what's the life expectancy of a fish
Freshwater. Many freshwater fish average about 1 to 3 years of life. Some of the more popular species with this short life span include fantail guppies, swordtail platy, mollies, rainbow fish, hatchet fish, corydoras catfish, some cichlids, rasboras and tiger barbs. There are also several fish that live around 3 to 5 years, with proper care and feeding.
Most published information about the life span of saltwater fish are from public aquariums where the fish are kept in the best possible conditions. Many saltwater fish succumb to illness early in life due to poor husbandry. Some saltwater species only live an average of 2 to 4 years.
Bettas on average live little more than two years, while Goldfish live for decades. Short Lifespans. Killifish are among the aquarium fish with the shortest lifespan. They generally only live a year or two. Bettas are not far behind, averaging only about 2 years. There have been documented cases of Bettas living 5 years or more, but that is not the norm. Livebearing fish such as Mollies, Platy s, and Swordtails, generally live less than 5 years. Long Lifepsans. On the other end of the lifespan spectrum, are Goldfish.