Classification of an Echinoderm

Dill, Henry Kennedy High School

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.
Return to Biology Index