Microbes at Red Sea vents show how life and geology shape each other

Study is first to report unusual life since discovery of the vents

King Abdullah University of Science & Technology (KAUST)

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A scanning electron microscopy image of microbe samples taken from the vents.

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Credit: Sharifah Altalhi

A new study led by King Abdullah University of Science and Technology (KAUST; Saudi Arabia) Professor Alexandre Rosado has revealed an unusual microbial world in the Hatiba Mons hydrothermal vent fields of the central Red Sea, a site first discovered by one of his co-authors and colleagues, Assistant Professor Froukje M. van der Zwan. To show this, the study delivers the first "genome-resolved" analysis of these hydrothermal systems, providing an unprecedented view into both the types of microbes present and the metabolic functions that sustain them. 

“Microbes from the Hatiba Mons fields show remarkable metabolic versatility,” said KAUST Ph.D. student and lead author of the study, Sharifah Altalhi. “By understanding their functions, we can see how life shapes its environment, and how geology and biology are deeply intertwined in the Red Sea.” 

The Hatiba Mons fields were first documented in 2023 by a KAUST–GEOMAR collaborative expedition, which uncovered low-temperature venting zones and towering iron-oxide mounds between 778 and 1,450 meters deep. These microbial iron mounds mark the largest known active low-temperature iron-oxyhydroxide vent system in the world. 

Building on that discovery, the new study used genome-resolved metagenomics to reconstruct more than 300 microbial genomes from five vent sites across the Hatiba Mons complex, capturing an ecosystem unlike any other known vent field. 

Unlike traditional genetic surveys that only reveal which microbes are present, genome-resolved analysis further enables scientists to determine how these microbes function to survive and contribute to their environment. 

The research team identified 314 microbial genomes, representing both bacteria and archaea, many of which were previously unknown to science. The analysis revealed an unexpected ecosystem dominated by microbes capable of iron, sulfur, nitrogen, and carbon cycling. These functions drive the chemical transformations that shape the vent environment and sustain microbial life under extreme conditions. 

 “What makes this site truly exceptional is the predominance of iron-driven metabolisms, a striking departure from the sulfur- and methane-based systems found in most hydrothermal vents. This unique metabolic landscape makes the Red Sea’s Hatiba vent a natural laboratory for studying life under extreme conditions and offers new insight into the microbial processes that sustain ocean resilience and global carbon cycling,” said Rosado. 

The microbes discovered in Hatiba Mons perform biogeochemical processes that are fundamental to the Earth’s systems. Their ability to oxidize and reduce iron, fix carbon, and metabolize sulfur and nitrogen connects microbial activity to the planet’s chemical and mineral cycles. 

Understanding these metabolic networks can inform biotechnological applications such as metal recovery, bioenergy generation, and environmental remediation. Moreover, studying how microbes thrive in this high-salinity, high-temperature environment provides clues about how life evolved on early Earth and how it might exist in similar conditions elsewhere in the solar system. 

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Journal

Environmental Microbiome

DOI

10.1186/s40793-025-00784-5 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Decoding microbial diversity, biogeochemical functions, and interaction potentials in red sea hydrothermal vents

 

No tricks, only treats: Bats glow under ultraviolet light

University of Georgia

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This is the first discovery of such a phenomenon for bats located in North America. The tricky thing now, the researchers said, is figuring out why. 

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Credit: Andrea Piazza

It may sound batty, but University of Georgia researchers have confirmed that North American bats glow under ultraviolet light.

The new study from the UGA Warnell School of Forestry and Natural Resources found that six different species emit a greenish light when exposed to UV rays.

This is the first discovery of such a phenomenon for bats located in this part of the world. The tricky thing now, the researchers said, is figuring out why.

“It may not seem like this has a whole lot of consequence, but we’re trying to understand why these animals glow,” said Steven Castleberry, corresponding author of the study and a professor in wildlife ecology and management. “It’s cool, but we don’t know why it happens. What is the evolutionary or adaptive function? Does it actually serve a function for the bats?”

Shining a new light on bats, literally

Previous research from UGA has revealed that some mammals, like pocket gophers, also emit a glow under ultraviolet light.

The present study found the trait is also found in big brown bats, eastern red bats, Seminole bats, southeastern myotis, gray bats and Brazilian free-tailed bats.

“Bats have very unique social ecology and sensory systems, and the characteristics we found in these species differs from many other observations in nocturnal mammals,” said Briana Roberson, lead author of the study and UGA alumna. “It’s possible for glowing functions to be more diverse than we previously thought.”

"It’s cool, but we don’t know why it happens. Does (glowing) actually serve a function for the bats?”

