TROY professor helps discover new species causing black gill in Georgia shrimp

The Skidaway Institute for Oceanography boat docks on the Skidaway River in Georgia.

The Skidaway Institute for Oceanography boat docks on the Skidaway River in Georgia.

A Troy University biologist recently identified the microscopic parasite behind a mysterious ailment ravaging the shrimp population off the coast of Georgia.

For years, Georgia’s shrimpers have watched in dismay as the shrimp population off the Atlantic coast has dwindled. As the Atlanta Journal Constitution reported, shrimpers there blamed “black gill,” an affliction that darkens the gills of shrimp. Although harmless to humans, black gill weakens shrimp and lowers their survival rates in the wild.

Scientists knew black gill was being caused by an immune response from the shrimp, but what they are reacting to and why it is becoming more prevalent remained a mystery. Researchers at the University of Georgia’s Skidaway Institute of Oceanography have spent years trying to crack the case, and enlisted TROY’s Dr. Stephen Landers, the Alfa Eminent Scholar for Environmental Science, for help.

Landers has been collaborating with the Skidaway Institute since 2015, and he’s well known for discovering new protozoan species. The process of identifying the organism causing black gill involved examining numerous samples of Georgia shrimp, and Landers even took a trip to the Georgia coast in August to gather fresh samples from the water system.

After months of painstaking study, Landers and the Skidaway team have announced the discovery of a new species of ciliate they have named Hyalophysa lynni. Landers said identifying the culprit behind the black gill outbreak will move researchers a step closer to understanding why it is happening.

Dr. Stephen Landers
Dr. Stephen Landers

“Now that we know the genus and species that it belongs to, it can help us in future work, including understanding how it invades the gill,” Landers said. “We can study the literature and compare it to related species.”

Ciliates are relatively common parasites that attach to shrimp gills. What’s unknown is why this species is suddenly thriving.

“For whatever reason, the population is now exploding and causing problems,” Landers said.

There appears to be correlation between rising water temperature and the growth in the ciliate population, but Landers said more work has to be done to prove that is the case.

“I hope to be able to go back to Skidaway Island next summer and continue working with the team there,” Landers said.