The northern snakehead fish is of Asian origin, and can displace other native fish when it enters local waterways.
The Rhode River in Anne Arundel County is the latest waterway where scientists have found the invasive northern snakehead, according to a report in the Baltimore Sun.
Biologists from the Smithsonian Environmental Research Center recently came across a 23-inch, egg-bearing female while taking fish samples.
Snakeheads are hardy predators native to Asia, and can create problems for native species. They first made a big splash locally in 2002 when they were found in a pond Crofton, Maryland. They've since appeared in the Potomac watershed.
The Rhode River is a tidal tributary south of Annapolis, which has scientists wondering whether the fish might have been able to swim into the river due to low salinity levels in the Chesapeake Bay.