Mealworms: The Other-Other-Other White Meat?
By Katherine Harmon, Associate Editor, Scientific American
December 19, 2012
Looking for the perfect holiday entrée? Something nutritious yet easy on the Earth? Something with a subtle, yet distinctive, je-ne-sais-quoi flavor? Have you considered the humble mealworm? What about the super superworm?
Before you click away in disgust, remember that the creeping, shelled, 10-legged crustacean we now so lovingly dip in butter (ahem, the lobster) was once considered so repulsive as to be inhumane to feed to prisoners. And in many parts of the world, insects are already a popular—and important—menu item.
A new study, published online December 19 in PLoS ONE, makes the case that the mealworm (Tenebrio molitor) and the superworm (Zophobas morio)—consumed as larval forms before they become beetles—are palatable (ecologically speaking) alternatives to traditional livestock products.
Rearing cows, pigs and chickens is an intensive ecological endeavor. Currently, more than two thirds of all agricultural land is used for animal production (whether housing the animals themselves or growing feed crops for them). This whole process—from fertilizing grain to raising (farting) cows to shipping milk—produces some 15 percent of all human-generated greenhouse gasses. Many climate-minded researchers have advocated switching to a more plant-based diet as a way to reduce these harmful emissions. But bugs might be an opportunity to keep animal protein on the menu.
Mealworms might be more familiar to pet owners as reptile, fish or bird food. But these insects are already available freeze-dried, canned or live for human consumption and can be baked into breads and cookies, deep fried with potatoes for more nutritious French fries or simply roasted with some salt for a protein-rich snack.
For the new study, researchers examined the process of raising these two insects—the “cradle-to-farm-gate approach,” as they noted. Dennis Oonincx, of the Department of Plant Sciences, and Imke de Boer, of the Animal Department of Animal Sciences (both at Wageningen University) studied a Dutch mealworm producer called van de Ven Insectenkwekerij in the town of Deurne. The worms were fed a diet of carrots and mixed grains. The insects also required recycled cardboard egg trays, a climate-controlled rearing station (which requires natural gas and electricity), cages, as well as water.
Nevertheless, they appeared to be a more sustainable source of protein than beef, pork, chicken or milk. To produce one kilogram of protein, including feed growing, the mealworms required just one tenth the amount of land required to produce one kilogram of beef—and much less than chicken, pork and milk, too. Producing one kilogram of mealworms generated about 2.7 kilograms of carbon dioxide equivalent in greenhouse gas (mealworms do not produce earth-warming methane, like gassy ruminants do, although the worms do produce their own tiny manure), which is far less than the standard livestock lineup. The lion’s share (42 percent) of the mealworms’ greenhouse gas contribution came from producing and transporting grain feed (26 percent of the CO2 came from the heating gas; 17 percent came from the electricity; and 14 percent came from the production and transportation of carrots).
The study authors suspect that with additional research, the bugs could become an even more Earth-friendly option. “Over the last two decades productivity of chickens and pigs has increased annually by 2.3 percent, due to the application of science and new technologies,” they wrote in their paper. “Further improvement of the mealworm production system by, for instance, automation, feed optimization or genetic strain selection is expected to increase productivity and decrease environmental impact.”
The mealworms are already quite efficient at turning mealworm food into mealworm-based food for humans. They can convert about 2.2 kilograms of food into a kilogram of total bug weight (which is similar to chickens and a much better rate than pigs and cows). They are also proficient reproducers. The female mealworm T. molitor matures in about 10 weeks and will lay some 160 eggs in her short three-month life; and the impressive female superworm Z. morio reaches maturity in three and a half months and can lay some 1,500 eggs in her year of life.
Perhaps most important, the authors concluded, was the mealworm’s small land demand. Forest clearing for agricultural use is a major global contributor of greenhouse gas emissions. “Since the population of our planet keeps growing, and the amount of land on this earth is limited, a more efficient, and more sustainable system of food production is needed,” Oonincx said in a prepared statement. “Now, for the first time, it has been shown that mealworms, and possibly other edible insects, can aid in achieving such a system.”
So perhaps insects will someday graduate from novelty candy and double-dare tequila shots to a meal’s main attraction. Even if they aren’t yet replacing many holiday hams.
New, Deadly Virus Related to Ebola ID'ed in Snakes
Sometimes, though not very often, a science story starts off as a love story. And it's likely that no other tale of scientific discovery, particularly one that touches on some of the most frightening diseases on the planet, begins with one woman's enduring love for a boa constrictor named Larry.
Yet an attempt to save Larry set in motion a series of events, many outlandishly serendipitous, that allowed scientists to hunt down a virus new to science. The virus is apparently the culprit for an infamous and deadly scourge of captive snakes called inclusion body disease, or IBD.
The newfound pathogen is also related to viruses that cause nasty diseases in humans called viral hemorrhagic fevers. The most famous of these is Ebola.
When a California woman named Taryn Hook brought Larry — all 7 feet (2 meters) of him — to the vet a few years ago, she never imagined that the trip would one day lead to such a remarkable discovery, which was announced today (Aug. 14) in the journal mBio. [Read Larry the Snake's Story]
IBD afflicts pythons and boa constrictors, causing a host of strange symptoms. The snakes tie themselves in knots, they projectile vomit and engage in an eerie behavior called stargazing; the snakes raise their heads over and over, stare into thin air, and sway drunkenly from side to side.
Biopsies from animals with the disease show their cells filled up with globules of proteins called inclusions, which may be responsible for the odd behaviors.
There's no cure for the disease. It moves swiftly in pythons, and can progress slowly in boa constrictors, but it is always fatal. And it's infectious, moving from snake to snake, though the mechanism of transmission isn't entirely clear. If one animal in a collection gets IBD, typically all the animals are euthanized.
Blood tests had suggested Larry, a Dumeril's boa constrictor, might have IBD. Wanting to know what could be done to save the beloved snake, Hook contacted Joseph DeRisi at the University of California, San Francisco, a virologist known for his work deciphering another mysterious virus, this one affecting macaws and parrots.
Her plea for help led DeRisi's lab to take on IBD. The scientists put out a call for samples of diseased and nondiseased snakes. Perhaps luckily, the Steinhart Aquarium at the California Academy of Sciences, just a few miles away, had a sudden outbreak of IBD.
Many snakes, both with and without IBD, had to be killed, providing the lab with plenty of freshly preserved tissue to start their investigation. [7 Shocking Snake Stories]
Postdoctoral researcher Mark Stenglein, the research's lead author, rifled through the genes of the dead snakes and soon had millions and millions of sequences. But to sort out which sequence might belong to any suspect viruses, he needed the ultimate genetic blueprint — the boa constrictor genome, which had never been put together.
Without the assembled genome, it would be extremely difficult to tell which sequences belonged to viruses that cause disease, and which were simply vestiges of viruses now rendered harmless by the rigors of time and evolution.
"They're the fossils of old infections," Stenglein said. "They're in every genome. So if we saw those, they might have been confusing to us."
