Science Sushi – Page 10 – Biology. Served raw.

Your Average, Everyday Zombie

She came out of nowhere.

All of a sudden, you are set upon by a flying nightmare whose body shines iridescent green. Limbs intertwine as she fights to subdue you. You struggle; every muscle in your body tenses and flexes as you try to fling the emerald harpy off your back, but you feel her jaws clamp down, and she remains attached.

Terrified, you helplessly twist and contort, unable to shake her. Then you feel it — she stabs her needle-like stinger into your abdomen. Your legs tingle, then fail. The paralysis won’t last long, but it’s long enough for your venomous assailant to carefully line up the next jab. She places the point of her stinger sharp on your neck, then drills it deep. You feel a prolonged burning pain as she feels around with her stinger and slowly pumps venom over the next minute into different parts of your brain. Then, as quickly as she came, your attacker is gone. Continue reading “Your Average, Everyday Zombie”

Damsels In Distress Chemically Call For Help

A dusky dottyback considers whether the damselfish in front will fit in its mouth. Photo by Christopher E. Mirbach — A dusky dottyback considers whether the damselfish will fit in its mouth. Photo by Christopher E. Mirbach

Life as a damselfish is hard. These small species are common on tropical reefs worldwide, eating tasty plankton and nipping at other fish. They’re known for their attitude and their beauty, and are often found in stunning schools that cluster around coral heads. But while they’re abundant and vibrant, what they lack are good defenses — no spines, no toxins. Indeed, they are the perfect morsel for other fish-eating fish, and they know it. The moment a predator is detected, they’ll dart for cover, their speed and agility their only hope of survival.

As perpetual menu items, damselfish have developed multiple mechanisms for detecting danger. They can even “smell” danger — when damselfish’s skin is injured, certain chemical compounds leech into the surrounding water. Other damsels can sense these chemicals — essentially “smelling” them — and when a damselfish catches a whiff of Eau de Injury, it runs and hides. But while these chemical alarms seem to benefit fellow damselfish, scientists have long debated whether the injured fish has anything to gain from sending out chemical cues. Are the compounds simply a byproduct of the physical damage? Or do they serve some greater purpose to the fish under attack?

Now, an international team of scientists have published the first evidence of an individual fish benefitting from releasing these chemical alarm cues in a new paper in Proceedings of the Royal Society B. Continue reading “Damsels In Distress Chemically Call For Help”

Poisonous Problems: Chemical Defenses Come With Evolutionary Cost

The chemical weaponry of this beautiful little dart frog come at a high evolutionary cost. Photo by Dirk Ercken

Poison dart frogs are some of the most stunning species on Earth. But their vivid colors aren’t for aesthetics: they’re meant as a warning to potential predators. For while these frogs are visually stimulating, they are also armed with potent toxins. The poisons in their skin are so powerful that local tribes have been known to create deadly darts simply by rubbing them on the frogs’ backs — hence the name.

One might expect that the evolution of such a successful defense would allow these frogs to diversify faster than their relatives and outcompete their kin for resources and habitats — and, according to a study published in the early edition of Proceedings of the National Academy of Sciences this week, their toxins do give them a speciation advantage. But, their defenses don’t come cheap: poisonous frog species also go extinct at a faster rate. Continue reading “Poisonous Problems: Chemical Defenses Come With Evolutionary Cost”

Toxic Toad Eaters Reveal How Evolution Repeats Itself

Bufos marinus, invasive species extraordinaire and one helluva toxic toad. Photo by Chris Ison — Invasive species extraordinaire and one helluva toxic toad. Photo by Chris Ison

At the time, it seemed like the logical thing to do. Australian farmers were desperate. It was the 1930s, and beetles were tearing through their crops, especially sugar cane. Word spread of a toad that loved to gorge itself on the problem pests, which had been successfully brought to Hawaii to manage beetles in sugarcane fields. The Australians could have turned to pesticides, sure, but pesticides are expensive and often harmful to people and the environment. And if the toad could be introduced once, why not again? Why shouldn’t they fix their bug problem once and for all with a harmless little amphibian? So in 1935, two suitcases of cane toads (Rhinella marina; formerly Bufo marinus) arrived in Australia.

