Nematodes

They are also known as Roundworms.

The some examples of Nematodes are: 

1. Ascaris lumbricoides (roundworm)

2. Trichinella spiralis (trichinosis)

3. Trichuris trichiura (whipworm)

 

Nematodes are colourless, unsegmented, lack appendages, predaceous, parasitic and may be free-living.