Answers from Katherine Zeratsky, R.D., L.D. Vitamin D deficiency â when the level of vitamin D in your body is too low â can cause your bones to become thin, brittle or misshapen.
All cnidarians have radial symmetrical. There are two major body forms among the Cnidaria-the polyp and the medusa. Sea anemones and corals have the polyp form, while jellyfish are typical medusae. When you look at them, you can see that these body forms are the same except that one is upside down.
There are many advantages for the Cnidarians having two stages in their life cycle. One is in their Polyp Form, one of the stages; they can grow from their juvenile stage easily like the Porifera's do. Another advantage comes from their second stage called the Medusas Stage. During this stage, the Cnidarians can move around in the water there-by allowing the Cnidarians to seek out different types of food.