Right, this is my third post “searching for immortality”…. there is so much diversity and interesting things to share, but this will be the last one (for the moment J ). Certainly, our guest does not belong into the category of the “immortals”, however, it is among the longest-lived known vertebrates: the Greenland shark or Somniosus microcephalus.
The Greenland shark is an iconic species of the Arctic Seas and widely distributed in the North Atlantic. It grows slowly and can reach over 5 m in length, suggesting a life span well beyond those of other vertebrates. They reach their sexual maturity around 156 ± 22 years and the largest know animal is around 392 (± 120) years old.
To estimate its age, researches did a radiocarbon dating of eye lens. Why lens? Because in vertebrates, crystalline proteins are formed during prenatal development and this tissue retains proteins synthetized at time. In other words, because in the crystalline we can find proteins as old as the shark itself. The results of this study show that the Greenland shark is the longest-lived vertebrate known, surpassing even the bowhead whale (Balaena Mysticetus, estimated longevity of 211 years).
This new data gives us new understanding about the shark in particular, but also about its ecosystem, raising concerns about this and others species´ conservation.