A strange transmissible cancer is spreading through the catfish in this lake

Researchers from the University of Cambridge and the Vermont Fish & Wildlife Department have discovered the first known transmissible cancer in fish, specifically affecting brown bullhead catfish in Lake Memphremagog. This cancer, identified as a type of melanoma, manifests as dark streaks on the fish’s skin, mouth, fins, and sometimes eyes. The condition was first noticed in 2013, with over a quarter of the catfish showing these symptoms. The cancer appears to spread from fish to fish, possibly through the aquatic environment. This discovery could provide insights into how tumors spread in humans, as the process might share similarities with how cancer cells invade new hosts in catfish. Researchers initially suspected environmental factors, such as pollutants, but the exact cause remains unclear. This finding is significant as it opens new avenues for understanding cancer transmission and its implications for both wildlife and human health. QUESTION: How might understanding cancer in fish help scientists develop better treatments for cancer in humans?