Typically, animal life cycles follow a well-known sequence: birth, growth, reproduction, and eventually death. Only a few species can break this sequence. A famous example is the 'immortal jellyfish' Turritopsis dohrnii, which can revert from an adult stage back to its juvenile polyp form. Now, this rare phenomenon also includes the comb jelly Mnemiopsis leidyi, expanding our understanding of such flexible life cycles.
"The work challenges our understanding of early animal development and body plans, opening new avenues for the study of life cycle plasticity and rejuvenation. The fact that we have found a new species that uses this peculiar 'time-travel machine' raises fascinating questions about how widespread this capacity is across the animal tree of life," said Joan J. Soto-Angel, a postdoctoral fellow in the Manet Team at the University of Bergen.
The discovery happened serendipitously when Soto-Angel noticed that an adult comb jelly seemed to have disappeared from a tank, only to be replaced by what appeared to be a larva. Investigating this curious observation, Soto-Angel and Pawel Burkhardt, group leader at the Michael Sars Centre, devised experiments to see if this reversion could be reproduced under controlled conditions. They found that under the stress of starvation and physical injury, Mnemiopsis leidyi could revert from its adult lobate form to a cydippid larval stage.
"Witnessing how they slowly transition to a typical cydippid larva, as if they were going back in time, was simply fascinating," Soto-Angel recalled. "Over several weeks, they not only reshaped their physical features but also adopted feeding behaviors typical of a larva."
The research highlights Mnemiopsis leidyi as an important model for studying developmental flexibility and aging. Given that ctenophores represent one of the earliest branches of the animal kingdom, the findings suggest reverse development might be an ancient trait. "This is a very exciting time for us," added Burkhardt. "This discovery will pave the way for important research into the molecular mechanisms behind reverse development and the changes occurring in the animal's nervous system during the process."
Research Report:Reverse development in the ctenophore Mnemiopsis leidyi
Related Links
University of Bergen
Darwin Today At TerraDaily.com
| Subscribe Free To Our Daily Newsletters |
| Subscribe Free To Our Daily Newsletters |
