Transplanted seaweed is attached to a reef by a team member. Credit: Image courtesy of University of New South Wales
Marine ecologists in Sydney have successfully restored a once thriving seaweed species, which vanished along a stretch of the city’s coastline during the 1970s and 80s when there were high levels of sewage.
A team of researchers from UNSW, the Sydney Institute of Marine Science and the NSW Department of Primary Industries has transplanted fertile specimens of the missing crayweed (Phyllospora comosa) onto two barren reef sites where it once grew abundantly.
They took seaweed from Palm Beach and Cronulla and transplanted it to Long Bay and Cape Banks. Their results are reported in the journal PLOS ONE.
“Seaweeds are the ‘trees’ of the oceans, providing habitat structure, food and shelter for other marine organisms, such as crayfish and abalone,” says lead author, Dr Alexandra Campbell, from the UNSW Centre for Marine Bio-Innovation.
“The transplanted crayweed not only survived similarly to those in natural populations, but they also successfully reproduced. This creates the potential for a self-sustaining population at a place where this species has been missing for decades,” she says.
Large brown seaweeds — known as macroalgae — along temperate coastlines, like those in NSW, also encourage biodiversity and are important to the region’s fishing and tourism industries.
However, these seaweed ecosystems face increasing threats of degradation due to human impacts and ocean warming. The authors say the potential environmental and economic implications of losing these habitats would be comparable to the more highly publicised loss of Australia’s tropical coral reefs.
In 2008, researchers from UNSW and the NSW Department of Primary Industries (DPI) showed that a 70 km stretch of this important habitat-forming crayweed had vanished from the Sydney coast decades earlier, coinciding with a period known for high levels of sewage.
Despite improved water quality around Sydney after the introduction of better infrastructure in the 1990s, which pumped sewage into the deeper ocean, the 70 km gap of depleted ‘underwater forest’ — between Palm Beach and Cronulla — has never been able to recover naturally.
Now, with some well-executed intervention, it looks as though this habitat-forming crayweed could make a successful comeback in Sydney’s coastal waters.
“This is an environmental good news story,” says research supervisor UNSW Professor Peter Steinberg, Director of the Sydney Institute of Marine Science.
“This kind of restoration study has rarely been done in these seaweed-dominated habitats, but our results suggest that we may be able to assist in the recovery of underwater forests on Sydney’s reefs, potentially enhancing biodiversity and recreational fishing opportunities along our coastline.”
The researchers say their results could provide valuable insights for restoring similar macroalgae marine ecosystems in Australia and globally, but further research is needed to understand the complex processes that affect recruitment and survival.
This project was funded in part by a grant from the NSW Recreational Fishing Trust.
Originally Published here: http://newsroom.unsw.edu.au/news/science/bald-reef-gets-seaweed-transplant
Posted January 27th, 2014. Add a comment
The Edwardsiela andrillae sea anemone measures less than 1 inch in length. (Credit: Courtesy Frank Rack, ANDRILL Science Management Office, University of Nebraska-Lincoln)
Using a camera-equipped robot to explore beneath the Ross Ice Shelf off Antarctica, scientists and engineers with the Antarctic Geological Drilling (ANDRILL) Program made an astonishing discovery.
Thousands upon thousands of small sea anemones were burrowed into the underside of the ice shelf, their tentacles protruding into frigid water like flowers on a ceiling.
“The pictures blew my mind,” said Marymegan Daly of Ohio State University, who studied the specimens retrieved by ANDRILL team members in Antarctica.
The new species, discovered in late December 2010, was publicly identified for the first time in a recent article in the journal PLoS ONE.
Though other sea anemones have been found in Antarctica, the newly discovered species is the first known to live in ice. They also live upside down, hanging from the ice, compared to other sea anemones that live on or in the sea floor.
The white anemones have been named Edwardsiella andrillae, in honor of the ANDRILL program. The discovery was “total serendipity,” said Frank Rack, executive director of the ANDRILL Science Management Office at the University of Nebraska-Lincoln and associate professor of Earth and atmospheric sciences at UNL.
“When we looked up at the bottom of the ice shelf, there they were,” he said.
Scientists had lowered the robot, a 4 1/2-foot cylinder equipped with two cameras, a side-mounted lateral camera and a forward-looking camera with a fish-eye lens, into a hole bored through the 270-meter-thick shelf of ice that extends more than 600 miles northward into the Ross Sea from the grounding zone of the West Antarctic Ice Sheet.
