Arctic pseudoscorpions' secret lives revealed
Many mysteries remain about 8-legged relic from woolly mammoth times
It looks like a creepy-crawly from an adventure movie set in a desert or tropical jungle, but this eight-legged creature with crab-like pincers makes its home in Canada's High Arctic.
And now we know a little bit about the Arctic pseudoscorpion, thanks to a Montreal researcher who spent more than seven years collecting and studying hundreds of the tiny predators in Yukon and the Northwest Territories, "just out of pure curiosity and fascination."
Pseudoscorpions are related to scorpions, spiders and ticks. They resemble a scorpion without a tail, says Chris Buddle, an assistant professor who studies insect ecology at McGill University.
Like scorpions, they have big pincers that they use to grapple prey such as fly larvae and springtails. Some even have glands in those claws that allow them to inject venom into their prey, Buddle said.
I slammed on the brakes and said, "'We've got to go look."- Chris Buddle, McGill University
But don't worry — even though there are about 30 species in Canada, including one that is quite common in people's homes, they can't harm you with their pincers.
"They're too small," says Buddle.
Most top out at three or four millimetres long.
Most of the 3,000 known species of pseudoscorpions live in tropical or temperate areas. The Arctic pseudoscorpion is the only species in North America that lives in the High Arctic.
It was thought to be a new species when it was first found in 1990 underneath some rocks along the shores of Sheep Creek in Yukon by Valerie Behan-Pelletier, a research scientist at Agriculture and Agri-Food Canada. Later, it was identified by University of Rochester pseudoscorpion expert William Muchmore as a species that was already known in Siberia, but little else was understood about it.
Buddle was fascinated after reading the reports by Behan-Pelletier and Muchmore.
While in Yukon with a team of scientists conducting research that had nothing to do with pseudoscorpions, he spotted a sign for Sheep Creek.
"I slammed on the brakes and said, 'We've got to go look,'" he said. "And we all piled out of the truck and went to the side of the river and started flipping rocks."
'A thrill to see them'
After 20 minutes, the team was about to give up when they finally found what they were looking for.
"It was just a thrill to see them there," Buddle recalled.
For the next seven or eight years, while conducting other research on insect and spider diversity and food webs in the North, he and his team collected 573 Arctic pseudoscorpion specimens in Yukon and Northwest Territories.
Buddle discovered that Arctic pseudoscorpions are found under rocks near the headwaters of creeks through parts of Canada that were once part of Beringia — an area that remained unglaciated during the last ice age, when the rest of the continent was buried under kilometres-thick sheets of ice. It would have lived among other Beringian species like woolly mammoths, many of which have since gone extinct.
"We're quite confident this small, tiny little arachnid is a relic of the past," he said.
The Arctic pseudoscorpions he collected ranged in size from about two to three millimetres, and many females were carrying sacs of eggs, each containing an average of 10.5 eggs. Because individuals of all different sizes and life stages were often found, Buddle thinks Arctic pseudoscorpions may take more than a year to mature and may be relatively long-lived, like many other eight-legged Arctic creatures.
He has published what he's discovered so far in the journal Canadian Field Naturalist.
Little hitchhikers?
Many mysteries remain about the Arctic pseudoscorpions, Buddle said.
For example, he doesn't know what they eat. Or how they get up to the headwaters of creeks, areas that flood frequently, washing small creatures downstream. Pseudoscorpions crawl very slowly in a crab-like motion and can't fly.
"We figure they must hitch a ride with another animal. But we don't know what that other animal is."
Buddle said other pseudoscorpions are known to hitch rides on birds and moths.
This summer, Buddle and his team collected a hundred or so more specimens, and he is keen to learn more about them.
A lot of Arctic research these days is tied in some way to developing resources in the North, he said. "This is really a project out of fascination and a love of biology. And that's a wonderful area to work in now and then."