Anxious animals

Zebrafish suffering from chronic stress as a result of a genetic mutation showed signs of depression in behavioural tests.

Meanwhile a doctoral thesis on stress response and frustration in fish by research fellow Marco Antonio Vindas at Norway's environmental and life sciences university has also established that salmon have emotional responses, defined as more or less unconscious reactions in the brain triggered by consuming or positive situations.

Research into the behaviour of shrimps exposed to the antidepressant fluoxetine, showed that their behaviour is dramatically affected. The shrimps are five times more likely to swim toward the light instead of away from it – making them more likely to be eaten by fish or birds, which could have devastating effects on the shrimp population.