Guidance

Zebrafish welfare

Guidance, information and recommendations for those working with zebrafish.

Refining housing and husbandry

Expert reports have been compiled to provide guidance on the following aspects of zebrafish care within a research environment [1,2]:

Housing and husbandry (see [2] Table 1 for summary).
Transportation and reception.
Breeding and identification.

See [3] for a review into the physical and social factors that contribute to zebrafish welfare, and how understanding the natural history of zebrafish can inform welfare refinements and improvements in experimental science.

See [4] for a review of the evidence and challenges related to environmental enrichment and laboratory zebrafish.

Refining procedures

See Chapter 5 of [1] for guidance and recommendations on a range of scientific procedures involving zebrafish. See the below publications for information on other potential refinements:

A refined protocol for VIE tagging [5].
A protocol for skin swabbing to collect DNA for zebrafish genotyping [6].
Validation of morphine for reducing pain in zebrafish that have undergone heart cryoinjury, without affecting the regeneration of heart tissue [7].
Validation of lidocaine hydrochloride buffered with sodium bicarbonate and ethanol for euthanasia of adult zebrafish [8] and embryos and larvae [9].
Discussions on analgesia, anaesthesia, and euthanasia in zebrafish [10,11].
An investigation of suitable protocols for repeated anaesthesia of juvenile zebrafish [12].

Community and databases

The Zebrafish Husbandry Association (ZHA) is a non-profit organization devoted to promoting and developing zebrafish husbandry standards through education, collaboration, and publication.
The Zebrafish Information Network (ZFIN) is a database of genetic and genomic data for the zebrafish (Danio rerio) as a model organism.

Zebrafish in Tech3Rs

Tech3Rs is our regular newsletter providing animal technicians with the latest news from the NC3Rs. Each issue features updates on recent advances in the 3Rs and highlights new resources, research and events that we think will be of interest to animal technicians, including information relevant for those working with zebrafish.

A 3Rs champions article featuring a technician who provides environmental enrichment to zebrafish (Issue 15, July 2022, page 5)
A front page feature introducing the zebrafish skin swabbing resource (Issue 14, March 2022, page 1)
A summary of three studies focusing on how different types of environmental enrichment and different exposure patterns can affect zebrafish welfare (Issue 10, February 2021, page 3).
The Aquarium Stock Resource Manager and NACWO at the University of Sheffield's Bateson Centre shares her experience of using the Zebrafish Embryonic Genotyper (ZEG) (Issue 7, May 2020, page 2).
A summary of three studies focusing on the welfare of laboratory zebrafish (Issue 2, February 2019, page 3).

Additional resources

FELASA working group report, Health monitoring for fish in research with supplementary resources including printable health monitoring sheets.
The North American 3Rs Collaborative (NA3RsC), zebrafish housing and handling.
Norecopa, zebrafish resources.
RSPCA, Focus on Fish 2021 summary meeting report.

References

RSPCA (2011). Guidance on the housing and care of zebrafish Danio rerio.
Aleström P et al. (2019). Zebrafish: housing and husbandry recommendations. Laboratory Animals 54(3): 213-224. doi: 10.1177/0023677219869037
Lee CJ et al. (2022). Improving zebrafish laboratory welfare and scientific research through understanding their natural history. Biological Reviews. doi: 10.1111/brv.12831
Stevens CH et al. (2021). Enrichment for laboratory zebrafish—a review of the evidence and the challenges. Animals 11(3): 698. doi: 10.3390/ani11030698
Rácz A et al. (2021). Identification of individual zebrafish (Danio rerio): A refined protocol for VIE tagging whilst considering animal welfare and the principles of the 3Rs. Animals 11(3): 616. doi: 10.3390/ani11030616
Tilley C et al. (2021). Skin swabbing protocol to collect DNA samples from small-bodied fish species. F1000Research 10(1064): doi: 10.12688/f1000research.73115.1
Lelek S et al. (2020). Morphine alleviates pain after heart cryoinjury in zebrafish without impeding regeneration. bioRxiv. doi: 10.1101/2020.10.01.322560
von Krogh K et al. (2021). Screening of anaesthetics in adult zebrafish (Danio rerio) for the induction of euthanasia by overdose. Biology 10(11): 1133. doi: 10.3390/biology10111133
JP Mocho et al. (2022). A multi-site assessment of anesthetic overdose, hypothermic shock, and electrical stunning as methods of euthanasia for zebrafish (Danio rerio) embryos and larvae. Biology 11(4): 546. doi: 10.3390/biology11040546
Collymore C (2020). Anesthesia, analgesia, and euthanasia of the laboratory zebrafish. In: The Zebrafish in Biomedical Research. Academic Press.
Köhler A et al. (2022). Analgesia, anesthesia, and euthanasia in zebrafish. In: Laboratory Fish in Biomedical Research. Academic Press.
Owen JP and Kelsh RN (2021). A suitable anaesthetic protocol for metamorphic zebrafish. PloS one 16(3), e0246504. doi: 10.1371/journal.pone.0246504

Skin swabbing for DNA sampling of zebrafish

Visit our resource on this refined method, an alternative to fin clipping for genotyping.

a zebrafish is held in a hand net and swabbed.

International survey on the use of zebrafish

Three zebrafish in a clear tank, set against a black background.

Social housing aids recovery from stressors in zebrafish

Procedures can be refined through social housing. Where temporary isolation of zebrafish is justified, it is recommended to provide some form of sensory contact between group mates (e.g. visual and/or olfactory).