Researchers from Arizona State University claimed to have witnessed the first case of shark-on-shark cannibalism.

The study, led by Dr Brooke Anderson and her team, involved a pregnant female porbeagle shark tagged as part of the research project.

The shark was fitted with tracking devices off Cape Cod in 2020 to study migration patterns. However, data from one of the tags, a pop-off satellite archival tag (PSAT), revealed an unexpected end to the shark's journey.

After months of normal tracking, the PSAT readings stabilised at a constant temperature and depth, indicating that the porbeagle had likely been eaten by a larger predator near Bermuda.

The tag, excreted by the predator, began transmitting data from the surface.

Researchers suspect the predator was either a white shark or shortfin mako, both capable of preying on porbeagles.

They belive the tag data indicated diving patterns inconsistent with the mako, leading researchers to believe a white shark was the likely predator.

Dr Anderson said: 'This is not just about one shark eating another; it's about understanding the broader implications for shark populations, especially those like the porbeagle, which are already facing significant threats.'

Porbeagles, endangered in parts of the Atlantic and Mediterranean, reproduce slowly, making predation events potentially devastating for their recovery.

The lead researcher added: 'We often view large sharks as apex predators, but this event shows us that even these formidable creatures can become prey, revealing a more intricate food web than previously thought.'

This event, detailed in a study published in Frontiers in Marine Science, has provided invaluable insights into the life-and-death struggles beneath the ocean's surface.