Altmetric Blog

May High Five – A Warm-Blooded Fish and Other Odd Discoveries

Paige Jarreau, 29th May 2015

Welcome to Altmetric’s “High Five” for May, a discussion of the top five scientific papers with the highest Altmetric scores this month. On a monthly basis, my High Five posts examine a selection of the most popular research outputs Altmetric has seen attention for that month.

The theme this month is odd discoveries.

Paper #1. Warm-Blooded… Fish?

Opah. Credit: NOAA Fisheries

Opah. Credit: NOAA Fisheries


All fish are cold-blooded ectotherms, right? You probably learned that in grade school. But now, we know that “fact” is wrong.

Our top paper this month, picked up by at least 87 news outlets and 20 blogs, documents the discovery of the first warm-bodied fish. The paper, “Whole-body endothermy in a mesopelagic fish, the opah, Lampris guttatus,” was authored by Nicholas Wegner, Owyn Snodgrass, Heidi Dewar and John Hyde, and published in Science on May 15th (incidentally the day I and many others graduated with a PhD!) On Twitter, the discovery received attention predominantly from members of the public, according to Altmetric data, as well as scientists and science communicators.

Mammals and birds warm their entire bodies above the ambient temperature. Generally, this ability is lacking in other vertebrates, although some highly active fish can temporarily warm their swim muscles. Wegner et al. show that the opah, a large deepwater fish, can generate heat with its swim muscles and use this heat to warm both its heart and brain. This ability increases its metabolic function in cold deep waters, which will help the fish compete with other, colder-blooded species. – Editor’s Summary, Science

Here, we describe a whole-body form of endothermy in a fish, the opah (Lampris guttatus), that produces heat through the constant “flapping” of wing-like pectoral fins and minimizes heat loss through a series of counter-current heat exchangers within its gills. Unlike other fish, opah distribute warmed blood throughout the body, including to the heart, enhancing physiological performance and buffering internal organ function while foraging in the cold, nutrient-rich waters below the ocean thermocline. – Paper abstract, Science

The study was covered extensively in the news, with stories in the New York Times, “In a First, a Fish Is Shown to Be Fully Warm-Blooded,” NPR, “First In Fish: ‘Fully Warmblooded’ Moonfish Prowls The Deep Seas,” and Science News, “Deepwater dweller is first known warm-hearted fish.”

“It’s hard to stay warm when you’re surrounded by cold water, but the opah has figured it out.” – Study author Nicholas Wegner, in NOAA Fisheries news release

Wegner realized the opah was unusual when a coauthor of the study, biologist Owyn Snodgrass, collected a sample of its gill tissue. Wegner recognized an unusual design: Blood vessels that carry warm blood into the fish’s gills wind around those carrying cold blood back to the body core after absorbing oxygen from water. – NOAA Fisheries news release

The opah is a large and colorful fish, weighing more than 100 pounds and resembling a fat car tire. It’s odd appearance may have added to the newsworthiness of the discovery of its warm-blooded nature. Not to mention that the opah, or moonfish, is camera-shy, unexpectedly fast in the water, and delectable raw or cooked!

“If you get in the way of their fins, they’ll smack you. They’re pretty feisty.” – Owyn Snodgrass, quoted in National Geographic article.

IFLScience also featured the discovery, “Revealed: First Warm-Blooded Fish (And We’ve Been Eating It For Years).”

This discovery is surprising since the opah is large and conspicuous; indeed, it’s already a favourite in fish markets and restaurants. Wegner and his colleagues deserve great credit for recognising and describing in detail the specialised gill heat exchangers that have been hidden right under the noses of fishermen and chefs for centuries. – Imants Priede, IFLScience!

The discovery was also featured in several well-known science blogs, including Nothing in Biology Makes Sense, Southern Fried Science, io9 and Not Exactly Rocket Science.

Realizing that opah’s are warm-blooded completely changes the way sceintist view life history strategies of this unique fish.  Once thought of as slow, ungainly predators, in reality opah’s are swift, actively chasing down and feasting on agile deep ocean prey like squid. – Kersey Sturdivant, Southern Fried Science


Elevated temperature in the eye and brain of the opah allow for enhanced vision. Image Credit: NOAA Fisheries, Southwest Fisheries Science Center

Most fish have body temperatures that match the surrounding water. A small number of them can warm specific parts of their bodies. Swordfish, marlins, and sailfish, can temporarily heat their eyes and brains, sharpening their vision when pursuing prey. Tuna and some sharks, including the mako and great white, can do the same with their swimming muscles, going into turbo mode when they need to. But none of these animals can heat their entire bodies. Their hearts and other vital organs stay at ambient temperature, so while they can hunt in deep, cold waters, they must regularly return to the surface to warm their innards. The opah has no such problem. It can consistently keep its entire body around 5 degrees Celsius warmer than its environment. It doesn’t burn as hot as a bird or mammal, but it certainly outperforms its other relatives. – Ed Yong, Not Exactly Rocket Science

For more information about the opah, see this Science video.