Yet fate smiled upon the effort yet again. A contest called Assemblathon 2 — which pits different groups against each another in a kind of genome-off — was getting under way. They chose to take a stab at sequencing the red-tailed boa constrictor's genome, and Stenglein got his hands on the results.
Yet to study a new virus, you must make more of it — which requires a host cell that will allow the virus to replicate itself. And here, Stenglein ran into yet another roadblock. He tried to grow the new virus in various animal cell lines — monkey cells, iguana cells, turtle cells, the cells of a viper — yet nothing worked. He needed a boa constrictor cell line. And since there was no existing boa constrictor cell line, he needed to start one himself.
"To do that, you need organs — tissue from the species," Stenglein said. "And as you might imagine, you can't go buy boa constrictor kidneys at the supermarket."
Kismet struck again, though this time the coincidence wasn't a happy one.
Chris Sanders, Larry's vet, owned a boa constrictor, Juliet, that was sick with lymphoma.
Right around that time, Juliet died, and Sanders, knowing Stenglein needed boa constrictor organs, put his pet of 20 years in the refrigerator and sent him an email.
The next day, the two men performed a necropsy, peeling back her skin and removing pieces of Juliet's organs, brain, and other tissue.
Stenglein prepped each sample, finely mincing the organs with a scalpel, putting them in petri dishes filled with a growth medium — and waited.
"Most of the organs I tried, all the cells died," he said. But Juliet's kidneys didn't die. In fact, the cells kept on growing, allowing Stenglein to grow more of the virus, and discover more of its secrets — which turned out to be a little bit scary.
Frightening family tree
Upon closer examination, it turns out the newfound virus has some dangerous relations. It looks like a mash-up of two different viruses that can jump from animals to humans, and cause diseases such as Lassa fever and Ebola. [10 Deadly Diseases That Hopped Across Species]
Although the newfound virus shares qualities of both, it most closely resembles an arenavirus. Until now, arenaviruses had been seen only in mammals — specifically, in rodents. And although the mice and rats that carry the arenaviruses are unaffected, they pass the virus on to humans through their urine or feces, causing diseases such as Lassa fever — a disease that kills some 5,000 people in West Africa each year, according to the World Health Organization — and Bolivian hemorrhagic fever, among others.
Some of these diseases can pass from person to person, once the virus jumps from animal to human.
Despite the newfound virus's menacing cousins, Stenglein and DeRisi emphasized that snake owners have no reason to worry. There's no evidence that the snake virus can affect humans. The fact that it refused to grow in any cells but a boa constrictor's suggests there is a strong species barrier that protects humans.
Yet is it possible the virus could be passed to humans? "The bottom line is, I don't know," DeRisi said. "That is the fairest answer. I don't think it's that likely."
"There's not a big epidemic of pet owners with crazy fevers and unexplained deaths. I think people would notice that," Stenglein said.
The scientists still have work ahead: To confirm IBD as the cause of the snake sickness, they must still inject a healthy snake with the virus and show that IBD develops. That's a project in the works. DeRisi said next on his list is to see if snakes in the wild are affected by IBD.
In addition, it's still unknown how snakes get the disease in the first place. Mites that feed on snake blood have been linked to IBD, but DeRisi and Stenglein said it's very interesting that the newfound virus so closely resembles a virus known to lurk in mice and rats — favored snacks for snakes.
The discovery of the virus may lead to a fast diagnostic test for IBD, which would allow institutions to identify and kill any infected snakes before they pass on the disease.
Thanks to Juliet's kidney cells, which continue to grow, the lab can continue to replicate the virus, and continue the search for answers. (Juliet herself was given a dignified send-off. "She's buried in the backyard," Sanders said.)
"There are a lot of evolutionary and genetic mysteries wrapped up in this research," DeRisi said. "This may have opened the door to whole new world of arenaviruses and hemorrhagic fevers."
Larry, the snake that started it all, apparently does not have IBD. He is, in fact, still alive, although Hook has had to put down two other pet snakes that got sick with IBD.
And although Larry still gets sick a lot, at 15 years old, "he's a wonderful animal," Hook said. He's an integral part of the family, "just like someone's dog or cat."
The American opossum is invulnerable to nearly all forms of poison. (Damian Dovarganes/AP)
Opossums may someday provide an antidote to nearly all forms of poison, including everything from snakebites to ricin.
The Journal of Venomous Animals and Toxins has found that the American opossum produces a protein known as Lethal Toxin-Neutralizing Factor (LTNF). And as the Boing Boing blog points out, the LTNF protein is exactly what it sounds like, seeking out otherwise lethal poisons that have entered an opossum's body and neutralizing them.
Amazingly, tests on the opossum LTNF found that the protein even left the marsupial creatures immune to poisons from snakes on other continents that the American opossum had not been previously exposed to.
The BittelMeThis blog goes into further detail, explaining that scientists then injected mice with the LTNF protein and subjected the rodents to venom from otherwise deadly creatures, including Thailand cobras, Australian taipans, Brazilian rattlesnakes, scorpions and honeybees.
When the venom did not kill the mice, the mice were then exposed to deadly poisons, including ricin and botulinum toxin. And again, the LTNF protein was able to diffuse the poison, leaving the mice unharmed.
Interestingly, the journal entry on LTNF was published more than 10 years ago, in 1999. As several readers have pointed out, this raises questions as to whether the protein benefits would be applicable to humans and why the test results are only now making news.
As the journal's own abstract notes, "Thus, natural LTNF from opossum serum has potential as a universal therapy for envenomation caused by animals, plants and bacteria."
A solar salamander? Scientists find photosynthetic organisms living inside a vertebrate's cells for the first time.
Scientists have long believed that only plants, algae, some bacteria, and a few invertebrates were capable of taking advantage of photosynthesis, which converts sunlight directly into energy. But now, for the first time, a photosynthetic vertebrate has been found, according to Nature.
The incredible creature is none other than the fairly common spotted salamander (Ambystoma maculatum). Ironically, the spotted salamander is not a new species for researchers, and it has long been known that the animal's embryos share a symbiotic relationship with photosynthetic algae. That relationship, however, was always assumed to be an outside one, whereby the algae and the salamander work separately toward a fair exchange of resources.
It turns out that researchers just weren't looking closely enough. While studying a batch of salamander embryos, scientist Ryan Kerney of Dalhousie University saw something different than the prevailing dogma would suggest — a bright green color coming from inside their cells.
That color usually indicates the presence of chlorophyll, which is the light-absorbing green pigment that makes photosynthesis possible.
"On a lark, I decided to take a long-exposure fluorescent image of a pre-hatchling salamander embryo," said Kerney. After backing that experiment up using transmission electron microscopy, he confirmed his suspicion. There were algal symbionts located inside the salamander cells.
In fact, the symbiotic partners were often found bordering mitochondria, organelles responsible for generating a cell's energy. Thus, it's likely that the mitochondria were taking direct advantage of the oxygen and carbohydrate, byproducts of photosynthesis that were generated by the algae.
