Gastrovascular cavity

The gastrovascular cavity is the main organ that helps with eating and moving food and nutrients in two important groups of animals: the Coelenterates or cnidarians (like jellyfish and corals) and Platyhelminthes (flatworms). This special cavity can spread out into many channels, helping these animals live. In cnidarians, it is also called the coelenteron. It is sometimes called a "blind gut" or "blind sac" because food goes in and waste comes out through the same opening.

Cnidarians have a simple body with two layers and a jelly-like layer in between. They digest their food partly inside this central cavity. This cavity has just one opening, and in most cnidarians, this opening is surrounded by tentacles that help catch their food.