articleThe first-ever transmissible cancer to spread among fish in a freshwater setting has been discovered among brown bullhead catfish in Lake Memphremagog. The sun sets on Lake Memphremagog, which stands the United States and Canadian borders on November 8, 2021. Brown Bullhead (Ameiurus nebulosus), Ictaluridae. They found evidence to suggest the cancer was indeed transmissible, and the first-known transmissible cancer in fish species as well as in freshwater. Lake Memphremagog, northern Vermont, looking north into Quebec.