Question

How is the anatomy of an earthworm different from a flatworm?

Answer 1

The anotomical difference between Flatworms and Earth worms:

1.Shape:

Flatworm: It had a thin dorsoventrally flattened body.

Earthworm: In this a long tube shaped cylindrical segmented body is present.

2. Body Surface:

Flatworm: The body Surface do not have a cuticle and often have cilia.

Earthworm: The body of earthworm divided into short segments. The dorsal surface of the body is marked by a dark median mid dorsal line and in the ventral surface is identified by presence of genital openings (pores). Mouthi s present in anterior end.

3. Body Cavity:

Flatworm: The body cavity is absent. Flatworms are acoelomate.

Earthworm: In earthworm body cavity is present.The body wall is the outer tube and the alimentary canal is the inner tube. The two tubes are separated by an extensive space, the body cavity or coelom.

4. Digestive system:

Flatworm: In flatworm gastro vascular cavity is present. In which a single opening that functions as both mouth and annus.

Earthworm: The digestive system of earth worm is extends from the mouth to its annus and it is differentiated into a buccal cavity, pharynx, esophagus, crop, gizzard and intestine.

5. Locomotion:

Flatworm: The gliding locomotion of a flatworm is powered by many tiny cilia on the outer surface of its body.

Earthworm: The locomotion is completely based on muscular contractions in which the alternately shorten and lengthen the body. This kind of movement is called peristalsis.