Classification of an Echinoderm
Dill, Henry Kennedy High School
1-312-838-5225
Objective
To understand how the starfish relates to its classification.
Materials
Preserved Echinoderms, spiders, and other invertebrates and vertebrates.
Microscope projector. Overhead projector
Slides for production including the arthropods and echinoderms.
Illustrations of the starfish.
Animals with exoskeletons.
Chart with the family tree of living organisms.
Recommended Strategy
1. Students will observe the changes in forms, behavior, and feeding
characteristics.
2. Ask the students, "Why can a starfish regenerate a missing arm?"
3. Students will be given an opportunity to observe the various parts of an
echinoderm.
4. Discuss the historical background of a starfish.
5. Explain how the animal obtain its food.
6. Students will be ask to use the microscope to identify different structures of
the organism.
7. Students will be asked, "Of what survival value is metamorphosis?". What is
metamorphosis?
8. Students will be asked to explain how starfish reproduce.
9. After all students have identified the various parts of a starfish, they will
compare the classification of the starfish with other invertebrates.
10. Students will show in which ways the echinoderms are similar to the chordates.
Activities
Students will give three characteristics of each animal, so they can identify the
organism. All students will discuss the relationship between the arthropods and
echinoderms.
Exercise 1:
Have students view how the echinoderms develop.
Exercise 2:
The students will dissect the dorsal side of the starfish to expose the internal
structures.
Evaluation
Have students write an essay entitled: How Invertebrates Live. The students will
observe the shift in body plan established in lower groups to bilateral symmetry in
the larva stage to secondary radial symmetry in the adult stage. The students will
compare these characteristics to the insects.
References
Laboratory Guide for the Biology Sciences, Modern Biology, and the Sciences of
Biology.
If you want to see this experiment performed, you can come to Kennedy High School.
Materials can be obtained at the American Science Center and the starfish, spider,
and the centipedes can be obtained from Ward's catalog.
Summary
Insects are the most numerous group of animals on earth today. They have survived and
flourished by combining a high reproductive rate with thousands of individual
adaptations to different environments. The phylum Echinodermata consists of animals in
which bilaterally symmetrical larvae undergo metamorphosis into adults with
pentaradial symmetry. All echinoderms are marine.
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