There’s a trick to finding new species of miniature snails: a bucket of water. “Microsnail” is the term for the creatures with shells measuring 5 millimeters or less, sometimes much less. A species described from China, photographed perched in the eye of a needle, ranked as the world’s smallest known land snail for five days in the fall of 2015. Then the journal ZooKeys described an even smaller species, from Borneo. “The very tiny ones you wouldn’t see even if you put your nose on the ground,” says Menno Schilthuizen, who described the Borneo miniature with colleagues. To avoid dirty noses, the researchers drop soil and leaf litter into a bucket of water, and shells float to the top. The shells are empty, alas, but “you can easily find thousands in just a few liters of soil,” he says. Even scooping bucket flotsam has its complications. Schilthuizen, of the Naturalis Biodiversity Center and Leiden University in the Netherlands, has been studying the snails of Borneo’s limestone hills and caves since 1997. “Sometimes people bury their dead in a cave,” he says. So they’re reluctant for anyone to enter, even for snail science. Bird nest collecting gets in the way as well. Families harvest cave swiftlet nests, a sought-after ingredient in exorbitantly priced bird’s nest soup. “These nests are very valuable and there’s a lot of poaching going on,” he says. Disputes are often settled with “a lot of shooting with homemade guns.” Of the 48 new species of snails from Borneo that Schilthuizen and colleagues named in November, the world’s smallest “was the most boring in terms of shell shape,” he says. In contrast, the region’s Plectostoma microsnails curl in fat whorls, like tubing that vents a clothes dryer. Some loop back on themselves or flare out like a tuba. “Sometimes, they tie themselves in knots,” he says. Perhaps the contortions make it more difficult for a predator to get a good grip. Snails typically have small, or even micro, habitat ranges. At some of Borneo’s isolated limestone peaks, “you can actually stand in front of the hill and see the whole world population of one particular snail species,” he says. The sad part of microsnail hunting, Schilthuizen says, is discovering that a company blasting a hill to extract the limestone has wiped out the entire world population. RIP, Plectostoma sciaphilum.
Acmella nana hiding among the small print of the ZooKeys paper where it is described. Credit: Prof. Dr. Menno Schilthuizen, Naturalis Biodiversity Center The world's record for the smallest land snail is broken once again. A minute shell with an average diameter of 0.7 mm was found in Malaysian Borneo by a team of Dutch and Malaysian biologists along with another 47 new species of greatly varying sizes. Called 'dwarf' ("nanus" meaning "dwarf" in Latin), the new snail, Acmella nana, is first-shown to the world in the open-access journal ZooKeys, where the last record-holder was announced only about a month ago. The world's tiniest snail has a shell of merely 0.50 - 0.60 mm width and 0.60 - 0.79 mm height. The previous holder of the title of world's smallest snail, the Chinese Angustopila dominikae, published earlier this year, measured just 0.80 and 0.89 mm respectively. Some of the new 48 species described in the present paper are widespread in Borneo and had been familiar to the team of snail researchers for decades. Yet, they had not got round to naming them until now. Others eke out a hidden existence on mountain tops or in rare vegetation types and, therefore, were only recently discovered by the authors. For instance, there are seven new species that can only be found on the 4,095-metre-high Mount Kinabalu. Another example, called Diplommatina tylocheilos, only lives at the entrance of the hardly accessible Loloposon Cave in Mount Trusmadi. The new information tells us more about isolated, or endemic, species such as the new record-holder. Moving so slowly, snails can easily get stuck in very small patches of a habitat. There they can spend long enough to evolve and adapt to the particular limited area, undisturbed by the rest of the world. This makes them excellent examples of how endemic species can arise. On the other hand, their restricted distribution makes them key targets for biodiversity conservation. "A blazing forest fire at Loloposon Cave could wipe out the entire population of Diplommatina tylocheilos," says co-author Schilthuizen. The discoveries are the latest result of an ongoing research project on the snail fauna of Borneo by the authors. For more than twenty-five years, Jaap Vermeulen, Thor-Seng Liew, and Menno Schilthuizen of Naturalis Biodiversity Center and Universiti Malaysia Sabah, have been documenting Malaysia's wonderful terrestrial molluscs. Only last year, also in ZooKeys, the team published ten new Malaysian species of the "micro-jewel" snails of the genus Plectostoma. Explore further: Malaysian microjewels going extinct as they are discovered More information: Jaap Vermeulen et al. Additions to the knowledge of the land snails of Sabah (Malaysia, Borneo), including 48 new species, ZooKeys (2015). DOI: 10.3897/zookeys.531.6097
