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.
The main characteristics of cnidarians are they are invertebrates that use stinging cells to paralyze and capture prey and to defend them selves. They reproduce both sexually and asexually. And some of them live in a colony.