👉 Nematoda are small, invertebrate animals that live inside other organisms. They are often found in soil and aquatic environments as parasites or predators of other organisms. Some examples include worms like tapeworms, giardia and cestodes. Nematoda can be classified into different types based on their function: parasitic, predatory, endoplasmic reticulum (ER) parasite, or endosymbiotic parasite.