| Observatory: Special Adhesive Helps Oysters Stick Together Understanding more about the unique, protein-based oyster adhesive could help scientists develop better synthetic glues for medical use. feeds.nytimes.com |
The Beagle, the astronaut and a party in Brazil put the awe back into science | Karen James A collaboration between the Beagle Project and Nasa is working to inspire kids to follow in the path of Charles DarwinKaren James is a botanist and blogs at the Beagle Project BlogBefore joining Nasa as a space medicine specialist, astronaut Michael Barratt had been a zoology graduate. He described himself as a James Cook freak, a sailing enthusiast and, at one time, a wannabe marine biologist.Three years ago, still an astronaut-in-training, Barratt came across a news snippet that caught his attention. A British team was planning to rebuild HMS Beagle, the ship that bore Charles Darwin on his historic voyage of discovery 180 years ago, as a way to "put the awe back into science". He decided to get in touch, to see how he might be able to help.As science director for the Beagle Project, I get a fair number of expressions of interest by email. None of them quite compared to the note I got from Barratt, though. Under the innocuous subject heading, "com request", Barratt explained that he was training for a six-month tour of duty, scheduled for 2009, aboard the International Space Station (ISS), and asked whether this might coincide with the inaugural voyage of the rebuilt Beagle. If so, could he help by providing some imagery of the voyage from space – plankton blooms, ships' wakes and other phenomena? Nasa, he said, and the Beagle Project had some joint goals to inspire new generations of scientists and explorers. He proposed that, as long as we were willing to weather some Nasa bureaucracy, we start up a collaboration.As a scientist and daughter of an officer in the US Air Force, this made me leap out of my chair and run shrieking up and down the modest length of my London flat. The delight stayed with me as we jumped through the bureaucratic hoops together and ultimately signed a formal International Space Act Agreement in October 2008, outlining plans for joint activities in science, education and public affairs. Astronauts aboard the ISS would track the voyage in photographs to correlate with physical data and biological specimens collected by scientists, teachers and students aboard the new Beagle as she circles the world over the course of several years, recreating Darwin's 1831-36 voyage aboard HMS Beagle."The voyage of the Beagle has been by far the most important event in my life and has determined my whole career," Darwin wrote in his autobiographical recollections, a full 40 years after his trip. "I have always felt that I owe to the voyage the first real training or education of my mind … I feel sure that it was this training which has enabled me to do whatever I have done in science."Inspiration, then, fuelled by adventure, was the trigger for Darwin's lifelong commitment to science. Over the past few years the Beagle Project team has worked to bring the adventure of science back into focus.Our plan is to raise £5m to rebuid HMS Beagle and a further £10m to sail her around the world in the wake of the same voyage of discovery that inspired Darwin to devote himself to science.Designed by master shipwright Detlev Loell, the new Beagle will be a modern rebuild of the ship Darwin boarded in 1831. Built in Pembrokeshire, where dry-dock space has already been designated for the purpose by the Milford Haven Port Authority, the new Beagle will be built of larch and oak planking on oak frames, just like her predecessor.But there are some advantages to building a square-rigger in the 21st, rather than the 19th century. As befits a modern working research vessel, she will have diesel auxiliary engines, radar, GPS navigation, satellite communications and modern safety equipment. And she will be equipped with laboratories and equipment to enable contemporary, original research. This is not only in keeping with Darwin's legacy but also creates an opportunity to engage students, teachers and other participants in the excitement of real scientific discovery.We're still working to raise the money needed to build and sail the new Beagle. But the delay hasn't stopped us from carrying out parts of our mission already.In September 2009, with Barratt six months into his seven-month flight aboard the ISS, we took part in a week of events in Paraty, Brazil, 250 kilometres south-west of Rio de Janeiro. The event was a mini version of our ultimate plan for the voyage of the new Beagle and brought together more than 20 professional scientists, including marine researchers from around South America, the UK and the US, and 60 local school children.Supported by the British Council, we put on a scientific workshop to identify research opportunities on sailing vessels, undertook two short voyages aboard the traditionally rigged Brazilian tall ship Tocorimé Pamatojari, or Spirit of Adventure (fitting considering the fact that HMS Beagle was originally supported by HMS Adventure during her 1831-36 voyage) and made sea-to-space connections with Barratt aboard the ISS.The