American lobster, Homarus americanus
Figure 1. American lobster, Homarus americanus.

How long do they live? A common theme that I am finding is that no one really knows how long they can live. There are estimates ranging from 50 years old to 140 years old based on the size of American lobsters. Surprisingly (at least to me), their longevity is just not all that well studied.

Homerus_americanus_distribution
Figure 2. Where you can find H. americanus.

Where are they found? The Atlantic coastal waters of North America. See figure 2.

What do they eat? They make a meal out of many creatures of the sea, including mussels, sea stars, and sea nettles.

What do they look like? A picture is always better than words, so refer to figure 3 for this question.

FMIB_41598_American_Lobster_(Homarus_americanus)_Male_upper_side
Figure 3. Male American lobster.

How do they reproduce? Like us, lobsters have eggs and sperm and the eggs are fertilized internally. They show no reduction in reproductive capacity as they age and this may be due to active telomerase in adult tissues [1]. Telomerase is an enzyme (protein that does work) that adds telomere sequences to the ends of chromosomes. Telomeres protect the ends of chromosomes and the loss of telomeres is associated with aging. Telomerase is usually only found in high amounts in our eggs and sperm, whereas it is found in most tissues of the adult lobster. This could be why the American lobster can achieve such long lifespans.

How do scientists know how old they are? Lobsters must molt to grow in size, which means that they must lose their protective shell called a carapace. Each time they grow, they molt, but that makes it very hard to figure out how old they are. So, without growth rings or any indication of age, most papers base age estimates on the size of the lobster and the temperature of the environment that the lobster was found in. Researchers released an article in 1996 that used a pigment called lipofuscin to estimate the age of American lobsters [2]. Although it is cited by many articles, I could find no further work indicating the use of this technique to estimate the age of lobsters.

Conservation status: Not threatened, although conservation strategies have been implemented to prevent over-fishing in areas.

So what are we lacking? Well, for starters, we need verified ages of American lobsters beyond just vague estimations. There’s also no information concerning the nuclear genome of Homarus americanus on NCBI (National Center for Biotechnology Information) . There is, however, information on the NCBI regarding the mitochondrial genome.

Please contact me if you have information regarding how this species ages, or relevant articles that are more current on age estimations.

  1. Klapper, Wolfram, et al. “Longevity of lobsters is linked to ubiquitous telomerase expression.” FEBS letters 439.1-2 (1998): 143-146.
  2. Wahle, R. A., and Oliver Tully. “Lipofuscin as an indicator of age in crustaceans: analysis of the pigment in the American lobster Homarus americanus.” Marine Ecology Progress Series 138 (1996): 117-123.