A new study in Canada has revealed that fish brains grow larger when they have to think more seriously, and then shrink again when they can relax.
The study compared the brain sizes of rainbow trout, which lives on a fish farm in Parry Sound, Ontario, with that of fish that slipped from the hatchery and became wildlife in a nearby lake, according to the New Scientist website.
And after 7 months, scientists discovered that the brains of the “trout” that live in the wild had become 15 percent heavier in weight than the “captive trout” inside the farm, in relation to their body size.
And integrative biologist at the University of Guelph in Canada, Frederic Laberg, pointed out that the growth spurt in the fish’s brain was limited to its gray matter, and did not affect its heart or other organs.
Labberg concluded that more complex living environments actually force fish to increase their mental strength.
He explained that fish brains are “flexible” and can grow larger when faced with more complex environments, he says.
It is noteworthy that scientists have proven, earlier, that fish in laboratories have smaller brains than their counterparts living in the free range, but Friedrich Laberge’s recent study is the first scientific research to show this discrepancy in wildlife.
Frederic Labberg also discovered in a previous study that trout brain size increases in the fall and winter, and then decreases in the spring and summer, after he had been studying it for several years while it was in two lakes in Ontario.
Explaining this phenomenon, he said, “The trout prefer to live in colder waters, but when the cold causes the lake to become very cold, they are forced to search for food near the surface and shore, which creates a more competitive and complex environment for them, which requires an increase in gray matter. in her brain.”