Dozens of unidentified bat species likely live in Asia — and could host new viruses

Trefoil Horseshoe Bat (Rhinolophus trifoliatus) show from below whilst roosting in Malaysia

There could possibly be extra species of horseshoe bat than beforehand thought.Credit score: Chien Lee/Nature Image Library

A genomic evaluation means that there are in all probability dozens of unknown species of horseshoe bats in southeast Asia1.

Horseshoe bats (Rhinolophidae) are thought-about the reservoir of many zoonotic viruses — which bounce from animals to folks — together with the shut relations of the viruses that brought about extreme acute respiratory syndrome and COVID-19. Figuring out bat species accurately would possibly assist pinpoint geographical hotspots with a excessive threat of zoonotic illness, says Shi Zhengli, a virologist on the Wuhan Institute of Virology in China. “This work is essential,” she says.

The research was revealed in Frontiers in Ecology and Evolution on 29 March.

Higher identification of unknown bat species might additionally help the seek for the origins of SARS-CoV-2 by narrowing down the place to search for bats that will harbour shut relations of the virus, says research co-author Alice Hughes, a conservation biologist on the College of Hong Kong. The closest recognized relations of SARS-CoV-2 have been present in Rhinolophus affinis bats in Yunnan province, in southwestern China2, and in three species of horseshoe bat in Laos3.

Cryptic species

Hughes needed to higher perceive the variety of bats in southeast Asia and discover standardized methods of figuring out them. So she and her colleagues captured bats in southern China and southeast Asia between 2015 and 2020. They took measurements and images of the bats’ wings and noseleaf — “the funky set of tissue round their nostril”, as Hughes describes it — and recorded their echolocation calls. In addition they collected a tiny little bit of tissue from the bats’ wings to extract genetic information.

To map the bats’ genetic range, the group used mitochondrial DNA sequences from 205 of their captured animals, and one other 655 sequences from on-line databases — representing a complete of 11 species of Rhinolophidae. As a basic rule, the larger the distinction between two bats’ genomes, the extra doubtless the animals signify genetically distinct teams, and due to this fact completely different species.

The researchers discovered that every of the 11 species have been in all probability truly a number of species, probably together with dozens of hidden species throughout the entire pattern. Hidden, or ‘cryptic’, species are animals that appear to belong to the identical species however are literally genetically distinct. For instance, the genetic range of Rhinolophus sinicus means that the group could possibly be six separate species. Total, they estimated that some 40% of the species in Asia haven’t been formally described.

“It’s a sobering quantity, however not terribly stunning,” says Nancy Simmons, a curator on the American Museum of Pure Historical past in New York Metropolis. Rhinolophid bats are a fancy group and there was solely a restricted sampling of the animals, she says.

Nevertheless, counting on mitochondrial DNA might imply that the variety of hidden species is an overestimate. That’s as a result of mitochondrial DNA is inherited solely from the mom, so could possibly be lacking essential genetic data, says Simmons. Nonetheless, the research might result in a burst of analysis into naming new bat species within the area, she says.

Additional proof

The findings corroborate different genetic analysis suggesting that there are a lot of cryptic species in southeast Asia, says Charles Francis, a biologist on the Canadian Wildlife Service, Surroundings and Local weather Change Canada, in Ottawa, who research bats within the area. However, he says, the estimates are based mostly on a small variety of samples.

Hughes’ group used the morphological and acoustic information to do a extra detailed evaluation of 190 bats present in southern China and Vietnam and located that it supported their discovering that many species had not been recognized in these areas. The research makes a robust argument for “the usage of a number of strains of proof when delineating species”, says Simmons.

Hughes says her group additionally discovered that the flap of tissue simply above the bats’ nostrils, known as the sella, could possibly be used to determine species with out the necessity for genetic information. Gábor Csorba, a taxonomist on the Hungarian Pure Historical past Museum in Budapest, says because of this hidden species could possibly be recognized with out doing intrusive morphology research or costly DNA analyses.