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
This particular longnose butterflyfish (Forcipiger longirostris) was collected in French Polynesia in 2004. Being preserved in alcohol has caused its colors to fade, but it was once bright yellow and black. (Sandra J. Raredon, Division of Fishes, NMNH)
One way to get at a skeleton, especially a large one, is through dissection. There are more than 4,800 such “dry” fish skeletons in the museum’s collection. Another method, used on small fish that would curl up if dried, is called “clearing and staining.” The specimen is soaked in trypsin, a digestive enzyme, to clear the flesh away, and the cartilage is stained blue while the bone is stained red. Stored in glycerin afterward, these are often referred to as “wet” skeletons; the museum has more than 5,300. But X-rays, which have been used to study fish since shortly after this form of radiation was discovered in 1895, are especially noninvasive. “Radiographs allow the study of the skeleton of a fish without dissecting or in any other way altering the specimen,” says Parenti.