Rattlesnake venom is a complex blend of necrotic toxins designed to quickly disrupt blood coagulation and destroy tissue cells. This effective biological weapon comes at a major premium, however. Snakes must regularly replenish their venom reserves, which means they need to dole out just the right amount with each bite. Injecting too little venom into prey may allow their next meal to escape, while delivering too much can leave a rattlesnake defenseless against its own predators.

But that doesn’t mean rattlesnakes adhere to a one-bite-fits-all policy. According to researchers at California’s Loma Linda University, the amount of venom routinely varies by individual reptile. Their recent findings published in Frontiers in Ethology indicate these dosage ranges aren’t randomly distributed, and that snakes and their venom are much more complicated than many people realize.

“This study gives us a better understanding that reptiles, such as rattlesnakes, are behaviorally complex and have personalities like humans do,” explained Loma Linda University biologist and study co-author Chelsea Martin.

Martin and her colleague, William Hayes, focused on the preferences of the Pacific rattlesnake (Crotalus oreganus helleri). On three occasions over a four-week window, the team offered 48 snakes the chance to sink their fangs into a membrane-covered beaker. Previous experiments mainly focused on the frequency of bites, but Martin and Hayes also measured the amount of injected venom in each instance. They then compared the data across snakes.

“The results were striking in their consistency,” the study’s authors wrote in an accompanying Phys.org rundown.

The team also reported measured behaviors like aggressiveness, bite willingness, and the amount of venom amount were statistically significant and repeatable across many of the snakes. Additionally, their study further debunks the lingering myth that larger snakes actually produce less venom.

“Larger snakes expended more venom than smaller snakes, as expected given their greater capacity for venom storage,” explained the biologists, while noting that actual delivered levels still occasionally varied regardless of size.

The study’s authors emphasize that their findings shouldn’t be held against the rattlesnakes themselves. While often feared, the snakes generally do everything they can to avoid confrontations with larger animals like humans. Bites are almost always the result of an unintentional encounter in the wild rather than an overly aggressive serpent. If anything, it’s people who aren’t paying attention to their surroundings, and not the other way around.

“One practical lesson remains unchanged: No rattlesnake should be approached or handled on the assumption that it will behave predictably,” the authors said. “Consistent individual differences do not make any particular snake safe.”

The post Rattlesnake bite venom is based on their personality appeared first on Popular Science.

Our fingerprints, patterns on whale flukes, and fur patterns on cheetahs are examples of the natural ways we can tell one individual animal from another. For an Amazonian treefrog called the egg-eating spiny-backed frog (Osteocephalus oophagus), we need to look into their eyeballs. Fine black radial lines cross their golden irises, and form a pattern similar to our fingerprints. A study recently published in the journal Herpetozoa details the discovery.

The project began with study co-author Mélissa Peignier, a behavioral ecologist at the University of Bern in Switzerland, admiring frog eyes. 

“At the time, I was doing my PhD, studying Allobates femoralis in the field in French Guiana,” Peignier said in a statement. “My first reaction was simply something along the lines of, ‘Wow, what beautiful eyes!’ That initial curiosity gradually turned into a genuine interest in the species, and I realised how little we actually know about them.”

There was also an ethical component. One of the standard ways to tell amphibians apart from one another is toe-clipping, where a section or all of a single toe is removed. This procedure can affect their survival, physiology, and behavior. 

“Other studies have used toe-clipping, which involves removing some of the digits. Personally, I was uncomfortable with this approach, especially given that these are arboreal frogs that rely on their limbs to climb trees.”

Looking for other markings could offer a more humane solution and a way to observe the animals natural behavior unimpeded.

For this study, fieldwork took place over three rainy seasons (2021 to 2023) on a river island in the Nouragues Nature Reserve in French Guiana. They identified 103 individual frogs over the course of the study.

During their later encounters, the team took pictures of each animal’s eyes without touching it and then compared the images with a reference library. This way, the recognised frogs were left undisturbed and their eyes appeared in their more natural state. The identifications were then independently verified using Wild-ID, a software package that analyzes photographic markings in animals.

They found highly distinctive iris patterns. Within one season, between 56 and 80 percent of the frogs were recaptured and reliably re-identified. According to the team, this indicates that the patterns on their eyes remain stable enough to monitor the frog in the short-term. Photographs could even be taken of frogs while in their mating embrace (called amplexus) without disrupting them. The team hopes that this method will spread. 

“In a world where biodiversity is declining at an alarming rate, it is essential that we minimise our impact on the animals we study,” added Peignier. “If we can reliably identify individuals using naturally occurring features, we may be able to reduce the need for more invasive marking techniques while still collecting the data needed to answer important scientific questions.”

