A new species of tarantula spider (Aphonopelma jacobii) has been discovered in the Chiricahua Mountains of south-east Arizona, United States.
These high peaks form the largest mountain range in the Madrean Archipelago – often referred to as the Madrean Sky Islands – and can become bitterly cold in the winter months. It's a tough place for any animal to survive, let alone a little tarantula. Yet survive Aphonopelma jacobii does.
The discovery is a bitter-sweet moment for the scientists who described the new species in a recent study published in ZooKeys. Despite only just becoming known to science, the tarantula is already at risk of extinction.
Into the Sky Mountains
The Chiricahua Mountains lie between the Colorado Plateau and Rocky Mountains in the south-west United States and the Sierra Madre Occidental in north-west Mexico. The complex range is renowned for its montane forest, its exceptional biodiversity and high levels of endemism. Like the other ranges in the wider Madrean Archipelago, the Chiricahuas form an 'island', separated from its neighbours by low deserts and dry grasslands.
This geography means the range has evolved in isolation, and with it numerous endemic species have also evolved, making the mountains totally unique.
Tarantula discovery
It was in the Chiricahuas that Aphonopelma jacobii was discovered, explains Dr. Chris Hamilton, assistant professor at the University of Idaho and co-lead author of the study.
“We often hear about new species being discovered from remote corners of Earth, but it is remarkable that these spiders are found in our own backyard, albeit in somewhat difficult-to-access areas of our backyard.
"With Earth in the midst of a human-mediated extinction crisis, it is astonishing how little we know about our planet’s biodiversity, even for conspicuous and charismatic groups such as tarantulas.”
Sinking islands
But the forests where this small, black and grey tarantula live are threatened by several factors, most notably climate change, and over the next several decades, as temperatures increase and precipitation decreases, researchers are worried that the forests that blanket the Sky Islands will be “pushed off”.
The impact on animals adapted to these cooler and more humid mountain tops – such as Aphonopelma jacobii – will likely become extinct as their habitat disappears, says Dr. Brent Hendrixson, professor at Millsaps College and co-lead author of the study.
And there are other threats too, explains Hendrixson. “These fragile habitats are also threatened by increased exurban development in the San Simon Valley and Portal areas, destructive recreational activities, and wildfires.
"In addition, there is some concern that these tarantulas will be exploited for the exotic pet trade due to their rarity, striking coloration, and docile disposition.
"We must consider the impact that unethical collectors might have on these spiders when determining the threats to this species and the implications for its conservation.”
“This discovery represents the 30th species of tarantula documented from the United States. Aphonopelma is the most species diverse tarantula genus on the planet (at least for documented species)," says Hamilton.
"Our research adds to this number and continues to advance our understanding of the true species diversity in this incredibly interesting and important biodiversity hotspot.”
Aphonopelma jacobii is named after Michael A. Jacobi, who helped find several of the first specimens which led to the description of the new species.
Read more about the study: Will climate change lead to the extinction of a newly discovered tarantula species?
Main image: A photograph of Aphonopelma jacobii's habitat high up in the Chiricahua Mountains. Credit: Michael A. Jacobi
More stories about wildlife from around the world