Paper #2. A Jurassic bird-like theropod with bat-like wings: Meet Yi qi

Restoration of the membrane-winged scansoriopterygid Yi (dinosaur). Emily Willoughby, (,

Restoration of the membrane-winged scansoriopterygid Yi (dinosaur). Image Credit: Emily Willoughby.


Our next High Five paper was published in Nature magazine in April 2015. The study, “A bizarre Jurassic maniraptoran theropod with preserved evidence of membranous wings,” documents the discovery of fossils of a small feathered dinosaur with bat-like wings. The Guardian covered the study with the headline “Is it a bird? Is it a bat? Meet Yi qi, the dinosaur that is sort of both.”

Researchers today announced the discovery of a stunning new dinosaur fossil: a glider with wings similar to both birds and bats. It has been named Yi qi (meaning ‘strange wing’) and is a small feathered dinosaur from the Middle Jurassic age fossil beds of China that have yielded a host of important fossils in recent years. Yi qi, like so many other small dinosaurs, is preserved with a full coating of feathers and was a close relative of the lineage that ultimately gave rise to birds. However, what sets this animal apart from numerous other dinosaurian gliders and proto-birds is the composition of its wings. In addition to some unusual feathers that are positioned on the long arms and fingers, there is a truly gigantic bone on each wrist that extends backwards, and between this bone and the fingers is preserved a membrane-like soft tissue that would have given the animal something of a wing, like that of bats. – David Hone, The Guardian

The study certainly grabbed imaginations. Sedeer el-Showk wrote for Nature’s Scitable blog Accumulating Glitches: “It’s wonderful to see this long-lost world grow ever more diverse. I would love to be ten years old again, my head burstingly full of names and pictures of dinosaurs, overflowing with knowledge about their lifestyle. This time, though, it wouldn’t be a drab world of lumbering grey and brown giant reptiles, but one also peopled by their colourful feathered cousins, including a tiny dinosaur with feathers on its head swooping among the gingko trees with bat-like wings.”

The study was also covered by io9, “Scientists Find New Dinosaur With Bat-Like Wings,”, “Weird bat-winged dinosaur may reveal evolution of birds,” and Not Exactly Rocket Science at National Geographic, “Chinese Dinosaur Had Bat-Like Wings and Feathers.”

These wings were mutually exclusive: dinosaur or pterosaur, feathery or leathery. But Yi went for both options! It had membrane wings with a feathery covering on the leading edge. It shows that at least some dinosaurs had independently evolved the same kind of wings as pterosaurs—an extraordinary example of convergent evolution. “This is refreshingly weird,” says Daniel Ksepka from the Bruce Museum, who was not involved in the study. “Paleontologists will be thinking about Yi qi for a long time, and we can surely expect some interesting research into the structure and function of the wing.” – Ed Yong, Not Exactly Rocket Science

Yi means “wing” and qi means “strange” in Mandarin. So Yi qi is the “strange winged” dinosaur. – Wonderful Scientific Names, Part 4: Yi qi, by Stephen Heard


Paper #3. 3.3-million-year-old Stone Tools Found in Kenya – Re-writing Textbooks


From Stony Brook Press Release


Our third High Five paper, “3.3-million-year-old stone tools from Lomekwi 3, West Turkana, Kenya,” was published in Nature this month. The study, covered by at least 53 news outlets and 9 blogs, describes the discovery of stone tools in Kenya that predate the previously earliest known stone tool archaeological site by 700,000 years. That’s enough to attract quite a bit of attention.

