http://swissbaync5d7ykaz7dh7v4qjrb4gmen5aj3bogxrcgbb43ij34bjuyd.onion/pdf/Books/Survival/Medicine/oddsnends.htm
The answer varies, of course, depending on the species, but it is extremely rare for a
fish to live more than 25 years. Many large fish live for 15-20 years, including
barracuda, tarpon and herring. Smaller fish live anywhere from one to five years - unless
they are caught and eaten by bigger fish (or by people).