Scientists discover tiny ‘pocket shark’ that glows in the dark
It's only the second pocket shark specimen ever discovered.
- The pocket shark is an extremely rare deepwater fish about which little is known.
- This new specimen, first discovered in 2010, measures just 5.5 inches long and has pocket glands thought to emit a bioluminescent fluid.
- The finding "underscores how little we know about the Gulf [of Mexico]," wrote one researcher involved with the recent study.
Scientists have identified a new species of tiny shark that secretes a glow-in-the-dark liquid.
The 5.5-inch specimen — dubbed the American Pocket Shark, or Mollisquama mississippiensis — was first discovered in 2010 in the Gulf of Mexico during a NOAA mission to study sperm whale feeding. In a recent study, researchers identified its species by using a dissecting microscope and studying radiographic (x-ray) images and high resolution CT scans.
The findings are published in a paper in the animal taxonomy journal Zootaxa.
"In the history of fisheries science, only two pocket sharks have ever been captured or reported," Mark Grace of the NMFS Mississippi Laboratories of NOAA said in a press release. "Both are separate species, each from separate oceans. Both are exceedingly rare."
The first pocket shark was discovered in 1979 in the East Pacific Ocean, but the new study confirmed that the shark found in 2010 was a separate species. Although "pocket" can refer to these sharks' small size, the term actually describes two pocket glands that scientists believe can produce a bioluminescent fluid that helps attract prey.
Still, little is known about these deepwater fish.
Henry Bart, director of the Tulane Biodiversity Research Institute, added: "The fact that only one pocket shark has ever been reported from the Gulf of Mexico, and that it is a new species, underscores how little we know about the Gulf — especially its deeper waters — and how many additional new species from these waters await discovery."
How many undiscovered species probably exist in the ocean?
Not only is it hard to answer this question, but it's even hard to tell exactly how many marine species have already been discovered. Finding that number would require sifting through thousands of scientific papers and reports, and cataloguing the results in one central database – like the World Register of Marine Species (WoRMS), which currently contains more than 240,000 marine species.
As for estimating the number of undiscovered species, scientists generally take one of two approaches, as described by Andy Solow, director of the Marine Policy Center and a Senior Scientist at Woods Hole Oceanographic Institution:
"One approach is based on the species-area curve, which summarizes how the number of species in a region increases with the area of the region," Solow wrote for Smithsonian Ocean. "By seeing how species accumulate as the area covered by taxonomic surveys increases, biologists can make estimates about how many species are in a region with an area as large as the ocean. A big problem with this approach is that the total area covered by taxonomic surveys is a miniscule part of the ocean, and thus different prediction methods can give vastly different answers.
"Another popular approach uses the way in which species discoveries accumulate with time to estimate future discoveries. For some groups, like marine mammals, the discovery rate has fallen off rapidly and perhaps not that many more species remain undiscovered. However, for other groups, such as invertebrates, the discovery rate has actually increased steadily over time, so an estimate based on this ever-increasing rate is essentially infinite. But this method has a more fundamental problem: the discovery record on which this approach is based is the product of human activity, not some natural process."
To create wiser adults, add empathy to the school curriculum.
- Stories are at the heart of learning, writes Cleary Vaughan-Lee, Executive Director for the Global Oneness Project. They have always challenged us to think beyond ourselves, expanding our experience and revealing deep truths.
- Vaughan-Lee explains 6 ways that storytelling can foster empathy and deliver powerful learning experiences.
- Global Oneness Project is a free library of stories—containing short documentaries, photo essays, and essays—that each contain a companion lesson plan and learning activities for students so they can expand their experience of the world.
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- The full eruption of the volcano last happened 640,000 years ago.
- The blast could kill billions and make United States uninhabitable.
Just before I turned 60, I discovered that sharing my story by drawing could be an effective way to both alleviate my symptoms and combat that stigma.
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A joint study by two England universities explores the link between sex and cognitive function with some surprising differences in male and female outcomes in old age.
- A joint study by the universities of Coventry and Oxford in England has linked sexual activity with higher cognitive abilities in older age.
- The results of this study suggest there are significant associations between sexual activity and number sequencing/word recall in men. In women, however, there was a significant association between sexual activity in word recall alone - number sequencing was not impacted.
- The differences in testosterone (the male sex hormone) and oxytocin (a predominantly female hormone) may factor into why the male cognitive level changes much more during sexual activity in older age.
Mathematicians studied 100 billion tweets to help computer algorithms better understand our colloquial digital communication.