Tag Archives: animals

First Lungless Frog Found

The first recorded species of frog that breathes without lungs has been found in a clear, cold-water stream on the island of Borneo in Indonesia. The frog, named Barbourula kalimantanensis, gets all its oxygen through its skin.
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Previously the only four-limbed creatures known to lack lungs were salamanders. A species of earthwormlike, limbless amphibian called a caecilian is also lungless. Tetrapods, or four-limbed creatures, that develop without lungs are rare evolutionary events, Bickford and colleagues write.

The trait in amphibians is likely an adaptation to life between water and land and their ability to respire through the skin. The researchers suggest lunglessness in B. kalimantanensis may be an adaptation to the higher oxygen content in fast-flowing, cold water.
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Wake added that for most amphibians, the majority of gas exchange happens through the skin. A low but significant amount of respiration occurs via simple, sac-like lungs. Most species, he noted, have mating calls that require lungs. So biologists are unsure why a few species have entirely gotten rid of the organs, Wake said.

Secrets of Spider Silk’s Strength

The strength of a biological material like spider silk lies in the specific geometric configuration of structural proteins, which have small clusters of weak hydrogen bonds that work cooperatively to resist force and dissipate energy, researchers in Civil and Environmental Engineering have revealed.

This structure makes the lightweight natural material as strong as steel, even though the “glue” of hydrogen bonds that hold spider silk together at the molecular level is 100 to 1,000 times weaker than the powerful glue of steel’s metallic bonds or even Kevlar’s covalent bonds.
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“Using only one or two hydrogen bonds in building a protein provides no or very little mechanical resistance, because the bonds are very weak and break almost without provocation,” said Buehler, the Esther and Harold E. Edgerton Assistant Professor in the Department of Civil and Environmental Engineering. “But using three or four bonds leads to a resistance that actually exceeds that of many metals. Using more than four bonds leads to a much-reduced resistance. The strength is maximized at three or four bonds.”

Giant Star Fish and More in Antarctica

photo of giant starfish

Photo by John Mitchell, New Zealand’s National Institute of Water and Atmospheric Research. Read a great deal about the New Zealand Census of Antarctic Marine Life project: 26 scientists and 18 crew took a 50-day voyage aboard RV Tangaroa in February-March 2008.

Benthic invertebrates in Antarctica are well known for their large size. This feature, known as “gigantism” is common amongst certain groups including sea spiders, sponges, isopods, starfish, and amphipods. The phenomenon is a subject of intense scientific investigation, but there are many contributing factors.

Slow growth rates, late reproductive maturation, prolonged periods of embryonic development, and low predation rates that are typical of Antarctic waters contribute to long life-spans for many species and can also result in large size animals. Animal physiology is thought to play a role as well, as those groups that require large amounts of calcium should not, in theory, grow well in Antarctic waters. This is because the calcium carbonate (needed for growth of shells, or starfish ‘tests’) has low solubility in very cold seawater. Yet starfish, which have a calcareous exoskeleton or ‘test’ which needs lots of calcium, can reach much larger sizes than found in New Zealand waters, as seen in [photo].

Another crucial part of the story is that the low sea temperatures allow more oxygen to be dissolved in the sea water than in warmer latitudes. Sea spiders for example are not only larger, but reach more than 1000 times the weight of most temperate species. Amphipod crustaceans in the Southern Ocean are also large; more than five times as long as the largest temperate species.

Baby Sand Dollars Clone Themselves When They Sense Danger

Baby sand dollars clone themselves when they sense danger

The odds of growing up aren’t good for baby sand dollars. Smaller than the head of a pin, the larvae drift in the ocean — easy prey for anything with a mouth.

But a University of Washington graduate student has discovered the tiny animal has a surprising survival strategy: Faced with the threat of being gobbled up, it makes like Dr. Evil from the Austin Powers movies and clones itself. The resulting “mini-me” may escape hungry fish because it is even teenier than the original — and harder to see.

“If you are eaten, but the smaller version of you survives, you’re still a winner from an evolutionary standpoint,” said Dawn Vaughn.
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Familiar inhabitants of Washington’s subtidal zone, sand dollars start life though the chance encounter of sperm and egg, simultaneously released into the water by mature adults. The larvae free-float for about six weeks before metamorphosing into miniature sand dollars that settle in colonies and eventually grow to full size.
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The white shells that wash up on the beach are the creatures’ external skeletons. Living sand dollars are covered with velvety, purple spines used to grab food particles. Vaughn knew many other marine invertebrates shift their shape to avoid being eaten. Colonial animals called bryozoans grow spikes when voracious sea slugs crawl across them. Barnacles take on a bent posture to repel snails. Vaughn’s own previous research showed periwinkle larvae narrow their shell openings to keep out marauding crab larvae.

Photos by Fritz the Cat

Fritz the cat - photographer

fritz-cam by Fritz the cat:

My name is Fritz [photo of me on the left] and I live at 23 Cat Street [in Germany]. My mistress is an artist, and now it’s my turn to show what I can do. Since September 2007 we’ve owned a Mr-Lee-Catcam
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Third time lucky. I went for a long walk with the camera. Perhaps a bit too long, because she was looking for me everywhere. Anyway, she was very pleased when I came home with the camera and a mouse. I’d taken over 200 photos while I was out. Unfortunately the battery gave up the ghost before the final capture … of the mouse, I mean.

See many more great photos by fritz at fritz-cam.

