A triploblastic organism which has an internal, fluid-filled body cavity derived from the blastocoel of the embryo. This cavity surrounds the gut, may contain various other organs, and is called the pseudocoel. It differs from the coeloms of true coelomates because it is not derived from or completely lined with tissue derived from the mesoderm. The term is used to classify multicellular animals by developmental pattern.
Selected pseudocoelomate links: