Gambusia is a fish that reaches a maximum length of 3.5 cm for males, while females also the 7 cm. These creatures have invaded several habitats, disrupting ecosystems from Europe to Australia. In a new document, scientists have tried to control these fish through “fear.”
According to a new article published in the iScience magazine on December 16, when researchers created a robotic fish designed to imitate one of the natural predators of Gambusia, the “invaders” fish increased their fear and response to stress, compromising
Invasive creatures like these are a problem, but according to the study there are “more creative ways to prevent unwanted behaviour than killing it,” says Michael Culshaw-Maurer, an ecologist at the University of Arizona (not Originally, Gambusia was released into the freshwater ecosystems of the world in the last century in an attempt to control malaria by eating mosquitoes. As we have already told you in our special on the most dangerous invasive creatures, this method does not seem to work.
However, creatures, instead of attacking mosquitoes, preferred to eat eggs and nibble the tails of other native fish and amphibians, making them one of the most destructive invasive species in the world. To limit the spread of the creature, several ways have been sought – all linked to decimation with traps, poisons and much more (that is why invasive species are a danger to the territory).
But if we think about it, their widespread spread is due to the lack of predators… and that’s what the researchers wanted to solve. Rather than introducing “true” predators into the ecosystems invaded by Gambuseia, experts introduced robot versions of largemouth bass (Micropterus salmoides). And the results actually surprised the researchers.
The fear of the robot has altered the behaviour, shape and fertility of the mosquito fish, both during exposure and after weeks. Stress has transformed the body of fish: the creatures had lost energy reserves, becoming slightly smaller and leaner, to accelerate the escape behaviors. The sperm count of fish, moreover, decreased on average by about half.
Surely a very successful experiment… because the researchers’ intention is not to release herds of these robot fish, but to seek methods to control their numbers.