New Slime Mold Species Named for Math Instructor

Photo submitted

Fruiting bodies of Dictyostelium barbarae. Dictyostelds are small, and the scale bar in the image represents one millimeter, about the thickness of a dime.

In May 2017, Steve Stephenson, a research professor in the Department of Biological Sciences, and his wife Barbara Stephenson, a U of A math instructor, visited Christmas Island, an Australian territory located in the Indian Ocean, approximately 200 miles south of Java and Sumatra. Christmas Island was so named when Captain William Mynors of the Royal Mary, an English East India Company vessel, sailed past it on Christmas Day in 1643.

The Stephensons were there to collect slime molds, a group of fungus-like organisms. Steve Stephenson has traveled the globe collecting slime molds and is considered one of the world's foremost experts on them. He has long been interested in studying slime molds on isolated islands, with the goal of developing a better understanding of their long-distance dispersal. He is particularly interested in myxomycetes, also called plasmodial slime molds, but he also studies dictyostelid cellular slime molds, usually referred to simply as dictyostelids.

While on Christmas Island, Stephenson collected soil samples to look for the presence of dictyostelids. To his surprise, he discovered two species that are new to science.

Discovering a new species is not a new experience for Stephenson; he and his research colleagues have discovered and named more than 100 species of slime molds. This time, however, Stephenson named one of the new species after his wife, who has accompanied him on collecting trips all over the world.

Thus, the newly described species of dictyostelid was named Dictyostelium barbarae, which formally appeared in the journal mSphere, the official publication of the American Society for Microbiology.

Steve coauthored the paper with Pu Liu, a mycologist at Jilin Agricultural University in China. Liu spent the 2015-16 academic year at the University of Arkansas working with Steve after receiving a fellowship from the government of China.