Write the important features of phylum Aschelminthes (Nematoda).
- Most of them are small and cylindrical. So they are also called as round worms.
- The body size ranges from microscopic to a few centimetres in length.
- They all are mainly heterotrophic animals.
- They are triploblastic.
- Body cavity has a true coelom.
- Respiratory and circulatory systems are absent.
- They have a complete alimentary canal.
- Sexes are separate.
Examples: Ascaris (roundworm), Enterobius, and Wuchereria (filarial worm).