A member of a new species of whip spider munches on a cricket in an Indonesian cave in an undated picture.
Found in 2004, the half-inch-long (centimeter-long) Sarax yayukae is one of four new whip spider species announced this month. All four were discovered during a series of expeditions in the Indonesian section of the island of Borneo (map), which also includes sections administered by Brunei and Malaysia.
These arachnids, also called tailless whip scorpions, are neither spiders nor scorpions and feature front legs that have evolved into long, flexible whiplike feelers. The "bizarre" creatures also have flat bodies and grasping appendages lined with spines, according to the study documenting the new species.
Though whip spiders have been crawling the world's tropics since the Devonian period, about 416 million years ago, relatively few whip spider species survive today, according to study leader Cahyo Rahmadi, a biologist at the Indonesian Institute of Sciences in Jakarta.
The surviving whip spiders—many found only in small cave systems—may be threatened by plans for coal and limestone mining on Borneo, Rahmadi said by email. (See cave-exploration pictures.)
New whip spider study published September 15 in the journal Zootaxa.
Photograph courtesy Cahyo Rahmadi
Its spine-studded pedipalp appendages may look fearsome in close-up, but the new whip spider species Sarax sangkulirangensis—found in limestone caves in 2004—is relatively small at about a third of an inch (eight millimeters) long.
To find the four new species, study leader Rahmadi and colleagues traveled to remote Bornean locations, some accessible only by helicopter. But the chance to explore sights such as the "magnificent" Sangkulirang (map) karst was worth it, he said by email. (See pictures of Indonesia.)
The newfound whip spider Sarax cavernicola is unique in that its primary pedipalp spines (pictured) are equal in size—other species in the genus have different-size primary spines, according to study leader Rahmadi.
Discovered in 2004, S. cavernicola also stands out because of its pale coloration and tiny eyes, adapted to dark cave life. In addition, S. cavernicola is big for a whip spider—about a half inch (12 millimeters) long.
Whip spiders hunt cave crickets, cave cockroaches, and other small invertebrates. Some Caribbean species will occasionally go underwater to hunt prawns, Rahmadi said.
Along with the new whip spiders (pictured, Sarax cavernicola head), Rahmadi's cave explorations uncovered new types of cave crabs and cave millipedes as well as a known species of giant cave cockroach.