acoelomate body plan

An acoelomate body plan refers to organisms that lack a true body cavity, called a coelom, between their digestive tract and outer body wall. Instead, their internal organs are embedded directly within the solid tissue mass, providing structural support without a fluid-filled cavity. This setup is common in simple, flat-bodied animals like flatworms. The absence of a coelom influences how these animals grow and move, typically limiting their size but allowing a straightforward organization of internal structures for basic survival functions.