Geckos Can Run on Water - via Herp Digest

Faster than ducks can swim in it.

Atlas Obscura, by Matthew Taub, 12/7/18

GECKOS BATHE WITH TINY DROPS, use their tails as optional legs, and can alter the stickiness of their feet as needed. They come in brilliant colors, and make charismatic mascots. And now we know that they can run on water, Inside Science reports.

Ardian Jusufi, a biophysicist at Germany’s Max Planck Institute for Intelligent Systems, was observing flat-tailed house geckos in a Singapore rainforest when he noticed their ability to evade predators by scampering over puddles. Not through them, he observed, but “on the water’s surface,” as Jusufi and his coauthors write in a Current Biology study published yesterday. It was an impressive sight, but it wasn’t until they conducted lab experiments that the true extent of the lizards’ aquatic dexterity was revealed. 

The researchers found that the geckos could run at the speed of nearly three feet per second. That’s faster than ducks, mink, muskrats, marine iguanas, and juvenile alligators can swim, the researchers write. Predators, in other words, can eat their wakes. 

But just how do the geckos do it? They’re not the only species that can walk on water—the basilisk lizard is famous for it, the insects called water striders, too—but the geckos don’t do it in quite the same way. They’re not heavy enough to create enough force just by slapping the water like the larger lizards, and they’re too heavy to sit on water’s surface tension like a bug. 

Experiments revealed that the geckos combine four distinct techniques. First, they actually do utilize surface tension. When the team added surfactant to the water, the geckos’ velocity was cut in half. Second, the geckos also slap the water with all four legs, which creates air cavities like basilisks do. Third, they benefit from their water-repellent skin. And finally, the geckos undulate their bodies—even their submerged trunks and tails—to propel themselves forward, a little like a butterfly stroke. 

There’s more at stake in these findings than geckos’ ability to outrun predators. Coauthor Robert J. Full, of the University of California, Berkeley, tells Inside Science that the geckos may provide a model for robots that could gracefully “run and climb and race across the water” to conduct rescue missions.

Tainted water can skew population toward males, study reveals – via Herp Digest

By Brian Nearing Thursday, November 24, 2016, Albany Times-Uniion

Salted frog may sound like a gourmet restaurant dish, but it actually could mean real trouble for coming generations of the amphibians.

New research done by Rensselaer Polytechnic Institute and Yale University has found that road salt finding its way to pools where frogs breed tilts the balance of offspring, resulting in more males and fewer females that emerge as tadpoles.

"How the salt is doing this, frankly, we don't yet know," said Rick Relyea, a RPI biologist and co-author of the study that was published this month in a Canadian aquatic science journal. "How many females you have in a population determines how many offspring you have. We are not in a position to make any conclusions about potential population decline, but what we do not need is more males.”

Normally, the ratio of male to female tadpoles is roughly equal, said Relyea, who runs the RPI Aquatic Laboratory in North Greenbush, where he conducted the frog study over the last year using massive 500-liter water tanks.

Some tanks contained leaves from oak and maple trees, which are common around

the forest pools where frogs and other amphibians lay their eggs.

Other tanks contained road salt, which is routinely applied to highways in the winter.

Some salt can get washed into drainage systems and potentially reach other bodies of water. For example, Lake George salt levels have been rising steadily.

During the last three decades, the lake's salt levels have tripled, making it now about 30 times saltier than an undeveloped Adirondack lake.

The problem is happening throughout the Adirondacks wherever there are roads, according to Dan Kelting, executive director of the Adirondack Watershed Institute at Paul Smith's College. He spoke at a regional summit last year aimed at addressing the growing threat of road salt.

In the salted water tanks at the RPI lab, there were 60 male tadpoles for every 40 females — a shift of 10 percent. The effect is called masculinizing. Also, female tadpoles exposed to salt were smaller than normal.

"The continual masculinization of frog populations for many generations in habitats contaminated with high concentrations of road salt ... could potentially affect the abundance of frogs in these habitats," said Relyea, who is also director of RPI's Darrin Fresh Water Institute.

"The research raises the possibility that many other aquatic species could be affected by road salts in sub-lethal ways, not only in terms of altered sex ratios, but potentially in many other traits.”

His experiments were conducted as part of the Jefferson Project at Lake George, a research collaboration among RPI, IBM and The Fund for Lake George, a not-for-profit advocacy group. The project is currently installing a series of water- and land-based sensors around the lake to study its water quality and ecosystem.

Part of that ecosystem includes what are called vernal pools, which are temporary pools of water that routinely form by snow melt in the spring, and where frogs and other amphibians lay eggs. "The vast majority of our amphibians come from vernal pools, not lakes," said Relyea. There are likely hundreds of such pools surrounding the lake, where road salt is applied every winter.

