Chapter 12

Other Invertebrates

12.1 Lesson 12.1: Mollusks

Lesson Objectives

• Discuss what characteristics define mollusks.


• Describe the different types of mollusks.


• Explain why mollusks are important.

Check Your Understanding

• What is an invertebrate?


• How are animals classified?

Introduction

Perhaps the best example of a wide variety of attainable mollusks is along a walk on the
beach (Figure 12.1). There you can find the calcified shells of many different types of
mollusks, most typically clams, mussels, scallops, oysters, and snails. Another reminder of
the treasures that mollusks yield up may be as close as a jewelry collection (Figure12.2).
There glossy pearls, mother of pearl (Figure12.3), and abalone shells reveal some of the
unique features of mollusks (Figure12.4).

As you learn about the different types of mollusks and their characteristics, consider how
these features help adapt the mollusks to their living conditions. Then also admire their
featuresandseehowpeople’singenuityhasusedthemollusk’sdesignandbeautyforpractical
and decorative purposes.