While the reliability of the eye markings will vary between species, and should be done case by case, the team sees considerable promise for amphibians with complex irises. And working with them offers its own benefits. 

“Honestly, the frogs themselves are incredibly beautiful and surprisingly chill, which makes working with them a real pleasure,” Peignier said. 

The post Treefrog ‘fingerprints’ are on their eyeballs appeared first on Popular Science.

Before giant manta rays (Mobula birostris) can grow to up to 30 feet long and 4,409 pounds, they must start small like most living things. Giant manta ray babies (called pups) in Central America don’t have their size to protect them from orca whales (Orcinus orca) and the numerous sharks in the open ocean. Their solution—sticking to the coast, where there is plenty of food to help them grow and defend themselves. A new study published today in the journal Frontiers in Fish Science details the baby rays’ behavior. 

“We show that manta rays’ lifestyle isn’t a one-size-fits-all behavior. Giant manta rays in Central America undergo a dramatic shift in space use as they mature,” Jeffry Madrigal-Mesén, a study co-author and project leader of Mantas Costa Rica, said in a statement. “Juveniles remained strictly within shallow nearshore waters that serve as coastal refuges, but most of the tracked adults executed long-distance transboundary migrations along the continental shelf break into Central America.”

Where the pups grow

In the study, the team used multiple methods to track and identify mantas at five locations between 2018 and 2025. Acoustic telemetry uses underwater sound pulses to monitor fish movements and allowed the team to track 59 individual rays. With satellite telemetry, transmitters track movement and behavior from a distance and helped the team track large-scale movements of 12 individuals. Lastly, photo identification helped to identify individual manta rays.

“If we hadn’t used all three technologies together, we simply wouldn’t have been able to piece this puzzle together,” explained Madrigal-Mesén. “Combining these tools turned fragmented data into a unified, undeniable story.”

The team ended up with a dataset of over 12,000 detections. The data showed that young mantas (those with a body about 10 feet or less) stick to shallow coastal refuges. In these more shallow spots, the pups have a safe place that doesn’t overlap with their predators’ hunting grounds. They have plenty of food and places to hide, and even get essential services like cleaning from reefs.

“Mature adults can rely on their massive body size and their ability to dive deep to evade threats. But juveniles don’t have that luxury,” said Madrigal-Mesén. “What is truly amazing is seeing how strictly young manta rays stick to coastal waters as long-term refuges. We see the same individuals more often than once a year. In fact, just recently, they were sighted again at the exact same tagging location. It is always a joy to see them again—they have truly become a part of the family.”

By comparison, nine mature mantas in the study went on expansive migrations along the continental shelf break. One manta ray nicknamed Mickey Mouse because of a spot pattern on his belly had movements that suggest the fish also continue to display loyalty to a particular site once they grow up. Unusually approachable for a manta, Mickey Mouse allowed the team tag him multiple times over several years, which provided a continuous dataset. In 2020, he logged 462 acoustic detections at a coastal hub called El Secreto. He returned to the same shelf in 2023, and stayed there for 38 days.

“Nearshore cleaning stations transcend basic hygienic function; they act as primary social hubs where courtship and reproductive interactions take place,” said Madrigal-Mesén. “Returning to a predictable coastal depot allows mature rays to prioritize social and cleaning needs before undertaking large-scale regional migrations.”

Traveling the manta swimway—safely

Once they leave coastal regions, adult manta rays face different dangers. Coastal areas are often legally protected marine reserves, but the open ocean is another story. They no longer have legal protection and are exposed to dangers from industrial fisheries and vessel strikes.

According to the team, this shows that marine protected areas alone are not enough to protect this highly mobile species as it swims across Central America. They say that multi-national “conservation swimways”  that link the domestic juvenile coastal refuges with adult migratory corridors could help keep the endangered rays safe. 

“This study opens a new chapter for manta ray research in Central America,” Madrigal-Mesén concluded. “We hope it sparks fresh enthusiasm and encourages future collaborators to join us in executing the new ideas and research projects we have planned for the conservation of this species.”

The post Baby manta rays stick to the shallows to avoid sharks and orca appeared first on Popular Science.

Most plants do not gather nutrients from the soil entirely on their own. Many form partnerships with microscopic fungi that grow inside their roots and extend into the surrounding soil. These partnerships, known as arbuscular mycorrhizal symbioses, help plants access nutrients, especially phosphorus. In return, the fungi receive carbon-rich compounds from the plants. But how does a plant coordinate the many signals needed to build and maintain this exchange?

