Graham, C., von Keyserlingk, M. A. G., Franks, B. 2018. Zebrafish welfare: Natural history, social motivation and behaviour. Applied Animal Behaviour Science 200, 13-22.
Zebrafish are now one of the most used animal model species in scientific research worldwide. Our current knowledge of wild zebrafish is limited to an estimated range of their natural habitats and their tendencies to form groups. In laboratories, zebrafish are typically housed in situations that differ greatly from their wild conditions. The disconnect between the characteristic features of animals’ natural environments and how they are housed in captivity has captured attention given the growing concern for the quality of life of animals under our care. As such, we propose that understanding zebrafish welfare must include in-depth knowledge of their natural behaviour, including research of their behaviour in semi-natural captive conditions, and how it may be affected by modern ‘standard’ laboratory housing. Moreover, as a highly social species, research investigating the social behaviour of zebrafish in natural and semi-natural contexts is particularly relevant. Thus, the four aims of this review are to: (1) synthesize the current state of knowledge regarding zebrafish welfare, focusing on their natural history, social motivation and behaviour, (2) describe the typical lives of laboratory zebrafish and what is known of their lives in the wild, (3) identify aspects of the current standard laboratory conditions that may affect zebrafish welfare and, (4) provide suggestions for practical changes that can be made to improve the captive housing environment that will ultimately enhance welfare and also identify promising areas for future research. We also discuss what is known about the cognitive ability of zebrafish and the research that supports concern for their welfare as well as the problems with studying animals housed in barren environments that reduce behavioural complexity and cognitive ability. Scientific investigation into the welfare of zebrafish opens the door to many exciting areas of research, such as determining which environmental parameters are most effective at mitigating behavioural abnormalities, refining and extending the study of fish emotion and affect, and discovering how to enhance zebrafish welfare in the many laboratories within which they live.