Their mission, financed by the National Science Foundation in the U.S. and the New Zealand Foundation for Research, was to learn more about the ocean currents beneath the ice shelf and provide environmental data for modeling the behavior of the ANDRILL drill string, Rack said. They didn’t expect to discover any organisms living in the ice, and surely not an entirely new species.
The discovery indicates that, even after 50 years of active U.S. research, more remains to be studied about the southernmost continent, said Scott Borg, head of the Antarctic Sciences Section in the NSF’s Division of Polar Programs.
“Just how the sea anemones create and maintain burrows in the bottom of the ice shelf, while that surface is actively melting, remains an intriguing mystery,” he said. “This goes to show how much more we have to learn about the Antarctic and how life there has adapted.”
Rack, who is U.S. principal investigator for the environmental surveys that were conducted as part of the international ANDRILL Coulman High project, had left the site just prior to the discovery. He was listening by radio when he heard the report from the robot deployment team — engineers Bob Zook, Paul Mahecek and Dustin Carroll — who began shouting as they saw the anemones, which appeared to glow in the camera’s light.
“They had found a whole new ecosystem that no one had ever seen before,” Rack said. “What started out as a engineering test of the remotely operated vehicle during its first deployment through a thick ice shelf turned into a significant and exciting biological discovery.”
In addition to the anemones, the scientists saw fish that routinely swam upside down, the ice shelf serving as the floor of their undersea world. They also saw polychaete worms, amphipods and a creature they dubbed “the eggroll,” a 4-inch-long, 1-inch-diameter, neutrally buoyant cylinder that seemed to swim using appendages at both ends of its body. It was observed bumping along the field of sea anemones under the ice and hanging on to them at times.
The anemones measured less than an inch long in their contracted state — though they get three to four times longer in their relaxed state, Daly said. Each features 20 to 24 tentacles, an inner ring of eight longer tentacles and an outer ring of 12 to 16 tentacles. After using hot water to stun the creatures, the team used an improvised suction device to retrieve them from their burrows. They were then transported to McMurdo Station for preservation and further study.
Because the team wasn’t hunting for biological specimens, they were not equipped with the proper supplies to preserve them for DNA/RNA analyses, Rack said. The anemones were placed in ethanol at the drilling site and some were later preserved in formalin at McMurdo Station.
Many mysteries remain. Though some sea anemones burrow into sand with tentacles or by expanding and deflating the base of their bodies, those strategies don’t seem feasible for ice. It is also unclear how they survive without freezing and how they reproduce. There is no evidence of what they eat, although they likely feed on plankton in the water flowing beneath the ice shelf, Daly said.
Rack said a proposal is being prepared for further study of this unusual environment using a robot to explore deeper in the ocean and further from the access hole through the ice. NASA is helping finance the development of the new underwater robot because the Antarctic discoveries have implications for the possibility of life that may exist on Europa, the ice-covered moon of Jupiter.
He said researchers hope to return to Antarctica as early as 2015 to continue studying the sea anemones and other organisms beneath the ice shelf.
Originally published here: http://newsroom.unl.edu/releases/2014/01/16/ANDRILL+team+discovers+ice-loving+sea+anemones+in+Antarctic
Posted January 23rd, 2014. Add a comment
The conch snail, which uses a strong foot to leap away from approaching predators, either stops jumping, or takes longer to jump, when exposed to the levels of carbon dioxide projected for the end of this century. (Credit: ARC Centre of Excellence in Coral Reef Studies)
Sea snails that leap to escape their predators may soon lose their extraordinary jumping ability because of rising human carbon dioxide emissions, a team of international scientists has discovered.
Lead author of the study published today, Dr Sue-Ann Watson from the ARC Centre of Excellence for Coral Reef Studies (Coral CoE) and James Cook University observed that the conch snail, which uses a strong foot to leap away from approaching predators, either stops jumping, or takes longer to jump, when exposed to the levels of carbon dioxide projected for the end of this century.
