For this week's theme, I chose this cool picture of a display at the California Academy of Science. This is a real flatfish, which has been prepared using a special staining process. The bones are stained red, while the cartilage is stained blue.
This is a common technique in science, and it can be used to study how bones develop, or how they work relative to each other. By leaving the specimen intact, one can see how the bones in the jaw move, without damaging any of the fine tissue and cartilage which holds it together.