As many as 99 new species have been found in Vietnam, according to a World Wildlife Fund report.

The report, titled Natures Mysterious Mekong, which was announced to celebrate the World Environment Day on June 5, said that a total of 367 new species had been discovered in the Greater Mekong in 2012 and 2013.

The region spans Cambodia, Laos, Myanmar, Thailand, Vietnam and China’s south-western Yunnan province.

Among the species newly identified by scientists are 290 plants, 24 fish, 21 amphibians, 28 reptiles, 1 bird and 3 mammals.

"The species discoveries affirm the Greater Mekong as one of the world’s richest and most biodiverse regions," said Thomas Gray, Manager of WWF-Greater Mekong’s Species Programme.

In Vietnam, scientists recently discovered Helens Flying Frog, (Rhacophorus helenae), a huge, green, "flying" frog discovered less than 100km from Ho Chi Minh City.

The frog can reach up to 10cm in length and belongs to a family of frog species that boast an ability to glide.

With large feet that are fully webbed and flaps of webbing on the outside of their arms, they can glide sometimes 50 feet (15 metres) down from trees to breed in forest pools, and even between trees.

The frogs spend most of their time out of human sight in the forest canopy, perhaps explaining why this distinctive new species has gone completely unnoticed until now.

To date, the frog has only been located in two patches of lowland forest surrounded by agricultural land in central Binh Thuan province and southern Dong Nai province.

"Lowland tropical forests are among the most threatened habitats in the world due to human activities, such as logging and degradation," said Thomas Gray, Manager of WWF-Greater Mekong’s Species Programme.

While Helens Tree Frog has only just been discovered, the species, like many others, is already under threat in its fast shrinking habitat, he said.

Scientists are warning that the frog may need to be listed as a threatened species with the International Union for Conservation of Natures Red List criteria.

Among the 28 new reptiles named in the report, the white-head Burmese viper (Azemi ops kharini), a primitive viper species, was found in northern Vinh Phuc province.

The venomous species is thought to be a primitive viper species due to it possessing an elliptically shaped, flattened head; enlarged head plates; smooth dorsal scales; folding front fangs; no heat-sensing pits and a coiled venom gland duct.

Scientists also identified the hunch-bat of Vietnam, (Hipposideros griffin) 248m above sea level in Cat Ba Island’s Cat Ba National Park in the northern region of Vietnam, as well as in Chu Mom Ray National Park, situated on the mainland more than 1,000km to the south.

The bat was first seen in 2008 on the island, but it was not until later, after a team of researchers caught some of the bats, that it was confirmed as a previously unknown species, the report said.

Griffins leaf-nosed bat is recognised by its grotesque, fleshy nose that assists in echolocation, the sonar-like ability bats use to help them navigate.

A new penis head fish (Phallostethus cuulong), is certainly among the more bizarre discoveries to surface in the Cuu Long (Mekong) Delta region of Vietnam.

The fish is a newcomer to the Phallostethidae family of fish, whose thin, nearly transparent bodies are characterised by the unusual placement of their sexual organs on their heads.

The male fishs priapium (the technical name for its sexual organ) is a complex, muscular organ located underneath the fish’s chin.

The female fish’s genitals are also located under her throat, and unlike most fish, fertilisation for the Phallostethus cuulong takes place inside the females body. Researchers say a hook possessed by the male probably increases the success of fertilisation.

The discoveries place Vietnam as the country with the third highest amount of new species on the list, after Thailand with 117 newly discovered species and China with 116.-VNA