The reason this discovery is surprising is because all vertebrates have what's known as an adaptive immune system, which naturally destroys any foreign biological material found inside the cells. How the algae in the salamander's cells bypass this defense is a mystery.
Even more interesting, Kerney also discovered that algae is present in the oviducts of adult female spotted salamanders, where the embryos form in their sacs. This means that it's possible symbiotic algae are passed from mother to offspring during reproduction.
"I wonder if algae could be getting into the germ [sex] cells," commented David Wake, from the University of California, Berkeley, who watched Kerney's presentation. "That would really challenge the dogma [of vertebrate cells disposing of foreign biological material]. But why not?"
Although this is the first time such a close co-existence with a photosynthetic organism has been found in a vertebrate, the discovery leaves open the question about if other animals might harbor similar traits.
"I think that if people start looking, we may see many more examples," said developmental biologist Daniel Buchholz.
The croak gave it away.
On a foray into the wilds of Staten Island in 2009, Jeremy A. Feinberg, a doctoral candidate in ecology and evolution at Rutgers University, heard something strange as he listened for the distinctive mating call of the southern leopard frog — usually a repetitive chuckle. But this was a single cluck.
“I started hearing these calls, and I realized they were really distinct,” Mr. Feinberg said.
Three years later, Mr. Feinberg and four other scientists who joined him in multiple field and laboratory studies, are finally comfortable making their declaration: a new species of leopard frog — as yet unnamed — has been identified in New York City and a number of surrounding counties.
The find is surprising on a number of fronts, not least of which is that the new frog was hiding in plain sight in one of the most populated centers in the world. (Most new species are found in remote areas.) And it illustrates the power of genetic testing in parsing more finely those animals that may be nearly identical in appearance, but are, in fact, of different species.
There are more than a dozen leopard frogs, ranging from Canada to Central America. Medium in size, with dark spots on a tan, olive or green background, they gravitate toward grassy meadows and breed in ponds or pools. The researchers say that the new frog species was confused for a long time with the southern leopard frog, which it closely resembles.
Its known range is limited, more or less, to commuting distance from Midtown Manhattan, stretching from around Trenton, N.J., in the south, to Putnam County, N.Y., to the north.
“Here is a brand-new species, and it’s not a species of bacteria or a barely visible insect,” said H. Bradley Shaffer, a professor in the department of ecology and evolutionary biology at the University of California at Los Angeles. “It’s a big amphibian, and kids have probably been catching and playing with it for years,” he said. “Even in an urban center like New York, where herpetologists have tromped all over for a century or more, there can be new species out there. That shows the importance of urban areas in terms of conservation and biodiversity.”
The findings are to be published in an issue of the journal Molecular Phylogenetics and Evolution, but are currently available online. Much of the genetic analysis was performed in Professor Shaffer’s laboratory at the University of California at Davis, where he worked until recently.
There, with his encouragement, Catherine E. Newman, an evolutionary biologist who had done her master’s thesis on the southern leopard frog, studied the frog’s DNA, taken from samples sent by Mr. Feinberg and others. She compared it with the DNA of southern and northern leopard frogs, which range widely north and south of New York City.
Local amphibian fans can be forgiven for not noticing the new frog’s unique nature. “I wouldn’t know which one I was holding because they all look so similar,” said Ms. Newman, who is now pursuing her Ph.D. at Louisiana State University. “But all of our results showed this one’s lineage is very clearly genetically distinct.”
So far, Mr. Feinberg has positively identified the new species on Staten Island, although he says it probably once inhabited Manhattan and the other boroughs. He has found specimens in the Meadowlands and the Great Swamp National Wildlife Refuge in New Jersey, and Putnam and Orange Counties in New York. Some frogs were also collected in central Connecticut.
“It’s a very small range and even if we went back 400 to 500 years, it probably would have been considered a rare animal,” he said.
The dead center of the known range, oddly, is near Yankee Stadium, even though the frog has not yet been found in the Bronx.
“I think that at this point it’s very important to do additional surveys,” Professor Shaffer said. The frog’s range “may be no wider than we have found or it may be wider.”
Over the years, a few other scientists almost identified the new species, but fell short. In 1936, one esteemed herpetologist wrote that he suspected there was a third frog species in the general New York City area. But he did not investigate further.
In the early 1970s, another scientist went on a listening tour of the various leopard frogs’ mating calls while driving from Florida to the Northeast. “She missed this entire area,” Mr. Feinberg said. “She might have been driving on I-95 and just skipped over the weird call area.”
As the lead author on a second paper that is to explore the physical characteristics and call of the new frog, Mr. Feinberg will have the honor of naming rights, choosing a scientific and common name. For now he’s not letting the frog out of the bag.
“I’ve given it lots of thought,” he said. “Part of me has always wanted to call these New York leopard frogs, but I think people in New Jersey and Connecticut will protest. I have to balance the politics with the naming.”
In this photo taken Wednesday, March 30, 2011 and released by The Wildlife Conservation Society on Wednesday, Jan. 11, 2012, a Matilda's Horned Viper is photographed in a forest habitat in southwestern Tanzania. The world's newest snake was discovered in a small patch of southwest Tanzania about two years ago and was introduced last month in an issue of Zootaxa as the world's newest known snake species - named after the 7-year-old daughter of Tim Davenport, director of the Wildlife Conservation Society in Tanzania, who was on the three-person team that discovered the viper. (AP Photo/Wildlife Conservation Society, Tim Davenport)
The world's newest snake has menacing-looking yellow and black scales, dull green eyes and two spiky horns. And it's named after a 7-year-old girl.
Matilda's Horned Viper was discovered in a small patch of southwest Tanzania about two years ago and was introduced last month as the world's newest known snake species in an issue of Zootaxa.
Tim Davenport, the director of the Wildlife Conservation Society in Tanzania, was on the three-person team that discovered the viper. Thanks to his daughter, the snake will always carry a family namesake.
"My daughter, who was 5 at the time, became fascinated by it and used to love spending time watching it and helping us look after it," Davenport told The Associated Press on Wednesday. "We called it Matilda's Viper at that stage ... and then the name stuck."
Only three new vipers have been discovered across Africa the last three decades, making the find rare and important. The Wildlife Conservation Society is not revealing exactly where the snake lives so that trophy hunters can't hunt it.
Davenport said he is not sure how many live in the wild because snake counts are hard to do. Twelve live in captivity and a breeding plan is being carried out.
Davenport, a Briton who has lived in Tanzania for 12 years, said that while many people fear snakes, most are harmless and help keep rodent numbers down. Matilda's horned viper can grow to 2 feet (65 centimeters) or bigger, he said.
"This particular animal looks fierce and probably is venomous (though bush viper bites are not fatal)," Davenport told AP via an Internet chat. "However, it is actually very calm animal and not at all aggressive. I have handled one on a number of occasions."
The Wildlife Conservation Society runs the Bronx Zoo and the Central Park Zoo in New York, and Davenport said it would be a "great option" to showcase the new horned viper at one of those locations, but that nothing has yet been decided.
