i've had a guppy live 5 years, seen a pacu and red-tail catfish that were both approaching 30 years, and the giant pleco on amazon abyss was estimated to be over 150 years old. koi can live up to 200 years and are in some families passed down as heirlooms from generation to generation. it all depends on the fish and the quality of life that you provide for it. even with the best of care not all fish will live out their expected life span. breeding and genetics has a lot to with it, just like any creature.
