With over 900 separate species and almost 40,000 animals, Steinhart Aquarium — part of the California Academy of Sciences — is one of the most biologically diverse and interactive aquariums on the planet, where visitors can come face to face with marine and freshwater creatures and learn all about the aquatic environment's role on Earth.

The aquarium is one-of-a-kind and undoubtedly one of the best around the globe, boasting a wealth of ecosystems that showcase subaquatic life across the continents, along with extraordinary species housed nowhere else. What's more, visitors can also learn about pioneering research through various exhibits dedicated to ocean ecosystems — many about which humans still know very little.

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But despite the wonders within and the incredible science on-show to budding future biologists at Steinhart Aquarium, there's one particular in-house critter that's been getting a lot of attention in recent years — an aging and literally death-defying scaly swimmer named Methuselah, who adores fresh figs and belly rubs, and is in fact thought to be the world's oldest fish.

The Oldest Living Fish On The Planet (Is In California)

In Biblical stories, Methuselah was the grandfather of Noah, who was said to have lived to be 969 years old. Today's Methuselah residing at the California Academy of Sciences doesn't boast quite that many years, but scientists estimate she is around 90 years old, which is a celebratory age for any human — never mind a fish.

Methuselah is an Australian lungfish — a primitive species with lungs and gills that's thought to be the significant evolutionary link between fish and amphibians. Though ancient she may be, her age isn't as modest as her size; she's 4 feet long (1.2-meters), and around 40 lb (18.1 kg). She has also traveled quite a fair distance, especially for a fish; she was first brought to the San Francisco museum in 1938 all the way from Australia, believe it or not.

She first acquired fame when she was featured in an article by the San Francisco Chronicle in 1947, which stated “These strange creatures, with green scales looking like fresh artichoke leaves, are known to scientists as a possible ‘missing link’ between terrestrial and aquatic animals.” Since her public introduction so many years ago, her global celebrity has been increasing faster than her age — gaining more and more intrigue as the world's oldest aquatic senior citizen.

Furthermore, what's even more intriguing is the species' name "lungfish," which does actually hold relevant meaning; in addition to her gills, Methuselah has a special kind of ancient "lung," which allows her to breathe air at the surface of the water. Being able to breathe both above and below the water is unarguably a useful evolutionary skill, and has likely caused the species many millions of years' success since its natural habitat in the wild typically involves pools, which can often dry up or become stagnant.

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Methuselah

In spite of her superior 400 million-year-old design, esteemed worldwide fame, and long-life achievement, Methuselah is no prima donna diva; she is a laidback creature with a chilled-out personality, enjoying life's simple things — like fresh figs and head scratches. She is well taken care of every day by an expert team, who ensures she enjoys a life of luxury throughout her golden years. In all honesty, who wouldn't live a long life if such zen was the order of every day?

Adorably, the senior biologist at the California Academy of Sciences — Allan Jan — said she particularly loves getting rubbed on her belly and back much like an underwater puppy dog, and described her personality as "mellow." According to Jan, she's "calm" and "gentle" for the most part, but will get "sudden bouts of energy when spooked."

She also has a distinct taste for seasonal figs. Jeanette Peach, a spokeswoman for the California Academy of Sciences, described her as a "little picky," commenting that she only eats figs when they are fresh and in season, and refuses them when they are frozen. Spoiled much? No — optimists would probably say Methuselah is cultured with a refined palate. After all, she's lived long enough to develop such fine tastes.

Interestingly, what's also fascinating about Methuselah is that her she/her pronouns may not be fully accurate; her keepers believe her to be female, however, it's incredibly difficult to determine this species' sex without drawing blood, which is invasive and risky — even for such an old-timer of a fish. Nevertheless, the academy does intend to confirm her sex and exact age by sending a fin sample to Australian researchers, which may help to answer their burning questions.

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Methuselah Isn't Alone

Methuselah didn't always hold the crown of the underwater coffin dodgers — the world's previous oldest Australian lungfish lived at Shedd Aquarium in Chicago. He was aptly named Granddad for obvious reasons, but unfortunately, Granddad passed away in 2017 at the ripe old age of 95.

By default, Grandad's passing meant that Methuselah took over as the fish queen of time, holding the title as the planet's oldest living fish — and one of the many goals of her caretakers is to give her the best possible care they can provide so that she thrives, and lives happily and healthily as long as possible.

Methuselah isn't alone in San Francisco either; the academy is in possession of two other younger Australian lungfish — both estimated to be in their 40s or 50s. Sadly, the species is now threatened, resulting in a ban on their exportation from Australia. This means that biologists at the academy likely won't be able to obtain any more individuals after Methuselah and her Australian lungfish roommates' eventual death.

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Visiting the California Academy of Sciences Is A Must

Since 1923, the California Academy of Sciences' Steinhart Aquarium has been at the forefront of aquatic development and history, championing a number of firsts in the global aquarium community. Among many significant achievements, it was the first public aquarium to show flashlight fish and coconut octopuses, and also advanced the exploration of the ocean’s vastly underexplored twilight zone.

Today, Steinhart Aquarium continues to be a model modern aquatic center, not only by hosting some of the world's richest aquarium biodiversity and executing cutting-edge research, but also by inspiring the public and educating people about the underwater world and the sustainability of the oceans and rainforests.

Overall, in terms of features, the innovative establishment combines an aquarium, planetarium, and natural history museum into a modern-day exhibition and exploration of the natural world. Home to the largest indoor living coral reef exhibit on the planet, a living rainforest contained within an impressive sphere, and over 200 further living and virtual exhibits, the one and only California Academy of Sciences promises an enriching, educational journey for all ages, and should be on everyone's to-do list when in the San Francisco area.

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