Jellyfish live through lean times by eating their young

JELLYFISH are able to survive through tough winters by eating their own offspring, research has found.

The comb jelly, an invasive species frequently seen in European waters, evolved its cannibalistic nature as a tactic to withstand severe conditions, the researchers said.

Experts previously believed the jellyfish, which has also been recorded off the Welsh and Scottish coast, were able to persist through “extreme events” because of a lack of predators.

However, a study carried out in the Baltic Sea by an international team found for the first time that adults were eating their own young. Researchers said it demonstrated the extent to which cannibalism is prevalent across the animal kingdom.

Prof Jamileh Javidpour, the lead author at the University of Southern Denmark, said: “We combined a study of the population dynamics with experimental feeding and geochemical tracers to show, for the first time, that adult jellies were consuming their offspring.”

Prof Thomas Larsen, a co-author of the paper from the Max Planck Institute for the Science of Human History, said: “In some ways, the whole jelly population is acting as a single organism, with younger groups supporting adults through times of nutrient stress. It enables jellies to persist through extreme events and low food periods.”

Cannibalism has been recorded among more than 1,500 species, including humans, squirrels and fish.

Prof Javidpour added: “Because comb jellies trace their ancestry back to the beginning of most animal life as we know it, during the Cambrian Period 525million years ago, it remains possible that it is a basic, unifying feature across the animal kingdom.”