what is the average lifespan of sharks?

Answer 1

Your question is a good one, albeit a little broadly formulated. but that's really okay. The first problem, aside from asking which species of shark you are interested in, is to determine the age of sharks in the first place. Obviously that is easily done when sharks are kept in captivity, but not all species do well in a tank. Most simply stop eating and have to either be released or will die. Consequently, there have to be other ways to determine age in order to answer your question.

There are a few methods that have been used over the years, some more successfully than others. For one, there are tagging studies, where animals are being caught, tagged, and released. If these individuals are re-caught later on, the date of the tag can help to get a feel for how long sharks may live. On the other hand, it is merely tentative, since we don't know how old they were when first caught and tagged, or how long they may live after the second release.

Another method are the age rings on vertebrae. All elasmobranchs (sharks, skates, and rays) are cartilaginous fish. As an effect of differential calcium deposites in the cartilage their vertebrae form rings. In many species, calcium content in the water changes seasonally and thus gives an indication of the age of the animal. In other words, it's a little like the rings in the stems of trees. I some species, like the spiny dogfish (Squalus acanthias), catch and release experiments have given good insights into how reliable these rings are. In this species, each dorsal fin has also a cartilaginous spine (hence the name) that also forms rings. They also ave been validated as markers of age, and together with the vertbrae work actually quite nicely.

Given the information from catch-release experiments, tagging experiments, and vertebrate ring experiments we have gained some insight into the age of animals at maturity and also in terms of maximum age. Spiny dogfish indeed mature after about 25 years and live up to around 75 years (possibly longer, although 100 years is, as far as I know, unconfirmed). Other species mature at around nine to ten years and probably live up to around 30 to 40 years.

These are ages that are estimated for animals in the wild. What you have to keep in mind is that animals here do not necessarily survive as long as in captivity, given that they survive in captivity in the first place. S. acanthias is notoriously difficult to keep, since the animals will simply not eat. Sandtiger sharks (Carcharias taurus) on the other hand do extremely well in captivity. Here survival rates may differ between the wild and capticity. So, when for some species maximum age is determined in captivity, it does not automatically imply animals reach similar ages in the wild.

Hope this helps.

Answer 2

well, that is a very general question and depends on the species, some can live many years, like the whale shark can live up to and around 50 years, while other smaller species may only live for a couple years.
Tyr to be a lttle more specific and you'll get more detailed answers. Hope that helps

Answer 3

20 years

Answer 4

Some of the larger sharks can live a very long time, partially because of their apparant immunity to cancers.

Answer 5

Life Cycle
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Average life span of a shark: Less than 25 years

Longest living shark species: Spiny dogfish, 70-100 years

Answer 6

i think the great white live up to 30 years