A female zebra shark in Dubai has successfully spawned pups - without the presence of a male.
Zebe, who was introduced to the Burj Al Arab's aquarium as a pup in 2001, has been laying eggs that have successfully hatched every year for the past four years.
It is the first time the species has been documented reproducing without being fertilised by a male, through a process called parthenogenesis.
Also known as virgin birth, parthenogenesis takes place when the female's egg cells double their genome and then split into two.
One of the egg cells takes on the role of the male sperm and effectively fertilises the other egg. They then merge back together to become an embryo with two female chromosomes.
Commonly witnessed in insects and some species of fish and reptiles, parthenogenesis is rarely seen in sharks and has been observed in other shark species only five times in the past decade.
"It was already known that a shark had done this before, but they were of a totally different lineage than zebra sharks; so, this is very exciting," said David Robinson, one of the marine biologists who has studied Zebe and her offspring.
The first such birth to be documented was in 2001 by a hammerhead shark at a zoo in Nebraska. The pup was killed by a stingray a few days later.
In another example, two white-spotted bamboo sharks were born in an aquarium in Detroit, but mysteriously disappeared from the tank.
Mr Robinson, who works as the assistant aquarium operations manager at the Burj Al Arab, said the pups were the first of Zebe's to have survived. The eldest hatched in 2008.
"These are the first animals that are alive and well, reproduced by parthenogenesis," he said. "And they're so pretty too - that's the best thing."
Mr Robinson and the aquarium's operations manager, Warren Baverstock, first discovered eggs laid by Zebe in 2007.
According to Mr Robinson, eggs are often laid by females even when there is no male present to fertilise them, but are normally discarded.
"We had heard about the other incidents, so we decided to leave the eggs alone to see what would happen, and three months later we discovered embryos inside some of the eggs," he said.
Together with Dr Kamal Khazanehdari, the head of molecular biology and genetics at the Central Veterinary Research Laboratory in Dubai, the process of parthenogenesis was confirmed by DNA analysis.
The test results were published in November's Journal of Fish Biology. The same day, the first pup of this year's batch of eggs hatched.
Zebe, who was caught in the Red Sea, has given birth to 21 pups since 2007, eight of which are still alive. The rest died from various complications, including accidents and infection.
"We've learnt a lot since the first year to find the right conditions for the sharks to develop, such as water temperature and pH [acidity] levels, but hopefully we've developed a fine art by now," he said.
Jonathan Ali Khan, a Dubai-based filmmaker who is producing a documentary called Shark Quest Arabia, says the virgin births are an "amazing example of nature's adaptability".
"Some species react to triggers, which cause survival mechanisms to go into action," he said.
According to Mr Khan, the female shark's captivity "triggered something in its genetic coding", enabling it to reproduce without being fertilised by a male.
Sharks have an XY sex-determination system, like humans - meaning females carry two X chromosomes, whereas males have an X and a Y. The result, in sharks, is that only female offspring can be produced by parthenogenesis, because there is no Y chromosome available.
Whether Zebe's offspring will be able to produce pups of their own is yet to be seen, although Mr Khan doubts it.
"These animals are clones, more than actual offspring, so I'm unsure whether they will actually be able to reproduce. They are born sterile, basically," he said.
But Mr Robinson has higher hopes. When the eldest pup reaches the age where it would normally become sexually mature, they will bring a male zebra shark to the aquarium, and see whether nature takes its course.
Grow an Olympic-sized heart with Burmese python plasma
By Janet Fang
October 27, 2011
Pythons are amazing.
(And I’m not just saying that because I’m a proud snake mama.)
The Burmese python (Python molurus) can go for a whole year without eating. And once they squeeze and swallow their prey, their hearts nearly double in size within days, and their metabolism speeds up fortyfold.
This incredibly expanding snake heart is similar to how highly trained athletes grow huge, strong hearts.
Now, a new study shows that this heart-ballooning in snakes is triggered by fatty acid molecules circulating in their bloodstream after they gorge.
The new findings could help researchers develop drugs to treat our own hearts – by boosting performance after a heart attack or stroke or, on the other hand, reducing dangerous kinds of heart growth caused by certain diseases.
Over the last 5 years, a team led by Leslie Leinwand from the University of Colorado, Boulder studied one of the largest snakes in the world, from the jungles of Southeast Asia. The Burmese python goes for months without eating, and then downs a deer.
To accommodate the sudden rush of sugars, fats, and proteins, ScienceNOW explains, the body goes into overdrive, and its heart expands over 40%, presumably to pump greater volumes of blood throughout its body.
“When a python eats, something extraordinary happens,” Leinwand says. “Its metabolism increases by more than fortyfold and the size of its organs increase significantly in mass by building new tissue, which is broken back down during the digestion process.”
They found that cardiac growth is triggered by 3 specific fatty acids and triglycerides (found in natural fats and oils) circulating in python plasma.
1. One day after eating, the amount of triglycerides increased more than fiftyfold in the blood, which made it “effectively milky.”
2. With this much fatty acid in their blood, there was no evidence of fat deposits on the heart, which led them to notice the increased activity of an enzyme called superoxide dismutase, a well-known ‘cardio-protective’ enzyme.
3. Dropping these fatty acids – myristic, palmitic, and palmitoleic acids – onto heart cells of pythons and mice (yes, mice, how poetic) actually stimulated chemical pathways linked to beneficial heart growth.
4. Then they injected fasting pythons and mice with either (a) ‘fed python’ blood plasma or (b) a fatty acid mixture they created to mimic plasma. Snakes and mice from both experimental groups showed increased heart mass and good cardiac health.
The next step is to test the fatty acid cocktail on mice with heart problems, like high blood pressure, to see if it would hike up cardiac function.
Some cardiac diseases cause heart muscle to thicken, decreasing chamber size and heart function because the organ must work harder to pump blood. But heart enlargement from exercise, Leinwand explains, is beneficial.
To reverse the effects of such diseases, drugs could promote good processes as a surrogate for very vigorous exercise. According to Leinwand in an interview with SmartPlanet’s Melanie D.G. Kaplan earlier this year, it would be like giving people a little bit of Michael Phelps or Lance Armstrong.
Boulder-based Hiberna Corp., which develops drugs based on animals with extreme metabolic regulation, signed an exclusive agreement licensing this tech.
Except during the winter, Agamemnon Fang (neither Greek nor a viper, discuss) eats a gourmet jumbo rat about once a month.
Celtic Biotech to start snake venom cancer drug trials
By Barry O'Halloran
October 28, 2011
AN IRISH biotech company will this week begin human trials of a new cancer treatment derived from rattlesnake venom.
Celtic Biotech, founded in 2003 by businessmen John Reid and Dr Paul Reid, has developed a treatment for advanced cancer from a powerful protein found in rattlesnake venom.
The company will this week begin testing the drug, now known as CB24, on patients at the George Pompidou University Hospital, Paris, under the supervision of consultant cancer specialist Jacques Medioni.
Celtic Biotech expects the trials to last about a year. They are designed to highlight the therapeutic value and safety of the drug.
