Leicester scientist leads project to investigate ways to improve welfare of fish in research

A new project, led by our University working with scientists from Nottingham Trent University and the Centre for Environment, Fisheries and Aquaculture Science (Cefas), will explore how less-invasive swabbing techniques can be used to collect DNA from fish during scientific research in order to reduce stress and better protect their welfare.

The project, funded by the National Centre for the Replacement, Refinement and Reduction of Animals in Research, aims to test the hypothesis that swabbing has a significantly lower impact on stress-related behaviour and physiology than fin clipping – and could therefore be used to refine current standard regulated procedures, benefitting fish welfare.

Collecting DNA samples to identify small fish is a common procedure in laboratories throughout the world. It is mostly done to confirm the genetic strain of fish, their population of origin, or whether an individual contains particular versions of genes that are relevant to the research. DNA sequences can be used as markers of other traits, including sex.

DNA sampling is typically performed by fin clipping, an invasive procedure carried out under non-terminal anaesthesia.

The new technique involves gently stroking a swab – effectively a sterile cotton-bud – along the flank of the fish whilst the fish is held in a net, and can be completed in just a few seconds. The research team has already demonstrated that this collects enough DNA for analysis.

Dr William Norton from our Department of Neuroscience, Psychology and Behaviour, who is leading the project, said: “In this project we will investigate the nature and magnitude of any welfare benefits of swabbing over fin clipping. Such information is essential to validate the swabbing technique and assure its wider adoption by the growing community of researchers that use fish as laboratory models.”