It’s A Lobster’s Life (Part 2)

Shell games (cont’d)

As we left our story in Part 1, the lobster has successfully completed molting...and shed its old shell for new body armor. But what happens to the old shell? Glad you asked. The old, discarded shell is one of nature’s metamorphic miracles – it retains the exact likeness of our newly re-shelled crustacean. From the claws, legs, the elements of its mouth, and everything right down to its eyeball covers, the old shell retains its structural look from when it covered its host.

Now, the lobster performs an eco-friendly act of cannibalism by consuming its old, discarded shell which is still soft from its formation. Eating the old shell helps the new shell on the lobster—which is still soft, to become stronger, faster. If you picked it up, it would have a rubbery feeling to it.

As a means of growth, the lobster takes in sea water that helps it grow close to 15% more in size, and increase its body weight by between 40-50%. But, to make sure that it’s big and strong enough to defend itself against predatory sea creatures, it will continue to hide away for about two weeks until its shell is nice and hard.

Room to grow

A fresh-shell lobster, otherwise known as a “shedder”, is mostly water. If you’ve ever dined on a soft-shell lobster (not to be confused with a soft-shelled crab), you’ll find that it’s quite watery. The new shell has to remain in a softened state to allow the growing lobster to fill it in, which typically takes over a year or more. Think of when you got clothes that were a few sizes larger when you were a child so you could ‘grow into them’. It’s a similar concept with lobsters and their shells.

To molt, or not to molt

When it comes to molting, a lobster is a picky creature. Running down a lobster’s checklist, these conditions have to be pretty close to “just right” before a lobster will undergo the molting process. The temperature of the water has to be at about 70º F for the lobster to grow at its best rate. Warmth helps a lobster grow at a faster rate than cold water, so in controlled environments like hatcheries where the water temperature can be consistent, lobsters can put on a pound in under a couple of years, whereas in cold waters like in the north Atlantic region, a lobster may take between 5 and 7 years to obtain the optimal market size preferred by restaurants. This size is referred to as a “chicken lobster”. There should be an ample food supply, shelter options, and the salinity (salt) of the water has to be just so. Seawater salt can differ from region to region and across seasons, so the lobster has to have just enough salt water content in most cases. More importantly, the sea bottom and water depth need to be right (remember we said that lobsters prefer a cobbled sea floor). When all the right conditions align, the lobster gets down to molting!        

Growing season

Lobsters take turns with each other in their growth rates. Unlike humans, where girls tend to grow faster than boys, in the sea world, male lobsters grow faster than females. In the tail, which is the abdomen for lobsters, female tails have the edge over male tails, however, the claws of a male lobster typically grow larger than a female’s, and in very large lobsters, they can account for over 45% of the lobster’s total body weight, which can be a good reason why you see the claws of lobsters bound. You don’t want to get pinched by those things!