How long does a hammerhead shark live?
There are actually 9 species of hammerhead sharks. But the one most people refer to is the great hammerhead shark. It can live up 20 or 25 years. The age of a shark can be determined by counting the rings of more and less dense cartilage deposition on a vertebrae. Staining the vertebrae with a dye, called tetracyline, that is fluorescent under ultraviolet light makes it easier the discern the rings. Male scalloped hammerhead sharks reach a length of 140 cm (5.6 feet) in eight years. These sharks certainly grow considerably older. The largest free-swimming hammerhead that I measured using a stereocamera was 361 cm (11.8 feet). Yet one can not simply extrapolate an age for this individual as the growth per year decreases as a shark gets larger. An Australian soupfin shark (Galeorhinus australis) tagged in the mid 1950s and estimated to be at least five years old was recaptured in the mid 1990s, giving an age of 35 years. This species is a member of the reef shark family Carcarhinidae, wh
