Mental health issues aren’t unique to humans, but until a recent study, people seem to have completely underestimated the way certain animals behave like humans.
Crayfish, which have never been regarded as having the higher brain functions that human’s exhibit, have been found to experience anxiety as a result of stress, a fact that animal rights activists will no doubt make good use of.
By exposing crayfish, a crustacean resembling a small lobster, to an electric field to induce stress, and releasing them into a specially designed, tank, researchers at the University of Bordeaux in France discovered that the behaviour of the crayfish is influenced by the presence of serotonin, an indicator of anxiety.
The specially designed tank was shaped like plus sign (+) and had two sections brightly lit and two sections left dark. It was found that crayfish who had been exposed to the electric field all moved into the dark, possibly seen as ‘safer’, areas whereas un-affected crayfish spread evenly throughout the tank.
After dosing the stressed crayfish with anti-anxiety medication (benzodiazepine anxiolytic chlordiazepoxide) used to treat humans, the crayfish exhibited normal behaviour again, showing that an increase in serotonin in their body affects their behaviour, just like in people.
It was not thought so far that invertebrates would behave like this, and that these kinds of reactions were only found in vertebrates like humans, chimps and mice.
In another animal related study, Dr. Jonathon Pruitt found that some of the species of spiders, the least cuddly of animals, which act in sociable colonies can have independent personalities depending on how they react to other spiders, with evidence suggesting some prefer to nestle against each other.
While that thought might leave your skin crawling, it indicates that animals might be a lot closer to us than we think, and the negative effects humans can have on them might go a lot deeper than we thought.
