Invasion of aggressive fish feared

The Saskatchewan government is telling people to not buy an invasive species of fish known as the northern snakehead.
The northern snakehead is native to China and Siberia, but could survive a Saskatchewan winter, experts say. (U.S. Department of the Interior)
A big, ugly, toothy aggressive fish that walks and breathes air has the Saskatchewan government worried.

It's an invasive species called the northern snakehead and the province is telling people to not buy it.

The fish, which is native to rivers in China and Siberia but has turned up in some aquarium shops in North America, grows up to a metre long.  

In a news release Tuesday, the Environment Ministry said it's believed there are some pet stores in the province that are selling them, although it is requesting they not do so.  

"It's the cool, thrill factor of the fish that encourages people to purchase it," ministry spokesperson Tanya Johnston said.

The government is worried that if the aggressive northern snakeheads are released from home aquariums into Saskatchewan lakes and rivers, there'll be no stopping them.

There are no known cases of the fish being caught in Saskatchewan waters.

The concern is the fish will out-compete native fish —like walleye and northern pike — for food, eventually wiping them out.

What makes the toothy fish a unique threat in Saskatchewan is that it can "walk" using its fins over short distances and breathe air.

Northern snakehead are also known to carry a disease, epizootic ulcerative syndrome, that can spread to other freshwater fish species.

On the plus side, from the perspective of anglers, at least, it is edible.

"In Asian cultures, it is a delicacy. If you want to give it a go, you can eat it," Johnston said.

The province says there's no known method of eradicating northern snakeheads once they have invaded a waterway.