In 2012, anglers in Lake Memphremagog, located on the U.S.-Canadian border, began noticing dwarf suckers with significant skin changes, with nearly a third of the fish affected. Researchers at the University of Vermont discovered that these fish had melanoma, a type of cancer. Their study published in 'Nature' revealed that the tumor cells were more closely related to each other than to their host fish, suggesting the cancer spreads clonally. The researchers hypothesize that the disease originated from a single fish that released cancerous cells into the water, which then infected other fish. This would mark the first known case of contagious cancer in fish. Contagious cancers have been previously observed in other species, such as facial tumors in Tasmanian devils, sexually transmitted cancers in dogs, and leukemia-like diseases in mussels. Scientists are now investigating how the cancer spreads among fish, noting that it appears only in breeding adults, possibly linked to close physical contact during spawning. While there is currently little evidence of contagious cancers in humans, experts suggest it remains a possibility.
Bias read (Center): The article discusses scientific research on contagious cancer in fish, focusing on findings from a study published in Nature and quotes from scientists. There is no political framing, bias, or controversy present in the content.
