- Bilateral symmetry; round, no segments
- Inhabit a very broad range of environments. More than half of nematode species are parasitic.
- Nematodes commonly parasitic on humans include Ascaris, hookworms, pinworms and whipworms.
- Other parasitic species also use animals as a host.
This is one of many types of round worm that can infest humans.
- Not all nematodes are bad! Many help keep down insect populations and others are decomposers that help keep the environment clean and healthy.
Nematodes decomposing a dead cricket.
- Have tubular digestive systems with openings at both ends.
Continue to Annelids
biodiversitybasics