“X-Ray Vision: Fish Inside Out,” is a new exhibition of striking x-rays that reveal the complex bone structure of fishes in the collections of the Smithsonian’s National Museum of Natural History. These x-rays allow scientists to study “the skeleton of a fish without dissecting or in any other way altering the specimen,” says curator Lynne Parenti. Ichthyologists at the museum study fish skeletons, fin spines, teeth and other morphological features to differentiate one species from another and exmaine evolutionary development. “X-Ray Vision: Fish Inside Out,” from the Smithsonian Traveling Exhibition Service, opens at the Natural History Museum in Washington, D.C. on Saturday, Feb. 4. More information about each of the fish species featured is available at: eol.org/info/xrayvision.”(All images by Sandra J. Raredon, Division of Fishes, National Museum of Natural History.)
Moray eel. Moray eels are legendary predators on coral reefs. Note the second set of jaws in the “throat”; these are the gill arches, which are present in all fish. Gill arches support the gills, the major respiratory organ of fish.
Lookdown. Because of its sloped head and the enlarged crest on its skull, the Lookdown appears to “look down” as it swims. These fish often swim in small schools.
Alligator Pipefish. Pipefish may be thought of as seahorses unfurled. The numerous bony body rings are used to differentiate one species of pipefish from another.
Ox-eyed Oreo. The name Oreosoma (“mountain body”) refers to the cone-shaped bony structures on the underside of this larval specimen. Adults are more elongate, less oval, and covered with scales.
Dhiho’s Seahorse. Just over one inch long, this elegant fish is readily identified as a seahorse by its characteristic head. The body ends in a tail that can curl around and hold on to algae or coral. This species is found only in the waters around Japan.