Sea Anemones
Sea anemones have the polyp body form: they live attached to the seafloor by an disk. The tentacles are lined with stinging cells and are used in capturing small animal prey. Depending upon the size and species of the anemone, prey can range from small plankton to larger fish. The mouth disc is also lined with microscopic hairs, called cilia, whose action creates currents important in sweeping debris from the anemone's surface. In some sea anemones, these ciliary currents are used in feeding, gathering tiny particles of food that drop from the water onto the disc.
Sea Anemones have primitive nervous systems, without a central point in the connection (a brain). Due to the lack of a brain and sense organs Sea Anemones have to rely on biochemical reactions to respond to various stimuli. The muscles and nerves are much simpler than those of most other animals, although more specialised than in other cnidarians, such as corals. Cells in the outer layer (epidermis) and the inner layer (gastrodermis) have microfilaments (small rod like appendages) that group into contractile fibers. These fibers are not true muscles because they are not freely suspended in the body cavity as they are in more developed animals. Some feelers are present on the center on the Anemone that identify harmful objects and brings in the tentacles in a defensive manner.
Sea Anemones have primitive nervous systems, without a central point in the connection (a brain). Due to the lack of a brain and sense organs Sea Anemones have to rely on biochemical reactions to respond to various stimuli. The muscles and nerves are much simpler than those of most other animals, although more specialised than in other cnidarians, such as corals. Cells in the outer layer (epidermis) and the inner layer (gastrodermis) have microfilaments (small rod like appendages) that group into contractile fibers. These fibers are not true muscles because they are not freely suspended in the body cavity as they are in more developed animals. Some feelers are present on the center on the Anemone that identify harmful objects and brings in the tentacles in a defensive manner.