Snow Fleas

Snow fleas are decomposers and eat decaying organic matter as well as bacteria, fungi, algae, pollen, roundworms and rotifers.After mating in the spring, females lay eggs in the soil. The emerging nymphs undergo several moltings; by winter they show all adult features, if you look closer, those tiny black dots are moving. If you get down even closer, say with a magnifying glass, you'd notice those dots have legs and can jump.
Sometimes so many snow fleas appear that the snow seems carpeted with ashes. Approach them, and the entire mass rises in a dark cloud, swirling chaotically before descending to coat the surface again. When there are fewer snow fleas, you might see only tiny black dots that suddenly vanish in your presence. The scene can be so strange you might think you're hallucinating.Catch one if you can, and check it out. Under strong magnification, you will see a lumpy and segmented body with bluish reflective scales. The snow flea, only one-sixteenth of an inch long, lacks wings, but it has three pairs of legs. It also has two antennae and two clusters of eyes, 16 in each.Turn the snow flea over, and you will see something really unusual. Beneath its abdomen is one of the most extraordinary devices found in the animal world: a lever-like appendage held under tension by a two-hook clasp. It's this appendage that gives the snow flea its incredible jumping ability.To understand how it works, think of a common spring-loaded mousetrap. Touch the trigger holding the peanut butter, and the wire bar slams shut. Now gently place the cocked mousetrap upside down on the floor. Tap it with a pencil, and the trap snaps and springs into the air. Finally, imagine tens of thousands of mousetraps flying in the air. That approximates what happens when you approach a bunch of snow fleas.Undisturbed, the snow flea walks on snow or ground pleasantly feeding and going about its business. When you arrive, it leaps hundreds of times its own body length (think of a human jumping over the Empire State Building), followed by just about every other snow flea in the area.Your arrival was just detected by a snow flea's eyes or antennae, and a nerve impulse was sent to the clasp, which instantly released the appendage that catapulted the little creature out of danger.After landing, the clasp will quickly grab and hold the appendage while internal (hydrostatic) fluid pressure builds up until the lever again becomes a cocked spring.The spring-like mechanism is not the only unusual feature on the underside of a snow flea. The tiny creature has a tubular peg used for "drinking" and taking in oxygen. Rapid absorption of moisture is necessary to rebuild that hydrostatic pressure in the lever.
For snow fleas during much of the year it's a relatively uneventful scene down at ground level. Like other springtails, snow fleas spend most of their time feeding on soil bacteria, fungi, algae, pollen and organic material. Sometimes they devour microscopic animals like rotifers and nematode roundworms. (During their brief appearances on snow, they mostly eat pollen and algal cells that have settled out of the air.)In spring, like many creatures, they mate. The reproductive process isn't dramatic: Males and females are seemingly oblivious of each other. Males deposit stalked droplets of sperm on the ground, and a wandering female picks up a droplet by chance and whisks it into her genital opening. Fertilization occurs, and eggs are laid in the soil.In a matter of days, tiny nymphs appear as simpler, smaller versions of the adults, and they begin their generally unnoticed lives – until winter when they impress a human visitor with their circus acts in the snow.
Scientists in Illinois and Pennsylvania are reporting development of a way to make the antifreeze protein that enables billions of Canadian snow fleas to survive frigid winter temperatures. Their laboratory-produced first-of-a-kind proteins could have practical uses in extending the storage life of donor organs and tissues for human transplantation, according to new research. "Our most significant advance was the use of the two mirror image forms of the protein to determine the previously unknown crystal structure of this unique protein. That is a first in the history of protein X-ray crystallography." Snow fleas know how to ward off cold. They have natural antifreeze in their bodies that keeps ice from forming it might also be developed to help increase frost resistance in plants or inhibit crystallization in frozen foods. If you've been skiing or snowshoeing you may have noticed a host of tiny black dots in your tracks.