Fish guide their friends to hidden patches of food

A study led by the University of St Andrews has revealed that stickleback fish recognise familiar fish that they've previously been housed with and spend more time interacting with these fish than with fish that are unfamiliar.

The study also revealed that fish show their friends the best places to eat; guiding them to hidden patches of food.

Researchers from the University of St Andrews, Anglia Ruskin University, and McMaster University in Canada caught 80 three-spined sticklebacks, a common native species found in rivers across the UK, and separated them into two groups for six weeks.

They were then formed into smaller groups of ten fish, including five fish from each of the two holding tanks. Over the following hours they were tagged and filmed as they searched for food.

Using techniques called Social Network Analysis and Network-Based Diffusion Analysis, the scientists observed that the fish interacted more often with familiar than with unfamiliar fish, and that fish were more likely to find hidden food if a familiar fish had recently found it.

The mechanism by which familiarity affects behaviour in fish is not yet clear, although scientists believe it may reflect a bias towards observing and responding to the behaviour of familiar fish.

"Our study has shown that we can use statistical tools to uncover the fine structure of animal groups, to understand how they move and to predict how information" explains Dr Mike Webster of the University of St Andrew's School of Biology.

"This has applications beyond the current project. It could potentially allow us to understand how new behaviours spread through animal populations, allowing them to respond and adapt to changes in the environment. It could also allow us to track or predict the spread of diseases, and to change the ways that we manage populations of livestock or wild animals in order to minimise the damage that these diseases cause"

The study "Familiarity affects social network structure and discovery of prey patch locations in foraging stickleback shoals" is published in the Royal Society journal Proceedings of the Royal Society B.

The paper is available online via Open Access.  

Image courtesy of Kevin Laland