Phylum Platyhelminthes: Platyhelminthes is a phylum of dorsoventrally flattened acoelomate but triploblastic animals having bilateral symmetry and blind sac body plan. Due to their flattened nature, Platyhelminthes are also called flatworms. The term Platyhelminthes was coined by Gegenbaur (1859). Characteristics of Phylum Platyhelminthes: Flatworms are free-living commensal or parasitic organisms. The free-living worms may be terrestrial or freshwater but a majority of endoparasitic. The body is dorsoventrally flattened, leaf-like or ribbon-like. The parasitic worms bear suckers and hooks to get attached themselves with hosts. Platyhelminthes are triploblastic animals with three germ layers- ectoderm, endoderm and mesoderm. Spaces between the body … Continue reading Phylum Platyhelminthes (The Flatworms)