Dolphin Rescues Beached Whales

New Zealand dolphin rescues beached whales:

The pygmy sperm whales had repeatedly beached, and both they and the humans were tired and set to give up, he said. But then the dolphin appeared, communicated with the whales, and led them to safety.

The bottlenose dolphin, called Moko by local residents, is well known for playing with swimmers off Mahia beach on the east coast of the North Island.
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Mr Smith said he felt fortunate to have witnessed the extraordinary event, and was delighted for the whales, as in the past he has had to put down animals which have become beached. He said that the whales have not been seen since, but that the dolphin had returned to its usual practice of playing with swimmers in the bay.

“I shouldn’t do this I know, we are meant to remain scientific,” Mr Smith said, “but I actually went into the water with the dolphin and gave it a pat afterwards because she really did save the day.”

Dino-Era Feathers Found Encased in Amber

Seven dino-era feathers found perfectly preserved in amber in western France highlight a crucial stage in feather evolution, scientists report. The hundred-million-year-old plumage has features of both feather-like fibers found with some two-legged dinosaurs known as theropods and of modern bird feathers, the researchers said.
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The find provides a clear example “of the passage between primitive filamentous down and a modern feather,” said team member Didier NÃ©raudeau of the University of Rennes in France. The study team isn’t sure yet whether the feathers belonged to a dino or a bird. But fossil teeth from two dino families thought to have been feathered were excavated from rocks just above the layer that contained the amber, Perrichot said. “It is entirely plausible that the feathers come from a dinosaur rather than from a bird,” he said.

Antarctic Fish “Hibernate” in Winter

This is the first time fish have been seen actively becoming torpid—a state similar to hibernation in land animals—as part of an annual cycle. “A lot of freshwater fish go [unexpectedly] dormant in winter because a drop in temperature lowers their metabolism,” said study co-author Hamish Campbell, a zoologist at the University of Queensland, Australia.

“By contrast, these Antarctic fish actively reduce their ‘cost of living,'” he said… “The fish became 20 times less active in winter compared to summer,”… About every week or so the cod wake up and swim around for a few hours, the team observed. “This is quite similar to ‘denning’ in bears, where the hibernation isn’t so deep and the animals can be disturbed, then spend some time awake before going back to bed,” Fraser said.

Full paper: Hibernation in an Antarctic Fish: On Ice for Winter – Arctic Sharks – Antarctic Robo-sub

Ancient Sea Monster

Sea reptile is biggest on record

A fossilised “sea monster” unearthed on an Arctic island is the largest marine reptile known to science, Norwegian scientists have announced. The 150 million-year-old specimen was found on Spitspergen, in the Arctic island chain of Svalbard, in 2006. The Jurassic-era leviathan is one of 40 sea reptiles from a fossil “treasure trove” uncovered on the island. Nicknamed “The Monster”, the immense creature would have measured 15m (50ft) from nose to tail.
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Unfortunately, there was a small river running through where the head lay, so much of the skull had been washed away. A preliminary analysis of the bones suggests this beast belongs to a previously unknown species.

Your Inner Fish

photo of Neil Shubin

Your Inner Fish: A Journey into the 3.5-Billion-Year History of the Human Body by Neil Shubin. A great piece from the University of Chicago, Fish out of Water, provides a good preview to the book:

What are the leading causes of death in humans? Four of the top ten causes—heart disease, diabetes, obesity, and stroke – have some sort of genetic basis and, likely, a historical one. Much of the difficulty is almost certainly due to our having a body built for an active animal but the lifestyle of a spud.
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The problem is that the brain stem originally controlled breathing in fish; it has been jerry-rigged to work in mammals… This works well in fish, but it is a lousy arrangement for mammals.
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The example from microbes is not unique. Judging by the Nobel Prizes awarded in medicine and physiology in the past 13 years, I should have called this book Your Inner Fly, Your Inner Worm, or Your Inner Yeast. Pioneering research on flies won the 1995 Nobel Prize in medicine for uncovering a set of genes that builds bodies in humans and other animals. Nobels in medicine in 2002 and 2006 went to people who made significant advances in human genetics and health by studying an insignificant-looking little worm (C. elegans). Similarly, in 2001, elegant analyses of yeast (including baker’s yeast) and sea urchins won the Nobel in medicine for increasing our understanding of some of the basic biology of all cells. These are not esoteric discoveries made on obscure and unimportant creatures. These discoveries on yeast, flies, worms, and, yes, fish tell us about how our own bodies work, the causes of many of the diseases we suffer, and ways we can develop tools to make our lives longer and healthier.

Two of my more controversial posts have been: Evolution is Fundamental to Science and Understanding the Evolution of Human Beings by Country. Evolution is not controversial scientifically. Just as gravity is not. Obviously this understanding is far from universal however.

But it is just a matter of time: similar to Galileo Galilei and heliocentric cosmology. See: Galileo’s Battle for the Heavens – Copernican System – Galileo). We now sit maybe 100 years after Galileo’s death (based on the evidence available in support of each scientific theory). At some point the evidence is accepted and life continues. Though I must admit it, I find it a bit disappointing how long it is taking for some people to accept the evidence of evolution. But I probably need to learn to be more patient – I have been told that more than once. All I can do is try to help present some small amount of the great work so many scientists have done to advance our knowledge. And here I am talking about evolution – for the 28% of those in the USA that couldn’t provide the answer that earth revolves around the sun, in 1998, well, they need much more help than I can provide.