The Irish company discovered a protein in rattlesnake venom that causes malignant cancer cells to self-destruct, a process known as cell death.
Two independent studies, by the US National Cancer Institute and University of Texas MD Anderson cancer center, have confirmed the protein’s anti-cancer properties.
Celtic Biotech has been researching this for the last seven years and made a number of breakthroughs during that time. It has applied for a number of patents and highlighted its findings in scientific journals.
Former assistant US surgeon general, Dr Roscoe Moore jnr, who is on Celtic Biotech’s scientific board of advisers, says that CB24 provides a “promising approach”.
Dr Paul Reid has a degree in microbiology from Trinity College Dublin and a masters in neurobiochemistry from Imperial College, London. John Reid has a masters in management from Trinity College Dublin.
The company maintains its own colony of breeding rattlesnakes in the US. Rattlesnakes are found throughout north America, from southern Canada to Mexico. They are responsible for more than 80 per cent of snake bite fatalities in the US, and the vast majority of snake bite injuries.
However, they only attack when provoked and the bites are rarely fatal if treated quickly.
About one in four people in industrialised countries are likely to contract cancer within their lifetime. The World Health Organisation says that the disease killed about 7.8 million people in 2008.
Pythons' big hearts hold clues for human health
By Lauran Neergaard
October 27, 2011
You don't think of pythons as big-hearted toward their fellow creatures. They're better known for the bulge in their bodies after swallowing one of those critters whole.
But the snakes' hearts balloon in size, too, as they're digesting — and now scientists are studying them for clues about human heart health.
The expanded python heart appears remarkably similar to the larger-than-normal hearts of Olympic-caliber athletes. Colorado researchers report they've figured out how the snakes make it happen.
"It's this amazing biology," said Leslie Leinwand, a molecular biologist at the University of Colorado Boulder, whose team reports the findings in Friday's edition of the journal Science. "They're not swelling up. They're building (heart) muscle."
Reptile biologists have long studied the weird digestion of these snakes, especially the huge Burmese pythons that can go nearly a year between meals with no apparent ill effects. When they swallow that next rat or bird — or in some cases deer — something extraordinary happens. Their metabolism ratchets up more than 40-fold, and their organs immediately start growing in size to get the digesting done. The heart alone grows a startling 40 percent or more within three days.
Leinwand, who studies human heart disease, stumbled across that description and saw implications for people. An enlarged human heart usually is caused by chronic high blood pressure or other ailments that leave it flabby and unable to pump well. But months and years of vigorous exercise give some well-conditioned athletes larger, muscular hearts, similar to how python hearts are during digestion.
So Leinwand's team — led by a graduate student who initially was frightened of snakes — ordered a box of pythons and began testing what happens to their hearts.
The first surprise: A digesting python's blood gets so full of fat it looks milky. A type of fat called triglycerides increased 50-fold within a day. In people, high triglyceride levels are very dangerous. But the python heart was burning those fats so rapidly for fuel that they didn't have time to clog anything up, Leinwand said.
The second surprise: A key enzyme that protects the heart from damage increased in python blood right after it ate, while a heart-damaging compound was repressed.
Then the team found that a specific combination of three fatty acids in the blood helped promote the healthy heart growth. If they injected fasting pythons with that mixture, those snakes' hearts grew the same way that a fed python's does.
But did it only work for snakes? Lead researcher Cecilia Riquelme dropped some plasma from a fed python into a lab dish containing the heart cells of rats — and they grew bigger, too. Sure enough, injecting living mice made their hearts grow in an apparently healthy way as well.
Now the question is whether that kind of growth could be spurred in a mammal with heart disease, something Leinwand's team is starting to test in mice with human-like heart trouble. They also want to know how the python heart quickly shrinks back to its original size when digestion's done.
The experiments are "very, very cool indeed," said James Hicks, a biologist at the University of California, Irvine, who has long studied pythons' extreme metabolism and wants to see more such comparisons.
If the same underlying heart signals work in animals as divergent as snakes and mice, "this may reveal a common universal mechanism that can be used for improving cardiac function in all vertebrates, including humans," Hicks wrote in an email. "Only further studies and time will tell, but this paper is very exciting."
The study was funded by the National Institutes of Health and a Boulder biotechnology company that Leinwand co-founded, Hiberna Corp., that aims to develop drugs based on extreme animal biology.
A monster 21-foot (6.4-meter) saltwater crocodile, believed to be the biggest ever captured, has been trapped in the southern Philippines after a spate of fatal attacks, officials said Tuesday.
The 1,075-kg (2,370-pound) male is suspected of eating a farmer who went missing in July in the town of Bunawan, and of killing a 12-year-old girl whose head was bitten off two years ago, crocodile hunter Rollie Sumiller said.
The hunter examined the crocodile's stomach contents by forcing it to vomit after it was captured Saturday, but there was no trace of human remains or of several water buffaloes also reported missing by locals.
"The community was relieved," Sumiller said of the capture, but added: "We're not really sure if this is the man-eater, because there have been other sightings of other crocodiles in the area."
The local government of the impoverished town of 30,000 people has decided against putting down the reptile, and will instead build a nature park where it will go on display.
Josefina de Leon, wildlife division chief at the Philippines environment ministry, said the beast was likely the biggest crocodile ever captured anywhere in the world.
"Based on existing records the largest that had been captured previously was 5.48 meters long," she told AFP.
The Philippine specimen would easily dwarf the largest captive saltwater crocodile, which the Guinness World Records website lists as Cassius, a 5.48-meter (18-foot) male which lives at an Australian nature park.
Press reports also describe other huge crocs including a 6.2-meter (20.3-foot) adult male killed in Papua New Guinea in 1982 that was measured after it was skinned.
The Bunawan hunting team, employed by a government-run crocodile breeding farm, began laying bait using chicken, pork and dog meat on August 15 in an attempt to snare the beast.
But the reptile, which measured three feet (0.91 meters) across its back, simply bit off both the meat and the line it was skewered on.
A heavy metal cable finally proved beyond the power of its jaws, and the beast was subdued in a creek late Saturday with the help of about 30 local men.
It was the team's second attempt after a failed expedition launched in response to the fatal 2009 attack.
Beyond the mark of the hook inside its upper jaw, the crocodile did not appear to have sustained any serious injuries, Sumiller said.
Bunawan Mayor Edwin Cox Elorde said the government would build a nature park showcasing the giant crocodile and other species found in the vast marshland on the upper reaches of the massive Agusan river basin on Mindanao island.
"It will be the biggest star of the park," Elorde told reporters.
Sumiller said the plan was the best option available for the creature.
"He's a problem crocodile that needs to be taken from the wild... and used for eco-tourism," he said.
Crocodylus porosus, or the estuarine crocodile, is the world's largest reptile. It grows to five or six metres in length and can live up to 100 years.
While not considered an endangered species globally, it is "critically endangered" in the Philippines, where it is hunted for its hide which is used in the fashion industry, de Leon said.
