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<\/div>There are probably many more earthworm species than those that have been officially recognised<\/p>\n
Andia \/ Alamy<\/p>\n<\/div>\n<\/figcaption><\/figure>\n<\/p>\n
Tens of thousands of species of earthworms are likely to be wriggling in the world\u2019s soil, yet to be discovered by scientists \u2013 which will probably take more than 100 years to do.<\/p>\n
Earthworms play a critical role in recycling organic nutrients in ecosystems. Researchers fear that without identifying all these species, they could be lost before we know they exist.<\/p>\n
More than 5700 species<\/a> and subspecies of earthworms have already been described by scientists. But Thibaud Deca\u00ebns<\/a> at the University of Montpellier in France wondered if this could be an underestimate when he noticed the diversity of earthworms while he was working in the Amazon.<\/p>\n To learn more, Deca\u00ebns and his team conducted sampling surveys in French Guiana, often flying by helicopter to remote areas of the Amazon rainforest and spending up to two weeks collecting every worm they could find in 1-hectare plots.<\/p>\n \u201cWe have only recorded 55 described species in French Guiana,\u201d says Deca\u00ebns. \u201cWhereas there are probably at least 2000 species there.\u201d The scientists did similar sampling in France, which together suggested that the diversity of earthworms is must greater than previously thought.<\/p>\n <\/p>\n In another part of the experiment, they worked with a statistician to estimate the number of earthworm species worldwide that haven\u2019t yet been discovered, according to existing records and the rate at which new species are described.<\/p>\n \u201cOn a global scale, we estimate that at least 30,000 species of earthworm exist on the planet,\u201d says Deca\u00ebns. Based on the number of worm taxonomists globally and the rate at which they classify specimens, it will take 120 years before they are all identified, he says.<\/p>\n \u201cIt is harder to conserve a group of species, such as earthworms, if we don\u2019t know the basics of how many species there may be and where those species are,\u201d says team member Helen Phillips<\/a> at the University of Helsinki in Finland.<\/p>\n