highlight was a live, public audio link-up between the children and Barratt. Little voices asked well-rehearsed questions (in English), each ending with a loud and emphatic "OVER". Wide-eyed, delighted faces greeted Barratt's answers from the ISS, as he hurtled around the Earth at 17,500mph. There were tears in the audience that day."Space stations, square riggers and marine biology: science does not get more exciting than this, and we need to get the inquiring young minds of today excited by science," Barratt said. "The ISS circling the world while a scientific square rigger with Beagle's pedigree rounds Cape Horn, making new discoveries at sea and on land, streaming footage back to labs and classrooms will be a great way to welcome young minds into the excitement and adventure of science."Darwin would have been proud.Karen James is a botanist and blogs at the Beagle Project BlogClick here to donate to the Beagle ProjectInternational space stationNasaCharles DarwinPeople in scienceBiologySpaceguardian.co.uk © Guardian News & Media Limited 2010 | Use of this content is subject to our Terms & Conditions | More Feeds guardian.co.uk |
You've discovered a whacky wood-eating catfish? So what's new? | GrrlScientist The press has recently been abuzz with news of a newly discovered species of catfish that eats wood, of all thingsThe press has recently been abuzz with news of a newly discovered species of catfish that eats wood, of all things. But since at least the 1990s, scientists have known that some catfish species consume wood. The news stories I have read haven't done a particularly good job of describing why journalists are so intrigued by this discovery, beyond the obvious twist: a fish that eats wood. But these fish are popular pets: If you look at the tropical fishes available for sale in your local pet shop, then you have probably seen at least one of the dozen or so species that are placed into the genus, Panaque. (For example, today in my local pet shop, there were three Panaque species - all coyly hiding under submerged bits of wood, so I couldn't get a decent photograph to share with you.)Panaque are medium to large freshwater fish that are placed in the taxonomic family Loricariidae, a large group of catfishes that are united by several common characteristics: their powerful suckermouths and the tough plates covering their bodies. Whilst Loricariidae are found throughout tropical and subtropical rivers in Central and South America, the Panaque, which are the wood-eating specialists in the family, appear to be limited to the Magdalena, Orinoco and Amazon River basins. These fish go by a number of names. The genus name "Panaque" (pronounced "pan ack" in Britain and Europe, and as either "pan aki" or "pan a kay" in America), is the Latinisation of a native Venezuelan name for these fish. The local indigenous people, the Sharanahua, call it Ishgunmahuan - "large armored catfish." Indeed, the Sharanahua are quite familiar with this new Panaque species, because it is a popular item on the menu. The fish, which can reach 70cm (2ft 3in) in length, can be located by characteristic rasping sounds produced when they chew on submerged wood. "They seem to be really tough to find and catch. You have to catch them with gill nets or cast nets, or shoot them," explained Paulo Petry, who is formally describing the new species for science based on three individual fish that he and his colleague, Peruvian biologist Roberto Quispe, captured. "Since they eat wood, you're not going to catch them with a line." Dr Petry, a zoology professor at Harvard University is also the Nature Conservancy's freshwater specialist for Latin America. During this past summer, Dr Petry was part of a scientific expedition to one of the remotest places on the Amazon River; the Fitzgerald Arch, located in Peru. The trip was sponsored by the US National Science Foundation and took place between 21 July and 3 August. "Right now, it's fairly isolated there," said Dr Petry. "There are just two flights a month there from [the] Peruvian Air Force to provide supplies. The other way to get in is by river, which is a very long way. We chartered a flight in there, flying over the most pristine rainforest you will ever see."Even though this species of Panaque had been previously known only from dried pieces of several specimens that the locals captured, this was the first time that live specimens had been captured and studied by scientists. "The particular specimens that we captured are the first that are fresh specimens, so we have the entire fish from which to take tissue samples," said Dr Petry, thereby allowing scientists to formally describe the species. "The formal complete description of this species will be published in December in the Copeia magazine," Dr Petry added. That description will no doubt carefully document one of the features that is unique to the Panaque: their teeth. Even though it is common for the 700+ species of armoured catfishes to suck organic material -- such as insect larvae, algae, microbes and detritus -- from the surfaces of submerged objects, actually ingesting wood is apparently unique to Panaque. Thus, these fish evolved special "spoon-shaped teeth" especially for