Sphen rose to global fame in 2018 when he partnered with fellow male gentoo penguin Magic, after the two were spotted waddling around and swimming together before breeding season.
The same-sex penguin power couple known as "Sphengic" inspired millions with their unshakeable bond and heartwarming family. Together they raised two chicks: Lara, 6, and Clancy, 4.
To help Magic, aged 8, process the tragic loss, aquarium staff took him to see Sphen "so that he could understand why his partner wouldn't return," the Sea Life Sydney Aquarium said in a statement.
"He immediately started singing, which was beautifully reciprocated by the colony."
Richard Dilly, the aquarium's general manager said: "The loss of Sphen is heartbreaking to the penguin colony, the team and everyone who has been inspired or positively impacted by Sphen and Magic's story."
"We want to take this opportunity to reflect and celebrate Sphen's life, remembering what an icon he was," he added.
Sphen lived a full life for a gentoo penguin, a species with an average life span of roughly 12 to 13 years.
He and Magic shared an inseparable bond - the two were often seen together outside of breeding season, a rarity for their species.
"The team's focus is now on Magic, who will soon prepare for his first breeding season without Sphen," Dilly said.
The pair inspired a Mardi Gras float, featured in the Netflix series "Atypical" and have been included in the education curriculum in New South Wales, their Australian home state. Countless books and movies also touch on their love story, the aquarium said.
In 2018, Sphen and Magic became parents after they were entrusted to hatch a "backup" egg given to them by another penguin couple, who had laid two eggs.
It's common for gentoo penguins to lay two eggs each breeding season, but the sub-Antarctic penguins usually only have the resources to incubate and raise a single egg, so the "backup" chick may not survive.
Not in this case. On October 19, 2018, an adorable 91-gram penguin chick named Lara was born to the doting parents. In 2020, the Sphengic family became four after Clancy joined the fold.
Sphen and Magic are not the only same-sex penguin couple to successfully hatch an egg. Couples in New York and Spain have also become parents.
Sphen not only helped in the championing of equality. Through the couple's fame, the aquarium was able to raise awareness and money for important causes including conservation, plastic pollution, climate change and the need to protect wild penguins, Sea Life said.
Tributes from fans poured in on the aquarium's website.
"Resting in peace I hope little guy, what a wonder to the world you were with your beautiful Magic," wrote Vivienne.
"RIP to a champion," wrote Vicki. "Love shows no boundaries."
The CNN Wire™ & © 2023 Cable News Network, Inc., a Warner Bros. Discovery Company. All rights reserved.