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Super Siphonophores

Lesson at a glance:

Students make a model of a colonial cnidarian that is called a siphonophore.

Common Curriculum Goals and Benchmarks:

These national standards and benchmarks come from the Content Knowledge Home Page, an effort by the Midcontinent Regional Educational Laboratory (McREL) to consolidate the many national, state and local efforts at defining what a student needs to learn. You can find them on the WWW at http://www.mcrel.org/standards-benchmarks/. Your state or district may have additional standards or benchmarks that may apply.

Life Sciences
Science Standard 4: Knows about the diversity and unity that characterize life.
Grade 6-8 Benchmark: Knows that animals and plants have a great variety of body plans and internal structures that serve specific functions for survival (e.g., digestive structures in vertebrates, invertebrates, unicellular organisms, and plants).
Grade 6-8 Benchmark: Knows evidence that supports the idea that there is unity among organisms despite the fact that some species look very different (e.g., similarity of internal structures in different organisms, similarity of chemical processes in different organisms, evidence of common ancestry).
Science Standard 5: Knows the general structure and function of cells in organisms.
Grade 3-5 Benchmark: Knows that each plant or animal has different structures which serve different functions in growth, survival, and reproduction (e.g., humans have distinct structures of the body for walking, holding, seeing, and talking).

Materials:

Background:

Siphonophores are related to anemones, corals and jellyfishes. They appear to be jellies, but are actually colonies of many organisms functioning as a single unit. These cnidarians vary in size from very small up to 66 feet (20 meters). Each unit is composed of many individuals, each with a different function. These functions include reproduction, feeding and defense. By working together as a single unit, a colonial organism can function more efficiently. One example of a siphonophore is the Portuguese man-of-war, Physalia physalia .

Activity:

1. Print out these directions.
2. Discuss with students what colonial animals and siphonophores are. Show slides or pictures of these organisms or have students do library research if slides or pictures are not available.
3. Provide the above materials and ask students to construct their own siphonophores. Each siphonophore should include:

• several parts, to make it a colony;
• separate parts for feeding, reproduction and defense; and
• other structures as students wish, such as bioluminescent parts.

3. Hang from classroom ceiling.

Summary:

Have each student explain how their siphonophore is able to feed, defend and reproduce. Have your class research and discuss other colonial animals such as corals, hydroids and some sea anemones.

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