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

Time

Lesson: 2 hours and 20 minutes

Resource available in:

English, Danish, French, German, Italian, Portuguese, Spanish and Romanian

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.

Equipment

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.

Equipment

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.

Equipment

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.

Equipment

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!