One of two British explorer ships that vanished in the Arctic more than 160 years ago has been found, Canada's prime minister says.

Stephen Harper said it was unclear which ship had been found, but photo evidence confirmed it was one of them.

I am delighted to announce that this year’s Victoria Strait Expedition has solved one of Canada’s greatest mysteries, with the discovery of one of the two ships belonging to the Franklin Expedition lost in 1846.

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.