MAINZ, Germany They lurk in crevices in the cliff face, amid leaves or under the bark of trees.

These giant crab spiders are "silent hunters" able to locate any insect scurrying past, thanks to highly sensitive hearing. They can also paralyze their prey with sharp fangs.

Though most species of this spider live in the tropics, Peter Jaeger from Mainz University in Germany has identified 50 new varieties which flourish amid the snow and ice of the Nepalese Himalayas, at altitudes of up to 3,800 meters.

Jaeger spent five years collecting and preserving hundreds of spiders from all over the highest mountain range in Asia. "These newly discovered species have, in contrast to their heat-loving relatives, specially adapted themselves to life in cooler and more elevated areas," says the qualified arachnologist.

He explains that in order to be able to survive the winter, the spiders, which can be distributed among three new genera, have developed "biological antifreeze" in the course of their evolution.

"They store highly-concentrated alcohols in their body fluids and this enables them to survive temperatures below freezing," says 32- year-old Jaeger, who has been fascinated by the long-legged predators since early childhood.

Morphological analysis made it possible for him to explain where several species came from. "Their ancestors came from the eastern end of the mountain range and made their way westwards. New and more highly evolved species kept appearing in the steep valley of the Himalayas."

Though they can be up to four centimeters in size, the giant crab spiders pose absolutely no danger to humans. About 1,000 varieties have been classified worldwide so far. Jaeger expects scores to be identified in Asia in the next few years: "If you think about how big China alone is then this is clearly just the tip of the iceberg regarding the variety of species."

He says that Asian arachnology is still in its infancy compared to Europe, and for this reason he wants to initiate closer cooperation between Beijing's Academy of Sciences and the 300-strong Arachnology Society, which he heads in the northern Bavarian town of Bayreuth.

Jaeger believes this research into the Himalayas' eight-legged inhabitants will not only benefit human understanding of the region's ecosystems but also prove of benefit to the area's economies. "Companies are always on the look out for new spider venoms, which can perhaps be of use in the pharmaceutical industry," he explains.

He also thinks that the newly-discovered species could make themselves useful in Chinese agriculture, which has to provide 1.3 billion people with food: "It would be interesting to release certain spiders into paddy fields to keep pests at bay - you wouldn't need to use insecticide any more."

(DPA)