Those toads would go on to produce more than 1.5 billion descendants, contending for the title of worst invasive species in history. Continue reading “Toxic Toad Eaters Reveal How Evolution Repeats Itself”

A #CuteOff Challenge: An Entire Kingdom of Cute

I have spent more hours than I want to admit scrolling through #CuteOff on Twitter. The hashtag (following on the heels of the much more R-rated #JunkOff) is a competition of sorts between tweeps to see who can post the cutest animal photo. But as I was sitting on the couch the other day, showing pic after pic to fellow biologist and science writer (and my boyfriend) Jake Buehler, we started to notice that vertebrates — animals, like us, with backbones — were highly overrepresented. Invertebrate species make up more than 95% of the diversity of animal life on this planet, including all of the major groups of animals (called phyla), yet there were choice few to be found in #CuteOff. The discussion went a little something like this…

J: It’s just not fair!

C: Well, I don’t know… most inverts are pretty… gross-looking.

J: You’re gross looking — to a ribbon worm!

C: <glare>

J: Just kidding. But being serious: there are lots of adorable inverts out there that deserve a little love.

C: Hm… You think so? Care to make a wager?

J: I’m listening.

C: How about we take the major phyla of animals, split them down the middle, and see who can assemble the cutest arsenal of inverts?

J: What does the winner get?

C: Bragging rights.

J: You’re on.

So we looked up a quick phylogeny of animals and decided to take turns starting with what is traditionally considered the most basal multicellular group: phylum Porifera. I drew the short straw, which meant I had to go first.

A possible phylogeny for all major animal phyla — and the road map for our #CuteOff challenge!

C: You ready for this?

J: I was born ready. Continue reading “A #CuteOff Challenge: An Entire Kingdom of Cute”

FYI: Giving Birth in the Ocean with Wild Dolphins is Still a Fantastically Awful Idea

Two years ago, a newspaper story about a couple from North Carolina heading to Hawaii for a “dolphin-assisted birth” caught my attention on Twitter. Now “spiritual healer” Dorina Rosin is planning a similar stunt, believing the birth will be more relaxing and natural than one in a hospital. She also believes that her child will be able to speak dolphin. Her birth is to be featured on a British documentary Extreme Births.

https://www.youtube.com/watch?v=puBDR_XM2tI

So far, there’s no info on whether the mother-to-be has gone through with the at-sea birth or not. For that matter, no one knows what happened to the couple from NC — as far as I can tell, no one has ever actually gone through with a wild dolphin-assisted birth. I was able to find one grainy video of what appears to be a birth with a live dolphin, but it’s clear that this woman is in a pool with a captive dolphin, not the ocean.

Update 9/2: According to the documentary, Dorina did not go through with her watery plans. She went into labor at night, and thus had a natural birth on land. But, she did say she could feel the dolphins ‘sending positive energy’.

Below is my original commentary on the practice of dolphin-assisted births, from 2013. But the tl;dr version: Dolphins are wild animals. Wild animals do not make good midwives.

Dorina on her 38-week blessing swim-with-dolphins — a practice considered harmful to the animals. Photo from The Daily Mail

Continue reading “FYI: Giving Birth in the Ocean with Wild Dolphins is *Still* a Fantastically Awful Idea”

Kelp Gulls Tear Out Baby Seal Eyes So They Can Feast On Their Remains When They Die

A kelp gull waits for an unfortunate pup to die. Photo by Naude Dreyer

I think it’s fairly safe to say that gulls are among the least-loved birds in the world. These loud and annoying seabirds have a disturbing lack of fear of large mammals — including us — and a seemingly insatiable appetite, as any beach picnicker can attest. It’s no wonder that the creators of Finding Nemo portrayed them as mindless feeding machines, the only species in the movie to lack intellect and personality. But they were wrong in at least one respect: while seagulls might be feeding machines, they are far from mindless. Continue reading “Kelp Gulls Tear Out Baby Seal Eyes So They Can Feast On Their Remains When They Die”

