Chapter 25, Problem 38A

Summary Introduction

To determine:

The group of flatworm that have least number of species.

Introduction:

The flatworms are worms that have a head and tail. As the name suggests they are flat and bilaterally symmetrical. They do not have body cavity. They are bilaterally symmetrical with a definite upper and lower surface.

Explanation of Solution

The flatworms are parasitic and free living. All the flat worms are classified into turbellaria, Trematoda and cestode. The class Trematoda and cestode are parasites. The cestode are the intestinal parasites that have least number of species. Total species of flatworms is around 20,000 and the cestodes are around 3400.