Tackling the Tun: Rehydration of Hypsibius dujardini

Grace Robinson

Tardigrades (Hypsibius dujardini) are a model organism for biological research, and their abilities to withstand harsh conditions has been well documented. In order to conduct tardigrade research, study animals must be maintained in a viable state in the lab. My original project focused on understanding the cues that trigger a desiccation response; however, tardigrades in the lab entered a desiccated state under conditions in which it was unexpected (e.g. in the presence of water, food, oxygen, and a regulated dark:light period). In an attempt to determine why this unanticipated behavior was occurring, I used purchased colonies of active tardigrades and transferred small aliquots to experimental well plates and petri dishes. I subjected these animals to a period of dehydration followed by a period of rehydration and recorded observations. I found tardigrades do slow their activity relative to the amount of water present, and that they will desiccate after all water has evaporated; however, I have had little success in reversing the desiccated state. This is a surprising observation as well since tardigrades are known for being so resilient.

• Grace Robinson is a biology major with a chemistry minor. She became interested in tardigrades about two years ago when she learned about their ability to survive such extreme conditions. Moving forward in her education and career, she hopes to study astrobiology.