Scientists have identified the first known cancer that can be transmitted among freshwater fish. The discovery involves catfish in a lake spanning the US and Canada.
The finding adds catfish to a short list of animals where cancer cells can spread directly from one individual to another. Previously documented cases include dogs, Tasmanian devils, and certain mollusks.
In humans and most animals, cancer does not pass between individuals. The new case shows that nature can produce exceptions where malignant cells survive transmission and grow in a new host.
Researchers described the phenomenon as rare but now confirmed in an additional species. The study focused on fish populations in the shared lake region.
