How to Scare an Invasive Fish? A Menacing Robot Predator. ...The research paper starts:
The mosquitofish is not a fussy creature: It can live in filthy bodies of water and has an undiscerning appetite. Larvae? Other fishes’ eggs? Detritus? Delicious. Often, the voracious few-inch creature chomps off the tails of freshwater fish and tadpoles, leaving them to die.
But the invasive fish is threatening some native populations in Australia and other regions, and for decades scientists have been trying to figure out how to control it, without damaging the surrounding ecosystem.
Now, the mosquitofish may have finally met its match: A menacing fish-shaped robot.
It’s “their worst nightmare,” said Giovanni Polverino, a behavioral ecologist at the University of Western Australia and the lead author of a paper published Thursday in iScience, in which scientists designed a simulacrum of the fish’s natural predator, the largemouth bass, to strike at the mosquitofish, scaring it away from its prey.
The robot not only freaked the mosquitofish out, but scarred them with such lasting anxiety that their reproduction rates dropped; evidence that could have long term implications for the species’ viability, according to the paper.
“You don’t need to kill them,” Dr. Polverino said. Instead, he said, “we can basically inject fear into the system, and the fear kills them slowly.”
Human activities have resulted in the rapid redistribution of the world's biota, assisting some species to colonize regions far beyond their natural rangeHere is another summary. Or here and here.