Sea Anemones (Actiniaria)
Size – Most range from a half an inch to 2 inches in diameter and 0.6 – 4 inches long.
Sea Anemones are named after the flower called an Anemone. They are very colorful and typically consist of a single polyp attached to a hard surface.
They are armed with stinging cells called “cnidocytes.” Their tentacles can actually retract or extend based on context, with the latter method being used to capture prey.
Sea Anemones can be found in all oceans and nearly all habitats around the world. They are known to dwell in both deep and shallow waters, but the most diverse habitat would be in the tropics.
They cling to hard surfaces such as rocks, shells, timber, or can sometimes be found in seaweed, sand, and mud.
Sea Anemones are typically predatory and have the ability to consume crustaceans such as crabs, as well as molluscs and even some small fish.
They have the incredible ability to retract or extend their tentacles and change their shape drastically. Their tentacles and column can twist, extend, bend, and retract.
They are almost entirely sessile, meaning they do not move much (if at all,) and can stay in the same spot for a long time, sometimes months. They are able to move, albeit very slowly, somewhat scooting or gliding to creep around their habitats.