Nine new species of colorful, arboreal tarantulas have been discovered in central and eastern Brazil, an area where only seven tarantula species had previously been known. All nine of the newly described species are threatened by habitat loss and potentially by overzealous spider collectors.

As described this week in the open-access journal ZooKeys, the newly discovered species have been named Typhochlaena amma, T. costae, T. curumim, T. paschoali, Pachistopelma bromelicola, Iridopelma katiae, I. marcoi, I. oliveirai and I. vanini. The Typhochlaena genus had last been seen in 1850.

The study of the area's tarantulas was conducted by Rogério Bertani, a researcher at the Instituto Butantan in Sao Paulo. A previous spider first described by Bertani, Pterinopelma sazimai, was named one of the top 10 new species of 2011. That spider, like many of the new ones he described this week, is also threatened by the exotic pet trade.

As Bertani writes in his 94-page paper, tarantulas—arachnids of the family Theraphosidae—have not been heavily studied to date, "despite their potential importance as top predators in ecological webs, the pet trade and a source of important tools for pharmacological research." He definitely picked up the slack here, studying specimens from the wild and nine different museums and other institutions in order to measure legs, hairs, eyes, claws and other physical attributes to determine the new species. The analysis also allowed him to re-describe dozens of previously identified tarantula species.

Unfortunately, just about all of the new species Bertani describes appear to be at least threatened, if not endangered. Of the five Typhochlaena species, only 40 specimens have been collected to date. The new Pachistopelma species he describes depend on high-elevation flowering plants called bromeliads, which offer both water and shelter from intense mountain sunlight but are themselves threatened by habitat destruction in some regions. Other species live in the Atlantic rainforest, which has been reduced to just 7 percent of its original size. Most of the species he describes are extremely colorful, and Bertani says this could lead to exploitation by the illegal exotic pet trade.

Bertani says the discovery of these new species shows how little is known about wildlife even in areas like the Brazilian rainforests that have been identified as biodiversity hotspots.

Photos by Rogério Bertani: 22–23: Typhochlaena seladonia female and immature; 24: Typhochlaena amma; 25: Typhochlaena costae; 26: Typhochlena curumim; 27: Typhochlaena paschoali. All used under Creative Commons license