Monday, February 19, 2007

Circulatory System / Excretion

Sponges do not have a true circulatory system, however, flowing water is used instead. Gasses are brought to the cells by the current and enters the cells through diffusion. Archaeocytes deliver the nutrients. Sponges do not have any excretory organs and excretion occurs on the cellular level with each individual cell diffusing their wastes into the water. The water that flows in through the pores of the sponge exit through the Osculum.

DID YOU KNOW? There are sponge fossils that actually date back to one billion years ago.

1 comment:

Unknown said...

whta does this mean and where is the excretion facts thats what im asking cause i still have to do my science work