Cnidarians were the first animals to have muscles and nerves to produce behavior. They were also the first to have a mouth and stomach to digest food. We learn about nematocysts when we watch an anemone catching a goby and two anemones fighting. Cnidarians come in various body shapes and have different ways of living. Corals are cnidarians that build reefs...
Find the full documentary at: https://www.shapeoflife.org/phyla