"When it comes to road salt, frogs are like canaries in a coal mine warning us of the need to dramatically cut back salt use," said Eric Siy, executive director of The Fund for Lake George. "An estimated 30,000 metric tons of road salt is applied annually in the Lake George basin — enough to fill 300 rail cars or a train 3 miles long every year.”

Across the U.S. each winter, more than 22 million metric tons of salt is applied on roadways, according to estimates by RPI.

Siy's group just held its second annual "salt summit" at the lake, where local officials and conservationists learn about potential methods to reduce use of road salt during the winter.

Previous studies have found effects on amphibian gender ratios caused by exposure to pharmaceuticals and pesticides, but the road salt study is the first of its kind.

"The health and abundance of females is obviously critical for the sustainability of any population because they're the ones that make the babies. So if you have a population that is becoming male-biased, the population might be at risk," said Max Lambert, lead author of the research study and a doctoral student at the Yale School of Forestry and Environmental Studies.

Other researchers included Aaron Stoler, a postdoctoral researcher at RPI, and Yale researchers David Skelly and Meredith Smylie.

Lambert said previous research suggests that such outcomes could be caused by a phenomenon in which simple elements — such as sodium — can bind to a receptor in cells, mimicking the actions of testosterone or estrogen.

This, in turn, can trigger masculinizing or feminizing functions.

"So there is a very small testosterone-like effect with one salt molecule," he said. "But if you're dumping lots and lots of pounds of salt on the roads every winter that washes into these ponds, it can have a large effect.”

Water Trapped For 1.5 Billion Years Could Hold Ancient Life – via D R Shoop

by ADAM COLE 

May 16, 2013 3:03 AM 

Scientists have discovered water that has been trapped in rock for more than a billion years. The water might contain microbes that evolved independently from the surface world, and it's a finding that gives new hope to the search for life on other planets. 

The water samples came from holes drilled by gold miners near the small town of Timmins, Ontario, about 350 miles north of Toronto. Deep in the Canadian bedrock, miners drill holes and collect samples. Sometimes they hit pay dirt; sometimes they hit water, which seeps out from tiny crevices in the rock. 

Recently, a team of scientists (who had been investigating water samples from other mines) approached the miners and asked them for fluid from newly drilled boreholes. 

Greg Holland, a geochemist at Lancaster University in England, and his colleagues wanted to know just how long that fluid had been trapped in the rock. So they looked at the decay of radioactive atoms found in the water and calculated that it had been bottled up for a long time — at least 1.5 billion years. 

"That is the lower limit for the age," Holland says. It could be a billion years older. That means the water was sealed in the rock before humans evolved, before pterosaurs flew and before multicellular life. 

As Holland announced this week in the journal Nature, this is the oldest cache of water ever found. 

Continued

Elephants Near Timbuktu Make Astonishing Migration Treks

A group of elephants near Timbuktu makes an epic journey each year in their quest for food and water. Researchers found that they travel across an area of 12,355 square miles (32,000 square kilometers) in the deserts of Mali, marking the largest known elephant range in the world.

The animals' extreme journey is a product of life in harsh conditions.

"It's incredible these elephants have survived. They have a truly stressful life with the lack of water and food, and their giant range reflects that," said lead researcher Jake Wall of the conservation organization Save The Elephants, Kenya, and the University of British Columbia.

Read on:  http://www.livescience.com/25495-record-breaking-elephant-range-found.html

How One Insect Jumps on Water's Surface

Pygmy mole crickets are skilled jumpers on land and amazingly on water, too. New research shows how their back legs act like spring-loaded paddles to propel them from the surface of a pond.

Researcher Malcolm Burrows, of the University of Cambridge, explained that water can be a deadly trap for many small insects.

"Water grabs and holds an insect, offering it as an appetizing snack for an alert fish. Pygmy mole crickets turn the stickiness of water to their advantage and use this property to enable jumping," Burrows said in a statement.

Read on:  http://www.livescience.com/25195-how-one-insect-jumps-on-water-s-surface.html

Huge potentially inhabited water lake found on Jupiter moon

In major extra-terrestrial news, scientists have announced the first discovery of at least one huge body of liquid water beyond planet Earth, offering confirmation at last of a potential offworld habitat for alien life.

The water in question - roughly enough to fill one of the North American Great Lakes - has been spotted beneath the ice cap covering Europa, one of the moons of Jupiter. Better still, it's thought that the ice floating atop the hidden lake is collapsing and mixing with the water below, offering evidence that the Europan ice cap mixes with the oceans of water beneath it - which makes it much more probable that life could exist in the deeps below.

One opinion in the scientific community has been, 'If the ice shell is thick, that's bad for biology — that it might mean the surface isn't communicating with the underlying ocean,'" says Britney Schmidt, lead author on the new study documenting discovery of the Jovian moon-lake. "Now we see evidence that even though the ice shell is thick, it can mix vigorously. That could make Europa and its ocean more habitable."

Read more here ...