Science Sushi – Page 4 – Biology. Served raw.

The Mechanics of Dolphin Sex: All The Dirty Details You Need To Know

It takes a lot of pressure to simulate an erection like this. Photo by Vladimir Wrangel — It takes a lot of pressure to recreate an erection like this. Photo by Vladimir Wrangel

Perhaps the hardest part about studying marine mammal reproductive anatomy using organs collected from deceased animals is that they can’t get an erection the easy way.

Reinflating human penises postmortem is a relatively trivial feat, says Diane Kelly, a research assistant professor at University of Massachusetts and penis inflation expert. Like most mammals, human penises are mostly fleshy, with lots of vascular space for blood to flow into to make the flaccid structure rigid with turgor pressure. But whale and dolphin penises are a lot tougher—quite literally. “It’s actually a real challenge to artificially inflate cetacean penises,” she told me. Yes, the size makes things difficult—it takes a lot more saline to fill a large penis than a small one—but it’s more than that. “They have what’s called a ‘fibroelastic’ penis,” she explained, which means their penile tissue contains “a lot of collagen, and it makes the penis, even when flaccid, very stiff and less extensible.”

Finding a way around this hard problem is a large part of why Dara Orbach and Patricia Brennan brought Kelly on to the project. The goal: make the first 3-D CT scans of simulated intercourse of any marine mammal species using real, post-mortem genitalia—scans that were just published in a paper in Proceedings of the Royal Society B. Continue reading “The Mechanics of Dolphin Sex: All The Dirty Details You Need To Know”

Whistling While They Work: Cooperative Laguna Dolphins Have A Unique Accent

Fishermen working with a cooperative dolphin to enhance their catch. Photo Credit: Carolina Stratico

When the mullet migrate northward, the fishermen in Laguna, Brazil are waiting. They rise early and take their places in line, waist-deep in the water, tarrafa—a kind of circular throwing net—in hand. Without a word, the dolphins arrive, herding schools of mullet towards the fisher line. The fishers say that the dolphins are an essential part of their fishing; they wait to fish until their marine helpers to arrive, in some cases standing for an hour or more, calling to the animals: “let’s work”. The fishers work as a unit, trading out their spots in line as the dolphins fill their nets.

But while the humans are united, the dolphin community is divided. Only some of the population cooperate with fishers in this manner. Scientists discovered that the ones that work with people form their own cohesive social network, separate from the other dolphins in the area. “The cooperative fishery appears to have influenced the structuring of this bottlenose dolphin population into social communities,” explain Bianca Romeu and her colleagues at Brazil’s Universidade Federal de Santa Catarina in a new paper this month in the journal Ethology. Their latest work reveals the depth of this rift: the cooperative dolphins don’t just behave differently, they communicate differently, too.

Continue reading “Whistling While They Work: Cooperative Laguna Dolphins Have A Unique Accent”

An Unprecedented Number Of Species Have Crossed The Pacific On Tsunami-Liberated Plastic Debris

These Asian amur sea stars (Asterias amurensis) were found ~5,000 miles from home on the Oregon coast. Image provided by Oregon State University — These Asian amur sea stars (*Asterias amurensis*) were found ~5,000 miles from home on the Oregon coast.
Image provided by Oregon State University

March 11, 2011, 2:46 PM, 45 miles east of Tōhoku, Japan. Fifteen miles beneath the waves, a magnitude-9 megathrust earthquake strikes. The Pacific and Eurasian tectonic plates suddenly shift, shaking the surrounding crust for six minutes and creating a tidal wave almost 40 meters high, which races towards the coast of Japan. In the hours that follow, it claims at least 15,894 lives, with thousands more unaccounted for. More than a million buildings are damaged or destroyed, causing nearly $200 billion in damages.

The remnants of those buildings and all sorts of debris liberated by the moving waters have since spread the tsunami’s legacy far beyond the site of impact. As a new study in the journal Science explains, thanks to objects set adrift by the tsunami’s waves, more than two hundred and eighty species have been found on the wrong side of the ocean.

How did hundreds of animals hitch rides across such vast distances? Well, to paraphrase the slogan from America’s Plastics Makers, plastics made it possible. Continue reading “An Unprecedented Number Of Species Have Crossed The Pacific On Tsunami-Liberated Plastic Debris”

Birds of a Feather Hunt Better Together

le there's no I in TEAM, each penguin benefits from hunting together. Photo credit Sergey Uryadnikov — While there’s no I in TEAM, each penguin benefits from hunting together. Photo credit Sergey Uryadnikov

They say that many hands make light work. Well, for African penguins, many beaks make for bountiful hunts, according to a new study in Royal Society Open Science. The results suggest that dwindling populations may have greater consequences than previously realized.

African penguins (Spheniscus demersus), or “jackass” penguins after their donkey-like calls, are currently endangered. Found only on the southern tip of Africa, populations of these flightless birds have dropped from an estimated 4 to 5 million in 1800 to a mere 50,000 or so animals today. Their situation is considered so dire that, if the penguins do not begin to rebound soon, it’s predicted they’ll go extinct in about a decade. Continue reading “Birds of a Feather Hunt Better Together”

Tiny Bat Shrugs Off Stings From Deadly Scorpion

These tough bats can tussle with the deadliest scorpions in North America and win. Photo by Connor Long — These tough bats can tussle with the deadliest scorpions in North America and win.
Photo by Connor Long

Pallid bats (Antrozous pallidus) are quirky little creatures, the sole species in their genus. Their long ears, which can equal half their body length, make them look quintessentially batty, but unlike most of their night hunting relatives, they prefer to tackle ground-dwelling dinners—a strategy called “gleaning.” Pallid bats glean as much as half their body weight in prey every night, and their diet includes a wide range of crunchy little critters, including crickets, praying mantis, and beetles.

