The age of a shark can be estimated from the growth rings on its vertebrae, seen in this x-ray. Growth rings are laid down annually, but this may stop as the sharks get older. The rings can also be affected by local conditions such as food shortages, by the demands of reproduction, or by the shark’s health. The method is therefore not totally reliable. The age of other, bony fish, is calculated from rings on the otolith or earstone, which sharks do not have.
Using this item
This item has been provided for private study purposes (such as school projects, family and local history research) and any published reproduction (print or electronic) may infringe copyright law. It is the responsibility of the user of any material to obtain clearance from the copyright holder.