A new species is being discovered in the Amazon every two days from fire-tailed titi monkeys and yellow-moustached lizards to pink river dolphins and honeycomb-patterned stingrays, according to a new report.

Conservation group World Wildlife Fund, who wrote the report along with Brazil’s Mamiraua Institute, said the astonishing rate of new finds showed scientists had still only scratched the surface of all the “incredible species” that live there.

But “relentless deforestation” of the Amazon means many of its undiscovered animals and plants will go extinct before they are found, WWF warned, urging governments in the region to take action.

The report revealed a total of 381 new species had been discovered in 2014 and 2015, including 216 plants, 93 fish, 32 amphibians, 20 mammals – although two of those were fossils – 19 reptiles and one bird.

Sarah Hutchison, WWF’s head of programmes for Brazil and Amazon, said: “We are only at the tip of the iceberg when it comes to unveiling the incredible species that live in the Amazon, yet instead of this precious area being safeguarded, it is under greater threat than ever before.

“There is a real risk that at the rate at which the Amazon is changing many species may become extinct before we have had a chance to find them.

“The discovery of 381 new species is a wake-up call for the governments of Amazon countries that they must halt the ongoing and relentless deforestation and work to preserve its unparalleled biodiversity.

“If they don’t, there will continue to be irreversible impacts on the Amazon’s much-loved wildlife, undiscovered species and the local and indigenous people that call it home.”

She said she hoped the report would “inspire” scientists to carry out more research.

“Sharing new discoveries is essential to supporting conservation efforts and, as one of the last great wildernesses, there are many more secrets left to uncover,” Ms Hutchison said.

Nearly a third of all the tropical rainforests on Earth are in the Amazon. Even though it covers about 1 per cent of the planet’s surface, it is estimated to be home to 10 per cent of known species.

The new species of pink river dolphin is estimated to have a population of 1,000, but they are under threat from the construction of hydroelectric dams as well as industrial and agricultural activity. The fire-tailed titi monkey, which has a bright orange tail, is also at risk from deforestation.

Animals in decline Show all 8 1 /8 Animals in decline Animals in decline Harbour seal (Phoca vitulina) Where: Orkney Islands. What: Between 2001-2006, numbers in Orkney declined by 40 per cent. Why: epidemics of the phocine distemper virus are thought to have caused major declines, but the killing of seals in the Moray Firth to protect salmon farms may have an impact. Alamy Animals in decline African lion (Panthera leo) Where: Ghana. What: In Ghana’s Mole National Park, lion numbers have declined by more than 90 per cent in 40 years. Why: local conflicts are thought to have contributed to the slaughter of lions and are a worrying example of the status of the animal in Western and Central Africa. Animals in decline Leatherback turtle (Dermochelys coriacea) Where: Indonesia, Malaysia, Mexico, Costa Rica. What: Numbers are down in both the Atlantic and Pacific. It declined by 95 per cent between 1989-2002 in Costa Rica. Why: mainly due to them being caught as bycatch, but they’ve also been affected by local developments. Alamy Animals in decline Wandering albatross (Diomedea exulans) Where: South Atlantic. What: A rapid decline. One population, from Bird Island, South Georgia, declined by 50 per cent between 1972-2010, according to the British Antarctic Survey. Why: being caught in various commercial longline fisheries. Alamy Animals in decline Saiga Antelope (Saiga tatarica) Where: Kazakhstan, Mongolia, Russia, Turkmenistan, Uzbekistan. What: fall in populations has been dramatic. In the early 1990s numbers were over a million, but are now estimated to be around 50,000. Why: the break up of the former USSR led to uncontrolled hunting. Increased rural poverty means the species is hunted for its meat Animals in decline Swordfish (Xiphias gladius) Where: found worldwide in tropical, subtropical and temperate seas. Why: at risk from overfishing and as a target in recreational fishing. A significant number of swordfish are also caught by illegal driftnet fisheries in the Mediterranean Animals in decline Argali Sheep (Ovis mammon) Where: Central and Southern Asian mountains,usually at 3,000-5,000 metres altitude. Why: domesticated herds of sheep competing for grazing grounds. Over-hunting and poaching. Animals in decline Humphead Wrasse (Cheilinus undulatus) Where: the Indo-Pacific, from the Red Sea to South Africa and to the Tuamoto Islands (Polynesia), north to the Ryukyu Islands (south-west Japan), and south to New Caledonia. Why: Illegal, Unregulated and Unreported (IUU) fishing and trading of the species

The current rate of species extinction is estimated to be 1,000 to 10,000 times that of the natural rate because of human activity.