Lying unnoticed on shelves, some of these species had to wait for many decades to be discovered with methods, unavailable at the time of their collection. Some collected 40 years ago, some as far back as a 100, the nine new species are described in the open access journal Phytokeys to showcase the importance of herbarium collections in Botany. "Although for many of the new species good flowering material became available only recently, this does prove the importance of herbaria, and the need for exploring their collections," explains the lead author, PhD student Paul H. Hoekstra, Naturalis Biodiversity Center and Wageningen University. "On the other hand, using DNA techniques we were able to link recently collected sterile collections to several of these poorly collected species, enabling us to improve their conservation assessment." Confined to tropical Africa and Madagascar, species from this genus all share similar features such as a typical climbing habit and bluish-green or glaucous leaves. Two of the newly described species come from West Africa, four from western Central Africa, and for the remaining three Tanzania, Southern Mozambique and the Comoros host one each. This distribution comes in confirmation of a general pattern in recent revisions of both the custard apple family Annonaceae and other tropical African forest taxa, where most new species are found in western central Africa and Tanzania. Giving important information about areas of potential botanical and ecological interest, this trend is supported by the high level of conservation concern among the newly described species. With five species classified as critically endangered, two as endangered, one as vulnerable the need of further collecting and studying those species and exploration of the relevant areas is warranted. "Exploring those areas for new species is rather important if we want to have a real idea of their truly amazing botanical diversity," explains Hoekstra. "Madagascar, for example, is also an area with many undescribed species, a fact also true for our group of interest, Monanthotaxis, and we anticipate for at least another seven new species to be described from this area." Explore further: Waiting to be discovered for more than 100 years—new species of bush crickets More information: Paul H. Hoekstra et al. A nonet of novel species of Monanthotaxis (Annonaceae) from around Africa, PhytoKeys (2016). DOI: 10.3897/phytokeys.69.9292
Deforestation adds up. New research finds that the Amazon region could lose more than half of its tree species by the year 2050 due to a combination of logging, agriculture, dams, fires, mining, climate change and human development. All told, at least 36 percent and as many as 57 percent of the Amazon’s more than 15,000 tree species should now be considered threatened with extinction, according to a paper published today in Science Advances. The paper, the work of 158 researchers from 21 nations, examined the forests of the Amazon basin and the Guiana Shield under two deforestation scenarios. Under the first “business-as-usual” scenario, which is based on deforestation rates matching what we’ve seen in recent years, the Amazon would lose about 40 percent of its forests by 2050. That would fall to 21 percent under the second scenario, which would see improved forest governance and a reduction in habitat loss. Either way, the collective impact would be huge. The paper estimates under these scenarios that the number of Earth’s threatened plant species is now at least 22 percent higher than realized. Many of the Amazon’s tree species, the researchers found, would probably quality as either endangered or critically endangered. At least 1,600 tree species will have fewer than 1,000 individuals by 2050. Some would undoubtedly face extinction. Even common species won’t be spared. The researchers found that commercially valuable species such as Brazil nut (Bertholletia excelsa), cacao (Theobroma cacao) and açai palm (Euterpe oleracea) will decline by at least 50 percent. Still, the problem is actually not quite as bad as the researchers expected, according to the paper’s lead author, Hans ter Steege, senior research fellow with the Naturalis Biodiversity Center in the Netherlands. “I had thought the situation was much worse,” he says. “If you are in the ‘arc of deforestation,’ it seems as if all is lost. But you can also realize that, just as in Europe, this deforestation offers opportunities for people to live. The good news is that over 80 percent of the Amazon forest is not deforested and that is an immense amount of forest.” About half of that land, he says, is in some form of conservation area. Some of it set aside as conservation reserves, while other areas are regulated for sustainable use or indigenous territories. All the same, some regions would be harder hit than others. “Many of