Fish with friends: The calming effect of group living in social fishes

Dr Lauren Nadler, OES; Dr Clive Trueman, OES; Dr Shaun Killen, University of Glasgow

Group living is common across the animal kingdom, ranging from the tiniest insects to the largest mammals. The ubiquity of sociality suggests that it imparts several benefits to individual group members. However, the evolutionary drivers of social behaviour within and among animal species remain obscure. One advantage of group living may come in the form of energy savings. Group-living individuals may reduce energy needs by sharing the costs associated with daily activities, such as movement and finding food. Social individuals may also benefit from the “calming effect”, in which energy use drops as the group can take advantage of having “many eyes” to scan for predators and reduce everyone’s investment in predator avoidance. Recent work in a social fish species found that socializing can reduce metabolic rate by 25% on average when compared to social isolation [1], with this calming effect persisting even under projected future ocean acidification [2]. This project will take a comparative approach to social fishes to identify what characteristics predispose a fish species to be “calmer” in a social context and determine whether environmental traits alter the magnitude of this energetic benefit. 



Using social fishes as models, this project will combine techniques in animal behaviour, ecophysiology, and otolith geochemistry to explore the energetic consequences of sociality, with results applicable to social species from a range of taxa and habitat types. This PhD project will take advantage of recent technological advances for measuring the metabolic rate of social fishes in the laboratory [1,2] and field [3] to test: 1) the prevalence of the calming effect among social fishes, 2) the role of environment and social context in modifying the strength of this effect, and 3) the mechanistic drivers underpinning calming effects. These research questions will be addressed using techniques such as animal personality tests, intermittent-flow respirometry, and assays of otolith geochemistry. Comparisons will be drawn among temperate and tropical fishes, with potential for fieldwork in a range of settings depending on the interests of the candidate.



The INSPIRE DTP programme provides comprehensive personal and professional development training alongside extensive opportunities for students to expand their multi-disciplinary outlook through interactions with a wide network of academic, research and industrial/policy partners. The student will be registered at the University of Southampton and hosted at the National Oceanography Centre Southampton. Training will focus on animal behaviour and physiology, using interdisciplinary approaches associated with fish biology, behavioural ecology, ecophysiology, otolith geochemistry, and quantitative data analysis. The results achieved will have implications for conservation, climate change, and fisheries management. This project will allow the student to gain skills both in the laboratory and the field as well as network with international scientists at the forefront of their discipline. If possible, travel to international scientific conferences will be encouraged to present this project’s results. The research skill set gained is highly marketable and the networking opportunities generated can provide diverse career opportunities. 


Eligibility & Funding Details: 

Please see for details.


Background Reading: 

[1] Nadler, L. E., Killen, S. S., McClure, E. C., Munday, P. L. and McCormick, M. I. (2016). Shoaling reduces metabolic rate in a gregarious coral reef fish species. J Exp Biol 219, 2802-2805.

[2] Nadler, L. E., Killen, S. S., McCormick, M. I., Watson, S. and Munday, P. L. (2016). Effect of elevated carbon dioxide on shoal familiarity and metabolism in a coral reef fish. Cons Phys 4, cow052.

[3] Chung, M. T., Trueman, C. N., Godiksen, J. A., Holmstrup, M. E. and Gronkjaer, P. (2019). Field metabolic rates of teleost fishes are recorded in otolith carbonate. Comm Biol 2, 24.