<meta http-equiv="refresh" content="1; url=/nojavascript/"> Importance of Mollusks | CK-12 Foundation
Dismiss
Skip Navigation
You are reading an older version of this FlexBook® textbook: CK-12 Life Science Concepts For Middle School Go to the latest version.

9.9: Importance of Mollusks

Created by: CK-12
%
Best Score
Practice Importance of Mollusks
Practice
Best Score
%
Practice Now

Where do pearls come from?

Pearls are highly valued as gemstones. Most gemstones come from the earth, but pearls come from living things. They are created by mollusks, such as oysters.

Importance of Mollusks

Mollusks are important in a variety of ways; they are used as food, for decoration, in jewelry, and in scientific studies. They are even used as roadbed material and in vitamin supplements.

Mollusks as Food

Edible species of mollusks include numerous species of clams, mussels, oysters, scallops, marine and land snails, squid, and octopuses. Many species of mollusks, such as oysters, are farmed in order to produce more than could be found in the wild (Figure below).

An oyster harvest in France

An oyster harvest in France.

Mollusks in Decoration and Jewelry

Two natural products of mollusks used for decorations and jewelry are pearls and nacre. A pearl is the hard, round object produced within the mantle of a living shelled mollusk. Natural pearls have been highly valued as gemstones and objects of beauty for many centuries. The most desirable pearls are produced by oysters and river mussels. Natural pearls form when a foreign object gets trapped in the shell. It's as if the mollusk has a splinter. The mollusk reacts by covering up that irritant. This is the process that creates a pearl.

Nacre, or mother of pearl, is an iridescent inner shell layer. It can be found in buttons, watch faces, knives, guns, and jewelry. It is also used to decorate various musical instruments.

Mollusks in Scientific Studies

Several mollusks are ideal subjects for scientific investigation of the nervous system. The giant squid has a sophisticated nervous system and a complex brain for study. The California sea slug, also called the California sea hare, is used in studies of learning and memory because it has a simple nervous system, consisting of just a few thousand large, easily identified neurons. These neurons are responsible for a variety of learning tasks. Some slug brain studies have even allowed scientists to better understand human brains!

Vocabulary

  • nacre: Or, mother of pearl, is an iridescent inner shell layer.
  • neuron: Nerve cell.
  • oyster: Mollusk with a rough irregular shell; lives in coastal waters and provides a food source.
  • pearl: Hard, round object produced within the mantle of a living shelled mollusk.

Summary

  • Some mollusks, such as oysters and scallops, are important food sources.
  • Mollusks are used for decoration and are important in scientific studies.

Practice

Use the resources below to answer the questions that follow.

  1. What large tubular structures did Professor Young find in squids? How big were these tubular structures?
  2. Why were the size of these structures important to Professor Youngs work?
  3. What did scientists discover when they were able to empty the contents of a squid axon?
  4. How did World War II help the study of neuron functioning?
  5. How are the nervous systems of cephalopods similar to the nervous system of mammals?
  1. How are natural pearls made?
  2. How are cultured pearls made?

Review

  1. Name two mollusks that are used for food.
  2. Where do pearls come from?
  3. What makes the California sea slug ideal for studies of learning and memory?

Image Attributions

Description

Difficulty Level:

Basic

Grades:

6 , 7

Date Created:

Nov 29, 2012

Last Modified:

Apr 11, 2014
Files can only be attached to the latest version of Modality

Reviews

Please wait...
You need to be signed in to perform this action. Please sign-in and try again.
Please wait...
Image Detail
Sizes: Medium | Original
 
SCI.LSC.823.2.L.1

Original text