Roundworm - a worm with a round, tube like body. Most are too small to be seen.

Example: hookworm


digestive system with 2 openings

take in food and eliminate waste

muscles that run length of body

reproduce sexually

nervous system with brain and simple sense organs

Adaptation - parasitic roundworms live in other animal’s body to get food and protection.

How do roundworms and flatworms differ? Roundworms have a digestive tract with two openings, muscles running lengthwise; flatworms can regenerate and have eyespots.