The northern snakehead (Channa argus), an invasive species that was first discovered in the United States in 1977, carries a bacteria that is harmful to other species. According to a study published by the U.S. Geological Survey, several snakeheads captured in Virginia’s Potomac River south of Washington D.C. were found to be infected with a mycobacteria. Scientists are not yet sure what species of mycobacteria the snakeheads were infected with but have pointed out that the bacteria can cause chronic disease in a range of animals, including mammals. Cooked snakehead fish though, apparently are not health risks to humans.
“Mycobacterial infections are not unusual among fish, but they are nonetheless noteworthy because they can have an impact at the population level and potentially even affect other fish and wildlife,” said Christine Densmore, a veterinarian with the USGS and lead author of the study.
“Another interesting feature of this particular mycobacterial organism is that we have not been able to identify it in the available gene sequence data base, so this may be a unique, undescribed species of Mycobacterium,” Densmore said. “However, more research is needed to further characterize the bacteria and its potential effects on the northern snakehead population and other native species.”
The northern snakehead is native to China, Russia, and the Korean peninsula. An important food fish in China, the snakehead is an invasive species in the United States, and was first found in the wild in California in 1977. The fish is a top level predator and has decimated native fish populations in virtually all places in which it is found. It is called a snakehead because its head resembles that of a snake. It is a hardy fish, capable of tolerating high salinity and is an obligate air breather, which enables it to live out of water for several days.