- feed in several ways
- predation on corals, absorbing dissolved organic chemicals, filtering food particles out of water, getting nutrients from algae with their cells
- depend mostly on absorbing dissolved nutrients uses tentacles to capture food
- tentacles have rows of cilia whose beating creates currents that flow towards the mouth
Respiration:
- there are no respiratory organs and cells layers absorb oxygen and expel carbon dioxide into the water
Circulation:
- they lack a circulatory system because they do not need one
Excretion:
- canal like cavity in they bodies for ingestion, digestion
- gas is eliminated by diffusion
- solid waste is dissolved
Response/ Movement:
- muscle surrounding cavity relaxes and contracts, causing it to move back and forth
- as water moves in one direction, it moves in opposite way
Reproduction:
- sexual and asexual
- assexually with diffusion
- sexually with the ova and sperm being released from the gonads and gastroderms