Sea cucumbers are cylinder shaped animals that live in many different ranges of the ocean. They can be found in warm tropical waters to deep cold sea trenches. Most sea cucumbers are 20 cm long and some adults may not even grow to a centimeter. The body lacks arms but instead it has tube feet. Each tube as a suction cup on the end which allows it to feel and move. The calcareous ring that encircles the throat. The ring is attachment point for muscles operating the tentacles. The tentacles are flexible and it makes it easy for them to grab food.