It was love at first parasite for Professor Andrew David, who discovered his penchant for pesky invasives as an undergraduate dissecting clams brimming with unwanted guests on a clam farm in Greenwich, Connecticut.

“It looked really gross to most people, but, to me, they were really cool,” says David, who shares his passion for marine biology and parasitology as an assistant professor in the biology department at Clarkson. “Marine biology allows me to do a bit of everything: genetic work, ecological work, biochemistry – it’s a very broad field.”

David’s passion for parasites is infectious. Recently, the curious and strong-of-stomach flocked to his local Science Cafe public lectures on "Triumph of the Micro-Monsters: How Parasites Shape Our Natural World." (Check out the Science Cafe schedule.) 

His parasitology course was highlighted in the professional journal Trends in Parasitology as a gold standard for teaching the topic – a recognition that David is proud of. While the course has traditional lectures, David engages his students with projects centered on tackling real-world problems that seriously affect human health. “Not just shellfish parasites,” notes David, “but human parasites like malaria, toxoplasmosis and trypanosomiasis, which causes sleeping sickness in tropical countries.”

While David’s research has taken him as far away as the tip of South Africa to study farmed shellfish, his latest research is located in the rivers and lakes of the Adirondack region.  Last year, David, along with Clarkson students Susan Verra ’17, Hanson Zhou ‘18, Ashley Lewis ’17, and Arianna Yhann ‘18, discovered a parasite that has never been recorded in the region. The parasite is a trematode worm that spends part of its life inhabiting the tissues of the banded mystery snail (Viviparus georgianus), an invasive mollusc to Northern New York that David and his team are currently investigating. While they think that the tremadtode may be using the Canada geese to complete its development to an adult, the life cycle of this parasitic species is still being determined.

“We think it’s being transmitted by Canada geese that migrate from Canada to the waterways of the Adirondacks,” says David. “This species partially develops into snails and the geese feed on the snails, completing its life cycle. Whether or not it’s a new species is something we’re still trying to figure out.”

Some students assisted David with initial research through identification of the host snail species using DNA barcoding. Others recorded the measurements of the snails collected, wrote scientific descriptions of the species and performed statistical analysis of the data collected. While the snails may be invasive, so far, David isn’t sure if they actually harm humans or if they’re just a nuisance parasite. Still, having a unique research focus so close to the university allows Clarkson students a great hands-on learning experience.

“All of these students took either my zoology or parasitology course,” says David. “So they were able to put what they learned in the classroom into actual practice.”