Zebrafish (Danio rerio)

A fish whose development you can see through the skin

The zebrafish (Danio rerio) lives in Southeast Asia in slow-flowing or stagnant waters, such as those found in rice fields. The species, also known as zebrafish in science, is popular as an aquarium fish all over the world

The fish has long been of interest in biological research. Its embryonic development in the egg takes place completely outside the mother fish and it remains transparent until it has fully developed. This makes it possible to study organ development entirely without invasive procedures. Under the microscope, the development of the heart, kidney and blood vessels can be followed particularly well. Since 70 percent of the zebrafish’s genes can also be found in a similar form in humans, it is a valuable model organism for science, also when it comes to researching the development of diseases.

A special feature of this fish, which is only a few centimeters long, is its enormous regeneration potential. Unlike most other vertebrates, it can almost completely regenerate appendages such as amputated fins or even damaged organs, such as the heart, kidney and brain, throughout its life. If we can understand how these mechanisms work and their molecular and genetic bases, new therapies can be developed in the future to treat diseases in humans.


Beating heart of the zebrafish (click to play)

Glowing kidneys: Regeneration under the microscope

Even though zebrafish are genetically and molecularly quite similar to humans, they differ in their ability to regenerate. To find out exactly where the differences lie, individual molecules in the kidneys of the zebrafish are made to glow. With this marking, the regeneration process can be followed precisely under a fluorescence microscope.

In addition, the zebrafish aids in the study of kidney development and the understanding of the underlying biological processes. This can help reveal the molecular basis of aging-associated diseases, thus contributing to the development of therapeutic approaches.

As a model of aging the zebrafish helps with research on:

  • the development and maintenance of organ function
  • organ regeneration in old age
  • aging-associated pathologies such as myocardial infarction and renal insufficiency
  • accelerated aging (in genetically modified fish)


10 facts about zebra fish as animal model in research (in German only, content from the initiative Tierversuche verstehen).