Comb jellyfish can change their development from adult to larva; This is a rare flexibility that may be a very ancient trait in the life cycles of animals. A recently published article PNAS published a remarkable discovery: the ability to reverse the development of clams, known as clam jelly. These results suggest that life cycle plasticity in animals may be more common than previously thought.
Animal life cycles often follow a familiar pattern, changing in countless ways: they are born, grow, reproduce and die, giving way to the next generation. Only some species can deviate from this general principle, the most famous example being the “immortal jellyfish”. Turritopsis dohrniican return from an adult jellyfish to a polyp. This elusive group of animals with flexible life cycles now includes crayfish Mnemiopsis leidyi.
“This work challenges our understanding of early animal development and body plans, opening new avenues on plasticity and life cycle rejuvenation. Manet’s doctoral student, Joan J. Soto-Angel, said: “We have found a new species that uses this special ‘time travel machine.’ Our presence raises exciting questions about how widespread this ability is in the animal tree of life,” said the team from the Department of Natural History at the University of Bergen.
gelatin time travel
A wonderful discovery began by chance. While observing the animals in the laboratory, Soto Ángel noticed that the adult crested fish was disappearing from the tank, as if it had been replaced by a larva. Wondering whether they were the same person, he and Pavel Burkhardt, team leader at the Michael Sars Center at the University of Bergen, designed experiments to try to reproduce this potential reversal under controlled conditions.
When Mnemiopsis leidyi Subjected to the stress of starvation and physical trauma, this creature displayed a remarkable ability to transition from its blade form to the cydippid larval stage. “It was truly fascinating to witness them slowly transforming into a typical dragonfly larva, as if they were going back in time,” Soto Ángel recalled. “Within a few weeks, they not only changed their morphological characteristics, but also had a completely different feeding behavior typical of cydippid larvae.”
An ancient model for studying life cycle evolution
The study expands the known flexibility of comb development and positions Mnemiopsis leidyi as a valuable model for future research in developmental biology and aging. Because crests are one of the oldest lineages of animals, the data suggest that reverse evolution may represent an ancient feature of the animal world.
“This is a very exciting time for us,” Burkhardt said. “This exciting discovery will open the door to many important discoveries. It will be interesting to unravel the molecular mechanism that drives reverse development and what happens to the animal’s neural network during this process.”
Source: Port Altele