Dr Watson explains that increased carbon dioxide and ocean acidification levels disrupt a particular neurotransmitter receptor in the snail’s nervous system, delaying vital decision-making on escape. This leaves the snail more vulnerable to the poisonous dart of its slow-moving nemesis, the marbled cone shell. The effects may be quite profound. “Altered behaviours between predators and prey have the potential to disrupt ocean food webs,” Dr Watson said. While this study shows that disrupted decision-making with elevated carbon dioxide levels can occur in marine invertebrates, scientists have also observed similar effects before, in fish. Co-author Professor Göran Nilsson, from the University of Oslo, explains, “this neurotransmitter receptor is common in many animals and evolved quite early in the animal kingdom. So what this study suggests is that human carbon dioxide emissions directly alter the behaviour of many marine animals, including much of the seafood that is part of the human diet.” Professor Philip Munday, from the Coral CoE, says past studies on the effects of ocean acidification on animals mostly focused on what would happen to the shells of marine snails and other calcifying animals — how could shells be built and maintained in a more acidic environment? This study shows that they actually face the dual threat of both weaker shells and impaired behaviour. Professor Munday says it is critical to study and understand more about the extent of these behavioural disturbances. The big question now, he adds, is whether sea creatures can adapt fast enough to keep up with the rapid pace of rising carbon dioxide levels and ocean acidification. The article ‘Marine mollusc predator-escape behaviour altered by near-future carbon dioxide levels‘ by Sue-Ann Watson, Sjannie Lefevre, Mark I. McCormick, Paolo Domenici, Göran E. Nilsson and Philip L. Munday appears in Proceedings of the Royal Society B: Biological Sciences.
Originally published here: http://www.coralcoe.org.au/news/jumping-snails-left-grounded-in-future-oceans
Posted January 20th, 2014. Add a comment
An adult European eel Anguilla anguilla. (Credit: J. Schröder, GEOMAR)
The European eel is one of the world’s many critically endangered species. Comprehensive protection is difficult because many details of the eel’s complex life cycle remain unknown. In a multidisciplinary study, biologists and oceanographers at GEOMAR recently demonstrated the crucial influence of ocean currents on eel recruitment. They did so by using, among others, a state-of-the-art ocean model developed in Kiel, in combination with genetic studies. The study appears in the international journal Current Biology.
Smoked, fried or boiled — the European eel (Anguilla anguilla) has always been a popular fish in Europe. Even though people have consumed it for millennia, the origin of the eel has long been shrouded in mystery. While the fish spend most of their lives in fresh and coastal waters, spawning and the birth of the larvae take place in the Sargasso Sea in the central Atlantic Ocean, about 4500 km away from the European coastlines. “Because the observation of eels in the Sargasso Sea is scarcely possible, some details of the life cycle are still unknown” says biologist Miguel Baltazar-Soares, from GEOMAR Helmholtz Centre for Ocean Research Kiel.
In a multidisciplinary study recently published in the international journal “Current Biology,” biologists, geneticists and theoretical oceanographers at GEOMAR, together with colleagues from Hamburg, London, Belfast and Antofagasta (Chile), discovered a relationship between ocean currents and the variation in eel recruitment.
The study is based on a latest generation ocean model developed in Kiel. Originally it was used to simulate the effects of melting Greenland glaciers on the North Atlantic. “It has a resolution approximately ten times larger than the conventional ocean and climate models,” explains Prof. Dr. Arne Biastoch, a theoretical oceanographer at GEOMAR. “The new model allows us to understand even small-scale changes in the ocean, so we came up with the idea of using it for a simulation of eel migrations,” adds Miguel Baltazar-Soares, lead author of the new study.
The model simulation was run for 45 years, and in each of these years, the researchers seeded the Sargasso Sea with 8 million tiny drifting particles. “They represent the eel larvae which, for the first few years of their life, mainly drift with the currents,” says biologist Dr. Christophe Eizaguirre from GEOMAR, who initiated the study. External factors, like wind and weather conditions, were the same in the model as the conditions observed in each year from 1960 to 2005. “We were able to track how the larvae migrated to Europe. Only those who reached the European shelf seas within two years were considered viable. This also corresponds to eel life cycle,” explains Dr. Eizaguirre.
