The zebrafish is famous for regenerating damaged fins, heart tissue and spinal cord.
The zebrafish, Danio rerio, is a small South Asian freshwater fish and a leading laboratory model. Unlike humans, it can regenerate several complex tissues after injury. Researchers have documented regrowth of fins, repair of portions of the heart and recovery from spinal-cord damage under experimental conditions.
Its regenerative abilities arise from populations of cells that respond to injury, divide and help rebuild missing structures. Scientists study the genes, signals and immune responses involved because some of the same biological pathways also operate in humans, even though human regeneration is much more limited.
The fish’s transparent embryos and rapid development make these processes easier to observe. Researchers can also use genetic tools to switch particular genes on or off and test their roles in repair.
Zebrafish regeneration does not mean every injury heals perfectly, nor does it make the species a direct medical treatment. It is instead an important research system for understanding tissue repair and why regenerative capacity differs among animals.