The University of Leicester study, funded by the Natural Environment Research Council, has important implications for understanding the dynamics of fish reproduction as well as environmental and habitat protection.

Dr Hart said: “People often think of individual animals as little machines, which can be moved around and dealt with as objects with no regard for how individuals relate to each other. “Our research, along with other studies elsewhere, are showing that even fish are not ignorant of who they are interacting with. “Our work suggests that although fish can recognize familiar individuals they do not do it through individual visual recognition.”