- According to the results of a decade-long study by biologists at Auburn University and Millsaps College, there are not, in fact, fifty or so different species of tarantulas in the US, as scientists previously believed.
- After studying nearly 3,000 specimens, the researchers found there are just 29 species in the US — 14 of which are entirely new to science.
- Aphonopelma johnnycashi males are generally solid black in coloration, which made them an even more fitting homage to Cash, who was known as “the Man in Black.”
Tarantulas in the genus Aphonopelma are some of the most unique spiders in the United States, but it turns out they haven’t been the subject of too much scientific inquiry.
For instance, according to the results of a decade-long study by biologists at Auburn University and Millsaps College, the results of which have been published in the open-access journal ZooKeys, there are not, in fact, fifty or so different species of tarantulas in the US, as scientists previously believed.
Many of those tarantulas were poorly defined and actually belonged to the same species, the Auburn and Millsaps biologists found. After studying nearly 3,000 specimens, they found there are just 29 species in the US — 14 of which are entirely new to science.
“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,” Auburn’s Dr. Chris Hamilton, a lead author of the study, said in a statement.
“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.”
One of the new species discovered by Hamilton and team has been named Aphonopelma johnnycashi after the legendary country artist, Johnny Cash, who passed away in 2003 at the age of 71. Dr. Hamilton said he came up with the name because the species is found in California near Folsom Prison, which Cash made famous with his song “Folsom Prison Blues” and a live concert album recorded at the prison.
Plus, mature Aphonopelma johnnycashi males are generally solid black in coloration, which led Hamilton to conclude it was an even more fitting homage to Cash, who was known as “the Man in Black” because of the all-black clothes he often wore.
Species in the genus Aphonopelma are found in 12 states across the southern third of the United States, from west of the Mississippi River to California. One of the more distinctive characteristics of the US’s various tarantulas is the extreme size differences that can be found between species. Some can reach as much as six inches (15 centimeters) or more in leg span, while others could fit easily on the face of an American quarter.
The research team spent more than a decade searching through deserts, mountains, and other locations in the American Southwest to collect the 3,000 specimens they examined. Because most US tarantula species are highly similar in appearance, the researchers used what they called an “integrative” approach to taxonomy, employing anatomical, behavioral, distributional and genetic data, to determine the proper classification for each species.
While the researchers say they found that most species’ populations are doing well and have relatively large distributions, they noted that some have highly restricted distribution areas and could require conservation efforts in the near future, especially as they lose habitat due to climate change and human activities.
“Two of the new species are confined to single mountain ranges in southeastern Arizona, one of the United States’ biodiversity hotspots,” Millsaps College’s Brent Hendrixson, a co-author of the study, said in a statement.
“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.”
- Hamilton, C.A., Hendrixson, B.E., & Bond, J.E. (2016). Taxonomic revision of the tarantula genus Aphonopelma Pocock, 1901 (Araneae, Mygalomorphae, Theraphosidae) within the United States. ZooKeys 560: 1-340. doi:10.3897/zookeys.560.6264