A review of Venom Doc, the adrenaline-packed adventures of one scientist and his almost-fatal obsession with the world’s deadliest species

Dr. Bryan Grieg Fry chasing down a specimen. Photo provided by B.G. Fry — Dr. Bryan Grieg Fry, author of *Venom Doc*, chasing down a specimen. Photo provided by B.G. Fry

Twenty-six snakes. Three sting rays. Two centipedes. One scorpion. Like a twisted version of the Twelve Days of Christmas, Dr. Bryan Grieg Fry goes through and lists the number of each group of venomous animals he’s been bitten or stung by. It’s November in Brisbane, and we’re sitting at a small table in the Red Room, the University of Queensland campus pub, in part so I can ask him a few more questions for an article I’m working on, and in part because I couldn’t go to Australia and not catch up with Bryan. I’ve known him for several years now; when I was in desperate need of stonefish antivenom to complete one chapter of my dissertation, I messaged him on Facebook, and he was nothing but eager to help out. He brought it with him less than a year later, carefully packed in his baggage, as he traveled from Australia to China and finally to Hawaii for the International Society for Toxinology meeting. “I carried this halfway around the world for you,” I remember him saying sternly as he handed over the glass vial, the first time I’d ever met him face to face. My heart stopped — had I somehow offended such an influential scientist in my field? — until a half a second later, when his mouth cracked a smile.

“What about hymenopterans?” I ask with a grin two and a half years later over a pint, knowing how he’ll reply.

“Who counts bees? You want me to count every fucking fire ant, too?” Continue reading “A review of Venom Doc, the adrenaline-packed adventures of one scientist and his almost-fatal obsession with the world’s deadliest species”

Venomous Frogs Are Super-Awesome, But They Are Not Going To Kill You (I Promise)

In the first chapter for my upcoming book Venomous (due out in 2016), I excitedly explain how nearly all the sundry branches of the tree of life have venomous leaves. I’m simply enthralled by the incredible diversity of venomous animals (and plants!) on this planet, from the tentacle-wielding jellies to the spiny scorpionfishes and, of course, the oft-feared and misunderstood snakes, spiders, and scorpions. But until today, there is one group that could not boast a single venomous member: the anurans, commonly known as frogs and toads. While there are plenty of poisonous ones, no one has ever found a venomous frog — that is, until now.

I know scientists are brazen, but I'm pretty sure that lead author Carlos Jared wouldn't hold this venomous Corythomantis greeningi with his bare hands if it were indeed "deadly". Photo by Carlos Jared c/o Current Biology 2015 — I know scientists are brazen, but I’m pretty sure that lead author Carlos Jared wouldn’t hold this venomous *Corythomantis greeningi* with his bare hands if it were indeed “deadly.”
Photo by Carlos Jared / Current Biology

Venomous animals are natural biochemists that take toxic to a whole new level. While it is true that venoms and poisons are both toxins, the two terms are not interchangeable. All toxins cause harm in low doses; Poisons are substances that cause such harm through ingestion, inhalation or absorption. To earn the title of venomous, on the other hand, an animal has to do more than just have toxins — they have to have a means of wounding their intended victims to force those toxins upon them. That “wounding” can be caused by any weapon of choice; jellies and other members of the phylum Cnidaria use specialized stinging cells that shoot out hollow tubes in less than a microsecond to deliver their potent venom. Snakes and spiders use fangs, the venomous fishes use spines, and the newest members of the venomous family — the frogs Aparasphenodon brunoi and Corythomantis greeningi — use their spiky heads. Continue reading “Venomous Frogs Are Super-Awesome, But They Are Not Going To Kill You (I Promise)”