Human evolutionary scholars have long supposed that the earliest stone tools were made by the genus Homo and that this technological development was directly linked to climate change and the spread of savannah grasslands. New fieldwork in West Turkana, Kenya, has identified evidence of much earlier hominin technological behaviour. We report the discovery of Lomekwi 3, a 3.3-million-year-old archaeological site where in situ stone artefacts occur in spatiotemporal association with Pliocene hominin fossils in a wooded palaeoenvironment. – S. Harmand et al. 2015

Scientists have long considered members of genus Homo to be the originators of complex stone tool manufacture and use. But a newly reported find is forcing a reconsideration of human history. Researchers working in Kenya have found 3.3-million-year-old stone cores and flakes, which indicate the manufacture of tools and are about 700,000 years older than the artifacts previously considered the oldest stone implements. – Bob Grant, The Scientist

I can’t help but think of the classic bone tool-wielding scene in “2001: A Space Odyssey.” Now the species wielding the first tool in that scene may no longer be thought of as an early Homo, but rather an older species of ancient apes, the likes of the famous Lucy fossil. According to Hannah Devlin writing for The Guardian, the finding “overturns idea that tool-making ability was unique to our own ancestors and is hailed as a ‘new beginning to the known archaeological record.’

The Homo genus, from which modern humans descend, only emerged around 2.5 million years ago, when forests gave way to open grassland environments in Africa. Until now, it was widely assumed that environmental changes around this time triggered the shift towards a bipedal hunter-gatherer life style. Jason Lewis, of Stony Brook University in New York and a co-author, said: “The idea was that our lineage alone took the cognitive leap of hitting stones together to strike off sharp flakes and that this was the foundation of our evolutionary success. This discovery challenges the idea that the main characters that make us human, such as making stone tools, eating more meat, maybe using language, all evolved at once in a punctuated way, near the origins of the genus Homo.”

The question of what, or whom, might have made the tools remains a mystery, but fossils from around the same period found at the site provide some clues. The skull of a 3.3-million-year-old hominin, Kenyanthropus platytops, was found in 1999 about a kilometre from the tool site and a skull fragment and tooth from the same species were found just a few hundred metres away. – Hannah Devlin, The Guardian

More reading on this study:

World’s Oldest Stone Tools Predate Humans, By Carl Engelking

As they dug deeper, they found a series of sharp stone flakes that bore the telltale marks of intentional engineering. In all, they uncovered 20 well-preserved flakes, cores, anvils — used as a base to shape stones — and an additional 130 other tools. To make these tools, hominins would have needed a strong grip and good motor control, scientists said, providing potential insights into the physical capabilities of human ancestors. – Carl Engelking

Chipping Away At The Mystery Of The Oldest Tools Ever Found, NPR

Stone Tools From Kenya Are Oldest Yet Discovered, John Noble Wilford, New York Times

Our Ancestors Made These Tools 3.3 Million Years Ago, by Gregory Filiano at Stony Brook

Watch: Stony Brook Team Finds Earliest Stone Tools


Paper #4. A Vegetarian (really!) relative of T. Rex.

Image: Skeleton reconstruction of Chilesaurus. Image Credit: Jaime A. Headden

Image: Skeleton reconstruction of Chilesaurus. Image Credit: Jaime A. Headden


The next High Five paper continues the “old and odd discoveries” theme for this month. The study, “An enigmatic plant-eating theropod from the Late Jurassic period of Chile,” was published online in Nature in late April. It’s not hard to see why this study was covered by over 55 news outlets and 9 blogs. NewScientist magazine headlined “Freakiest dinosaur ever found is a vegetarian relative of T. rex.”

Meet T. rex‘s bizarre vegetarian relative. Chilesaurus diegosaurezi was discovered in southern Chile where it lived around 150 million years ago. It looks like a mosaic of several other dinosaurs. It had a tiny head, a 3-metre-long body and small arms like T.rex – but with blunt fingers instead of raptorial claws. And unlike T. rex, it had broad hind feet more like those of Diplodocus, while its pelvic girdle tipped back like that of Triceratops. “This dinosaur was a plant-eater, based on its teeth and jaws, but the rest of the skeleton looks like a strange chimera of various meat- and plant-eating dinosaurs,” says Darla Zelenitsky, a dinosaur palaeontologist at the University of Calgary in Alberta, Canada. – Andy Coghlan, NewScientist

“It really is a very strange and exciting combination of features. If I hadn’t seen an articulated [assembled] specimen, I’d have found it hard to believe.” – National Geographic Explorer Paul Sereno of the University of Chicago, T. rex’s Oddball Vegetarian Cousin Discovered

The evolution of herbivores like Chilesaurus diegosaurezi from meat-eating ancestors is uncommon but not unprecedented. Daniel Culpan writes in, “today’s placid, plant-munching pandas actually evolved from carnivorous ancestors related to the grizzly bear.

