CNIDARIA
Organisms of Cnidaria Phylum are found in both fresh and salt water. Their egneral defense against predators involves stinging cells. These water dwelling organisms are usually free floating as adults and swim as larva.Also, many of their basic bodily proceeses involve diffusion, and passive transport. The three classes within the phylum are Anthozoa, Hydrozoa, and Scyphozoa. Sme example of species within this Phylum are: the jellyfish, the hydra, coral and sea anemones. The Cnidaria nervous system is simple, as they are close to not even having one. They have no brains or even a central nervous system. Instead these, they have simple nerve nets of intertwined nerves which are made up of sensory neurons. These neurons react to different stimuli with signals that cause other neurons to send other signals, like motor neurons that contract muscles. The cilia found in their neurons detects physical contact. These systems of web like neurons are necessary for the organisms coordination, movement, and reactions to certain odors that are vital for survival.