It is their taste for scorpions, though, that is particularly intriguing, and piqued the curiosity of scientists. It was unknown whether the bats have a trick for catching scorpions that keeps them from being stung, or whether they are resistant to the animals’ agonizing toxins. In a new PlosONE paper, researchers show it’s the latter: the bats’ laissez-faire attitude towards venom stems from an invulnerability to scorpion neurotoxins due to alterations in the voltage-gated sodium channels that the toxins target. Continue reading “Tiny Bat Shrugs Off Stings From Deadly Scorpion”

Scientists Turn Back Time, Find a Way to Study Ancient Venom Toxins

A black mamba's sinister smile. Photo by James Arup — A black mamba’s sinister smile. Photo by James Arup

As a species, there is perhaps no topic that fascinates us more than mortality, especially our own. So unsurprisingly, there’s no shortage of science fiction based on the idea of scientifically circumventing our mortal coils, most of which seems rather fantastical. But bringing the dead back to life isn’t as impossible as it might appear. While we’re still a long ways away from Dr. Frankenstein, recent developments in understanding how proteins and genes evolve has allowed scientists to raise dead proteins from the grave. In a new paper in Scientific Reports, a team of French scientists uses this cutting edge tech to resurrect extinct three-finger venom toxins and compare how they work to modern forms. Continue reading “Scientists Turn Back Time, Find a Way to Study Ancient Venom Toxins”

Under The Surf Turf War: Watch Male Lionfish Duke It Out

There's nothing romantic about this cheek to cheek dance between tao large male lionfish. Photo Credit: Alex Fogg — There’s nothing romantic about this cheek to cheek dance between two large male lionfish. Photo Credit: Alex Fogg

Understanding animal behavior can be tough, as observing individuals for hours can be incredibly boring and our mere presence can affect how they act. Things get even harder when those animals happen to live in the ocean; our inability to breathe water makes quietly sitting and watching creatures significantly more difficult. So it was lucky to say the least that Alex Fogg captured a clear video of two large male lionfish exhibiting a behavior rarely caught on film: battling for dominance.

Fogg, a biologist with Coast Watch Alliance, a non-profit out of Pensacola, Florida, and his girlfriend were on vacation in Roatan, Honduras when they came across the remarkable sight. As avid divers, the pair had spent the week diving from boats, so to mix things up, they decided upon an afternoon shore dive instead. The water was crystal clear, which allowed Fogg to spot a very large, dark lionfish on an isolated coral patch about 75 feet away. When the pair approached, they realized the ‘lionfish’ was actually two, battling for dominance 55 feet below the waves.

Continue reading “Under The Surf Turf War: Watch Male Lionfish Duke It Out”

Shark Survives Over A Year With A Hole Between Its Stomach And The Sea

Think you could survive this? Photo ©Joanne Fraser/Ocean Artworks LLC

Sharks are pretty incredible animals. They’ve lived on this planet for more than 400 million years, and in that time, come to dominate the oceans they inhabit. That kind of survival when so many other lineages have gone extinct requires serious resilience. Now, a lemon shark off Florida has shown off just how tough these animals can be: he survived for at least 435 days with a hole in his body created as he shoved a swallowed fishing implement out of him through his flesh. Continue reading “Shark Survives Over A Year With A Hole Between Its Stomach And The Sea”

African Wild Dogs Can’t Take The Heat, Face Extinction From Climate Change

New study suggests African wild dogs may be doomed by climate change. Photo by Mathias Appel

Things aren’t looking good for Africa’s iconic wildlife. Already, many species are threatened by human activities and habitat loss. Even species once thought to be resilient, like giraffes, are suddenly struggling. Just earlier this week, scientists reported that aardvarks, one of sub-saharan Africa’s most successful and adorable insect-eaters and essential ecosystem engineers—face severe declines and even extinction as rising temperatures and declining rainfall dry out the continent. Now, a new paper in the Journal of Animal Ecology adds African wild dogs to the growing list of species that may be eradicated by our changing climate.

Continue reading “African Wild Dogs Can’t Take The Heat, Face Extinction From Climate Change”

Acidifying Oceans Favor Sea Vermin

A common triplefin, one of the fish species that may dominate acidic temperate habitats in the near future. Photo c/o Wikimedia — A common triplefin, one of the fish species that may dominate temperate habitats in the near, acidic future. Photo c/o Wikimedia

Scientists predict that in the next twenty years, the amount of carbon dioxide (CO₂) in our atmosphere will rise from the roughly 404 ppm it is now to over 450 ppm—and as a result, ecosystems worldwide will change. Many impacts will be particularly felt in our planet’s oceans. As atmospheric CO₂levels rise, more of the gas dissolves into our seas, causing a chemical chain reaction which makes the water more acidic. Acidification can act independently or synergistically with rising temperatures, impacting different species in different ways. In a desperate rush to conserve species, scientists are racing against the clock to understand how marine habitats and the species that live in them will be affected by acidification and identify the best ways to retain our marine biodiversity going forward.

The bulk of the research on acidification to date has focused on reef-building corals, and rightfully so, as these reef-producing species are the foundation of some of the richest ecosystems on Earth. But reefs aren’t the only prolific habitats in the sea, and corals certainly aren’t the only species that changing water chemistry will affect. Lab-based studies have found that all kinds of organisms, including fish, are sometimes affected by acidified waters, but how these individual impacts on species translates to ecosystem-level effects is less clear. So to understand how acidification might impact fish communities, a team of scientists led by Professor Ivan Nagelkerken, a marine ecologist in the University of Adelaide’s Environment Institute, turned to natural laboratories. Continue reading “Acidifying Oceans Favor Sea Vermin”