
Zebrafish
One action identified by the research community and included in the report Reducing Administrative Burden for Researchers: Animal Care and Use in Research in response to the 21st Century Cures Act is to consider changing the applicability of the PHS Policy to zebrafish larvae from immediately after hatching (typically 3 days post fertilization [dpf] under optimal conditions) to when larvae begin free feeding (at approximately 5 – 7 dpf).
While OLAW encourages institutions to use flexibilities to reduce administrative burden while using zebrafish in research (NOT-OD-21-118), the PHS Policy continues to cover zebrafish larvae immediately after hatching.
On this page:
Policies and Laws
PHS Policy III.A.: Defines an animal as "[a]ny live vertebrate animal used or intended for use in research, research training, experimentation, or biological testing or for related purposes."
PHS Policy IV.D.1.A.: "All Institutions: Applications and proposals (competing and noncompeting) for awards submitted to the PHS that involve the care and use of animals shall contain the following information:
a. identification of the species and approximate number of animals to be used;"
U.S. Government Principles IV: "Proper use of animals, including the avoidance or minimization of discomfort, distress, and pain when consistent with sound scientific practices, is imperative. Unless the contrary is established, investigators should consider that procedures that cause pain or distress in human beings may cause pain or distress in other animals."

Guidance
Notice Number | Description | Date |
---|---|---|
NOT-OD-21-118 | Request for Information (RFI) on Flexibilities to Reduce Administrative Burden While Continuing to Apply the PHS Policy to Zebrafish Immediately After Hatching | May 7, 2021 |
Resources
FAQs
FAQ A.4 Does the PHS Policy apply to live embryonated eggs?
FAQ A.5 Does the PHS Policy apply to larval forms of amphibians and fish?
Yes, larval forms of fish and amphibians have vertebrae and are covered by the PHS Policy. As noted in FAQ A4, the PHS Policy applies to the offspring of egg-laying vertebrates only after hatching. Zebrafish larvae, for example, typically hatch 3 days post-fertilization. [A21]
FAQ D.17 What guidelines should IACUCs follow for fishes, amphibians, reptiles, birds, and other nontraditional species used in research?
PHS Policy is intentionally broad in scope and does not prescribe specifics about the care and use of any species, assigning that task to the IACUC and allowing for professional judgment. Many of the principles embodied in the Guide can generally be adapted to the care and use of various kinds of nontraditional research animals. IACUCs may seek the advice of experts when necessary, and refer to scientific-based publications prepared by professional organizations with interest in various species. Appendix A of the Guide references many such publications. [A7]
FAQ F.2 Is the IACUC responsible for tracking animal usage?
Webinars
Webinar Link | Webinar Date |
---|---|
Zebrafish 101 for IACUCs | March 12, 2015 |
Articles
Title | Description | Date |
---|---|---|
Zebrafish 13(6):1-2 | Hatching Fish - When should animal tracking begin? | 2016 |
Lab Animal 35(1) | Should you count your mice before they're weaned? | 2006 |
Questions?
Call (301-496-7163) or e-mail (olaw@mail.nih.gov) OLAW for answers to your questions.