I've kept fish as pets, but I've never seen one as colourful as this. Scientists have genetically altered a zebrafish so that its skin fluoresces in thousands of colours.
Each cell in the 'rainbow' zebrafish's outer skin shines a different combination of colours. This lets the scientists study how skin heals after a wound. They do this by watching the colours change during healing.
The researchers found three separate processes that protect a wound. I think it's exciting to see something so beautiful also contributing to scientific discovery.