Extremely Rare Fish With Mutation Caught in Virginia, Returned to River

An extremely rare fish with an unusual mutation has been caught swimming in a Virginia river.

Jacob Moore had been fishing for largemouth bass in the lower portion of the James River when he caught the strange-looking fish.

In a photo shared by the Virginia Department of Wildlife Resources (DWR), the fish appears bright gold in color.

Golden largemouth fish
A photo of the largemouth bass on the boat. The fish was completely golden in color because of a rare genetic mutation. Jacob Moore/DWR

Moore had been practicing for a fishing tournament at the time of the catch. He thought the species was a saltwater fish at first, but upon closer inspection, he realized that it was a largemouth.

After Moore had taken a few photos of his catch, the fish was then returned to the water.

Largemouth are usually a black, green color, meaning that this completely golden catch certainly stood out.

"I haven't seen anything like that before. I've seen bass with black spots, but I'd never seen an albino one," Moore told the DWR.

However, this fish was not albino. The golden color was caused by a genetic mutation called xanthism that affects the fish's skin pigments. In this condition, yellow pigmentation stands out, resulting in the bright gold color of this specimen.

Dr. Katrina Liebich, a fisheries expert at the U.S. Fish & Wildlife Service, told Newsweek: "Xanthism isn't seen very often in the wild because it causes a normally cryptic animal to stand out. Being well-camouflaged helps you hide from potential predators and, on the flip side, makes you a better predator. If you're yellow or orange, everyone can see you—and either eat you or avoid you eating them.

"If you look at the typical color pattern of a largemouth bass, or a bowfin, or a gar—other fishes that have been caught recently exhibiting xanthism—they're usually greens and browns and tans, colors that match their environment and blend in," Liebich added.

Alex McCrickard, Virginia DWR aquatic education coordinator, said in a press release that most people have never seen a golden largemouth bass, "let alone heard of them before."

Largemouth bass are common in Virginia. This particular one measured at 16.5 inches, which is the average size for the species.

Genetic mutations occasionally happen in fish species, and xanthism is not the only one.

"There are a number of other pigment-related departures from the norm in addition to xanthism: albinism, leucism, melanism, erythrism, and axanthism, the opposite of xanthism where yellow pigment is absent," Liebich said.

Only last week, a ghostly looking fish with leucism—a genetic mutation where there is a partial loss of pigmentation in the skin—was discovered in a Vermont pond.

Fish are also not the only animal that genetic mutations can affect.

"Just this year in Alaska, a leucistic bull moose with a partial lack of pigment just made the news when biologists from the Alaska Department of Fish and Game easily spotted it from the air during a population survey," Liebich said.

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