Women surveyed about their treatment for hyperemesis gravidarum, a severe form of nausea and vomiting during pregnancy, reported delayed or missed diagnoses, inadequate clinician knowledge of treatment guidelines, denied or discontinued medicines, and structural barriers restricting access to appropriate care. The qualitative study of 189 women, published in the Journal of Pharmacy Practice and Research, found that these experiences accompanied enduring emotional and psychological effects, including anxiety and post-traumatic stress syndrome. Associate Professor Luke Grzeskowiak, who led the research team at Flinders University, said the condition affects almost 4% of pregnancies.

The survey identified several issues affecting how hyperemesis gravidarum is recognised and treated. Participants described clinicians who lacked suitable training to diagnose the condition and who were either unaware of clinical management guidelines or did not follow them. Some women said they were not diagnosed with hyperemesis gravidarum when they should have been, while others reported receiving a diagnosis only late in the course of their illness. Other participants said health professionals denied prescribing or dispensing medications. The researchers also identified educational and financial status as possible influences on treatment outcomes, together with systemic barriers within Australia’s healthcare system.

Misinformation about medicine safety further disrupted care for some participants. Some women said they stopped taking medication after reading reported safety concerns that the researchers said were not aligned with current research and management guidelines. Participants also described poor management of medication side effects, including constipation and mood disorders. Current treatment focuses on supportive care and on medicines, including antiemetics, that address nausea and vomiting. Nevertheless, women reported that their symptoms were often not taken seriously and that clinicians in several professions commonly lacked appropriate education and training to recognise and manage hyperemesis gravidarum.

The study documented emotional and psychological effects during and after the illness. Participants cited impaired quality of life, anxiety and post-traumatic stress syndrome. The researchers said some women reported that hyperemesis gravidarum influenced their decision to terminate an otherwise wanted pregnancy, while others said the trauma of a previous episode left them afraid to consider another pregnancy. Collectively, the researchers proposed improving experiences and outcomes through better education for health practitioners, greater public awareness, clearer clinical practice guidelines, expanded outpatient care, investment in specialist hyperemesis gravidarum clinics and services, changes to the Pharmaceutical Benefits Scheme, and strategies to improve medicine availability and affordability. Because the research was a qualitative survey based on reported experiences and perceptions, it does not quantify how frequently these barriers occur among all pregnancies affected by the condition.

Subject of Research: Women’s experiences of pharmacological care for hyperemesis gravidarum

Article Title: Greater access to help needed for women with nausea during pregnancy

Article References: Greater access to help needed for women with nausea during pregnancy. Original publication (Bibliographic details unavailable.)

Image Credits: AI Generated

DOI: Not provided

Keywords: hyperemesis gravidarum, pregnancy, nausea and vomiting, antiemetic medicines, qualitative survey, clinical guidelines, healthcare access, medication safety, mental health, Greater, access, help

Modelli basati sui fossili indicano che il Platecarpus accelerava più degli altri mosasauri, mentre il Tylosaurus poteva raggiungere circa 24 km/h a scatti.

Bacteria and the viruses that infect them—known as phages—coexist in soils, oceans and living organisms. Scientists have long thought this coexistence reflects a microscopic version of an evolutionary arms race: As parasites and hosts continually adapt to one another, both evolve ways to survive. But a joint study by researchers at the University of Maryland and the University of Exeter shows different pathways to coexistence.

Bacteria and the viruses that infect them—known as phages—coexist in soils, oceans and living organisms. Scientists have long thought this coexistence reflects a microscopic version of an evolutionary arms race: As parasites and hosts continually adapt to one another, both evolve ways to survive. But a joint study by researchers at the University of Maryland and the University of Exeter shows different pathways to coexistence.

A pilot study tested an electronic nose, called NOS.E, alongside human-remains detection dogs to see whether it could detect buried remains and help confirm dogs' signals.

Whenever a cell divides, it has to split its chromosomes perfectly between two daughter cells, and even a single mistake can be disastrous. Now, researchers from Japan have found that one of the key structures that makes this possible takes a surprising shape: a hollow sphere.

On a frigid February morning in Edinburgh, Scotland, Patrick Hickey had run out of living things to put under his microscope. The plants and fungi in his garden had dried up, and summer puddles, with their flamboyant biological complexity, had long frozen over. Hickey, a mycologist at Hypha Research Ltd., was using plant leaves to study mitochondria, cellular organelles that generate energy.

Source

Naturalists thought they'd found a spider killed by a parasitic fungus. Then it moved.

Plastic can fool nature’s cleanup crew, but one bacterial enzyme knows exactly where to bite.

Honeybees pack tens of thousands of nestmates into a small space, a setup that should invite disease.

The post Honeybee Hives are Living Immune Systems, Scientists Say appeared first on Sci.News: Breaking Science News.

