5/11/2014

A Desert Spider with Astonishing Moves

Contributed by Anila Bangash




A spider newly discovered in the Moroccan Sahara can do powerful, acrobatic flips through the air.

Like a gymnast, it runs for a short time, then stretches out its front legs, spinning into the air and returning to touch the ground with its hind legs. Peter Jäger, a taxonomist at the Senckenberg Research Institute and Natural History Museum in Frankfurt, Germany, who identified the spider, has nicknamed it the flic-flac for the maneuver its leap resembles.

The move doubles the spider’s speed, to 6.6 feet per second from 3.3. But since it uses so much energy, the maneuver is a last resort, called on only to escape predators.

“I can’t see any other reason,” Dr. Jäger said, adding: “It is a costly move. If it performs this five to 10 times within one day, then it dies.”

The spider lives in a tubelike structure it weaves in the sand, staying hidden under a sandy lid and emerging at night in search of food.


At first Dr. Jäger mistook the spider for a sister species that lives in Tunisia and Algeria, but was able to distinguish the two through a close comparison of their copulatory organs. He describes the new spider in the journal Zootaxa.

Another arachnid, the golden rolling spider, exhibits a similar flipping behavior, but can only roll rapidly downhill, with the aid of gravity; the flic-flac spider can do its tumbling uphill, as well as on level ground and downhill. Although the newly discovered spider usually does its flips forward, it can do a back flip as well, Dr. Jäger said, justifying its nickname, a gymnastics term for a back handspring.

Officially, the spider has been named Cebrennus rechenbergi, after Ingo Rechenberg, a bionics expert at the Technical University of Berlin. Dr. Rechenberg spotted the spider five years ago while taking an evening stroll (with a bright flashlight) in Erg Chebbi, a sand desert in southeastern Morocco.

“I picked it up by hand — I wasn’t scared,” Dr. Rechenberg said.

He didn’t witness the rolling then, but instead took the unusual spider back to his caravan. In the morning when he witnessed the flic-flac behavior for the first time, he started crying.

“It was sensational,” he said.

Every year Dr. Rechenberg, who is 80, drives his caravan, outfitted with scientific equipment, from Germany via ferry to Morocco to study desert species and build robotic models based on their behavior. He has constructed a robot that mimics the flic-flac spider’s motions as well.

Robots struggle with moving over loose sand, and studying the spider could help solve this problem in an efficient way, Dr. Rechenberg said.

“I do my work in the desert where there is not much energy available,” he said. “That’s the reason I have gone every year for more than 30 years — to find out what the animals do to save energy.”

Despite Dr. Rechenberg’s regular visits to the region, the spider remained undiscovered by outsiders until now. As Dr. Jäger said, “Some secrets of nature are hidden although they are really close to us.”

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