—Steven Castleberry, Warnell School of Forestry and Natural Resources

The researchers examined 60 specimens from the Georgia Museum of Natural History under UV lighting and found that their wings and hind limbs give off photoluminescence. With a light measurement tool, the researchers determined the glow was a shade of green.

The color and location of the glow suggest that this is a genetic characteristic, not something related to the environment the bats inhabit.

“It’s ultimately some sort of mutation, and then that mutation somehow gets perpetuated usually because it’s beneficial. Individuals that have that trait tend to survive and reproduce better, so it gets more common in the population. There is evidence that glowing is a common trait,” Castleberry said.

Further research needed to understand mysterious glow

How the glow benefits the bats — or the other mammals — is still unknown.

Researchers found the color was the same between sexes and among the species, suggesting that it is not for sex or species recognition. It also did not appear to be used as camouflage or to attract mates.

Instead, because many bats can see the wavelengths emitted, they think the glow may be an inherited trait used for communication.

“The data suggests that all these species of bats got it from a common ancestor. They didn’t come about this independently,” Castleberry said. “It may be an artifact now, since maybe glowing served a function somewhere in the evolutionary past, and it doesn’t anymore.”

Revealing the evolutionary drivers of species traits could be critical to understanding how bats have adapted in the past and how they can adapt to future environmental changes.

“While it’s still unknown whether photoluminescence may serve an explicit ecological purpose, additional information on adaptive advantages it may provide could be valuable for further understanding bat behavior and ecology,” Roberson said.

This study was co-authored by UGA alumnus Santiago Perea and Warnell graduate student Daniel DeRose-Broecker.

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Journal

Ecology and Evolution

DOI

10.1002/ece3.71885 

Article Title

Glowing Green: A Quantitative Analysis of Photoluminescence in Six North American Bat Species

 

Big claws, big costs: Trade-offs in crayfish signaling

University of Chicago Press Journals

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A new study from researchers at The University of Queensland has revealed that the impressive claws (chelae) of freshwater crayfish come with certain costs: The size slows their swimming and saps energy. The findings, published in the article, "Honesty is costly in a deceptive system: locomotor costs of producing large and strong weapons for the crayfish, Cherax destructor," shed light on the evolutionary trade-offs of animal signaling, particularly how "unreliable signals" of strength can persist in nature. The article will appear in an upcoming issue of Ecological and Evolutionary Physiology.

"Our study is the first to demonstrate the independent costs of both signal size and their reliability," write authors Lana A. Waller, Simon P. Lailvaux, and Robbie S. Wilson. "While individuals must bear the costs of signaling large weapons, the costs of their reliability may also incentivize the use of unreliable weapons."

Animals often use physical traits to signal fighting ability and deter costly battles. In crustaceans, large claws serve as both weapons and displays of strength. However, some individuals display large but relatively weak claws—creating a mismatch between signal size and actual strength.

The research team studied 145 male and female Cherax destructor Australian freshwater crayfish, measuring their claw size, claw strength, and swimming performance. Crayfish were tested intact, after removal of one or both claws, and again after complete removal of all claws. 

The study provides evidence that both the magnitude and reliability of animal signals are independently costly. Both sexes with larger chelae swam more slowly, suggesting an energetic trade-off between claw muscle investment and locomotion. Removal of one claw boosted speed by 11.6%, while removal of both claws improved speed by 14.6%. Crayfish with disproportionately large claws gained the greatest boost in speed once claws were removed—highlighting the physical burden of carrying oversized weapons. 

"While crayfish will benefit from producing larger chelae as they can intimidate opponents during disputes with conspecifics, large chelae can have costly consequences," the authors write. "Therefore, the display of these weapons provides information to a receiver on both the probability of their strength – albeit with variance – and their ability to survive with the additional locomotor burden of their larger weapons."

The paper highlights the trade-offs animals face when allocating resources to growth, strength, and survival. "Male C. destructor more frequently escalate to fights, which should directly limit the benefits accrued to males who signal unreliably," the authors write. However, the findings suggest that males who were weaker for their size, and thus possess unreliable signals of strength, were faster when both chelae were intact. "Therefore, this benefit could also provide an important incentive for unreliability in male C. destructor, despite the higher likelihood of combat."

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Ecological and Evolutionary Physiology primarily publishes original research examining fundamental questions about how the ecological environment and/or evolutionary history interact with physiological function, as well as the ways physiology may constrain behavior. For EEP, physiology denotes the study of function in the broadest sense, across levels of organization from molecules to morphology to organismal performance and on behavior and life history traits.

