Space Bears – Lab-experience with Tardigrades

Brief description:

In this set of experimental activities, students will investigate the survival abilities of tardigrades, also known as water bears.

They will expose conditions and come to a conclusion about which environments they can survive in. The aim of this resource is to test tardigrades’ resilience to extreme environmental conditions and link their survival ability to the space environment.

Before beginning this activity, we suggest that you complete the activity “Could life survive in alien environments?” which provides an introduction to life in extreme environments.
Subject: Science, Biology
Learning Objectives:

  • Learning about tardigrades and the extreme conditions they can survive in.
  • Learning about cryptobiosis and how this helps tardigrades survive.
  • Investigating the effects of changing a variable in a system.
  • Carrying out experiments appropriately, having due regard for the correct manipulation of apparatus, the accuracy of measurements and health and safety considerations.
  • Evaluating methods and suggesting possible improvements and further investigations.
    Age range:
    12 – 16 years old
    Lesson: 2 hours and 20 minutes
    Resource available in:
    Activity 1: Collecting the tardigrades

    In this activity, students will learn how and where they can collect tardigrades. They will carry out these steps and prepare tardigrade samples for the following activities.

  • Student worksheet printed for each group.
  • Moss or lichen sample for each group
  • Pen/pencil
  • Tap water or de-ionised water
  • 1 petri dish for each pair
  • Activity 2: Sending tardigrades to sleep

    In this activity, students will transfer their tardigrades to small containers and induce anhydrobiosis by leaving them to desiccate. Students should understand that tardigrades will enter a new metabolic state, in response to the adverse environmental conditions. It is essential that tardigrades enter this tun state in order to survive these extreme environmental conditions.

  • Student worksheet printed for each group
  • Pen/pencil
  • Microscope and/or loupe
  • Small transparent container (coin boxes or similar)
  • Pipettes
  • Petri dish with soaked moss (from Activity 1)
  • Black cardboard or similar to place under the micro aquarium to improve contrast
  • Torch
  • Activity 3: Can they endure? Performing the experiments

    In this activity, students will expose the dried-in samples to different conditions, simulating extreme environments.

  • Small transparent container with tardigrade sample for each pair (from Activity 2)
  • Pipettes
  • Lab thermometer
  • Refrigerator/Freezer
  • Microwave oven
  • Hot water or heat source (infra-red lamp or similar)
  • Salinity solutions of varying concentrations
  • Solutions of varying pH-levels
  • Microscopes and/or loupe
  • Activity 4: Tardigrades in space

    In this activity, students will link the experiments they completed to the quest to find life elsewhere in the Universe.

  • Student worksheet printed for each student.
  • Pen/pencil
  • Did you know?

    In 2007, as part of ESA’s Tardigrades in Space (TARDIS) experiment, 3000 tardigrades were taken into space.

    They were exposed to the vacuum of space for 12 days where they experienced extreme dehydration, alongside high levels of cosmic radiation, and survived!

    Biopan, the small container that hosted tardigrades in space