Scientists discovered that psilocybin can make one of nature's most aggressive fish surprisingly mellow.

At least in fruit flies

The post How Hunger Can Trigger Alcohol Cravings appeared first on Nautilus.

Certain viruses attack bacteria and can sometimes clear antibiotic-resistant infections. Researchers said they had tailored a virus to attack one patient’s illness.

The ‘love hormone’ oxytocin may rise and fall in tandem in cats and the people who live with them, according to a new study published in the journal iScience.

The post Cat Hormones and Owner Moods Appear to Move Together: Study appeared first on Sci.News: Breaking Science News.

Two new studies follow ocean ingredients into plume ice and test methane production in a laboratory seafloor analogue. Both refine how scientists could search for life.

The post Enceladus May Sort Ocean Chemicals Before They Reach Space appeared first on Curiosmos.

In hot weather, trees “sweat” to cool down by releasing water from their leaves or needles and then replacing it with water from the soil. But during long periods of high temperatures, trees may release more water than they can replace. To strengthen forests against heat stress and other environmental hazards, scientists have suggested adding fungi to the soil. 

Soil fungi living on tree roots are called ectomycorrhizal fungi. They help trees absorb water by expanding their root networks, and trees help the fungi by providing them with sugars for energy. This beneficial partnership is known as symbiosis. Scientists at Fujian Agriculture and Forestry University in China tested whether symbiosis with ectomycorrhizal fungi could help the pine trees Pinus massoniana survive warmer temperatures. 

For their experiment, the researchers grew pine seedlings with and without ectomycorrhizal fungi in a greenhouse under different temperature conditions. First, they grew fungi called Cenococcum geophilum for 45 days on a gel-like substance called agar. At the same time, they grew the pine seedlings for 30 days, then transferred them into pots with natural soil. 

After 15 days in the pots, the researchers spread the gel-like agar containing the fungi over small 1 x 1 centimeter (cm) areas of the pine root tips to introduce the fungi to the seedlings, a process called inoculation. They assumed that the fungal network would expand from the starting area to colonize new root tips as the seedlings grew. The team’s inoculations included 6 different C. geophilum strains and 1 fungi-free control. To simulate heat stress, the researchers replicated each of the 7 inoculations at 25°C (77°F) and 35°C (95°F). They repeated each inoculation condition in 3 pots with 3 seedlings, for a total of 126 seedlings. 

After 60 days, the researchers harvested the pine seedlings and used a microscope to count how many of their root tips had fungi. They divided the number of root tips with fungi by the total number of root tips to calculate a colonization rate. They considered seedlings with a colonization rate of 80% or higher to have successfully formed a symbiotic relationship with the fungi. Then, the researchers analyzed seedlings with an 80% colonization rate to investigate their symbiotic partnerships.

The team observed that pine seedlings grown under heat stress at 35°C were 24% to 59% smaller than those grown at 25°C, and their needles were yellow instead of a healthy green. However, the seedlings that formed a symbiotic relationship with the ectomycorrhizal fungi were greener and 80% heavier than the control seedlings. 

Investigating the trees further, the team measured 3 chemical compounds related to plant stress, including malondialdehyde (MDA), proline, and nitric oxide. Plants release MDA when damaged, so high MDA levels mean a plant is struggling. In contrast, plants release proline and nitric oxide to repair cells or hold water, so high amounts of these compounds mean a plant is healing.

To measure MDA and proline levels in the pine needles, the researchers mixed them with different acids that change color depending on the sample’s MDA or proline content. To measure nitric oxide, the researchers mixed the needles with a protein that converts the compound into a chemical that changes color. They found that inoculated seedlings at 35°C had about 30% to 40% less MDA, 15% to 30% more proline, and 150% more nitric oxide in their roots than the control seedlings. 

Finally, the researchers measured changes in gene activity in the inoculated pine seedlings. They identified active genes by analyzing RNA molecules from the pine seedling roots with a process called RNA sequencing or transcriptomics. They found that inoculating the seedlings with ectomycorrhizal fungi activated more genes related to root strength, water retention, cell defense, and general plant protection than were activated in the control seedlings. 

By combining chemical analyses with growth measurements, the team concluded that a symbiotic partnership with the ectomycorrhizal fungi helped the pine seedlings survive heat stress. They demonstrated that through prolonged heat, inoculated seedlings maintained greener needles and lower levels of stress chemicals. They suggested that ectomycorrhizal fungi could be an ecological tool to help trees stay hydrated in a warming world. They recommended that future researchers conduct field trials with inoculated trees to translate these findings into forest management strategies. 

The post Fungi help pine trees survive heat stress appeared first on Sciworthy.