Shark Lifespan
Identifying how long do sharks live is certainly a hard work, as they are extremely difficult to monitor in the ocean due to their migratory and feeding patterns. Even more, it has been demonstrated that the lifespan of sharks in captivity is considerably shorter from those in the wild, making impractical to generate conclusions from those individuals in captivity.
Lately, GPS systems have brought a new way to track migration and how long do sharks live, providing more accurate information about them.
Shark lifespan vary by kind and it is very different for each of them. While many types live 20 to 30 years in the wild, there are some types that live much longer than others.
As an example, the spiny dogfish has one of the longest lifespan at more than 100 years, while the blue shark in the wild has an average lifespan of 15-16 years. Unfortunately, as we mention before, blue shark expectation of life decreases down to 8 years when held in captivity, probably as a result of the lower activity.
The life-span of tiger sharks in the wild is considered to be 27 years in average, even though some may live up to 50 years of age. As with other species, tiger sharks in captivity do not live as extensive as in wildlife reaching only 17 to 20 years.
Some experts presume that the lifespan of the Great White Sharks is approximately 30 years (Levine, 1988) but other research indicates that they can reach up to 40 years.
The typical life expectancy in the wild for Hammerhead Sharks is from 20 to 30 years approximately.
Whale sharks (Rhincodon typus) are also believed to live above 100 years, suggesting that the time to reach maturity is longer and young will take longer to born, making this type of shark more vulnerable. In captivity, whale sharks able to reach a long expectancy as they have died within days, but in best cases they have reached just 8 years.
The impact of captivity in the life expectancy of Leopard Sharks is certainly dramatic; if they are kept in more compact tanks they have a really short span of approximately 9 years while larger aquarium tanks can help them to have a longer life that can reach up to 25 years. In the wild, it is believed that their life expectancy is about 30 years.
Sandbar sharks or Brown sharks are thought to live between 20 and 30 years. Investigation made by Joung (2004) found to be about 20 years of age. While, Sminkey (1996) mention that sandbar sharks can live to be more than 30 years old.
The age of silky or Blackspot sharks can be determined by calculating the number of growth rings that develop on their vertebrae as with other species, having each band standing for approximately one year of life. It is estimated that Silky Sharks can live up 25 years in the wild.
