The robot inspires fear in the predator, which prefers to flee rather than reproduce: in Australia they’re using a robot to drive out a dangerous predator
There are two laws in nature that apply to this story: a predator is not always gigantic – and this little shark proves it -, and invasive species can cause great damage to ecosystems.
Researchers at the University of Western Australia know this well, and they’ve found a solution to the Gambusia invasion: a small robot.
A Dangerous Predator: the Gambusia
The Gambusia, or “mosquitofish” in English, is a small freshwater fish, 3.5 centimeters in size if male and 7 centimeters if female.
It’s not a picky creature: it survives in the dirtiest, stagnant pools of water, and will eat whatever is in front of it – larvae, eggs of other fish, trash. It often bites the tails of other fish or tadpoles, leaving them for dead.
Native to the Gulf of Mexico, they were introduced to aquatic ecosystems around the world in the 20th century as a means of controlling mosquitoes that carried malaria. In some areas it worked: in Russia, for example, a statue was even erected for the Gambusia.
In Australia, however, something went wrong: the Gambusia multiplied exponentially, and became invasive and dangerous to the entire habitat.
A robot to solve the situation
The small robot created by researchers at the University of Western Australia has the features of the trout perch, the natural predator of Gambusia.
Even just a glimpse of the shape of a trout perch scares the gambusia away from their prey. In fact, it threw them into such a state of anxiety that their ability to reproduce dropped dramatically.
“There was no need to kill them,” explained Giovanni Polverino, author of the research. “It was enough to introduce the fear factor into their daily lives.”
The robot has a camera installed, allowing it to distinguish Gambusia from other freshwater species. The researchers placed their robot, six gambusia and six tadpoles in a tank full of water. Each time the gambusia approached a tadpole, the robot moved as if to attack. After a 12-week study, the scientists found that the invasive species was more busy running away from its predator than reproducing. The number of sperm in the males had dropped, and the females produced more fragile eggs. And the weight of the animals had also declined.
Now all of this invasive species’ prey is safer, and in Australia there were many: including the Blue-eyed Red Finned and Edgbaston’s Goby, two of the most endangered fish species in the country.