Lobsters Keep Growing

Lobsters keep producing telomerase in many cells for much of life. This enzyme helps rebuild the protective caps on chromosome ends, which is one reason lobster cells can keep dividing as the animal grows.

But lobsters are not ageless. Older, larger lobsters face rising costs from molting, shell disease, predation, and injury. They can keep growing for a long time, but that is not the same as never weakening.

So what finally kills a lobster? Not old age — molting. To grow, a lobster must shed its hard shell and build a larger one, and that costs enormous energy. The bigger it gets, the more brutal each molt becomes. The largest lobsters simply run out of energy mid-molt and die of exhaustion. In a strange way, they outgrow their own bodies.