Discovery of organisms that can transmit cancer

This strange creature can develop tumors on its own if it eats too much, and then pass them on to other individuals.

A new study of jellyfish-like creatures known as hydras (full name: Hydra oligactis ), suggests they can develop tumors if eaten in large quantities.

Microscopic image shows a hydra "giving birth" by detaching an individual from its body (Photo: iNaturalist).

Remarkably, the tumors were able to be passed on to their cloned offspring , a rare case of cancer being transmitted between living organisms.

To come to this conclusion, the research team collected 50 hydras from Lake Montaud (France) and raised them in the laboratory.

After feeding these creatures large amounts of brine shrimp larvae, the team found that they began to swell, and tumors appeared after two months.

The tumour was later found to be passed down from parent to offspring rather than spontaneously developing. They were four times more likely to develop the tumour than individuals with normal parents, even though they were all genetically identical.

From this finding, the team confirmed that tumors can indeed arise in H. oligactis and that their transmission rates increase over time. This is the first experimental observation of the evolution of transmissible tumors.

This, together with the tendency to form tumors under laboratory conditions, suggests potential for studying the genetics of cancer development.

The researchers say the work is the first contribution to understanding the conditions under which infectious cancers emerge, and their short-term consequences for the host.