The Steinhart Aquarium, San Francisco, believes one of their residents may be the oldest fish in captivity.
Methuselah the Australian lungfish, Neoceratodus forsteri, which is named after the biblical character has been in the aquarium for 65 years, and was an adult when he arrived.
The 90cm/36" fish weighs 40lbs and shares his tank with another lungfish called Herb, who is a youngster - having been resident for a mere 52 years.
The Australian lungfish is a rare fish and protected by international law under CITES Appendix II.