the species that are predicted to go extinct have their full range in Eastern or Southern Amazon,” ter Steege says. “Species with small ranges or small populations are likely to go extinct more than species with large ranges.” One of the most striking things about this paper is that many of the species that are most at risk are already so rare that they have never been fully, or even at all, described by science. Instead, just a few common trees dominate our understanding of the Amazon forests. A previous paper by the same team found that the 227 most common Amazon tree species represent more than half of the individual trees in the region. The new paper, meanwhile, documents population counts for fewer than 5,000 species. Many of the rest of the Amazon tree species—about 10,000 additional species—remain unknown or understudied, what the researchers dubbed dark biodiversity. “The majority of extinctions will indeed be in the ‘dark biodiversity,’” ter Steege says. The loss of so many trees would obviously have a cascading effect on the Amazon’s biodiversity and put many other species at risk. “Extinction is not just one species,” ter Steege says. “Many species will be affected. For large carnivores and primates, deforestation coupled with immense habitat fragmentation will have a much more immediate effect. Hunting in fragments may also decrease other mammals and affect the dispersal of many other species.” The paper warns that tropical trees may now be one of the world’s most threatened groups of species—on par with cycads, amphibians and corals—but it also makes clear that the existing system of protected networks in the Amazon is working and that many species may be saved if we continue to improve these protections. “The message that we can make a difference should be embraced,” ter Steege says.
News Article | November 4, 2015
Just when everybody thought the smallest snail in the world has finally been discovered in China, scientists in Borneo stumble upon the shell of a new mollusk species with a shell minute enough that it could very well break the record for the tiniest land animal ever. Biologists from the Universiti Malaysia Sabah and the Naturalis Biodiversity Center gave the new snail species the name Acmella nana, which comes from the Latin word "nanus" which means dwarf. The shell of this tiny creature is around 0.50 to 0.60 millimeters in width and 0.60 to 0.79 millimeters in height. The Angustopila dominikae, which was discovered in China earlier this year, previously held the title for the smallest species of snail in the world. It was measured at around 0.80 millimeters in width and around 0.89 millimeters in height. The Acmella nana is part of a group of 48 new snails found in Malaysian Borneo. The researchers have long been familiar with the snails for years but they have not been able to give each species a proper name until now. Some of the snail species kept a well-hidden existence in the Bornean mountains or in rare types of vegetation, making it difficult for the researchers to find them initially. These include seven new snails that are native only to the jungles of the 4,095-meter (13,435-foot) high Mount Kinabalu. The Diplommatina tylocheilos, another one of the newly-discovered snails, can only be found at the entrance of the Loloposon Cave located in Mount Trusmadi. The discovery of the new species of snails provides scientists with a better understanding of endemic creatures such as the Acmella nana. The slow movement of snails often gets them stuck in very small sections of a habitat. This leaves them with enough time to adapt to their new environment without any disturbance from the outside world, which makes them an ideal subject for research on endemic species. The limited distribution of the creatures also makes them crucial targets for conservation efforts on biodiversity. "A blazing forest fire at Loloposon Cave could wipe out the entire population of Diplommatina tylocheilos," Menno Schilthuizen, one of the scientists who discovered the new snail species, said. The findings of the Universiti Malaysia Sabah and the Naturalis Biodiversity Center study are featured in the journal ZooKeys. While the record for the smallest snail is still being updated based on recent discoveries, occupying the spot for being one of the largest gastropod mollusks in the world is the giant African land snail (Achatina fulica), which can grow up to 3 to 8 inches in length. The average life span of the giant African land snail is about five to seven years, but with enough food and comfortable living conditions this massive mollusk can live up to 10 years. Compared to the new snail species found in Borneo, which tended to live hidden in the mountains, the Achatina fulica is considered to be a highly invasive creature. According to the Department of Agriculture, this giant snail is one of the most damaging species in the world for agriculture and crops in the United States, consuming at least 500 different plant species.