The remains of an Oarfish was discovered on the Kingston beach by Sharryn Tiller and her dog Hugo on November 11.
Living in the deep sea, the fish is rarely seen and its behaviour not widely studied, and it is believed to have inspired tales of sea serpents.
"I was taking Hugo for a walk along the beach and we came across this great big dead fish," said Sharryn.
"I thought what on earth is it? I stood there thinking maybe it was an eel.
"But eels don't have whiskers, this fish had great long hard whiskers.
"I came home and my husband was chatting to our neighbour, Dan Watson and I mentioned what I had seen on the beach.
"Dan said he said seen a similar photo of a fish on Facebook called an Oarfish and they are really rare.
"After hearing that I went back to the beach and took quite a few photos and showed the fisheries.
"The fisheries were very interested and I also phoned the Adelaide museum where I spoke to Mr (Ralph) Foster (a Collection Manager at the museum).
"On the Tuesday I had a phone call from the fisheries saying they were unable to find the Oarfish, I met up with them and we went down to the beach together but unfortunately I couldn't find it again.
"I felt extremely privileged to have been able to see, feel and photograph a rare fish.
"I did feel a bit saddened that a beautiful fish like that was dead on the beach.
"I first photographed the fish how I initially saw it on the beach and than I managed to turn it over and saw that the eye was still there.
"I also used my thong to show the size of the fish and to measure how long it was, at a general guess it was 10 and a half feet long.
© Sharryn TillerThe Oarfish on the beach with a thong for size comparison.
"The fish felt like a very sand paper and it had no scales, the whiskers were hard."
The Oarfish are mysterious sea creatures that almost exclusively stay in the darkest depths of the ocean - between about 1000 and 3000 feet below the surface.
Oarfish will only typically come near the surface if they are dead or sick, making them largely unstudied.
Because of their appearance the fish is said to have spawned tales of sea monsters.
In 2013 a dead Oarfish was discovered by a snorkeller off the Californian coast measuring 5.5m.
A second 18-foot Oarfish was found washed up on a Californian beach in 2015.
The scope of this ocean disaster is there to see if you will just SEE it, The demise of aquatic life is going to be a very big problem for mankind, there is NO doubts about this.