Can Lobsters Live Forever?

There are 6 stages to the human lifecycle.

1. Foetus - when you grow inside your mother’s womb. 2. Baby - when you are born. 3. Childhood - when you learn to do things like walk and talk. 4. Adolescence - when you become a teenager. 5. Adulthood - when your body is fully developed. 6. Old age/elderly - when you become elderly, and eventually die.

As we go through each stage of the lifecycle, there are things that happen to us, which have finite end points, such as growing to a set height where we stop getting taller.

These changes come about because of something called our genetics, which in turn are the result of DNA replication.

Over a long time, our cells lose their power to divide and grow, and our body begins to deteriorate due to age. Because of this we are not able to live forever.

The condition or process of deteriorating with age is called ‘senescence’ and is partly the result of an enzyme we have called telomerase.

Telomerase is a reverse transcriptase enzyme which carries its own RNA molecule which it uses as a template when making the telomeres longer. The shorter your telomeres are, the shorter your life span.

To be biologically immortal (meaning that you could biologically live forever but could still die from disease or injury), you would need your telomeres to be replicated almost perfectly, without getting cut shorter.

Telomerase is an enzyme which can lengthen the telomeres, it keeps organs healthy, and keeps you looking younger for longer. So you would think that if you wanted to live forever, all you would need to do is to keep your telomeres long.

But this is not so, in fact it is quite the opposite. One of the issues is that the telomerase enzymes help tumours to grow and spread, cancer cells are immortal but are also life shortening!

Recent studies on lobsters found that they are able to delay the sixth stage of the human lifecycle, the old age and elderly part.

And this is because they use telomerase, (the telomere lengthening enzyme) to keep their telomeres pretty much the same length and condition. In other words they don’t age in the normal way, and are technically ‘biologically immortal’ because their cells are not damaged in the replication process.

An easier way to think about this, might be to imagine a photocopier, photocopying a page of writing, and then you photocopy the copied paper from each new copy.

Eventually the end result is faint and unrecognisable as words. That’s pretty much what happens in humans when their cells get replicated.

But in the lobster, the photocopied page remains almost in original condition with each replication, so the notes are readable for much longer.

In other words, ’senescence’ - the process of ageing does not affect lobsters.

Because the lobster’s body does not deteriorate over time, they are able to do all their usual activities right up until they eventually die - they can reproduce, continue to eat, stay strong, and there is no end point to how big they can grow.

So the older they are, the bigger they are.

Some lobsters have been aged at 140 years, but most are likely to die of disease or to be killed for food long before they reach old age. Most male lobsters live to around 30 years before being caught, and females to around 54 years.

The process of ageing lobsters is incredibly difficult, because they have an exoskeleton, which they moult around 44 times before they are a year old, and then moult once a year, each year after that.

The moulting process is incredibly stressful for the lobster as it leaves them without their claws, and without protection from predators until their new shell hardens, as well as using up a lot of metabolic energy.

As lobsters get older, it becomes more and more difficult to shed their exoskeleton and they can end up caught in the shell in the process, or the shell can become soft from a bacterial infection.

The moulting process becomes more difficult and energy expensive, because the lobsters are bigger each year, with new shells sometimes reaching the size of a human toddler!

To age a lobster, you need to examine the exoskeleton closely, but if the lobster is in process of developing a new shell, it can be difficult to calculate the age.

Scientists count the number of bands or rings on the exoskeleton to determine its age (a bit like you would count the rings on a tree). They can also look at the fat residues in the lobster’s eyestalk or measure a pigment in the lobster’s brain, called neurolipofuscin to determine its age (you can only do this on dead lobsters).

The ability to lengthen their telomeres means that lobsters are able to regrow limbs if they lose one. Which is a pretty cool superpower if you had to chose one!

So in answer to the question, can lobsters live forever? The answer is no, but they can increase the longevity of their life, due to their ability to lengthen their telomeres.

Whilst they have been known to live for over 140 years, lobsters tend to die from disease or from being caught and eaten, rather than dying from old age per se.