Even to a trained zoologist, one earthworm looks very much like the next. So much so, in fact, that one species generally can’t be distinguished from another just by looking—unless the animal has been painstakingly dissected. Exposing its internal morphology in this way destroys the specimen. The earthworm at right, with its life systems laid out in color, was “wild caught,” according to its record in Harvard’s Museum of Comparative Zoology (MCZ) specimen database, MCZbase. Aporrectodea caliginosa, a common species, was collected in the vicinity of 26 Oxford Street in Cambridge, where the museum is located. “You can imagine the drama” of its capture, quips James Hanken, Agassiz professor of zoology, curator in herpetology, and director of the MCZ.
What makes this lowly worm special is that it has been scanned using micro-computed tomography (microCT). The technology allows investigators to peer inside, to “see” the worm’s internal structures, including the digestive tract (pink), nervous system (yellow), and circulatory system (blue). Each can be studied separately and rotated in space in any direction to facilitate close inspection.
Read the complete Harvard Magazine story, "Taxonomic Riddles," online.