A snorkel guide on Queensland’s Great Barrier Reef is the first to capture an incredibly rare juvenile oarfish, which can grow up to eight meters in length.

Reef guide Tahn Miller had been leading a group of snorkelers through the shallow Opal Reef, between Port Douglas and Cape Tribulation, when he noticed a glint of light that was the mirror-like, elongated fish gliding past.

Miller was with marine biologist Jorja Gilmore at the time, and both immediately recognized that they had come across a rare and unique find.

“At first I couldn’t quite place which fish it was, but then I saw the shiny mercury-colored body, two dominating eyes and the ultra-fine dorsal fin that ran from head to tail, undulating like mini-waves propelling through the water,” said Molenaar.

“I knew we had come across something rarely seen on the Great Barrier Reef.

“Fortunately, I had my camera with me and started filming right away.

“At that moment, I felt like the ocean had provided us with a secret treasure. It was truly a once-in-a-lifetime encounter.”

The pair returned to their boat to try to identify the fish.

“The oarfish wasn’t on board in any of the reef guides, so we used the Master Reef Guide network and experts from the Great Barrier Reef Marine Park Authority to help identify the species,” Miller said.

Oarfish are considered the world’s longest bony fish and are rarely seen in such shallow water.

The captured Oarfish Miller had a body of 35 to 40 cm, but was one to two meters long when you look at its fins.

Oarfish can grow up to eight meters in length, leading experts believe the observed oarfish was a juvenile.

dr. Tyson R Roberts, a leading oarfish expert, said the oarfish filmed by Miller was the species regalecus russellirecognizable by its single dorsal fin and several extremely elongated rays.

“This is the first sighting of this species on the Great Barrier Reef and on the east coast of Australia,” Roberts said.

“The only other Australian record of regalecus russelli was at Port Hedland in Western Australia.”

Miller said people can log their rare finds and help researchers and conservationists with apps like Eye on the Reef.

“The reef has an amazing power to connect people with nature. When you see it first hand, it entices you in, you fall in love with this environment and you are inspired to protect it,” he said.