Poriferas form a complex system of pores and canals called canal system which helps in regulating the flow of water within them. E.g. Sycon.

Aschelminthes possess jointed appendages. E.g. Ascaris.

Annelidans possess metameric segmentation in body. E.g. earthworm.

Arthropodans possess jointed appendages in each segment of their body. E.g. Cockroaches

Echinoderms possess water vascular system or ambulacral system E.g. starfish