A Twitter thread is making more people aware that while lobsters can live for hundreds of years, they actually die in a rather morbid manner.

Lobsters are known for their long lives. The oldest lobster ever caught was estimated to be 140 years old. In 2017, a 120-year-old lobster was found staying at a seafood restaurant in New York for 20 years.

As lobsters age, they also tend to grow bigger and heavier. The 140-year-old lobster weighed 44 pounds. In 2012, fishermen caught a lobster in Maine that weighed 27 pounds or about the size of a toddler.

Because of lobsters' long life, the species were thought to be immortal or that they only die when caught and made food. However, as one Twitter user pointed out, lobsters die through a process called "molting."

Lobsters Are Mortal

The now-viral Twitter thread explained that for lobsters to accommodate their immense sizes as they age, they need to get rid of their exoskeletons occasionally. The process of getting rid of their exoskeletons is called molting. It happens forcefully, far from natural shedding of skin among other species.

For lobsters to molt, they first need to reduce the size of their extremities by drawing water from their own bodies. This way, their old shells will not be too tight. Their shells will then break between the tail and their bodies.

How Lobsters Can Endure Pain

The secret why lobsters can endure this painful process lies in a structure at the end of their chromosomes called the "telomeres." These structures prevent lobsters from disentanglement.

In humans, the bodies lose some part of their telomeres each time a human cell divides. Essentially, as humans age and grow, they lose a significant amount of telomeres until the cells could no longer divide.

While lobsters have a seemingly endless supply of telomeres compared to humans, the molting can reach a point where the whole process can already be taxing for an old lobster. The old lobsters eventually die while they attempt to meet the physical requirement of getting rid of their exoskeletons or the physical requirement of growing old. Essentially, they eventually die of exhaustion.

The Twitter user, who goes by the handler Junius_64, made an interesting metaphor about lobster's mortality.

"Lobsters made a deal with the devil for conditional immortality and it backfired on them [because] the devil always gets his due," the tweet reads.

Lobsters' 'Immortality' Theory Debunked

Lobsters' "immortality" was long debunked in 2013 by Carl Wilson, a lobster biologist with the Maine Department of Marine Resources. He explained at the time that between 10 and 15 percent of lobsters die because of molting.

As lobsters grew older, the process of molting requires more and more energy, doubling or rippling compared to their previous molting. When old lobsters run out of the energy required to undergo molting, their shells become weak and tattered until eventually becoming hosts to bacterial infections.

Bacterial infections can crawl into the lobsters' bodies. They form scar tissues that trap the bodies inside the shells like glue.

The old lobsters, who can no longer exert the needed force, will end up stuck inside the shell and die there. In extreme cases, a bacterial infection can make the entire shell rot, killing the animal inside.

Wilson added that if there is one question about lobsters that remained unanswered, it will be how to accurately determine their ages.

"The problem with lobsters is when they molt, they molt their entire exoskeleton, including their digestive tract and gastric mill and the like, so there are no hard parts that are left," explained Wilson.

Without these parts, the scientists were left only with the option of estimating their ages rather than making précised calculations.