X-ray Vision: Fish Inside Out

When we see the structure of a fish, we learn volumes about its behavior. Laid out in evolutionary sequence, from the most primitive jawless hagfishes to the most evolved spiny-finned species like the striped bass, the exhibition’s startlingly beautiful digital x-rays deepen our scientific understanding of the incredible diversity of fishes.

The Smithsonian’s National Collection of Fishes is the largest and most diverse collection of its kind, with an estimated four million individual fish specimens representing more than 70 percent of the world’s fish species. Encompassing males, females, juveniles, larvae, and even eggs, these specimens serve as a historical record of fish biodiversity and a working reference library for scientists around the world.

The care, maintenance, and loan of these collections are the responsibility of a handful of museum specialists, like Sandra Raredon, who has been at the Smithsonian's National Museum of Natural History for more than 25 years. For most of that time, radiology has also been part of her job responsibilities. Her striking black-and-white radiographs, or x-rays, of fish, stingrays, eels, and seahorses—“anything with a backbone,” she notes—reveal the complex bone structure in a level of detail reminiscent of fine engraving.

At the same time, the images (99 percent of which are digital rather than film) provide a wealth of valuable information. “Radiographs allow the study of the skeleton of a fish without dissecting or in any other way altering the specimen,” says Lynne Parenti, curator of the exciting exhibition X-ray Vision: Fish Inside Out.

X-Ray Vision: Fish Inside Out is organized by the Smithsonian’s National Museum of Natural History and the Smithsonian Institution Traveling Exhibition Service (SITES). It was inspired by the book Ichthyo: The Architecture of Fish (Chronicle Books in association with the Smithsonian Institution, 2008) by Stephanie Comer and Deborah Klochko.