How long do they live? Red sea urchins have been found to live over 100 years and perhaps up to 200 years old [1]. They also have the ability to regenerate spines that get damaged or lost. This species of urchin show no signs of aging, which is referred to as negligible senescence.

Where are they found? Along the coast of the Pacific Ocean from Alaska to California. They prefer to be just below the low tide line to depths up to 100 feet [2].

aristotle's lantern
Figure 1. The underside of an urchin showing the teeth to Aristotle’s Lantern.

What do they eat? They enjoy a diet of seaweed and algae and they eat with one of the coolest named jaws on the planet: Aristotle’s Lantern (see figure 1).

What do they look like? They’re red and spiky and look like figure 2.

Figure 2. Red sea urchin.

How do they reproduce? Like many of the sedentary ocean dwellers, eggs and sperm are released into the water and fertilized externally. They begin life as larvae and then go through metamorphosis to become the spiny creatures that you avoid stepping on when surfing the Pacific.

How do scientists know how old they are? Researchers tag the urchins in the ocean and then make measurements of growth. They then use radiocarbon analyses to confirm their estimates [1].

So what are we lacking? There’s no information regarding the nuclear genome of Strongylocentrotus franciscanus on NCBI (National Center for Biotechnology Information) . There is, however, information on the NCBI regarding the mitochondrial genome. Interestingly, active telomerase was measured in both long- and short-lived sea urchins and it was found that there is a lack of telomere shortening in both species, which wasn’t really expected [3]. I could not track down any information concerning reproductive senescence of this species. They are not listed at all on the IUCN website (that I could find).

Please contact me if you have information about this species.

  1. Ebert, Thomas A., and John R. Southon. “Red sea urchins (Strongylocentrotus franciscanus) can live over 100 years: confirmation with A-bomb^ 1^ 4carbon.” FISHERY BULLETIN-NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION 101.4 (2003): 915-922.
  2. Britton-Simmons, Kevin; et al. (2012). “Habitat and bathymetry influence the landscape-scale distribution and abundance of drift macrophytes and associated invertebrates”. Limnology and Oceanography.
  3. Francis, Nicola, et al. “Lack of age‐associated telomere shortening in long‐and short‐lived species of sea urchins.” FEBS letters 580.19 (2006): 4713-4717.