Invasive Walking Fish Headed for Australia
Posted on June 4, 2015
Australian scientists at James Cook University are monitoring the movements of the climbing perch as it moves south from Papa New Guinea towards Australia. Researchers say the aggressive fish has already overrun two Australian outposts in the Torres Strait islands of Boigu and Saibai. The fish can live out of water for up to six days and crawl across dry land by using its grill plates to walk. It can kill predators by swelling up in their throats when it gets swallowed.
It is a freshwater fish but the climbing perch has been observed tolerating some exposure to saltwater. The perch can out compete native species for resources when it establishes itself in a new environment. It can hibernate in dried-up creek bed for up to six months. The fish has spread across Indonesia and Papa New Guinea over the past four decades.
Dr. Nathan Waltham, a scientist at James Cook University, says in a statement, "It does seem to be able to handle a little bit of salt. In our trip up there in December we found it in some hyper saline water holes, so there is some ability to resist exposure."
Dr. Waltham thinks it is more likely the fish could get closer to mainland Australia in a fishing boat than by swimming. He says, "But I still think the chances of it getting to Australia by swimming are quite low. There is more chance it will arrive in the bottom of a fishing boat or as discarded live-bait fish."
Dr. Waltham thinks the fish can be kept under control through active education and monitoring. Here is a video of the climbing perch walking across a road: