Phylum Porifera (sponges)

This is a “loofah sponge”…

…which is most certainly NOT A SPONGE!

A “loofah” is a type of gourd.

• 5,000 species known• Primarily marine dwelling• Body Plan

– Asymmetric

• Simplest cellular organization– No specialized systems (nervous, circulatory,

digestive)

• Filter feeder– diet of bacteria and other nutrients in water

• Sexual reproduction• 3 types of “skeleton” (some have all three)

– spongin (flexible protein)– CaCO3- shallow marine “spicules”– SiO2- deep marine

spongin fibersspongin fibers

CaCO3 - spicules

SiO2 –

silicon dioxide

Cladograms