CAROLINE COUNTY, Va. (WRIC) — After fishing in the same private pond in Virginia’s Caroline County for 20 years, one fisherman reeled in a catch he never would have expected.

John Byrd, of Bowling Green, had caught a rare 11-and-a-half-inch blue-mouth chain pickerel.

Byrd contacted a Virginia Department of Wildlife Resources regional fisheries biologist and was told that the fish had a “wild genetic pigment mutation” and that the catch “pretty much falls into the one-in-a-lifetime category of catches” but was otherwise normal.

“The coloration expressed by the blue pickerel is extremely rare,” the DWR said.

The chain pickerel, which nearly resembles a northern pike, is commonly found in rivers, streams and reservoirs. The fish is native to states along the East Coast in the South, from Maine to Florida and west to Louisiana and parts of Texas, according to the U.S. Geological Survey.

The DWR said the fish are typically yellowish or greenish in color, with a chain-like pattern of black lines along their sides.

It isn’t clear what causes the blue-tinted mouth. In 2014, Maryland wildlife officials said it may be due to genetics, the fish’s diet, a lack of pigment, excess pigment or something in the environment. The mutation has also been reported in Pennsylvania, according to Virginia DWR.

Byrd kept his vibrantly-colored catch and has plans to have it mounted.