Madagascar cichlid (Paretroplus polyactis)

At times, art and science converge, as you can see in these glorious images. They’re photos of whole fish, with skin and innards intact. Museum ichthyologist John Sparks treated the fish (including the cichlid, inset) with a calibrated series of chemical dyes. Red dye tints bones, blue dye clings to cartilage, and enzymes “clear” tissues rendering them transparent.

Next comes the pure science: Sparks uses the image of the fish, along with DNA analysis and other techniques, to study the differences among species. In these images, he is able to observe the cichlid’s unique hearing structures and the ponyfish’s bioluminescent chin. An added treat: a just-consumed fish lies in the mackerel’s stomach.