A routine fish survey in the lower Great Lakes has led to an extraordinary discovery: a rare, bright yellow burbot with an unusual pigmentation condition.
Biologists from the US Fish and Wildlife Service were surveying Oswego Harbor for invasive fish when they unexpectedly caught the unusually colored fish.
Burbots typically have yellowish-brown, green or brown coloring, making this bright yellow specimen an especially rare find. Its unusual appearance is caused by xanthochromism, a rare biological condition linked to a genetic mutation that affects normal pigmentation, producing a yellow or orange coloration.
According to the Lower Great Lakes Fish and Wildlife Conservation Office, xanthochromism in wild fish is considerably rarer than albinism or melanism, making the discovery particularly unusual.
The office described the capture as an exceptionally rare occurrence, highlighting just how uncommon it is to encounter such a striking fish in the wild.
While the fish’s color also made this a rare find, even more extraordinary is the fact that burbot populations in Oswego Harbor are already low, and the species typically inhabit deeper, cooler waters than those found within the harbor.
The conservation office said the discovery is the first documented detection of a burbot during a fisheries survey in Oswego Harbor, though a few anglers have reported catches.
US Geological Survey (USGS) biologists noted while processing the fish that it was emaciated and in poor health.
The Lower Great Lakes Fish and Wildlife Conservation Office said the fish was transferred to the Cornell University College of Veterinary Medicine for a health assessment, given its condition and ongoing concerns about factors contributing to the species’ declining population.
Despite its poor health, the discovery could prove valuable for burbot conservation. Scientists hope the exceptionally rare specimen may provide important insights into the health of burbot populations across the Great Lakes basin and help guide future conservation and management efforts.
“The discovery could turn out to be lucky for the burbot too; this exceptionally rare fish may provide valuable insight into the health of the species’ populations throughout the basin that can inform management actions,” the conservation office said.
The US Fish and Wildlife Service also highlighted the wider significance of the find, explaining that routine aquatic surveys do more than monitor invasive species.
According to the agency, long-term monitoring programs help scientists document biodiversity, identify unusual biological occurrences and gain a better understanding of the overall health of Great Lakes ecosystems.
