Close-up view of a tardigrade's claws that can range from two small 'Y' shaped points to oddly-shaped barbed fish hooks depending on the species. (Photo by Rebekah Brassfield, Kenai National Wildlife Refuge)

Close-up view of a tardigrade's claws that can range from two small 'Y' shaped points to oddly-shaped barbed fish hooks depending on the species. (Photo by Rebekah Brassfield, Kenai National Wildlife Refuge)

Refuge Notebook: Moss piglets? More common than you think on the Kenai

Mosses and lichens are among the most abundant plants on the Kenai Peninsula, both of which contribute to the ecosystem on a large scale. But at the microscopic level, they are home to an astounding number of organisms, including an invertebrate called a tardigrade and, in some circles, a water bear or moss piglet. They have eight legs with complex claws at the apex of each, and are slightly smaller than the period at the end of this sentence.

The photographs may make them look agile but, in reality, they bumble around their environment slowly and use their claws to hold on to the debris that is often found in moss or lichen. The slightest current can pull them away, and their claws don’t work well as boat paddles, making swimming difficult. In fact, the name Tardigrada means “slow stepper.” Quite coincidentally, it was given that Latin name in 1776, a special year that we celebrate every 4th of July.

Perhaps the most fascinating feature of the tardigrade is their ability to enter a hibernation stage known as cryptobiosis. During adverse environmental conditions such as drought, flood, and changes in air pressures, they can put all their biological processes on hold like a pause button. In times of drought, they shrivel up like a microscopic raisin and can stay like that until water levels return to normal, sometimes for 30 or more years!

During floods, the opposite happens. They swell up like a balloon and bounce around safely until water recedes. This is an important adaptation because at the microscopic level even the slightest change in temperature or water can drastically affect its inhabitants. Without the ability to enter the cryptobiotic stage, tardigrades would likely be extinct.

Tardigrades are considered “extremophiles” which means they live in the most extreme places on earth. They have been found on mountain tops where cold winds and low pressure are common companions. They are also in deep sea vents that spit out sulfuric acid and boiling water. But they don’t just call those places home — they can be found in freshwater streams and lakes, saltwater flats, estuaries, and in leaf litter on the ground. They are most commonly collected on moss and lichen because of the ease of collection, and because they can be found right in your backyard.

I collected a small sample of caribou lichen in the woods just behind the Kenai National Wildlife Refuge’s Headquarters on Ski Hill Road. I put it in a dish of water overnight to see what species of tardigrade lived in the area. Almost immediately after placing the slide under the microscope, I spotted a tardigrade crawling around on debris. Beside tardigrades, I observed mites, rotifers, and nematodes, truly a diverse community. Both tardigrades I collected and identified were from the genus Macrobiotus, which is the most common genus in Alaska. Unfortunately, identification to species requires high powered microscopes and, in some cases, the specimen’s eggs.

What do tardigrades do? This is a tricky question, and one I get asked often. It is important to know the purpose of organisms and research. I had a professor call it “taking up space.” All organisms take up space, and tardigrades are no exception. They eat rotifers and nematodes, which are also common microorganisms. Tardigrades exist in many unique microscopic habitats which might have different inhabitants without the predation and competition for resources posed by tardigrades.

Tardigrade research is an ongoing effort by biologists and even researchers at NASA. In 2007, NASA launched two colonies of tardigrades into space to take a closer look at how radiation affects living cells, searching for possible enhancements to manned space missions in the future. Not only were they the first organism to survive the vacuum of space and sub-zero temperatures, tardigrades also showed an ability to decrease the effects of solar radiation and oxidative stress — a potential cause of many human diseases including Parkinson’s and Alzheimer’s. There is continued research on tardigrades in space, and they are a common addition to most space missions.

Although we don’t know much about their life cycle or their ecology, they could be valuable in unforeseeable ways. So take a look in your backyard — odds are it is teaming with life and almost certainly tardigrades.

 

Rebekah Brassfield is a biological intern at Kenai National Wildlife Refuge. She is an undergraduate student at Concordia University in Nebraska, majoring in Conservation Biology. Find more information at http://www.fws.gov/refuge/kenai/ or http://www.facebook.com/kenainationalwildliferefuge.

Side view of a moss piglet with the head on the right side of the photo, and the last of four pairs of legs on the left side.  This tardigrade is 0.4mm long and was collected on the Kenai National Wildlife Refuge. (Photo by Rebekah Brassfield, Kenai National Wildlife Refuge)

Side view of a moss piglet with the head on the right side of the photo, and the last of four pairs of legs on the left side. This tardigrade is 0.4mm long and was collected on the Kenai National Wildlife Refuge. (Photo by Rebekah Brassfield, Kenai National Wildlife Refuge)

More in Life

Frenchy Vian, who posed for many photographs of himself, was acknowledged as a skilled hunter. (Photo courtesy of the Viani Family Collection)
Unraveling the story of Frenchy, Part 2

In fact, Frenchy’s last name wasn’t even Vian; it was Viani, and he and the rest of his immediate family were pure Italian

File
Minister’s Message: Share God’s love even amidst disagreement

We as a society have been overcome by reactive emotions, making us slow to reflect and quick to speak/act and it is hurting one another

This image shows the cover of Juneau poet Emily Wall’s new book “Breaking Into Air.” The book details a wide array of different birth stories. (Courtesy Photo)
A book is born: Juneau author releases poetry book portraying the many faces of childbirth

It details “the incredible power of women, and their partners”

Lemongrass chicken skewers are best made on a grill, but can be made in the oven. (Photo by Tressa Dale/Peninsula Clarion
On the strawberry patch: Tangling with waves

Lemon grass chicken skewers top off a day in the surf

This photo of Frenchy with a freshly killed black bear was taken on the Kenai Peninsula in the early 1900s. (Photo courtesy of the Viani Family Collection)
Unraveling the story of Frenchy, Part 1

The stories were full of high adventure — whaling, mining, polar bear hunting, extensive travel, and the accumulation of wealth

File
Seeing God’s hand in this grand and glorious creation

The same God of creation is the God that made me and you with the same thoughtfulness of design, purpose and intention

Chewy and sweet the macaroons are done in 30 minutes flat. (Tressa Dale/Peninsula Clarion)
Sophisticated, simplified

When macarons are too complicated, make these delicious, simple macaroons

Michael S. Lockett / capital city weekly
Gigi Monroe welcomes guests to Glitz at Centennial Hall, a major annual drag event celebrated every Pride Month, on June 18.
Packed houses, back to back: GLITZ a roaring success

Sold-out sets and heavy-hitting headliners

Michael Armstrong / Homer News 
Music lovers dance to Nervis Rex at the KBBI Concert on the Lawn on July 28, 2012, at Karen Hornaday Park in Homer.
Concert on the Lawn returns

COTL line up includes The English Bay Band, a group that played in 1980

Marcia and Mary Alice Grainge pose in 1980 with a pair of caribou antlers they found in 1972. The sisters dug the antlers from deep snow and detached them from a dead caribou. (Photo provided by Marcia Grainge King)
Fortune and misfortune on the Kenai — Part 2

In Kasilof, and on Kachemak Bay, in Seldovia and later in Unga, Petersen worked various jobs before being appointed deputy marshal in 1934