Culum Brown, a leading researcher in the field of fish cognition, is based at Macquarie University, where he runs the Fish Lab — the Behaviour, Ecology and Evolution of Fishes Laboratory. His fascination for fish stems from growing up in parts of south-east Asia, where he would spend every possible hour in the ocean with a snorkel.

As an adult, Culum's Marine Biology studies around the world (including the UK and Finland) have revealed many facts which upend the basis of our common understanding of fish. His research has shown that even the smallest fish are capable of learning and can retain memories for months - and within schools of fish, there is often a strict social hierarchy which can include forms of bullying.

Find out even more about fish behaviour in Culum's podcast.