By Jody Bourton
Earth News reporter
A river giant vanishes
One of the world's largest freshwater fish is on the verge of going extinct.
A three-year quest to find the giant Chinese paddlefish in the Yangtze river failed to sight or catch a single individual.
That means that the fish, which can grow up to 7m long, has not been seen alive for at least six years.
There remains a chance that some escaped the survey and survive, say experts, but without action, the future of the species is bleak.
The concern for the Chinese paddlefish is that its fate will parallel that of the Yangtze river dolphin, a large mammal species that was once abundant in the Yangtze river system, but has recently been declared extinct.
A number of fish species vie for the position of the world's largest freshwater fish, including the arapaima (Arapaima gigas) of the Amazon river and the Mekong giant catfish (Pangasia