More reading:

‘Frankenstein’ dinosaur was a mash-up of meat eater and plant eater, by Ashley Yeager, Science News


Paper #5. Your Facebook Filter Bubble MAY Be Your Own Fault, Facebook Says

Facebook is often criticized of creating echo chambers. Hamilton Mausoleum has a spectacularly long lasting unplanned echo. Image Credit: I, Supergolden. Licensed under CC BY-SA 3.0 via Wikimedia Commons.

Facebook is often criticized of creating echo chambers. Hamilton Mausoleum has a spectacularly long lasting unplanned echo. Image Credit: I, Supergolden. Licensed under CC BY-SA 3.0 via Wikimedia Commons.


Our final High Five paper veers from the “odd discovery” theme of our first four. The study, “Exposure to ideologically diverse news and opinion on Facebook,” was published in Science magazine this month and received some controversial coverage online.

The study, conducted by three researchers with affiliations with Facebook, examined how 10.1 million U.S. Facebook users interact with socially shared news. The researchers measured the extent to which Facebook friends expose each other and others to ideologically cross-cutting content, for example news slanted in the opposite direction of one’s own political affiliation. The researchers “then quantified the extent to which individuals encounter comparatively more or less diverse content while interacting via Facebook’s algorithmically ranked News Feed, and further studied users’ choices to click through to ideologically discordant content,” (Bakshy, Messing and Adamic, 2015).

What did the researchers find as a result of this study? “Compared to algorithmic ranking, individuals’ choices about what to consume had a stronger effect limiting exposure to cross-cutting content,” (Bakshy, Messing and Adamic, 2015). In other words, the “filter bubble” or “echo chamber” effect of Facebook is not (all) Facebook’s fault, according to this study.

If the results of the 2015 General Election did not reflect the conversation on your News Feed, Facebook wants you to know it’s mostly your fault — not theirs. The social network reports in a study published in Science that the choices a user makes about who they follow has a greater impact on the political tone of their news feed than its own content algorithms. – Michael Rundle,

Stand back, Facebook conspiracy theorists: according to the study, we can’t blame algorithms for our newsfeeds’ tendency to turn up yet more baby pictures or Rand Paul political ads. Instead, our likelihood of encountering content shared by people with opposing points of view depends more on the political views of our friends and what links we’re most likely to click. – Andrew Freedman, Mashable

For those who aren’t aware, Facebook’s news feed does not show you every post from your friends (which is what I have always like about Twitter – it generally shows you most posts from those you follow). Rather, Facebook generates a selection of posts to insert into your news feed based on an algorithm that “guesses” what it thinks you will like most, based on your previous activity on the site. The algorithmic decision of what goes onto your news feed has been a source of concern for some, who suggest that Facebook generates a “filter bubble” or “echo chamber” effect by limiting the news and updates you could potentially be exposed to.

“Of algorithms are going to curate the world for us, then… we need to make sure that they also show us things that are uncomfortable or challenging or important.” – Eli Pariser

But according to Eytan Bakshy, Solomon Messing and Lada Adamic, it is Facebook users themselves, to the same or greater extent than Facebook’s news feed algorithm, that are limiting their own exposure to politically or otherwise cross-cutting content.

The authors found that Facebook’s algorithm had a modest effect on the kind of content people saw, filtering out 5 per cent of news that conflicts with conservative views and 8 per cent for liberals. However, they found that self-screening had a much bigger effect. People showed a clear preference for stories that fit their own world view: liberals clicked on only 7 per cent of conflicting content, while conservatives clicked on 17 per cent. The authors conclude that individual choices, more than algorithms, limit exposure to diverse content. Or, as Christian Sandvig, an internet policy researcher at Harvard University, put it in a blog post yesterday: “It’s not our fault.” – Aviva Rutkin, NewScientist

The Facebook researchers’ findings have not been immune to scrutiny, however. Many have criticized the peer-reviewed Science study over the last few weeks, citing importantly a lack of representativeness of the Facebook users examined in the study. Aviva Rutkin also writes about several criticisms of the study. Zeynep Tufekci, a professor at the University of North Carolina, Chapel Hill, writing on Medium, responded to the study thus:

