L is for Lobster

There are hundreds of lobsters in the sea of all shapes, sizes and colors. Some are green-blue or green-brown. There is the occasional blue or red, and rarer still the yellow or calico. There are spiny lobsters and slipper lobsters.

But of the true lobsters, the most recognizable may be the standard American and European clawed lobsters. That's because they are the most likely to end up on your plate. Lobster may be considered a delicacy today, but that wasn't always the case.

It wasn't until the mid-1800s that lobster became a feast for the elite. Before that, the crustacean was reserved for the impoverished and incarcerated. There were even limits to how frequently a person could be made to eat lobster meat.

The lobster's poor reputation was due, in part, to its bottom-dwelling nature. Found throughout oceans around the world, lobsters spend most of their lives burrowing among the rocks, sand and mud of the seafloor.

There, the indiscriminate omnivores feed on fish, mollusks, other crustaceans, algae and plants. Meals make their way into the lobster's stomach where they are crushed by the gastric mill, a grinding structure with three "teeth."

Lobsters have a few aquatic predators of their own and are especially vulnerable as juveniles or when soft-shelled between molts. Luckily, they have a few tricks up their sleeves. Lobsters can swim backward and, as a last resort, amputate an appendage as a means of escape. With time, a new limb will grow back in its place.

Like other arthropods, lobsters have a hard exoskeleton. They frequently molt as they grow, shedding their old armor for a newer model. In fact, the average lobster molts more than 40 times in its first year. But research suggests that lobsters don't age quite like other animals; they don't have an off switch.

Lobsters grow indeterminately. They even continue to reproduce well into their geriatric years, which begs the question... is there a giant, age-old lobster roaming the ocean's depths?

Not so fast.

Although lobsters grow continuously throughout their lives, the rate at which they grow slows. They also experience a type of senescence, the deterioration that comes with age. Molting is particularly stressful on lobsters. It requires a significant amount of metabolic energy, a quantity that increases with a lobster's size.

When a lobster becomes too large and weak to molt, its shell slowly deteriorates. That can lead to infection and disease... and eventually to the lobster's demise.

Scientists have long been seeking a reliable way to determine a lobster's true age, like counting the growth rings on its eye stalks. But in the meantime, they can say with confidence that lobsters do not live forever.