"There have been very few sightings of porosus in the wild in the Philippines in recent years," she added.
In July, a saltwater crocodile measuring almost 14 feet (4.2 meters) was caught on the western Philippine island of Palawan after it killed a man.
The first (A) and fourth (B) day after seeding the mesh frame, the researchers found the skin cells spread from the corners into the meshes, reaching one another within a week.
CREDIT: Hanna Wendt et al., PLoS ONE
The secret to creating artificial skin might be spider silk, researchers now suggest.
Skin grafts are vital for treating burn victims and other patients. For instance, chronic wounds such as bedsores in hospitalized patients afflict 6.5 million in the United States alone for estimated costs of $25 billion annually.
Instead of using skin from a body for a graft, scientists are investigating artificial skin. Ideally such a graft would be of a material tolerated by the body, have skin cells embedded within it to replace lost tissue, degrade safely over time as the new skin grows in and be strong enough to withstand all the rigors ordinary skin experiences. Materials investigated until now did not seem strong enough for the task, said tissue engineer Hanna Wendt at Medical School Hannover in Germany.
Now Wendt and her colleagues suggest silk might be up for the job.
Spider silk is the toughest known natural material. Moreover, there is abody of folklore dating back at least 2,000 years regarding the potential medical value of webs — for instance, in fighting infections, stemming bleeding, healing wounds and serving as artificial ligaments.
The extraordinary strength and stretchiness of spider silk "are important factors for easy handling and transfer of many kinds of implants," Wendt said. In addition, unlike silk from silkworms, that from spiders apparently does not trigger the body's rejection reactions.
To test spider silk's usefulness, first Wendt and her colleagues essentially milked golden silk orb-weaver spiders by stroking their silk glands and spooling up the silk fibers that came out. They next wove meshes from this silk onto steel frames. [See images of skin cells growing]
The researchers found that human skin cells placed on these meshes could flourish, given proper nurturing with nutrients, warmth and air. They were able to cultivate the two main skin cell types, keratinocytes and fibroblasts, into tissue-like patterns resembling epidermis, the outermost layer of skin, and dermis, the layer of living tissue below the epidermis that contains blood capillaries, nerve endings, sweat glands, hair follicles and other structures.
"It was impressive to observe how human cells use spider silk," Wendt told LiveScience.
Currently, harvesting large amounts of spider silk for industrial standards is not practical. "I think in the long term, for widespread daily clinical use, synthetic silk fibers providing the same mechanical- and cell culture- properties will be needed," Wendt said. Currently, many research groups are investigating ways to grow synthetic spider silk.
The scientists detailed their findings online July 26 in the journal PLoS ONE.
Physicists from the University Munich in Germany and the University of Topeka, Kansas have strong new evidence that snakes can hear through their jaws. Snakes don't have outer ears, leading to the myth that they can't hear at all.
But they do have complete inner ear systems, including functional cochlea, which are carefully connected to and stimulated by their lower jaw. Resting on the ground, a snake's jaw can detect vibrations as small as an angstrom in amplitude (a motion roughly as large the diameter of a single atom), which act like sound waves to the inner ear.
The physicists performed a geometric study of the anatomy of horned desert vipers as well as the ground waves created by the footfalls of their prey. They showed mathematically that the jaw-to-cochlea system is sensitive to the frequencies of the prey's ground vibrations. From their analysis, the physicists also found that the snake's notorious ability to unhinge their jaws and swallow their prey whole means that the right and left side of their jaws can receive vibrations independently, and the snakes hear in stereo.
The paper provides data supporting the theory that as the cochlea is stimulated, the snake’s auditory neurons create a topological map of its environment. Thus, as experiments have shown, some snakes can catch their prey using only vibration cues.
The physicists believe their study shows that ground vibrations to the lower jaw should be regarded as a significant source of sensory input for the snakes, and that this finding strongly supports the idea of the auditory stimulation creating a neural map.
The scientists report their finding in the upcoming issue of Physical Review Letters.
The newly discovered lizard, reaches 6 feet (1.8 meters) and is related to the world's largest lizards, the Komodo dragons.
A giant, spectacularly colored new species of monitor lizard has just been revealed to scientists in the Philippines.
The reptile, which is roughly 6 feet long (1.8 meters), is kin to Komodo dragons, the world's largest lizards. Named Varanus bitatawa, this newly discovered species, decorated in stripes of gold flecks and armed with huge, curved claws for climbing trees, is one of only three fruit-eating monitor species in the world.
New to science, not residents
As humans continue to explore the last uncharted regions of the planet, discoveries of previously unknown species of large vertebrates have become rare. It remains doubly surprising this reptile managed to escape the attention of the many biologists that work on the heavily populated island of Luzon.
"I am most impressed that such a large, conspicuous, brightly colored species of monitor lizard escaped the notice of biologists for the past 150 years," said researcher Rafe Brown, a field herpetologist at the University of Kansas.
Still, remarkably few surveys have explored the reptile diversity of the island's northern forests. The reptile also seems highly secretive and dislikes traversing open areas.
"At the same time, we are humbled because the species is not really new — it is only new to us as Western scientists," Brown said. "In fact, resident indigenous communities — the Agta and Ilongot tribes — have known about it for many generations. If only scientists had listened to them earlier!"
Discovering the giant
Rumors of the lizard's existence floated among biologists for the past 10 years, Brown explained.
"People had taken photographs of hunters from the resident tribespeople as they were carrying the reptiles back to their homes to feed their families in 2001," Brown said.
In 2005, two different groups procured juvenile specimens. "However, both of those efforts didn't collect genetic samples, so we couldn't yet prove that it was genetically distinct and didn't just look different," Brown said. "Also, we wanted a full-sized adult to see how big it got in life."
Last summer, the researchers set out on a two-month expedition to scour the forests for the animal. "We began in July, and the rainy season began early that year, so we were just working in a deluge the whole time," Brown recalled. "Getting up those mountains with a big team of 20 people and all their equipment and gear in those muddy conditions was difficult."
"We knew it was there in the forests around us," he added. "We had seen its scratch marks on trees, we had seen its footprints along stream banks, and we had found its scat."
Near the very end of their complicated, exhausting trip, when they were low on food and out of money, they got a large adult male specimen, captured by the snares of a tribal hunter. "It was like a prize at the end of a marathon," Brown said.
The Agta and Ilongot tribes call the reptile "bitatawa," which the new scientific name for it reflects, and rely on the animal for its meat.
"I have not tasted it myself — the specimen we caught was too important for us to just try," Brown said. "I only know the hunters report it as better tasting and less smelly than the other monitor lizard in the area, a scavenger."
Science of the lizard
Although closely related to the slightly smaller Gray's monitor lizard (Varanus olivaceus), it remains separated from its cousin by a more than 90-mile (145 km) stretch that includes at least three river valley barriers. Genetic analysis confirms V. bitatawa is a new species, as do its coloration, scales, body size, and reproductive anatomy.
