Research led by the University of California, Los Angeles, has created a valuable genetic resource to help control poaching, the main cause of pangolin endangerment. Credit: Richard Rossumoff
There’s a lot scientists don’t know about the pangolin—a strange, scaly mammal that looks like a cross between a porpoise and an armadillo. Now, a new paper has been published in the journal Chromosome Research It reveals what researcher Gene Tensman of the University of California, Los Angeles, calls a “scientific surprise” that confirms just how unusual this animal is.
Scientists have discovered that a female white-bellied pangolin has 114 chromosomes, more than any mammal except the Bolivian bamboo rat, which has 118 — and far more than humans, who have 46. Other pangolin species have more typical numbers of chromosomes, ranging from 36 to 42. .
Scientists have also identified another genetic whim. Male white-bellied pangolins have a different number of chromosomes, 113, than their female counterparts. In most species, males and females have the same number.
“There is nothing else like them on this planet; they are in their own order, their own family,” said Tensman, a research fellow at UCLA and co-author of the study, adding that pangolins’ closest relatives are cats and rhinos.
Tinsman collaborated on the study with colleagues from UCLA and many other universities around the world, as well as zoos and research organizations. The research was conducted to produce information about the pangolin genome in order to support conservation efforts – all four species of pangolin are endangered.
One reason why so little is known about pangolins is that they are so difficult to study. Their performance in captivity is poor. Only a few zoos have been able to successfully house them. In the wild, they are hard to spot, and the technology scientists use to monitor other species often fails when it comes to pangolins—the animals sometimes use trees to rub radio tags off their scales.
What foragers know about the animals is that they dig and use their long tongues to eat ants, termites, and other insects. Some species, including the white-bellied variety, live in trees, hanging from trunks and branches. Others live in burrows. When threatened, pangolins curl up into a ball. (Lions have been known to beat them, not sure what to do with them.)
The white-bellied species is relatively small, at three or four pounds and less than a foot long, while some ground pangolins grow to 80 or 90 pounds, about the size of a large dog.

Tom Smith, co-director of the Congo Basin Institute, with a pile of pangolin scales. “It is this wonderful creature that we are seeking extinction.” Credit: Tom Smith
Aside from its scientific value, the research has created a valuable genetic resource to support conservation efforts, especially attempts to control poaching, a major cause of animal endangerment. Pangolin scales are sold illegally on international markets for use in traditional medicine from Nigeria to China. They are also hunted as a food source—locally as bushmeat, which they sell for the equivalent of about $10 each, or for exotic meals in faraway regions, which they can fetch over $1,000 in international markets.
“I’ve seen pangolin scales trafficked along with guns, fake IDs, and drugs,” Tensman said. “The problem extends all the way to major international crime syndicates.”
Using genomics can help determine which species of pangolin are sources of animal-derived products. What’s more, the information can help conservationists and researchers understand differences within species whose habitats cover 6 million square kilometers (2.3 million square miles) and 23 countries.
“Understanding chromosomes and gene structure is important for conservation,” said Ryan Harrigan, assistant professor at UCLA’s Center for Tropical Research and a co-author on the paper. “It could determine how we manage populations — if you find significant genetic differences between two populations, it might manage them differently.”
“This paper is a great example of how a study focused on saving critical endangered species can also advance basic science,” said UCLA evolutionary biologist Tom Smith, a co-author of the study.
vice versa. With the rapid development of conservation methods and techniques, it is increasingly likely that research findings will yield practical applications in the months and years after their discovery.
In this case, the new findings could be particularly valuable as technologies such as artificial intelligence and emerging conservation methods such as environmental DNA, or eDNA, are developed and refined.
The study also supports a broader effort to track and map pangolin poaching by the Congo Basin Institute, a joint initiative of UCLA and the International Institute of Tropical Agriculture. The institute, which Smith co-directs, is located in Yaounde, Cameroon, and has two rainforest field stations.
“It’s this delightful creature that we’re hunting to extinction, which makes me really sad,” said Smith, who said similar genetic research is planned to conserve other pangolin species.
more information:
Hook et al., Chromosome length genome assemblies and cytogenetic analyzes of pangolins reveal remarkable chromosome counts and plasticity, Chromosome Research (2023). DOI: 10.1007/s10577-023-09722-y
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