Using genetic engineering to make zany-looking zebrafish isn't exactly new. (You can buy neon-tinted "GloFish" at just about any pet store.) But this time, the pops of color serve a purpose other than brightening up your aquarium or a David Blaine trick: learning how skin grows back.

Scientists at Duke University created a new line of zebrafish and programmed each cell in the zebrafish's skin to be a different color, using an adaptation of a technique called "brainbow." Because normal skin cells look pretty much identical, each color operated as a "barcode" of sorts for a cell or a small group of cells. "This is a cutting-edge way to visualize hundreds or thousands of cells at once in a regenerating tissue," lead researcher Kenneth D. Poss, a professor of cell biology at Duke, told the university's news site.

Chen-Hui Chen / Duke University

By observing how the cells in the zebrafish's skin responded to injury, the Duke team learned a lot about the skin regeneration process and were surprised by its complexity. They saw that in the hours following a fin amputation, for example, zebrafish regenerated skin through three different mechanisms: the "recruitment" of spare skin cells from other areas, a temporary doubling in size in some pre-existing cells, and the creation of completely new cells.

Zebrafish weren't selected at random. The zebrafish is a "model organism" — an organism that's especially easy to study — because its embryos are transparent, it has a sequenced genome, it reproduces a lot, and its genes are really easy to manipulate. The medical school at Duke has a facility called "Z-Core," which hosts 12,000 tanks full of the little guys.

Scientists believe that the color-coding technique they used in this study could be applied in future research to see how tissues age and how certain cancers (basal cell carcinoma specifically) form and grow.

These colorful little critters could be a big help to medical researchers down the line, on top of being a treat for the eyes!