The right character for aquaculture

Just like people, fish have a personality. There are shy fish, bold fish, peace-loving and aggressive fish. In this project scientists are studying sole to find out what behaviour results in the best growth.

Sole is a difficult fish to farm. It grows very slowly, primarily because it does not eat well. Sole are fussy eaters: they refuse dried feed and even live feed – mussels and ragworms – they only eat in small quantities. In this project researchers are trying to find out whether there is a relationship between the rate of growth and fish behaviour. First they determine the growth rate of individual sole and then they assess the fishes’ behaviour: how curious, alert or easily scared they are. The results of the first experiments suggest that twenty per cent of the difference in growth can be explained by differences in behaviour.

Fishes’ behaviour is strongly influenced by their environment. A bold fish will behave differently in an outside pond than in tanks inside. Light, temperature and oxygen content all affect fish behaviour, but in ways that are difficult to predict. In a second series of experiments, therefore, scientists will examine the relationship between behaviour, different environmental conditions and growth. The ultimate aim is to work out which sole genotype fares best in different types of aquaculture – inside or outside – and to select for the appropriate characteristics.