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Journal

Ecological and Evolutionary Physiology

DOI

10.1086/738377 

Article Title

Honesty is Costly in a Deceptive System: Locomotor Costs of Producing Large and Strong Weapons for the Crayfish, Cherax Destructor

COACHING IS ABUSE

Study uses GPS technology to find football practices can be up to 40% more demanding than games

Wearable tech found workloads by position, can help coaches, trainers design optimal prep for athletes

University of Kansas

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LAWRENCE — Until recently, there has been little data available on how much effort football players exert in games versus practices, which position groups run the most or how to balance loads in practice to best meet the needs of game day. New research from the University of Kansas is using global positioning system technology to provide those answers to coaches and trainers.

In research conducted with the football team at Division II University of Nebraska-Kearney, KU researchers found practices could be 20% to 40% more physically demanding than games, defensive backs tended to run farther distances than other position groups and that practices declined in intensity the closer they were to game day. But using technology to measure training loads and indicating how to use the data to improve performance may be the biggest contribution of the research.

“Quantifying these training loads is ultimately the first step. We have this technology in the football space, but there is room to determine how we use it,” said Quincy Johnson, assistant professor of health, sport & exercise science and assistant director of the Jayhawk Athletic Performance Laboratory, who led the study. “It’s now getting to the point where we can action the insights.”

The research team used GPS technology that placed a chip in mesh vests worn between the players' shoulder blades. The chips are connected to satellites to provide accurate information on physical activity. For the study, researchers gathered data on total duration, total distance covered, yards per minute, hard running distance and hard running efforts. 

Data was gathered from 27 players over 32 total practices and 11 games over the course of a season. Players were measured by position groups, including line, big skill (including linebackers, quarterbacks and tight ends) and skill (such as wide receivers and defensive backs).

Results showed there were significant differences in the three position groups in terms of total distance, yards per minute, hard running distance and hard running efforts, but there were not significant differences in total duration. For each position group, training load in practices was significantly higher than it was during games. For linemen, practices were as much as a 22% higher training load, while big skill and skill were as much as 28% and 24% higher, respectively.

The study measured efforts for 14 starters and 13 nonstarters and found starters had significantly higher measures of yards per minute, but nonstarters had significantly higher measures of hard running distance and hard running efforts. The researchers also noted that five of the players went on to play professionally. Their data showed higher training load in several measures. 

Essentially, Johnson said, the data showed those players had the capacity to do more work in the same amount of time as their teammates. Such data could potentially be used by athletic staff to identify talent or continue developing talented athletes, he added.

The study, co-written with Yang Yang, Dimitrije Cabarkapa, Madi Rink and Andrew Fry of KU; and Dayton Sealey and Clay Freels, Shane Stock and Dalton Gleason of the University of Nebraska-Kearney; was published in the journal Frontiers in Sports and Active Living.

Football, like all sports, has many different schools of thought on how best to prepare players for game competition. One common approach is to have more intense practices early in the week and gradually reduce workload the closer the team gets to game day. The UNK team followed that approach, and the data confirmed that the first practice after a game had a higher training load for all position groups than each subsequent practice, concluding with a low-intensity walk-through the day before a game. The results provide support to the notion that football players need to be able to train harder during practice and exert more effort than they will during game day to maximize performance.

Similar research has been done in soccer for years, but little has been conducted to quantify the training load in football.

“These findings support the notion that training has to be intense and that training loads sometimes need to be higher than they are in a game,” Johnson said. “Football requires more. What we know about managing load and monitoring it usually requires the load to be lower in most sports. We saw on the first and second days of practice it was more intense than the game, but by the third it tended to get lower.”

The Jayhawk Athletic Performance Laboratory, part of the Wu Tsai Alliance on Human Performance, is continuing GPS monitoring of athlete training loads and is now partnering with the KU football team. Having athletes at the highest level of the game will enable researchers to continue collecting data on training load and help coaches, trainers and athletic staff design more effective practice schedules. That in turn can not only help maximize performance on game day but also shed further light on timelines for returning from injury and potentially provide a competitive edge to teams that know how to interpret the data, Johnson said.

“With this data we can know and work toward better understanding, the best way to preparing athletes,” Johnson said. “This will help add to that understanding of preparation by position group and not just the performance piece, but better understanding injury risk, how to return from it and be ready for those situations.”

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Journal

Frontiers in Sports and Active Living

DOI

10.3389/fspor.2025.1662240 

Method of Research

Data/statistical analysis

Subject of Research

People

Article Title

Periodization for success—in-season external training loads relative to competition load in American football