DISCOVERING UNKNOWN SPECIES

About 90 % of all animal species have still not been identified by humans. Many of the creatures have conquered small natural niches or exist in deserted regions, where they are living under cover – until scientists discover their hiding places.

Think you know animals? Not even science knows all the animals. Hundreds - if not millions - of species remain to be discovered.

From the deck of the ship, scientists lower a customized underwater elevator into the water towards the deepest place on Earth, the Mariana Trench in the Pacific Ocean. The elevator can reach a depth of 11 km. On the way down, cameras will record life in the unexplored "terrain". The scientists have also placed mackerel on the elevator to attract fish and other hungry marine animals, so the elevator can function as a kind of fish trap, which can bring specimens to the surface.

The trip to the ocean floor lasts about four hours, during which the camera captures fascinating footage of large rock grenadiers and cusk-eels, and after a couple of hours, the elevator finally reaches the upper Mariana Trench. Fish have never before been observed at such extreme depths, and so, scientists open their eyes wide, when they see an odd little fish swimming about at a depth of 8 km. There is no doubt that they have just discovered a new species.

Millions of new species

The fish is one of 15,000-18,000 new species that are added to biologists’ list of all the world’s animals annually. Not surprisingly, discoveries of new insects make up a large portion of the finds, but once in a while, scientists also some across large, unknown animal species such as a new orangutan discovered in Sumatra in 2017.

According to a study made by scientists from Canada and Hawaii, biologists might have many more new acquaintances to look forward to. Via statistical analyses, the scientists calculated that some 86 % of all terrestrial species and 91 % of marine species have not yet been identified. The calculation showed that the world is the home of 8.7 million animal species, of which only about 955,000 have been classified as we speak. The majority of the

unknown species are animals that might be difficult to find for different reasons. They could be very small or hide in imaginative and impassable places. So, scientists estimate that 7.7 million animals – or about 88 % of all species – remain unknown.

Although at first sight, the number seems very high, historic examples indicate that the calculation is correct. In 1980, a team of scientists ventured into Panama’s tropical forest to explore the immense biodiversity. Their studies of 19 trees caused the discovery of 1,200 different beetle species, of which 80 % were unknown.

Rare species

The many species can remain undiscovered, because they often live in extremely small niches and only in one specific place in the world, in one particular forest, or in one particular lake.

When British scientist Charles Darwin went to the Galapagos Islands aboard the HMS Beagle, he encountered lots of new, unknown animal species that had lived in isolation in the remote territories. And Earth includes many similar small islands, which are the homes of rare animals and unique ecosystems. The world’s smallest chameleon, Brookesia micra, has just been found on the small, rocky, desolate island of Nosy Hara off northern Madagascar, where the 30- mm- long chameleon lives in cracks in the rocks.

Earth’s lush rainforests such as in Borneo and Madagascar are also known to be ripe with unique wildlife, and scientists almost cannot help being successful, when they go on expeditions to discover new species. It is more difficult for scientists in the huge oceans, which cover 71 % of the world’s area. Only a fraction of the ocean floor has been mapped out, and many places are difficult to explore due to the depths and the high pressure far beneath the sur-face. So, scientists annually “only” discover 1,500-2,000 new marine animals, although the oceans probably includes millions of more of them. However, scientists need not always go to extreme depths to find new species. In 2013, a new hermit crab was caught by a trawler at a depth of 200-300 m off the west coast of South Africa. The species is special, because it does not use abandoned sea shells, etc., as its house like other crayfish do, rather it carries a home made of living, anemone-like creatures on its back. Discovery reveals special gifts Examinations of the snailfish from the Mariana Trench have shown that the fish uses an unknown adaptation strategy to survive under the intense pressure at a depth of 8 km. Scientists have found special enzymes in the fish’s muscles, which are adapted to function optimally under the high pressure, and they have observed high levels of the TMAO compound in the cells, which protects proteins from collapsing. By copying the fish’s biology, scientists might be able to help divers explore even larger ocean depths, where they could discover more of the millions of species, which continue to live in hiding.