Nematodes vs Cestodes Nematodes and Cestodes are worm groups. The key difference between Nematodes and Cestodes is that Nematodes are roundworms whereas Cestodes are flatworms. The kingdom Animalia is comprised of several phyla. Phylum Nematoda includes round worms, which are pseudocoelomates. Phylum Platyhelminthes includes worms that are flattened dorsoventrally and acoelomates. Cestoda is parasitic worm […]