My collaborator/3yo cousin Marina and I wandered together into the microcosmos – it was so much fun. We happened to be near a lake, and there was quite a lot of moss, so we figured might be a great time to look for tardigrades!

Sample preparation . We pulled a small piece of moss from a rock in the shade. Some dirt came along for the ride. We put the moss in a cup, then we added an equal volume of lake water to hydrate the moss. We let the moss soak for about 10 minutes. To prepare slides, we cut smaller pieces of wet moss and sandwiched them between transparent Foldscope stickers.

Hello tardigrade! We were sitting at a picnic table and our uncle was nearby hitting golf balls into the lake (then he snorkels to retrieve them). In our first couple of attempts, we did not find tardigrades, though the moss itself was interesting. Then, we found a tardigrade! I could not contain myself and shouted, “WATER BEAR!” Not the best golf etiquette – but it was so exciting, and my uncle still managed a lovely shot. I will have to proceed with caution if I ever bring Foldscope to a golf course. I bet there is tons of awesome microbial life in the ponds.

Observations and questions . Marina and I could see its segmented body and cute little legs. We used the magnetic coupler, so we could look together on my phone. We were both captivated. Marina asked some fantastic questions such as, “Is it fast or slow?” which I think is a wonderful question and leads to so many interesting follow up questions. (I later learned that tardigrade means “slow stepper.” But as the movie shows, the tardigrade could move about a body length per second.)

Cryptobiosis . Tardigrades are fascinating creatures. For one, they are capable of cryptobiosis, which means they are ultimate survivors. Even Bear Grylls might have a thing or two to learn from tardigrades. For example, as noted by Sarah Bordenstein here , tardigrades have been reported to survive temperatures as low as -200 ˚C and as high as 151 ˚C, or severe desiccation, or numerous other awful conditions I would never hope to experience. Can you imagine?! I am so curious how their molecules and cells allow the organism to withstand such extremes.

As noted in the cryptobiosis Wikipedia site , other creatures are capable of cryptobiosis, so such incredible behavior may not be uncommon. For example, bdelloid rotifers (I still gotta catch more of ’em ) can also survive severe desiccation. Makes me wonder about life in difficult places, such as on nearby planets. From what I read so far on the NASA Mars Atmosphere and Volatile EvolutioN (MAVEN) mission site, Mars lost its atmosphere about 4 billion years ago. Check out this wicked lesson !

The tardigrades Wikipedia site and other articles on tardigrades note some have survived for years in a cryptobiotic state! Though they may be increasingly less likely to survive the longer they remain in a cryptobiotic state, and 4 billion years is relatively a long time. Many tough questions, many more experiments needed.

Foldscope operation . Marina was interested in the operation of the Foldscope, such as turning the LED on and off. We disassembled the Foldscope to have a look inside, so we removed the back magnetic coupler for focus locking. Plus our sample was rather thick, so this was our best movie with the tardigrade in focus. In our next attempt, we might try focus locking with a thinner sample.

Others in the Foldscope community have posted gorgeous images of tardigrades, such as these incredible posts by the Stanford Tardigrade Project , Cristina Bosch , and Tom Hata .

Looking forward to next time . Several hours later, in the evening, Marina asked to see again the images we took on my phone. I think the Foldscope gave another young scientist an exciting view of the microcosmos. I feel so happy, and I cannot wait until our next collaboration!

Up next . We also observed pond scum. In our excitement we forgot to take a picture. So in my next post, I would like to attempt a description and sketch à la Antony van Leeuwenhoek. I recently started to look at some of his writings, would be fun to attempt his style.