"Lizards keep their male reproductive organs inverted inside their bodies like a sock turned inside out, and when it's time to use them, they evert them, flipping them out of their body and filling them with fluid so they can rigidly protrude for reproduction," Brown said. "We call this a hemipenis, and lizards have two of them. They have elaborate structures that we assume are unique to each species — we think they have to fit like a lock and key, preventing hybridization between species."
Both males and females seem to possess golden stripes. "In general, reptiles are very visual, so the different coloration may serve as a signal to other members of its own species," Brown said. "Bright coloration often helps reptiles find and attract mates."
The new species is a keystone in its environment. It eats the fruit of the palm-like Pandanus trees, "and as the seeds travel through its gut, it helps remove their coats so they germinate faster, thus promoting forest growth," Brown said. "You see these trees growing in little circles like fairy rings, evidence that this lizard came by, spreading the seeds around the forest by dropping a bunch of scat."
The researchers expect the lizard to instantly become a flagship species for conservation.
"Given that rapid deforestation in the major threat to many Philippine species, especially the ones restricted to areas with tree cover, we suspect that the new species is a major conservation priority," Brown said. "We need to know the size of its home range, exactly what it eats, how long it takes to mature, how often it breeds, and details of its ecology and population structure."
Efforts to defend the lizard's forested habitat could help protect many hundreds to thousands of unrelated animals and plants as well, they added.
"It is a Philippine national treasure," Brown said.
Brown and his colleagues detailed their findings online March 7 in the journal Biology Letters.
New species of Papua New Guinea frog changes colour
All change for the Papua New Guinea frog (left: a young frog and right: an older member of the same species)
A new species of frog undergoes a remarkable transformation as it grows into an adult, report scientists.
Shiny black juvenile frogs with yellow spots dramatically change into peach coloured adults with bright blue eyes.
Scientists discovered the unique frog in a remote part of south-eastern Papua New Guinea.
The bright pattern of the young frog could act as a warning to predators, they say, but it is a mystery why the adult then loses this colour.
The scientists from Bishop Museum in Honolulu, Hawaii, US, report their findings in the journal Copeia.
Amphibian species come in a range of colours and patterns, from the brightly patterned poison dart frogs to the plainer greens of the common toad.
After metamorphosising from a tadpole, some frogs change in colour as they get older.
However, it is unknown for juveniles and adults of a species to have strikingly different colour and pattern schemes.
The research team came across the new species of frog Oreophryne ezra while on a expedition to find new species on Sudest Island, Louisiade Archipelago, off the south-eastern tip of New Guinea.
Of the new species they found, the frog particularly caught their attention.
"It's always exciting to discover a species you know to be new. However, the obviously unusual biology of this frog made its discovery especially exciting," says Dr Fred Kraus who along with Dr Allen Allison undertook the study.
"The remarkable thing about this frog is the drastic nature of its change in colour pattern as it matures from a tiny froglet into adulthood," Dr Kraus says.
As a juvenile the frog is dark black with yellow spots and black eyes but then switches to a uniform peach colour with blues eyes.
"This raises the question of what possible function the striking colours of the juveniles might serve," says Dr Kraus.
Juveniles closely resemble the general appearance of some of the poison dart frogs from the tropics.
Like these frogs, the colouration could serve as a warning to potential predators.
Although untested, the frog may also have harmful toxins in its skin like those present in poison dart frogs.
Poison dart frogs have skin that contains harmful alkaloids acting as a chemical defence against predation.
"If this is the case this would make this species another instance of the independent evolution of such a system," says Dr Kraus.
The behaviour of the frog also points to the idea that its colour advertises that it is toxic.
The researchers write how the juvenile frogs perch in conspicuous places during daylight hours and also demonstrated a lack of a well developed escape behaviour, indicating that they have another form of defence.
One aspect that cannot be explained is if the colour offers protection to the juvenile, why does the frog then change its colour scheme as it ages to one that offers no protection.
For now this poses further questions for the researchers.
"No other such instance is known in frogs," Dr Kraus says.
"If it does serve as protective warning colouration, the reason for its loss remains a mystery."
Axolotl eggs could provide a potent weapon in fight against cancer
By Darren Quick
January 19, 2011
A common cause of cancer is when cells are altered or mutated and the body’s tumor suppressor genes are switched off. Scientists at the University of Nottingham have managed to bring cancer cells back under control by reactivating the cells’ cancer suppressor genes using an extract from axolotl oocytes. The scientists say the discovery could form a powerful new technology platform for the treatment of a variety of cancers.
The process of cell division is controlled by specific genes and these are turned “on” or “off” depending on their function. Among the most important of these genes are tumor suppressor genes. These genes repress the development of cancers and normally act as a control point in the cell division cycle. Therefore, the switching off of tumor suppressor genes is a common cause of cancers.
The on/off switch in genes is controlled by the modification of proteins that are bound to the DNA in a cell, which are known as epigenetic modifications. Tumour suppressor genes in many cancers are switched off by epigenetic marks, which is the underlying cause of tumors.
In an effort to reverse this process the researchers looked to the axolotl salamander – an animal well known for its ability to regenerate most of its body parts. The scientists found that humans evolved from animals that closely resemble axolotls and therefore, proteins in axolotls are very similar to those in humans. Axolotl oocytes – eggs prior to ovulation – are also packed with molecules that have very powerful epigenetic modifying activity and a powerful capacity to change epigenetic marks on the DNA of human cells.
By treating the cancerous cells with axolotl oocyte extract, the researchers were able to reactivate the tumor suppressor genes and stop the cancer from growing. After 60 days there was still no evidence of cancerous growth.
The researchers say the identification of the proteins in axolotl oocytes responsible for this tumor reversing activity is a major goal of future research, and could form a powerful weapon in the fight against cancer.
The University of Nottingham team’s research appears in the journal Molecular Cancer.
A delicious bug meal, another way to reduce your carbon footprint.
There is a rational, even persuasive, argument for voluntarily eating insects: Bugs are high in protein, require less space to grow and offer a more environmentally friendly alternative to the vertebrates we Westerners prefer, advocates of the bug fare say.
However, this topic is not a hotbed of research, so while some data exist — in particular on the protein content of insects — there are some assumptions built into the latter part of this argument.
"The suggestion that insects would be more efficient has been around for quite some time," said Dennis Oonincx, an entomologist at Wageningen University in the Netherlands. He and other researchers decided to test it, by comparing the greenhouse gas emissions from five species of insects with those of cattle and pigs.
The results, Oonincx said, "really are quite hopeful."
For much of the world, eating insects — officially called entomophagy — is neither strange nor disgusting nor exotic. In southern Africa, Mopani worms — the caterpillars of Emperor moths — are popular snacks. The Japanese have enjoyed aquatic insect larvae since ancient times, and chapulines, otherwise known as grasshoppers, are eaten in Mexico. But these traditions are noticeably absent in Europe and European-derived cultures, like the United States.
Insects' nutritional content, small size and fast reproduction rates have also made them appealing solutions to problems traditional agriculture can't solve. For instance, a task force affiliated with the Japanese space agency has looked to insects like silkworms and termites as a self-replenishing supply of fats and amino acids for astronauts on extended missions.
