Body shape: Platyhelminths are flat, while nemathelminths are round.
Body symmetry: Platyhelminths have bilateral symmetry, while nemathelminths have radial symmetry.
Digestive system: Platyhelminths have a gastrovascular cavity, while nemathelminths have a complete digestive system with a mouth, an anus, and a gut.
Nervous system: Platyhelminths have a simple nervous system with a nerve net, while nemathelminths have a more complex nervous system with a brain and nerves.
Reproductive system: Platyhelminths are hermaphroditic, while nemathelminths are dioecious.
Habitat: Platyhelminths can be found in both freshwater and saltwater environments, while nemathelminths can be found in soil, freshwater, and saltwater environments.
In addition to these differences, platyhelminths and nemathelminths also differ in their life cycles. Platyhelminths typically have a complex life cycle that involves multiple hosts, while nemathelminths typically have a simpler life cycle that involves only one host.