Fish that inhabit coral reefs become stressed and lose weight when separated from the group they live with , and that reduces their chances of survival, according to Australian research recently published in the Journal of Experimental Biology .
The study, carried out by researchers from James Cook University, in the Australian state of Queensland, was carried out with specimens of the species of green damsels ( Chromis viridis ) from the Great Barrier Reef , on Lizard Island.
The scientists captured a group of these fish and isolated some of them from the rest, in order to analyze and understand why they are so gregarious and prefer to move in schools (schools of fish). To do this, they carried out a measurement of their metabolic rates .
The lead author of the study, Lauren Nadler, explained that the isolates lost weight and had a higher metabolic rate ; which is an indicator that they were more stressed than those who continued to live in a group.
“We suspected that for fish moving in schools, living in groups had a calming effect. But until now we had not been able to measure to what extent that factor was tangible in each fish,” said Nadler. “Those that were isolated lost weight after one week, which means that their state of health was less good than that of those who continued to live in a group “ , specified the researcher.
“Fish are calmer, less stressed, when their congeners are close, with a metabolic rate 26% lower than that of isolated individuals .” But what does a lower metabolic rate imply? They need less energy to survive and, therefore, can be used for other types of issues, such as growing or passing their genes on to the next generation.
Image: Paul Asman and Jill Lenoble via Wikimedia / CC
