8. Keeping Wet

Lesson at a glance: Many rocky shore creatures spend part of their time on land but need to stay wet to survive. In this activity, students see how animals use different adaptations to keep wet.

Goal: Students will be able to explain animal adaptations for protection from the sun.

Oregon Content Standards:

Science

  • 1.1 Structure and Function: Living and non-living things have characteristics and properties.
  • 1.2 Interaction and Change: Living and non-living things interact.
    • 1.2L.1 Describe the basic needs of living things.
  • 1.3 Scientific Inquiry: Science explores the natural world using evidence from observations.
    • 1.3S.1 Identify and use tools to make careful observations and answer questions about the natural world.
    • 1.3S.2 Record observation with pictures, numbers, or written statements.

Ocean Literacy: Essential Principals and Fundamental Concepts

5. The ocean supports a great diversity of life and ecosystems.

5.d. Ocean biology provides many unique examples of life cycles, adaptations and important relationships among organisms (symbiosis, predator-prey dynamics and energy transfer) that do not occur on land.

Materials:

  • Three wet paper towels
  • Three plastic containers with lids

Background:

Barnacles and snails are only a few of the animals that can tightly close their shells to the drying air. Later, when submerged again, they can open their shells and feed.

Time: 20 minutes, total but over 24 hours

Guiding Question:

What do shells do to help an animal meet it's need to stay wet?

Activity:

Engage

Place biofacts in front of a group of students.

Explore

Using the biofacts, have students observe different clams, barnacles and other bivalves.

Explain

Review with students that a need of many tidepool invertebrates is too stay wet. Lead a discussion about how a shell might help an animal with their needs. Introduce that shells help the soft bodies of bivalves stay wet when the tide, waves, etc go out.

Explain that this activity is a demonstration of how bivalves shells keep moisture.

Elaborate

Place the wet paper towels inside the three plastic containers with lids.

Close the lid of the first container tightly. Pop off the lid of the second container and place it lightly over the top without sealing it. Remove the lid entirely from the third container.

Place all three containers in a hot spot—outside on a sunny day, on a radiator inside, or in a sunny window.

Check periodically and see what happens to the paper towels.

Evaluate

Have the students make conclusions about their observations and how that might represent the function of shells. Evaluate students on the accuracy of their answers and how they connect their observations to their conclusions.