Pangolins: What are they and why are they linked to Covid-19?

As scientists work to get to the root of Covid-19, the world’s attention is turning to a little-known, strange, scaled animal.

Meet the pangolin, the real-world Pokemon that could hold clues to the novel coronavirus.

Here’s everything you need to know about these mysterious creatures — and what the research has to say about their potential role in the global pandemic underway.

What is a pangolin?

Native to Asia and part of Africa, the scaly pangolin doesn’t look a lot like other mammals.

Pangolins are solitary creatures, and are mostly nocturnal, according to the World Wildlife Fund.

Like their fellow armored mammals, armadillos, pangolins can roll themselves up into a well-protected ball, especially if they’re touched or grabbed. They are also armed with sharp tail spikes that can be used as a weapon.

But these creatures typically aren't a danger to anything much bigger than an unsuspecting bug. Ants and termites are among pangolins’ favorite food. They are even referred to as “scaly anteaters.”

Where do pangolins live?

Most pangolins are found in Asia, though there are a growing number in Africa, too.

Altogether, there are eight species of pangolin, and all of them range from “vulnerable” to “critically endangered” status, as ranked by the WWF.

Four pangolin species live in Africa:

• Black-bellied pangolin (Phataginus tetradactyla)
• White-bellied pangolin (Phataginus tricuspis)
• Giant Ground pangolin (Smutsia gigantea)
• Temminck's Ground pangolin (Smutsia temminckii)

And four species live in Asia:

• Indian pangolin (Manis crassicaudata)
• Philippine pangolin (Manis culionensis)
• Sunda pangolin (Manis javanica)
• Chinese pangolin (Manis pentadactyla)

All these species are protected by national and international laws.

But pangolin meat and scales are valuable wares for poachers, and they are an unfortunate victim of the illegal wildlife trade.

What is the link between pangolins and Covid-19?

In short, scientists are not sure. But some theories suggest that pangolins may be the source of the novel coronavirus.

The idea is that pangolins carrying the virus, SARS-CoV-2, came into contact with humans. The virus then made the jump from these creatures to humans, kicking off the pandemic we’re now facing.

In certain wildlife markets, and despite the laws protecting them, pangolins may be among the animals sold, along with turtles, bats, birds, reptiles, and other wildlife species.

The scaly anteater’s pricy place in this underground commerce means humans — both poachers and patrons — can get up close and personal with pangolins. It is this covert contact that scientists believe may have led the novel coronavirus to make the leap to humans.

Pangolins are not the only animal suspected of transferring the virus. In the early days of the outbreak, researchers in China originally reported that snakes were the likely culprit. Scientists have since refuted that idea.

In a new study published March 22, researchers report that the virus’ protein structure and genome effectively rules snakes out as the source of the virus. The evidence “refutes snakes as its intermediate host,” the authors write.

So if not snakes, then what animals do the researchers believe played this role?

The consensus right now is that a coronavirus in bats seems to be the original source, the new study shows. Bats are a natural reservoir for the SARS-CoV-2 virus, or Covid-19. Bats were also responsible for the deadly SARS virus that struck China in the early 2000s.

But there's an idea that another animal may have transported the virus from bats into humans. And that is where the pangolin comes in. The new analysis suggests “the pangolin as a missing link in the transmission of 2019-nCoV from bats to human.”

The results were published March 22 in the Journal of Proteome Research.

What does this mean for pangolins?

Pangolins were already a suspected source of the coronavirus, as Nature reported in February. And with those speculations now bearing out in published research, it means scientists may be a step closer to understanding how this pandemic came to be.

In China, officials are taking this as a sign to crack down on wildlife markets.

“We can’t be indifferent anymore!” declared China’s President Xi Jinping, in reference to people consuming wildlife.

The Chinese government has now banned wildlife markets, and in February, it passed a law called “Comprehensively Prohibiting the Illegal Trade of Wild Animals, Eliminating the Bad Habits of Wild Animal Consumption and Protecting the Health and Safety of the People.”

Despite laws to protect wildlife like pangolins, however, their trade has continued, writes journalist Wufei Yu in an opinion piece for The New York Times. Yu delves into the history of pangolin as a delicacy and medical treatment — and finds that ancient texts actually advise against eating pangolin.

Yu suggests this fact might be a more convincing one to stop pangolin trade than the even idea that the animals are contributing to a disease.

“In any event, yet another ban on trading and eating pangolins isn’t likely to help them, especially with its caveats for medical use,” Yu writes.

“Better instead to take on modern misconceptions about health and traditions — and for that, nothing beats going back to centuries-old texts.”

Abstract: As the infection of 2019-nCoV coronavirus is quickly developing into a global pneumonia epidemic, the careful analysis of its transmission and cellular mechanisms is sorely needed. In this Communication, we first analyzed two recent studies that concluded that snakes are the intermediate hosts of 2019-nCoV and that the 2019-nCoV spike protein insertions share a unique similarity to HIV-1. However, the reimplementation of the analyses, built on larger scale data sets using state-of-the-art bioinformatics methods and databases, presents clear evidence that rebuts these conclusions. Next, using metagenomic samples from Manis javanica, we assembled a draft genome of the 2019-nCoV-like coronavirus, which shows 73% coverage and 91% sequence identity to the 2019-nCoV genome. In particular, the alignments of the spike surface glycoprotein receptor binding domain revealed four times more variations in the bat coronavirus RaTG13 than in the Manis coronavirus compared with 2019-nCoV, suggesting the pangolin as a missing link in the transmission of 2019-nCoV from bats to human.