Like finding a needle in a haystack, a team of scientists has discovered a new species of shark that glows in the dark and weighs less than 1kg at full growth.
The miniature, glow-in-the-dark shark was a member of the Lanternshark family, which was serendipitously found in the Pacific Ocean off the coast of the northwestern Hawaiian Islands.
It had taken more than 17 years to identify this new species since it was first discovered - but was well worth the wait, as the elusive creature is yet to be seen in the wild.
It often took many years to identify a new species from the time it is discovered to the moment the news was shared with the scientific community.
"There are only about 450 known species of sharks worldwide and you don't come across a new species all that often," said Florida Atlantic University's Professor Stephen Kajiura, who described the species in the journal Zootaxa.
"A large part of biodiversity is still unknown, so for us to stumble upon a tiny, new species of shark in a gigantic ocean is really thrilling.
"This species is very understudied because of its size and the fact that it lives in very deep water.
"They are not easily visible or accessible like so many other sharks."
At first, Kajiura and his colleagues didn't think they'd discovered a new species until they submitted their research findings to a journal.
The reviewer told them that the shark was not what they originally thought it was - and that it might be a new species.
Formally identifying it required an extensive list of measurements, diligent categorisation and thorough comparisons with other museum specimens.
"The unique features and characteristics of this new species really sets it apart from the other Lanternsharks," Kajiura said.
"For one thing, it has a strange head shape and an unusually large and bulgy snout where its nostrils and olfactory organs are located.
"These creatures are living in a deep sea environment with almost no light so they need to have a big sniffer to find food."
Some of the other distinctive characteristics of this new species are its flank markings that go forward and backward on their bellies, a naked patch without scales on the underside of their snouts, as well as internal differences such as the number of vertebrae they have as well as fewer teeth than the other sharks.
Like other Lanternsharks, the Etmopterus lailae is bioluminescent and the flanks on the bottom of its belly glow in the dark.
Possible reasons why Lanternsharks glow in the dark include "mate recognition", to ensure they are mating with the right species, camouflage to protect them from predators in the deep sea, and attracting little fish or shrimp.
The science of.... near death experiences
No one really knows what happens when we die, but many of us have stories to tell about what they experienced while being close to death.
People who have had a near-death experience usually report very rich and detailed memories of the event.
Although these can take many different shapes, the best known include seeing a bright light, experiencing a feeling of peace, having an out-of-body experience and perceiving a tunnel.
A first-of-its kind study, featuring in the journal Frontiers in Human Neuroscience, examined more than 150 accounts to examine how frequently, and in what order, these different aspects of self-reported experiences happen.
The researchers found that on average, a person experiences about four different phenomena, including feelings of peacefulness, seeing a bright light, and encountering spirits.
A third of the subjects experienced an out-of-body experience as the first feature, and the most frequent last feature was returning to the body.
"This suggests that near-death-experiences seem to be regularly triggered by a sense of detachment from the physical body and end when returning to one's body," said study author Dr Charlotte Martial, of Belgium's University of Liege.
Overall, the most commonly shared experienced order of occurrences was out-of-body experiences, experiencing a tunnel, seeing a bright light, and finally feeling peace.
Yet no universal sequence of events could be established, suggesting that each experience had a unique pattern of events.
"Our findings suggest that near-death-experiences may not feature all elements, and elements do not seem to appear in a fixed order," she said.
"Further research is necessary to explore these differences and the precise extent of which content of those experiences reflects their expectations and cultural backgrounds, as well as the neurophysiological mechanisms underlying near-death experiences."
The perfect gift is one for yourself as well
If it's the thought that makes a gift count, here's a thought that can make your gift count extra: get a little something for yourself.
A new study in the Personality and Social Psychology Bulletin shows gift recipients are happier with a present when the giver got themselves the same present.
The marketing researchers behind the study, Professors Evan Polman and Sam Maglio of the University of Wisconsin-Madison and the University of Toronto Scarborough, call it "companionising".
"The fact that a gift is shared with the giver makes it a better gift in the eyes of the receiver," Polman said.
"They like a companionised gift more, and they even feel closer to the giver."
Hundreds of participants in the study rated how likable, thoughtful and considerate they would find each of a long list of gifts - and what difference an attached card with a message like, "I hope you like the gift. I got myself the same one too!" would make.
Scores went up for gifts - such as staplers, umbrellas, wool socks and headphones - that also found a home with the giver.
"We were inspired originally by things like friendship bracelets, where two people would have two things that kind of make up a whole," Polman said.
But experiments within their study showed the giver and receiver didn't have to be close friends or relatives for the companionisation effect to work.
That was particularly helpful for givers who didn't know their recipients well, Polman said, as lack of familiarity could make it even harder to pick a great gift.