Lifestyle Pets The World's Oldest Living Aquarium Fish Is a Californian Who Loves Belly Rubs Named Methuselah Methuselah is a 90-year-old, 4-foot-long, 40-pound, Australian lungfish that resides at the California Academy of Sciences' Steinhart Aquarium in San Francisco By Kelli Bender Published on January 26, 2022 05:56 PM Share Tweet Pin Email Photo: Jeff Chiu/AP/Shutterstock The world's oldest living aquarium fish is a nonagenarian. Methuselah is a 90-year-old, 4-foot-long, 40-pound Australian lungfish that resides at the California Academy of Sciences' Steinhart Aquarium in San Francisco. According to The Associated Press, Methuselah the fish — named after the biblical figure said to have lived 969 years — is the world's oldest living fish residing in an aquarium, inheriting the title from Granddad. Granddad, another Australian lungfish, died at the age of 95 at Chicago's Shedd Aquarium in 2017. The California Academy of Sciences isn't certain about Methuselah's sex and exact age because getting this information required a blood draw that could harm the aging fish. The academy believes Methuselah is female but will know for sure after sending a small fin sample to researchers in Australia. This less invasive testing method should reveal the fish's sex and exact age. Methuselah keeps a "calm," unjaded attitude about her impressive status, Allan Jan, a senior biologist at the California Academy of Sciences, told AP. "She's an underwater puppy, very mellow, gentle, but of course, if she gets spooked, she will have sudden bouts of energy. But for the most part, she's just calm," he added. World's Oldest Male Gorilla Dies at 61 in Atlanta Zoo: 'This Is a Devastating Loss' An unripe fig is one of the few things that get Methuselah's scales in a bunch. "She's a little picky and only likes figs when they are fresh and in season. She won't eat them when they're frozen," Jeanette Peach, a spokeswoman for the California Academy of Sciences, told AP. RELATED VIDEO: Meet This 63-Year-Old College Golfer & One of the Oldest Student Athletes in the U.S. Along with ripe figs, Methuselah enjoys snacking on blackberries, grapes, lettuce, clams, prawns, and earthworms. She is one of three Australian lungfish living at the California Academy of Sciences. North Carolina Man Catches Fish With Human-Like Teeth Australian lungfish are primitive species with both lungs and gills. Scientists believe the species is an evolutionary link between fish and amphibians, according to AP. The outlet also reported that the Australian lungfish is a threatened species and can no longer be removed from Australian waters.