Locals shocked by mysterious discovery on Aussie beach: 'Pretty unusual'

The massive sunfish first appeared on Sunday and measures close to three metres wide.

Giant sunfish washed up on beach at Petrel Cove, Victor Harbor in South Australia.
Locals flocked to a South Australian beach after a giant sunfish washed up onto the sand. Source: Facebook/Youtube

Curious residents have flocked to the shores of an Aussie beach after a mysterious and giant discovery was made on the sand, with locals describing the scenes as both "amazing" and "sad.

Photos and videos taken at Petrel Cove in South Australia show what some believed was a "big boulder" or oversized rock. But it's the carcass of a giant sunfish, the South Australia Museum confirmed to Yahoo News Australia.

It's not the first time Aussies have been wowed by the mysterious beaching of the giant disc-shaped creature. In November last year, the bodies of two elusive sunfish were mysteriously found dead within days of each other on a 70km stretch of Australia’s coastline, leaving one leading expert "lost for words".

Local woman Dani Brown said she'd heard about the stranded sunfish and headed down to Petrel Cove at Encounter Bay to check it out. "It was pretty cool to see, this is the first time I've seen one," she told Yahoo.

Sunfish are known to grow up to four metres wide. According to locals, this particular one measured roughly 2.7 metres. A photo shows Brown nestled beside it for scale.

The sunfish beached at Petrel Cove in South Australia. Dani Brown lies behind it, showing she is much smaller than the fish.
The sunfish, measuring about 2.7 metres in diameter, on the beach with Dani Brown in the background.

People responding on social media, where photos have been shared, thought it was "sad to see" while others were in awe of the sight of the huge sea creature.

"Wow! Pretty unusual sighting," said one. "Amazing," another said, asking "I wonder how prolific they are?" "Beautiful gentle creatures," said a third.

The South Australian Museum confirmed the fish is "almost certainly a bump-head sunfish, mola alexandrini" and while sunfish are found worldwide, this particular species "is the one most often encountered in South Australia.

"You can tell it's a bump-head sunfish rather than one of the other two types (Mola tecta, the hoodwinker sunfish and Mola mola, the ocean sunfish) because of the prominent chin you can see in the photo. The other two species don't have that," they said.

It's not known how the sunfish died, with Brown suggesting it's been there since Sunday. Danish marine biologist Dr Marianne Nyegaard previously told Yahoo it's almost impossible to determine what kills them.

"Stranded sunfish typically appear to have been healthy with no obvious cause of death, or impairment to explain why they ended up on the beach," she said.

She believes it's possible they sometimes "fall onto land" in the same way humans "fall into the ocean". However the science on this is not settled.

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