Photo credit: Bernard Picton
The lobster is an animal that fascinates men. This marine crustacean is very appreciated for its tasty flesh. The stories surrounding its exceptional longevity diffuse a scent of eternity. It is even said that he is immortal… The belief has grown to the point of intriguing the scientific community. Put on your diving masks, because we’re going to plumb the seabed in search of the truth.
The life cycle of a lobster
Lobsters are particularly robust animals. They can survive extreme temperatures, illnesses, and even serious injuries. Their life cycle begins with the hatching of a larva called a nauplius. After some time, the nauplius turns into a juvenile. Then the lobster becomes an adult. Even at this stage, its growth continues in length, as its scales shed and grow back regularly.
Each stage of lobster growth is marked by molting periods. During these, the crustaceans get rid of their too narrow exoskeleton to develop a larger one. During this period, their body is vulnerable, but once the molt is complete, they are healthy with a new exoskeleton. This process could therefore be repeated as much as possible.
However, it is difficult to define their life expectancy, which depends on several factors:
Water temperature: lobsters live longer in cold water. Access to food: lobsters who have enough to eat live longer. Predators: lobsters that are less exposed to predators live longer. What truth lies behind the immortality of the lobster?
In fact, the theory of lobster immortality is based on the fact that this crustacean does not age in the same way as other animals. In fact, their cells do not die, because they divide indefinitely. This extraordinary characteristic allows them to regenerate damaged tissues and even regrow lost limbs. Thus, lobsters are able to regrow a claw or a leg after suffering serious injuries. It is precisely this capacity for regeneration which is at the origin of the belief in their immortality. Following this reasoning, it seems that it is possible for them to return to life after sustaining serious injuries.
The lobster molts almost all its life, changing its shell with each molt. However, over the years, the rate of molts becomes slower and slower and more and more difficult for the crustacean which must make significant efforts. It is aging which is fascinating. Researchers have closely studied genes related to regeneration and have discovered several mechanisms that contribute to lobsters’ ability to regenerate.
To better understand, we can make a comparison between the lobster and other mammals, including humans since we all suffer the pangs of old age.
Organs and tissues are made up of cells, which are renewed through mitosis, a phenomenon which allows the renewal of cells through their division. But with each division, a piece of the end of the chromosome called the telomere is lost and over time the telomeres become too short. At this point, the cell can no longer divide, because there is a risk of loss of genetic information. At this stage, the cell wears out without being able to renew itself. This is the aging process.
In the case of lobsters, each division results in telomerase production. It is an enzyme whose function is to restore the lost parts at the ends of chromosomes. In this way, the chromosomes no longer have the end of their life and the crustacean organism does not age. This gives him eternal youth.
The lobster: immortal or not?
It is important to differentiate tissue and limb regeneration from immortality as such. The lobster’s ability to regenerate is limited in time. In fact, the more the lobster molts, the thicker its shell becomes. After a while, the shedding phenomenon stops. However, the lobster continues to grow in its shell, so much so that it becomes too narrow. It therefore becomes vulnerable and its cells begin to degrade from the inside. He falls ill and eventually dies. But few lobsters reach this stage because they get caught in fishing nets, which also leads to their death… but also to our plates!
There is therefore no doubt that lobsters live a very long time. But saying they are immortal is not the reality. They are marine beings and are sensitive to pollution and diseases, not to mention the risks they run of being attacked by predators. But one thing is certain, the lobster is a fascinating animal that will continue to intrigue us for a long time to come.