Pangolins are famously the most trafficked animal in the world, their scales used as an ingredient in traditional Chinese medicine and their meat considered a delicacy. Millions are hunted annually, and all eight species are endangered.

In the West, we often assume most of this trade is being played out via supply and demand in Africa and Asia. A new report has revealed however that before the importing of pangolin was banned there in 2000, the US was a major market for pangolin leather, which was used to make cowboy boots, belts, and wallets, and this significantly contributed to their decline.

What’s more, the report suggests that though the US trade in pangolin, illegal or otherwise, is down since 2000, it has been substituted by the import of arapaima, a fish found in Brazil that produces a similar type of leather, whose numbers are now also declining.

The report, published in Conservation Science and Practice, looked at the historic trade of exotic leather entering the US between 1999 and 2015, using both the US Fish and Wildlife Service and Law Enforcement Management System data, and found that as the trade in pangolin leather decreased, the import of arapaima increased.

They then analyzed pangolin and arapaima leather products listed for sale on eBay in the US between 2017 and 2018, specifically looking at states of origin of the products being sold, and found a correlation between the states previously trading in pangolin leather and the ones now selling products made of arapaima.

This led them to conclude the existing pangolin leather trade in the US appears to be moving to the arapaima trade, which puts this species at risk.

They found that between 1999 and 2015, despite the US ban on importing pangolin in 2000, 163 incidents of pangolin trade were recorded involving an estimated 21,411 pangolins. Trade did drop abruptly after 2000, but has not stopped totally, with the trade in parts for “medicine” making up the majority of incidents since 2007.

There were 130 arapaima leather trade incidents reported using an estimated 5,524 arapaimas in the same time period. The trade in arapaima appears to have commenced in 2011 and increased rapidly since then.

Arapaimas are the largest fish in the Amazon basin, and possibly the world’s largest freshwater fish, reaching up to 200 kilograms (440 pounds) and 3 meters (10 feet) in length. Strangely, they can breathe air and though they can submerge themselves for up to 20 mins without taking a breath, they do need to come to the surface. This makes them easier to catch.

Their skin, when dried, produces a leather that carries a similar diamond pattern to pangolin skin. A study in 2014 revealed the fish has already gone locally extinct in many parts of the Amazon basin and their numbers are dwindling. If the new demand for arapaima goes unchecked, the study authors warn, they may soon be in serious danger.

“Considering the huge historic popularity of pangolin in the US, there is likely a big market there for arapaima,” lead author Sarah Heinrich told National Geographic. “The trade may quickly get out of hand.”