Optimizing zebrafish welfare - effects of environmental enrichment, tank volume and fish density

This is an ongoing project aimed at generating a scientific basis for recommendations for zebrafish husbandry.

The specific husbandry requirements for zebrafish are still far from understood and protocols for housing fish varies between laboratories.

Fish are often reared in barren, transparent tanks, which is likely to have negative effects not only on fish welfare but also on the quality of the results obtained. So far, we have studied effects of fish density, showing that low density results in aggression and chronic stress.

We now aim to generate knowledge on effects of tank sizes and environmental enrichment on physiology, behaviour and neurobiology in zebrafish.

Plastic plants are not optimal since they may release toxic compounds to the water, do not provide enough shelter and refuges, and even worse, are easy for the socially dominant fish to monopolize which will result in severe stress in subordinates. In this project we will develop enrichment prepared from material that does not contaminate the water.

We will also study effects of tank sizes as well as separate rearing of males and females and isolation, procedures often applied in zebrafish labs.

The knowledge gained from this project could be used to generate scientifically validated recommendations for the rearing of zebrafish.