[C]onfusingly, the researchers compare whether algorithm suppression effect size is stronger than people choosing what to click, and have a lot of language that leads Christian Sandvig to call this the “it’s not our fault” study. I cannot remember a worse apples to oranges comparison I’ve seen recently, especially since these two dynamics, algorithmic suppression and individual choice, have cumulative effects. Comparing the individual choice to algorithmic suppression is like asking about the amount of trans fatty acids in french fries, a newly-added ingredient to the menu, and being told that hamburgers, which have long been on the menu, also have trans-fatty acids — an undisputed, scientifically uncontested and non-controversial fact. – How Facebook’s Algorithm Suppresses Content Diversity (Modestly) and How the Newsfeed Rules Your Clicks

Eli Pariser, author of The Filter Bubble: How the New Personalized Web Is Changing What We Read and How We Think, also responded to the study on

Yes, using Facebook means you’ll tend to see significantly more news that’s popular among people who share your political beliefs. And there is a real and scientifically significant “filter bubble effect” — the Facebook news feed algorithm in particular will tend to amplify news that your political compadres favor. This effect is smaller than you might think (and smaller than I’d have guessed.) On average, you’re about 6% less likely to see content that the other political side favors. Who you’re friends with matters a good deal more than the algorithm. But it’s also not insignificant.

In its press outreach, Facebook has emphasized that “individual choice” matters more than algorithms do — that people’s friend groups and actions to shield themselves from content they don’t agree with are the main culprits in any bubbling that’s going on. I think that’s an overstatement. Certainly, who your friends are matters a lot in social media. But the fact that the algorithm’s narrowing effect is nearly as strong as our own avoidance of views we disagree with suggests that it’s actually a pretty big deal. – Eli Pariser

More reading:

On Facebook, you control the slant of the news you choose, by Bruce Bower, Science News

Don’t (just) blame Facebook: We build our own bubbles, by Scott Johnson, ArsTechnica

Surprise: Facebook Says that Facebook A-Okay for News! By John M. Grohol, PsychCentral

The Problems With Facebook’s Polarization Study, by Annie Lowrey, ScienceOfUs

[D]espite the buzz this study is getting, we still don’t have a very good sense of how Facebook and other social-media services might or might not contribute to polarization. – Annie Lowrey


That’s it for this month! What did you think of these top five scientific studies? Come back next month for more!

19 Responses to “May High Five – A Warm-Blooded Fish and Other Odd Discoveries”

InvestigaUNED (@InvestigaUNED)
May 29, 2015 at 12:00 am

May High Five – A Warm-Blooded Fish and Other Odd Discoveries

Altmetric (@altmetric)
May 29, 2015 at 12:00 am

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May 29, 2015 at 12:00 am

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Dr. Paige Jarreau (@FromTheLabBench)
May 29, 2015 at 12:00 am

Which scientific papers got most attention online last month? May High 5: Warm-blooded fish and other odd discoveries

Jean Peccoud (@peccoud)
May 30, 2015 at 12:00 am

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May 30, 2015 at 12:00 am

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May 30, 2015 at 12:00 am

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May 31, 2015 at 12:00 am

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May 31, 2015 at 12:00 am

May High Five – A Warm-Blooded Fish and Other Odd Discoveries

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Digital Science (@digitalsci)
May 31, 2015 at 12:00 am

.@FromTheLabBench takes a look at odd discoveries in this month's @altmetric High Five!

Digital Science (@digitalsci)
June 1, 2015 at 12:00 am

In the latest @altmetric High Five @FromTheLabBench explores some very odd discoveries #altmetrics

Adrian Stanley (@AdrianStanley13)
June 1, 2015 at 12:00 am

Some interesting papers & attention to articles in Altmetric's May high-five

June 2, 2015 at 12:00 am

Top 5 articles in May with highest #altmetric scores: warm blooded fish, dinosaurs, stone tools & filter bubbles.

Digital Science (@digitalsci)
June 3, 2015 at 12:00 am

Discover odd discoveries in @altmetric's latest High Five: #altmetrics

Jonathan Hernández (@jbilbob)
June 4, 2015 at 12:00 am

May High Five – A Warm-Blooded Fish and Other Odd Discoveries -

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June 5, 2015 at 12:00 am

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Digital Science (@digitalsci)
June 6, 2015 at 12:00 am

Some intriguing discoveries in @altmetric's latest High Five - check it out: #altmetrics

Digital Science (@digitalsci)
June 7, 2015 at 12:00 am

Interesting discoveries in @altmetric's latest High Five - check it out: #altmetrics

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