National Lobster Day

What the day is

National Lobster Day is observed on September 25. Congress has passed a Senate resolution designating this date nearly every year since 2016, usually sponsored by senators from Maine.

Origin and background

Lobsters are widely described as biologically immortal, and they are not. The claim grows from something real. They show little of the gradual decline with age that most animals do, they keep growing throughout life, and they maintain high levels of telomerase, the enzyme that repairs the ends of chromosomes. Older lobsters are frequently more fertile than younger ones, which reverses the usual pattern.

What kills them is the growing itself. A lobster can only get bigger by shedding its entire shell and building a new one, and the process is enormously demanding, taking more out of the animal the larger it becomes. Eventually a molt fails, or the animal stops molting and the old shell deteriorates around it, and the outcome is fatal either way. Exhaustion during molting is the normal end, so the largest lobsters are simply very old rather than immortal.

The color change on cooking is a tidy piece of chemistry. Lobster shells contain astaxanthin, the same red pigment found in salmon and flamingos, but in a living lobster it is held inside a protein that distorts the molecule and shifts the color to dark blue-green. Heat unfolds that protein, the pigment springs back to its usual shape, and the shell turns red within seconds.

Their reputation has traveled a long way. In colonial New England lobster was cheap and abundant enough to be fed to prisoners and servants, and it became a luxury only once railways could carry it inland alive.

How to kill them humanely is now taken seriously, and several jurisdictions formally recognize decapods as capable of feeling pain.

How to take part

• Buy from a fishery with size limits, which protect the large breeding females.
• Chill the lobster thoroughly before cooking, which is standard humane practice.
• Do not overcook it. The meat goes rubbery fast.
• Watch the shell turn red, and know what is actually happening.