05/10/2016 11:08 AM AEDT | Updated 05/10/2016 5:28 PM AEDT

Whale Sharks Keep Their Private Life Very Private

No public displays of affection for these 30ft lovers.

Getty Images
Fin flicks and chill?

For the biggest fish in the sea, whale sharks are pretty darn good at evading our prying eyes.

We know so little about these gentle giants, and attempts to track their movements are usually evaded by the dark depths they dive to.

Things we don't know about whale sharks

  • No one's ever seen them have sex. We don't know how they do it or where they do it.
  • No one's ever seen them pup (give birth) but a pregnant female was once found to have more than 300 near-term embryos all with the same father, but at different stages of development.
  • Most whale shark hot spots are full of young males, so where do all the female whale sharks hang out?
  • We don't know how deep they can dive.

Basically they are the greatest living mystery in the ocean and Murdoch University research associate Brad Norman told The Huffington Post Australia it was every day tourists who were helping scientists understand them by sharing photographs.

"The thing about whale sharks is they're beautifully adorned with spots and these great patterns can be used to identify them," Norman told HuffPost Australia.

Among the thousands of whale sharks identified on citizen scientist project Wildbook for Whale Sharks are the two longest-studied whale sharks Stumpy and Zorro that Norman's been seeing for more than 20 years on Ningaloo Reef in Western Australia.

They may have fathered thousands of young, we just don't know where they go to do it.Brad Norman

"Over two decades as they visit Ningaloo, we've watched Stumpy and Zorro grow," Norman said.

"They've gone from immature to mature, which is a rare thing to observe, and then we see that they've mated.

"They may have fathered thousands of young, we just don't know where they go to do it."

Indian Ocean Imagery
Stumpy has a curious tail, making him easy to recognise.

As whale sharks were this year added to the IUCN endangered list mostly due to finning and fishing pressures, the need to understand these gentle giants has never been more pressing.

Norman said whale sharks kept their secrets because our technology wasn't up to scratch for the depths they dive.

"Whales and dolphins and other air-breathing mammals come to the surface from time to time so we can track them with a satellite but because whale sharks dive to at least 2000 metres, any tagging device has electronics, salt water and crushing pressure."

China Stringer Network / Reuters
Whale sharks are caught by fisheries and their fins are sadly prized for shark fin soup.

It doesn't lend itself to good results. That's where tourists come in.

"People in 54 different countries are adding to the database.

"The hope is that when people get involved, they inform themselves about whale sharks and are adding to conservation of the species as a whole."

As for Zorro and Stumpy, Norman said he hoped we could one day follow them as they left Ningaloo Reef, to determine where they go, who they meet, and possibly, where all the female whale sharks are hiding.