this job (see electron micrographs in top right and lower left panels in the figure below).But how did such a unique diet evolve in fish? Xylivory -- wood-eating -- likely evolved due to competition with other catfish species for food in the Amazon Basin rivers, said the researchers.Ecophysiologist Donovan German, who did not participate in the expedition, provided additional insight. Dr German is a postdoctoral researcher at the University of California at Irvine, but while a graduate student in biology at the University of Florida, he studied the digestive physiology of wood-eating catfish. These fish are not strong swimmers so they have to attach themselves to a solid object with their powerful sucking mouth to avoid being washed downstream. "There're not a lot of rocks in the Amazonian Basin, where these fishes live," explained Dr German. "There's mud and water, and the one consistent substrate at the bottom is wood. It's [also] the one place where fish can go to get food off a surface." But are Panaque species true xylivores -- are they actually digesting the wood they consume, as do beavers, porcupines and termites? The same question occurred to Dr German while he was in graduate school. To better understand the structure and function of the gastrointestinal (GI) tracts of wood-eating catfishes, Mr German conducted a series of comparisons between the intestinal structure of wild-caught Panaque and a closely-related species detritus-feeding fish that does not consume wood. In short, Mr German found that Panaque digestive tracts are similar in shape and size to those of detritivorous fish. Panaque had none of the special anatomical features that other wood-eating animals possess for providing a home for beneficial bacteria that break down wood so the fish may then absorb the nutrients. [DOI: 10.1007/s00360-009-0381-1]"People think they must have an amazing consortium of microbes in their guts to help the fish digest wood, but that isn't really what I've found," Dr German pointed out. Earlier work that attempted to isolate gut microbes and identify digestive enzymes that break down various components of wood provided ambiguous results. [DOI: 10.1111/j.1095-8649.1999.tb00858.x] The other key factor suggesting that Panaque probably do not digest wood is their rapid gut transit time, which reduces the numbers of wood-digesting bacteria that can reside in their intestinal tract. "The fish pass wood through their guts in less than four hours, which is incredibly fast for an animal that supposedly digests wood," remarked Dr German. Wood-digesting animals typically retain wood in their GI-tracts for longer than 24 hours. At this time, it is thought that wood-eating catfish are not digesting wood at all but, by chewing up rotting wood into tiny pieces, they are digesting the organic matter, microbes, and microbial byproducts that reside in the spaces between wood fibers. The wood itself is excreted as waste. "The amazing microbes are in the river, on the wood itself."Due to their feeding behavior, Panaque catfishes appear to play a valuable role in the ecology of the Amazonian rainforest. By reducing large chunks of wood into microscopic fragments they are speeding up the process of decay and carbon recycling within the environment. According to Dr Petry, these fish are found in an area that is filled-to-bursting with biodiversity -- a poorly-known area that is under threat from development. "There are several proposed infrastructure development projects and roads -- with them will come lumber extraction, cattle ranching and slash-and-burn agriculture," stated Dr Petry. He also noted that on average, over 100 new fish species are discovered every year in South America. This year alone, 69 new species have been described thus far. "These numbers show very clearly that we are far from knowing the number of freshwater species in South America."This makes me wonder how many species will disappear before we even know they are there? And how will this loss of biodiversity affect these ecosystems?Sources:Nelson, J., Wubah, D., Whitmer, M., Johnson, E., & Stewart, D. (1999). Wood-eating catfishes of the genus Panaque: gut microflora and cellulolytic enzyme activities Journal of Fish Biology, 54 (5), 1069-1082 DOI: 10.1111/j.1095-8649.1999.tb00858.xGerman, D. (2009). Inside the guts of wood-eating catfishes: can they digest wood? Journal of Comparative Physiology B, 179 (8), 1011-1023 DOI: 10.1007/s00360-009-0381-1Quotes:Nature Conservancy interview [30 August 2010]GrrlScientistguardian.co.uk © Guardian News & Media Limited 2010 | Use of this content is subject to our Terms & Conditions | More Feeds guardian.co.uk |
EU experts to tackle toxic sludge EU experts are to begin work in Hungary to assess the toxic sludge spill as officials try to lessen the impact of an "inevitable" new reservoir collapse. bbc.co.uk |
Gulf corals in oil spill zone appear healthy By BRIAN SKOLOFF 2010-10-22T15:32:40ZON THE FLOOR OF THE GULF OF MEXICO (AP) -- Just 20 miles north of where BP's blown-out well spewed millions of gallons of oil into the sea, life appears bountiful despite initial fears that crude could have wiped out many of these delicate deepwater habitats.... hosted.ap.org |