Evaluating and Optimizing Fish Health and Welfare During Experimental Procedures.

Many facilities house fish in separate static containers post-procedure, for example, while awaiting genotyping results. This ensures fish can be easily identified, but it does not allow for provision of continuous filtered water or diet. At the Wellcome Trust Sanger Institute, concern over the housing conditions led to the development of an individual housing system (GeneS) enabling feeding and water filtration. Trials to compare the water quality measures between the various systems found that fish housed in static containers experienced rapid deterioration in water quality. By day 1, measures of ammonia were outside the Institute's prescribed values and continued to rise until it was 25-fold higher than recommended levels. Nitrite levels were also outside recommended levels for all fish by day 9 and were twofold higher by the end of the trial. The water quality measures for tanks held on the recirculating system were stable even though food was provided. These results indicate that for housing zebrafish, running water or appropriately timed water changes are a critical component to ensure that the ethical obligations are met.

Standardized Welfare Terms for the Zebrafish Community.

Managing the welfare of laboratory animals is critical to animal health, vital in the understanding of phenotypes created by treatment or genetic alteration and ensures compliance of regulations. Part of an animal welfare assessment is the requirement to record observations, ensuring all those responsible for the animals are aware of their health status and can act accordingly. Although the use of zebrafish in research continues to increase, guidelines for conducting welfare assessments and the reporting of observations are considered unclear compared to mammalian species. To support the movement of zebrafish between facilities, significant improvement would be achieved through the use of standardized terms to ensure clarity and consistency between facilities. Improving the clarity of terminology around welfare not only addresses our ethical obligation but also supports the research goals and provides a searchable description of the phenotypes. A Collaboration between the Wellcome Trust Sanger Institute and Cambridge University (Department of Medicine-Laboratory of Molecular Biology) has led to the creation of the zebrafish welfare terms from which standardization of terminology can be achieved.