The planet is home to anywhere between two million and 50 million undiscovered species, many of which are at threat from rampant habitat destruction, according to a report by an international team of researchers.
Bill Laurance, Distinguished Research Professor of Marine and Tropical Biology at James Cook University and co-author of the report, said that although species for some groups of living things – such as plants and birds – are well-known, “it is almost impossible to guess how many unknown of species of insects and fungi there are.”
Biologists are thought to have catalogued about 97% of species for mammals, between 80% and 90% for flowering plants, 79% for fish, 67% for amphibians, about 30% for arthropods and less than 4% for nematodes, the authors say in their report, published in the journal Trends in Ecology and Evolution.
They say unknown species could be crucial for developing new pharmaceuticals and products, providing disease-resistant germplasm for crops, and yielding insights into the way nature functions.
Venom from the Magician’s Cone, a type of cone snail which is especially abundant on the Great Barrier Reef, can be used to develop a pain reliever 1,000 times more powerful than morphine, whereas compounds from other Conus species are being used to treat many neurological diseases.
“Many species of these snails are newly discovered and many more await discovery,” Professor Laurance said. A conference last week heard that the Great Barrier Reef, like other vast coral systems of the world, is at threat from local pollution, overfishing, rising temperatures and ocean acidification.
“We simply can’t afford to lose these species because of neglect and short-sided economic gains,” Professor Laurance said.
Lead author Brett Scheffers, from the Department of Biological Sciences at the National University of Singapore, said that most unknown species were likely to be living in places where they are in danger of extinction: “We could lose many of them before we realise how valuable they are.”
Another co-author, Lucas Joppa, an ecologist in the Computational Science Laboratory at Microsoft Research in Cambridge, said that “many missing species are hard to find, such as deep-sea organisms, high mountain species or those that live underground”.
Most are thought to be small in size and living in small geographic areas, such as high-elevation rainforests in the Wet Tropics of north Queensland.
The process of cataloguing species is made more complicated by the fact that some different species have accidentally been assigned the same name, and also because some animals look nearly identical and therefore can only be identified by genetic analyses.
“New technologies such as environmental DNA analyses can detect a species presence from mere water samples without our ever seeing it,” Mr Scheffers said.