Archive · 31 Jul 2026
Freshwater Catfish Found with Rare Transmissible Cancer in Lake
Scientists found a special kind of cancer that can jump from one catfish to another in a lake.
The cancer cells are almost identical in different fish, showing they move directly between fish.
This is only the fourth time such a cancer has been seen in nature and the first time in a freshwater fish.
The fish live in Lake Memphremagog, which is on the border of Vermont and Quebec.
The cancer probably spreads when fish touch each other while spawning or through dirty water.
Even though the cancer can move between fish, it does not mean people can catch it.
Humans get cancer from their own cells, not from other people.
The study helps scientists learn how cancer can hide from the immune system and might help future cancer treatments.
Researchers discovered a transmissible cancer in brown bullhead catfish in Lake Memphremagog.
The cancer cells are genetically identical across fish, indicating direct cell transfer rather than independent tumors.
This is the fourth known naturally occurring transmissible cancer and the first in a freshwater fish.
Transmission likely occurs via close contact during spawning or contaminated water, though the exact route remains under study.
The finding does not pose a risk to humans, as cancer is not contagious in people.
- Who
- Scientists and researchers
- What
- Discovery of a transmissible cancer in brown bullhead catfish
- When
- Recently, published in Nature
- Where
- Lake Memphremagog between Vermont, USA and Quebec, Canada
- Why
- To understand cancer evolution, immune evasion, and clarify that human cancer is not contagious
- Species
- Brown bullhead catfish
- Location
- Lake Memphremagog, Vermont/Quebec
- Discovery
- First freshwater transmissible cancer
- Known transmissible cancers
- Four
- Transmission route
- Likely close contact during spawning or contaminated water