This image shows hundreds of living cells from a tiny piece (0.0003348 square inches) of skin on the tail fin of a genetically modified adult zebrafish. Zebrafish are normally found in tropical freshwaters and are a preferred research model for studying offspring development and tissue regeneration. Cells were highlighted with a fluorescent imaging tool called Skinbow. It uniquely encodes cells by causing them to express genes coding for red, green and blue fluorescent proteins.