Fungie has been described as a one-off solitary dolphin, by one of the world's leading dolphin and whale charities.
Marine Connection, a charity dedicated to the protection of whales and dolphins, officially named the much-loved Dingle mammal as the longest-living solitary dolphin on the planet in a study published two years ago.
'The Lone Rangers' report catalogued a global list of 114 solitary whales and dolphins which interact with humans, with the oldest record dating back to 109AD when a pair of dolphins in Tunisia befriended a young boy.
As hopes of finding Fungie were fading this week, co-founder of Marine Connection Liz Sandeman said they have been flooded with messages from dolphin lovers all over the globe.
"Fungie is known globally, we've been inundated with calls and emails. Fungie really, really is a one-off solitary dolphin. He is the granddaddy of all solitary dolphins."
The London-based welfare charity has spent decades examining the phenomenon of sociable marine mammals who enjoy human company for decades.
Fungie held the record for the longest known solitary animal of his type to interact with humans in the world.
"As far as solitary dolphins are concerned, he is extremely unique," Liz Sandeman said.
"There is another dolphin called JoJo in the Turks and Caicos, but apart from that there has never been another dolphin that has actually stayed in an area for this amount of time.
"We monitor another dolphin called George on the Dorset coast but he originally came from Ireland and then he was spotted around the UK and then he moved to France.
"He is a dolphin we have known for least 20 or 25 years and he is still alive but he has never stayed in the same area like Fungie."
The conservationist said she had noticed Fungie ageing in recent years.
"Fungie, without question, over the last two or three years looked much older. He must be at least 43 or 44 years."
She remembers first seeing Fungie in the Kerry town around 30 years ago.
"In the early days, when I used to go out and see him in the 90s, people just really enjoyed this majestic dolphin. He is very gentle."
She said most bottlenose dolphins and whales tend to sink to the bottom of the seabed if they do pass away at sea.
"Obviously some of them can be washed up, but on the whole, the majority of dolphins, if they are ill, they are conscious breathers, if they stop breathing, they will basically sink.
"It's the same with whales, there are lots of whales found on the bottom of the seabed."
Sadly, the marine conservationist said she finds it hard to imagine why Fungie would leave the bay after 37 years.
"Fungie has never actually disappeared before. Nobody really has an answer to this.
"Personally, I don't think he has taken off, as someone who has studied solitary dolphins."