Black and white confocal micrograph of a cavefish embryo at around 5 days post-fertilization. The embryo has been stained with an antibody that marks a calcium binding protein (calretinin). This highlights different neuronal types and their processes in the nervous system. This staining also labels taste buds, which can be seen as dark black dots located around the mouth and running along the body. Cavefish live in dark caves and thus their natural habitat has no light. As a result adult cavefish are blind. Their eyes do develop and are still present at the embryonic stage shown in this image, but they will naturally degenerate during later stages. The same image has been reflected to create a symmetrical mirror image.