Some fish mix in social groups and follow each other's recommendations on the best eating spots, scientists have found.

Researchers studied the behaviour of two separate groups of sticklebacks and discovered that familiarity between shoal members had a clear effect on their ability to find food.

The fish visited food locations that had already been visited by their "friends".

William Hoppitt, senior lecturer in zoology at Anglia Ruskin University which was part of the study, said: "Our results provide evidence of an effect of familiarity upon group social organisation, with fish being more likely to associate with familiar than with unfamiliar individuals.

"These results demonstrate that factors that affect social interactions can influence how individuals encounter and exploit resources, and suggests that researchers should take into account social factors when investigating how information and behaviour spread through different populations."

Scientists from Anglia Ruskin, the University of St Andrews, and McMaster University in Canada initially separated 80 three-spined sticklebacks, commonly found in UK rivers, into two groups for six weeks - long enough for them to recognise and identify with one another.

They were tagged and videoed as they set about discovering food.

The results showed that familiarity had a clear effect on their ability to find food, with sticklebacks more likely to discover the food source if a member of the same shoal has also previously found it.

The reasons why familiarity affects behaviour in fish are not fully clear, although the scientists believe it might reflect a bias for observing or responding to the behaviour of familiar individuals.