[ad_1]
The mosquitofish is not a fussy creature: it can live in sludge and has an indistinguishable appetite. Larva? Eggs of other fish? Debris? Tasty. Often, the voracious few inches creature will tear off the tails of freshwater fish and tadpoles, leaving them to die.
But the invasive fish threatens some native populations in Australia and elsewhere, 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 mate: a menacing fish-shaped robot.
It’s “their worst nightmare,” says Giovanni Polverino, a behavioral ecologist at the University of Western Australia and lead author of the book. An article published on Thursday In iScience, scientists designed a simulacrum of the fish’s natural predator, the largemouth bass, to attack the mosquitofish and scare it away from its prey.
Not only did the robot scare the mosquitofish, it scared them with such persistent anxiety that their reproductive rate dropped; evidence that could have long-term implications for the viability of the species, according to the paper.
Dr. “You don’t need to kill them,” Polverino said. Instead, he said, “we can basically inject fear into the system, and fear slowly kills them.”
Mosquito fish native to North America are named for their penchant for eating mosquito larvae. In the 1920s, fish began to be introduced around the world to control the population of this insect, which is a vector for malaria.
In some places (where they planted), including some regions of Russia a monument to fish) the campaign may have had some success, but this is debatable.
But in other parts of the world, aggressive fish have evolved uncontrollably, regardless of their natural predators. In 2000, the International Union for Conservation of Nature classified marine animals. among the worst Invasive species in the world.
In Australia, where the research was conducted, the mosquitofish preys on many native fish and frog species, including the redfin blueeye and Edgbaston goby, two of the most critically endangered fish species in Australia.
“They thrive because they eat pretty much anything that moves, and there’s plenty of food to eat,” says biologist Francesco Santi of Vicenza, Italy, who was not involved in the study and has never been before. studied the diet of mosquito fish. “I have no idea of any place where they could actually eliminate them,” he added.
For the study, Dr. Polverino and his colleagues designed a mechanical predator in the shape of largemouth bass. The robot fish used a camera to distinguish between the mosquitofish, which is its “prey,” and the tadpoles of the Australian motorcycle frog, which the mosquito fish prey on.
The researchers put their Terminator-like creatures in a tank with six wild-caught mosquito fish and six wild-caught tadpole. When a mosquito fish approached a tadpole, the robot lurched forward as if it was about to attack.
After experimenting with 12 separate groups of fish and tadpoles over several weeks, the researchers discovered that stressed mosquitofish took more energy to escape the robot than to reproduce: The males’ sperm count dropped and the females began producing lighter eggs. Fish also lost weight; especially men’s bodies became thinner and more prone to escape.
Dr. “Not just because they were afraid,” Polverino said. “But they’ve also become unhealthy.”
The experiment isn’t the first time scientists have created robot imitators to study animals’ behavior more closely.
scientists in the UK robotic hawk “attacking” a flock of pigeons and observing the birds’ reaction. in Germany, researchers made a bee that directs other bees to a food source by “shake dance.” a biologist in California a sage grouse “fembot” From an embalmed bird to understand the mating habits of threatened species.
However, in the case of the mechanical largemouth bass, the scientists say the robot still has a long way to go before it is released into the wild.
“This is an important proof of concept,” said Peter Klimley, a marine biologist and a recently retired professor at the University of California, Davis, who was not involved in the study. But he questioned the feasibility of introducing the creature into a real-world setting.
Dr. “This work will not be a solution to the problem,” Polverino said, adding that the next phase of their project will involve testing the robots in a larger, open, freshwater pool.
He said the robot should be thought of as a tool that can reveal the weaknesses of an insect. Dr. “We created a kind of vulnerability profile,” Polverino said, which could help biologists and others redesign how to control invasive species.
“This fear,” he added, “has a secondary effect.”
[ad_2]
Source link