocytes
Fertilization is internalZygote develops into a larva that is free floating and carried by water currents until it settles and attaches to a surface
Asexual Budding a new individual grows on the body of the parent and detaches forming a separate organismGemmules a group of archaeocytes surrounded by spicules
Can withstand extreme temperatures and drought
Why are sponges important?Provide habitats for marine animalsForm partnerships with algae and bacteriaSpicules can direct light for photosynthesis even in dim water