Bangkok - More than 1,000 new species, including the world's largest huntsman spider and the Laotian rock rat, have been discovered in the Greater Mekong Region of Southeast Asia between 1997 and 2007, the World Wildlife Fund (WWF) revealed Monday.

The huntsman spider has leg span of 30 centimetres, and the rock rat was previously thought to have become extinct 11 million years ago, according to the report, First Contact in the Greater Mekong.

Some of the 1,068 newly discovered species were found in surprising places, said the report.

"The Laotian rock rat, for example, thought to be extinct 11 million years ago, was first encountered by scientists in a local food market, while the Siamese Peninsula pit viper was found slithering through the rafters of a restaurant in Khao Yai National Park in Thailand," the WWF said.

The Greater Mekong region comprises southern China, Cambodia, Laos, Myanmar, Thailand and Vietnam.

The new species identified include 519 plants, 279 fish, 88 frogs, 88 spiders, 46 lizards, 22 snakes, 15 mammals, 4 birds, 4 turtles, 2 salamanders and a toad.

"We thought discoveries of this scale were confined to the history books," said Stuart Chapman, director of WWF's Greater Mekong Programme. "This reaffirms the Greater Mekong's place on the world map of conservation priorities."

The report stresses economic development and environmental protection must go hand-in-hand to ensure the survival of the region's array of species and natural habitats.

"This poorly understood biodiversity is facing unprecedented pressure. For scientists, this means that almost every field survey yields new diversity, but documenting it is a race against time," said Raoul Bain, biodiversity specialist from the American Museum of Natural History. (dpa)