Brown Bullhead Catfish

• Species: Brown bullhead catfish.
• Habitat: Lake Memphremagog, located between Quebec in Canada and Vermont in the United States.
• Research significance: Researchers studied melanoma in this fish, which could provide clues to preventing the human body from rejecting a transplanted organ.

• Scientific finding: A 2026 study published in Nature identified the melanoma as a clonally transmissible cancer—tumour cells themselves can spread between individual fish.
• Significance: The research may help scientists understand how cancer cells evade a host’s immune system. Its implications for human organ transplantation remain a potential research avenue, not an established treatment.
• Melanoma: A cancer that develops from melanocytes, the cells that produce the pigment melanin.
• Other naturally occurring transmissible cancers: Reported in dogs, Tasmanian devils and some bivalves, such as shellfish.

Prelims Practice Question

Consider the following statements:

1. Brown bullhead catfish is associated with research on transmissible melanoma.
2. Lake Memphremagog lies between Quebec in Canada and Vermont in the United States.
3. Melanoma originates from cells that produce melanin.

Which of the statements given above are correct?

(a) 1 and 2 only (b) 2 and 3 only (c) 1 and 3 only (d) 1, 2 and 3

Answer: (d) 1, 2 and 3

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