Platyhelminthes Characteristics

Symmetry
Platyhelminthes have a bilateral symmetry. If you divide the flatworm in half, it develops a two mirror images. This is called bilateral symmetry. There are other types of symmetry, including radial, bilateral, and spherical. As you continue reading, you' ll learn about other animals that have these symmetry.

Reproduction
Flatworms reproduce sexually, but other species of flatworms do produce new flatworms using asexual reproduction. In asexual reproduction, a new flatworm is formed when the adult flatworm splits into two pieces, just like how mitosis functions. In sexual processes, Parasitic Platyhelminthes deposit their eggs in their host (an organism that parasites suck nutrients from) or bore themselves into the host tissues. There are also called hermaphrodites. These are organisms that have not only just female or male sexual organs, but they contain both organs.

Organs
When flatworms first start developing unique survival structures, they go through the process of  cephalization . This means they develop a head and brain during their embryo (unborn offspring) stage. Afterwards, platyhelminthes  now have a acoelomate body plan, meaning they lack a coelom (a body cavity located between the intestinal canal and the body wall). This also includes their gastrovascular cavity, which is different from other creatures. After they digest their nutrients, the remaining non-digestible pieces are released through the mouth. In addition, they don't have the organ systems we have. For instance, they don't contain a circulatory system. This is because oxygen and carbon dioxide is simply carried by diffusion. Scientists believe this is the effect of the flatworms having a high surface area.