Carolyn C. Smith
The Life Cycle of Crabs
Objectives
The students will be able:
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1. to discuss the reproduction of crabs.
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2. to identify the stages of development of crabs.
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3. to identify marine crabs and terrestrial crabs.
Vocabulary
marine, terrestrial, environment, cycle, larva, molting, exoskeleton
Materials Needed
Paper, pencil, crayolas or colored pencils
Procedures
Introduce the vocabulary. Discuss the mating process of crabs and the early stages of development of the crab stressing the rerelationship of the molting process with growth. Point out the fact that crabs are invertebrates and they have an exoskeleton. Make sure the students understand when the terrestrial crabs leave the waters after birth to make their home on land. Discuss the systems of the crabs and compare them with the human system.
Questions for Discussion
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1. How long do crabs live?
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2. How much of the shell of crabs is shed at molting?
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3. How often does a crab shed its shell?
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4. Do crabs eat while in soft-shell condition?
Related Activities
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1. Collect articles from newspaper and magazines related to crabs.
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2. Using papier mache, make the various stages of the crab and write a brief description of each for display purposes.
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3. Make a chart and have the students to graph the life span of crabs. They could also research to find out the oldest crab the largest crab, and where was it found.
Field Trip
Arrange for a visit to a local fish market to learn more about crabs, lobsters, and shrimps of the area.