A city in China is biting back after a resident complained that piranhas in the river had attacked him – offering a reward of 1,000 yuan (£101) to anyone who catches one of the predators.
Zhang Kaibo, from Liuzhou in the south-west Guangxi Zhuang autonomous region, said he needed stitches in his hand after three of the fish attacked him as he washed his dog in the river. He managed to grab one, but it died shortly after he took it home.
"Later on, my mum cut it into pieces and we planned to eat it. [But] some local officials came to my home and collected it to study," he said.
Officials confirmed that the specimen was a sharp-snouted piranha – which, like all piranhas, is native to South America and rather less common in Guangxi Zhuang. "There are far fewer people swimming in the Liu river than usual, but some people are not worried about piranhas at all. They're still enjoying swimming," Zhang said.
Zhou Quan, a spokesman for Liuzhou government, assured the state-run China Daily newspaper: "Residents in this city have no need to worry about piranhas in the Liu river." He added that the fish could not kill humans and could not live in water colder than 15C – giving them little hope of surviving and reproducing.
Authorities nonetheless trawled the river with a vast meat-baited net, but failed to find the piranhas among the 10kg of fish they caught. They hope the 1,000 yuan bounty will spur amateur fishermen into action.
"I assume these piranhas were dumped into the river by a tropical fish keeper, as this species can hardly survive naturally in the Liu river where water temperatures fall below what these fish require," Li Xinhui, a researcher at the Chinese Academy of Fishery Sciences, told the state-run Global Times.
But other experts warned that the piranhas had no natural predators in China. "There have been cases of piranhas recorded in parts of the US and other countries [outside South America], so it's not a one-off," said Dr David Morgan, an expert on freshwater fish at Murdoch University in Australia. "It's bad news if you introduce non-native species into a new area because you may never get rid of them."
But he added that the piranhas could disappear naturally and noted: "It's native aquatic animals that are going to be at more risk than humans."
Xu Xiang, an official from Liuzhou's water authority, told China Daily: "We will take strict measures to inspect markets selling birds and fishes as pets. It will be good for the people, if the government can take measures to prevent more piranhas coming into the river.
The Legal Daily said that media had previously reported that piranhas were on sale in Chinese markets. The fishery bureau at the agriculture ministry even issued an urgent circular 10 years ago, requiring local governments to control piranhas, it said – a claim that could not immediately be confirmed by the ministry.
"However, there is still no regulation governing alien species. It is no wonder piranhas are found in rivers around the country," the newspaper concluded.
