What You See When You Turn a Fish Inside Out
Smithsonian scientists use X-rays to classify different species, but when viewed outside the lab, the images provide stunning art
- By Megan Gambino
- Smithsonian.com, February 07, 2012
The critically endangered smalltooth sawfish (Pristis pectinata) uses its "saw" more like a rake, dragging it through sand to find crustaceans, or a sword, swinging it through schools of fish to cut and stun them. (Sandra J. Raredon, Division of Fishes, NMNH)
In 23 years of working in the museum’s division of fishes, Raredon has taken more than 11,000 X-rays of specimens, including sawfish, moray eels, seahorses and piranha. She logged the first 10,000 using a chemical film-developing process. In 2001, she switched to taking digital X-rays after the museum purchased its first digital radiographic machine. Whereas a conventional X-ray requires about 30 minutes to develop and longer to dry, the digital versions are instantly ready for study or to be sent to researchers around the world. What’s more, scientists can zoom in on or invert the black-and-white X-rays to see a fish’s bone structure more clearly. Raredon is gradually X-raying her way through the collection, giving first priority to “types,” or the original specimens from which species were identified and named. After that come old specimens that are degrading and fish that resident and visiting scientists request she examine for their research.