Spiders, tarantulas and scorpions may be creepy to many, but it turns out there's a gargantuan market for arachnids as pets, and it is mostly unregulated -- posing problems for the sustainability of their species.
Nearly 80% of the global arachnid trade, which is quite larger than previously estimated, is not monitored or regulated, researchers who studied the market over two decades discovered.
More than 1,200 species of arachnids, including spiders and scorpions, have been or are currently being traded around the world, according to the findings of a study published in Nature on Tuesday. About 79% of the creatures are listed on arachnid-selling websites but not included in trade databases, according to the research.
Wildlife trade is a "huge issue" for biodiversity, Alice Hughes, conservation biologist at the University of Hong Kong and author of the study, told ABC News. However, it tends to be the illegal trade of bigger, more "charismatic" animals that people tend to think is the wider problem, she said.
"But the fact that they are being traded legally does not mean that it's sustainable," she said.
The researchers investigated global arachnid trades between 2000 and 2021 by combining data from the U.S. Law Enforcement Management Information System with the international trade databases of the Convention on International Trade in Endangered Species of Wild Fauna and Flora, which contains detailed information on global online arachnid retailers.
Among popular traded species, the researchers found that 77% of emperor scorpions were caught in the wild, with 1 million individuals imported into the U.S. alone during the study period.
More than 50% of tarantula species had been traded, including 600,000 Grammostola tarantulas, a group that includes the common pet species Chilean rose tarantulas, according to the researchers.
Two-thirds of arachnids from all traded species were reportedly wild-caught, which could have negative impacts on wild populations if they are harvested to an unsustainable extent, according to the study.
"I don't think anyone who was buying these animals is really aware of just how likely it is that a couple of weeks prior, that animal was wandering around a rainforest or a desert somewhere," Hughes said. "So this is a major threat to the future survival of the species."
The lack of regulation of the market could lead to these species becoming vulnerable to unsustainable harvesting and trade, the scientists said.
Hughes described the findings as "shocking" due to the threat the species are likely under.
To further complicate matters, the researchers found that out of over 1 million known invertebrate species, under 1% had been assessed by the International Union for Conservation of Nature. In addition, only a small fraction of invertebrate species was regulated by the Convention on International Trade in Endangered Species of Wild Fauna and Flora, such as 39 of the 52,060 known species of spiders.
"These are under-appreciated, neglected taxa that are threatened by the pet trade," she said.
The lack of data indicates that the vulnerability of these heavily traded species is unclear, making the development of appropriate management or conservation policies "currently almost impossible," according to the authors.
"So only about 2% of all species in trade are listed by scientists, and that's a vanishingly small proportion of all arachnids," she said. "But 2% of insight is is really nothing. It means 98% of species can be traded with no overarching regulations, outside those that are instigated by their country."
The research also poses concern about the individuals who are buying these arachnids, Hughes said. There is no vetting of potential owners, a demographic consisting largely of younger people, many of whom may release the animal when they no longer want them.
They then could become an invasive species that competes with the native species, or be infected with mites or other parasites that then spread to other species, Hughes said.
The findings highlight that millions of spiders, scorpions and their relatives are being bought and sold, and there is a pressing need to monitor trade to prevent biodiversity losses, the researchers wrote. Hughes urged pet owners to be conscientious when deciding whether to buy one of these creatures.
"People just need to be aware that when they are buying an exotic pet, they need to check out where it's come from," she said.