This bright-background microscope image shows two sand grain-size Daphnia crustaceans. The one on the left has three healthy embryos in its brood chamber. The one on the right has three embryos that have been attacked by the virulent parasite Blastulidium paedophthorum.

A months-long literature search that involved tracking down century-old scientific papers and translating others from Czech and French helped University of Michigan ecologist Meghan Duffy answer a question she'd wondered about for years.

The early studies helped Duffy determine that the microscopic aquatic parasite she first observed as a graduate student, and which her research team had recently collected in more than a dozen southeast Michigan lakes, is the same fungus-like organism that a French biologist first described in 1903.

"The longer historical perspective – especially that provided by the non-English literature – has been essential," said Duffy, an associate professor in the Department of Ecology and Evolutionary Biology. "If not for those papers, we would think that this parasite hadn't been described before and was in need of a name."

But it already has a name: Blastulidium paedophthorum, coined by biologist C. Pérez when he described it in 1903. Bp, the shorthand name favored by Duffy and her colleagues, attacks the developing embryos of Daphnia, the sand grain-size freshwater crustaceans also known as water fleas.

In the cover story of the August 2015 print edition of Applied and Environmental Microbiology, Duffy and two colleagues connect previous descriptions of the parasite with new information about its ecology and evolutionary history.

Read the full Michigan News press release