For children from 6 months to 3 years of age, low calories and low protein are the main causes of death, about 5 million a year, according to Frank Franklin, a professor and director of pediatric nutrition at the University of Alabama at Birmingham. Protein from insects could offer a less expensive solution if processed into a form similar to Plumpy'Nut, a peanut-based food for those suffering from malnutrition, he said.
Franklin embraced the arguments for entomophagy after learning about it roughly a year ago.
"The more I looked at it, the more it made incredible sense that this would be an important nutritional advance that is only going to bring back what has probably been there since the primitive man," he told LiveScience.
A 2006 report by the U.N.'s Food and Agriculture Organization blamed the livestock sector for a sizable portion of humans' greenhouse gas emissions – 9 percent of our carbon dioxide emissions (much of this originates in changes in land use), 37 percent of our methane and 65 percent of our nitrous oxide emissions.
Oonincx and his colleagues used two important livestock animals, pigs and cattle, and compared existing data on their emissions of these greenhouse gases, plus ammonia, with data they collected from five species of insects: mealworms, house crickets, migratory locusts, sun beetles and Argentine cockroaches. The latter two species are not considered edible, at least not directly. Their taste is just not good, Oonincx said, however, protein extracted from them could be added to foods.
To quantify the animals' greenhouse gas footprints, the team measured the five insects' growth rates and their production of the greenhouse gases and ammonia — also a pollutant but not a greenhouse gas. They compared these to data already available on the cattle and pigs' growth rate and the rates at which they emitted the same pollutants.
Cattle produced the least carbon dioxide per unit of body mass. However, the picture changed once growth rate was considered. The data indicated that insects grow more rapidly, and they emit less carbon dioxide per unit of weight gained than do cattle and pigs. The cockroach was the clear winner in this latter category; meanwhile, cattle produced the most carbon dioxide per pound (or kilogram) gained. [The Truth about Cockroaches]
The insects generally produced less methane, nitrous oxide and ammonia both per unit of body mass and per unit of mass gained than pigs or cattle.
"It proves the hypothesis that insects can be a more efficient source [of protein], and I definitely believe there is a future for edible insects," Oonincx said. "It may not be as the animal as such but regarding protein extraction there is a lot to be learned and a lot to be gained."
Solving the livestock problem
There are strategies that can reduce greenhouse gas emissions associated with raising livestock but these improvements can't bring about reductions necessary to meet emissions targets intended to curb global warming, write the authors of a paper published in the medical journal the Lancet in November 2009.
Their solution: a 30 percent reduction in livestock production, and therefore, a drop in meat consumption. This would mean diets with less saturated fat and fewer premature deaths caused by heart disease, they write. (The researchers note that not everyone needs to reduce meat consumption; agriculture produces enough fat, protein and other nutrients to feed all of us, but food isn't distributed equally, resulting in malnutrition and starvation in some places.)
A policy that reduces our hamburgers and barbeque is likely to encounter resistance, one of the authors, Alan Dangour, of the London School of Hygiene & Tropical Medicine, acknowledged. However, so will a push to switch to insects, he told LiveScience in an e-mail.
"It is clearly worthwhile investigating alternative sources of high-quality protein," Dangourwrote. "However, the practical barriers to eating insects (in Westernized societies) are extremely large and perhaps currently even likely to be insurmountable."
David Gracer, an American advocate for entomophagy who co-organized a conference on the subject in December, welcomed the findings.
"It is wonderful to see science showing the world that what is instinctively apparent is actually factually correct," Gracer said. "The point is that most scientists in Western nations are too busy ignoring this subject to go ahead and take it seriously, and as soon as people do so, the experiments simply reinforce what we already assumed was true."
A vampire bat drinks fresh cow blood at the ZooAmerica North American Wildlife Park in Hershey. Researchers are using enzymes taken from vampire bat saliva to develop a blood-clot-dissolving drug called Draculin to help stroke victims recover.
The vampire bat leaned into the bowl of blood on Saturday morning and drank as easily as a cat would lap milk.
Not far away, a Gila monster stared at visitors with cold eyes, looking far too mellow to grip a small animal with crushing intensity and inflict a venomous bite.
Not all the animals at ZooAmerica North American Wildlife Park in Hershey are cute creatures.
But instead of saying ick, think about how bats and Gila monsters might be just what the doctor ordered.
Researchers are using enzymes taken from vampire bat saliva to develop a blood-clot-dissolving drug called Draculin (yes, named after Count Dracula) to help stroke victims recover. Researchers also have learned that a component of Gila monster venom can reduce blood-glucose levels, something potentially helpful to diabetics, officials at ZooAmerica said.
“Scientists study many species to see how they can help people,” said Dale Snyder, ZooAmerica general curator. “We don’t have the animals here just because they are beautiful, but for benefits down the road, too. A lot of these species hold promise for researchers.”
Snyder and Elaine Gruin, ZooAmerica curator of education, this weekend are discussing characteristics of the ZooAmerica species during the zoo’s 25th annual community weekend of free admissions. The event, which includes free parking, continues from 10 a.m. to 4:30 p.m. today.
Standing near 19 vampire bats, Gruin said that only three of 1,000 bat species drink blood. Vampire bats — nocturnal, flying mammals — weigh about 2 ounces.
Gruin said that after the bats use their sharp incisor teeth to bite into flesh, an anticoagulant in the bat’s saliva lets the blood flow instead of clotting. The bat then uses its grooved tongue to drink the flowing blood.
Vampire bat saliva, rich in anticoagulants, could reopen clogged human blood vessels so that damage and even death from some strokes could be prevented, she said. Patient testing is under way.
Vampire bats need about two tablespoons of blood a night, which they usually get from domestic animals such as cows, pigs and horses.
“Vampire bats are found in Mexico, Central America and northern South America but not here,” she said. “They can drink blood for up to a half hour but spend a lot of their time hanging upside down.”
Although bats have a bad reputation, Gruin said they’re useful, too.
“They eat thousands of insects a night, which makes them nature’s bug zappers,” she said. “Some bats pollinate. Some eat fruit seeds, then drop them elsewhere.”
Pennsylvania has nine species of bats, none of them blood-drinkers.
Snyder held a Gila monster, a sluggish 2-pound, 18-inch-long lizard. Gila monsters and Mexican beaded lizards are the only venomous lizards of the 3,000 lizard species in the world. Gila monsters live in Arizona, southern California and Mexico.
“We have four Gila monsters,” Snyder said. “When they bite, they’re hard to get off because they clamp down. The venom glands are in the lower jaw.”
He said that the opening and closing of the mouth sends the venom into the saliva, along the grooved teeth and into the intended victim. The longer the lizard holds on, the more severe the venomous bite.
All rights reserved. Commercial inquiries welcomed. Optimized for 1280 X 1024 screen resolution. Best viewed full screen with Chrome 4.0+, Firefox 3.0+, Internet Explorer 8.0+, Opera 9.0+ or Safari 4.0+