Chapter 25.3, Problem 6MI

Summary Introduction

To distinguish:

The two ways of mollusks feed.

Introduction:

Mollusks are soft-bodied, triploblastic, coelomate and bilaterally symmetrical animals. Most of them are aquatic and few are terrestrial and found in moist soil. They have a well-developed digestive system and the radula is the rasping organ for feeding.

Explanation of Solution

Radula:

The radula is tiny teeth made of chitin. Herbivore mollusks used radula to scrap and tear food such as algae off a surface and drawing them into the mouth. Predator mollusks use the radula to drill holes in the shells of their prey.

Filter feeders:

Filter feeders are mollusks such as bivalves which feed by straining suspended matter and food particle from water by passing water over their gills. The radula is absent in filter feeder.

Conclusion

The radula is a tongue-like organ with rows of teeth used to scrape, drill and tear up food whereas filter feeders draw in food from the water and strain it.