The newfound spiders double the number of known tarantula species from the region, according to a study published in the journal ZooKeys.
“We often hear about how new species are being discovered from remote corners of the earth, but what is remarkable is that these spiders are in our own backyard,” Chris Hamilton, lead author of the study, said in a press release. “With the earth in the midst of a sixth mass extinction, it is astonishing how little we know about our planet’s biodiversity, even for charismatic groups such as tarantulas.”
Hamilton, a researcher at the Florida Museum of Natural History, and his team spent more than a decade searching for tarantulas throughout scorching deserts, frigid mountains, and other locations in the American Southwest, sometimes literally in the backyards of homeowners. The scientists also looked at specimens in museums.
Overall, the researchers studied nearly 3,000 specimens, undertaking what they say is the most comprehensive taxonomic study ever performed on a group of tarantulas.
Many of the leggy spiders look alike, so the researchers had to employ a combination of anatomical, behavioral, distributional, and genetic data to tell the different species apart from one another.
The results indicate there are 29 tarantula species in the United States, 14 of which are new to science. All belong to the genus Aphonopelma, but sizes can widely vary. Some reach 6 inches or more in leg span, while others are about the size of a quarter.
Johnny Cash the tarantula (Aphonopelma johnnycashi) was found near Folsom Prison, the subject of singer Cash’s song “Folsom Prison Blues.” The music star’s nickname, based on his distinctive dressing style, was the “man in black,” which led to another connection with his namesake spider. Mature males of the species are generally solid black in coloration.
Most of the newly discovered species are abundant and have relatively large distributions, but others have highly restricted distributions and could require conservation efforts to save them.
“Two of the new species are confined to single mountain ranges in southeastern Arizona, one of the United States’ biodiversity hotspots,” explained co-author Brent Hendrixson. “These fragile habitats are threatened by increased urbanization, recreation, and climate change. There is also some concern that these spiders will become popular in the pet trade due to their rarity, so we need to consider the impact that collectors may have on populations as well.”
Tarantulas can bite when they feel threatened, with the bites feeling like a bee sting. Their imposing appearance has not helped their reputation much either, making images of them creepy favorites around Halloween time.
Hamilton, however, notes that tarantulas are usually easy going, do not readily bite and pose little danger to humans. He prefers to describe them as being “teddy bears with eight legs.”