In fact, the eel recruitment in the model fluctuated significantly, mimicking the patterns reported across Europe. “In the early 1980s, for example, only a fraction of the larvae managed their way to Europe,” reports Professor Biastoch. The researchers found that small-scale, wind-driven ocean currents strongly determine the eel population fluctuation. Depending on the presence of regional currents in the Sargasso Sea, the larvae’s path to Europe was either extended and led to low recruitment or shortened leading to high recruitment in Europe. “We had not seen these flow changes in any of the older ocean models. But they seem to play a crucial role in the migration of the eel larvae,” explains Professor Biastoch.
Combining those discoveries with genetic analyses, the scientists found evidence that, contrary to what is typically thought, eels do not return to random locations in the Sargasso Sea to reproduce but rather return to where their mother spawned in particular locations within the Sargasso Sea. “This is a new finding — so far, it was assumed that the mating in the Atlantic takes place completely independent of the area of origin and future scientific expeditions will have to verify this result in situ ” says Baltazar-Soares.
The ultimate fate of eels making the long migration from the Sargasso Sea to the continental waters of Europe is still very difficult to predict, even using state of the art techniques. Indeed, from the 1960s to the 1980s, the results of the computer simulation matched up well with the observed occurrence of young eels reaching the European coasts. After that, however, the status of eel populations seems to be disconnected from the climatic influences in the Atlantic. “Since then fishing pressure, habitat destruction in European rivers and diseases appear to play an increased role” said Baltazar-Soares. Today, the European eel is on the list of endangered species and biologists, managers, fishers and politicians across the continent are working together to conserve eels and the valuable fisheries they support.
Although the current study does not solve all the lifestyle mysteries of the eel, “it clearly shows that not only biological, but also climatic, oceanographic and genetic conditions must be taken into account for a meaningful management of fish stocks,” says Dr. Eizaguirre who has recently relocated from Kiel to Queen Mary, University of London. And for co-author Arne Biastoch the study illustrates the potential that lies in the interdisciplinary cooperation between biologists and oceanographers: “The ocean models are becoming more and more accurate. This offers a great opportunity for reassessing the threats to marine organisms and understanding their fundamental biology.”
Originally published here: http://www.geomar.de/en/news/article/aale/
A crawfish that lives on the seabed along the Norwegian coast, Campylaspis costata is one of the 76 known species of crawfish found in Norwegian waters that we now know more about as a result of inventories conducted for the Norwegian Taxonomy Initiative. (Credit: Photo: Henrik Glenner, University of Bergen)
More than a thousand new species -nearly one-quarter of which are new to science — have been discovered in Norway since a unique effort to find and name all of the country’s species began in 2009.
The Norwegian Taxonomy Initiative is one of just two government efforts worldwide where scientists are being funded to find and catalogue the country’s true species diversity.
The Norwegian initiative is focused on describing poorly known species groups across the country’s varied habitats, from its alpine plateaus to the northernmost reaches of the island archipelago of Spitsbergen.
The finds range from new species of insects and lichens to new species of molluscs and cold-water sponges. The information gives scientists and policymakers a better platform for understanding of the complexity and function of Norway’s ecosystems.
“These are very good results that provide new knowledge of both individualspecies and ecosystems,” says Ivar Myklebust, director of the Norwegian Biodiversity Information Centre, which is coordinating the taxonomy initiative on commission from the Norwegian Ministry of the Environment.
Scientists believe that there are roughly 55,000 species in Norway, but until now only 41,000 have been discovered. The 1165 new species discovered by the taxonomy initiative over the last four years are thus an important addition to this number. However, it will take time before the species that are thought to be new to science can be added to this list. These newly discovered species must first be given a scientific name and a description of the species must be published in a scientific publication.
“Norway’s land, seas and coastal areas have a unique variety of landscapes and ecosystems with great variation over short distances, which is rare in a global context,” said Tine Sundtoft, Norway’s Minister of Climate and the Environment. “This gives us a rich and varied flora and fauna. The Government will take our management responsibilities seriously.”
Many new insect species The biggest discoveries have been made in the major species-rich groups where previous knowledge has been poor — including in the groups that include wasps, flies and mosquitoes.
Scientists believe that there are thousands of species in Norway yet to be discovered in these groups. The figures from the taxonomy initiative shows that nearly 60 per cent of the new species are insects or other small terrestrial invertebrates (729 species), including 667 new species of insects, 17 new spider species and 18 new springtail species.
A boost in knowledge about fungi Fungi represent another large and species-rich group in Norway. Since 2009, scientists have found 227 new fungi species as part of the taxonomy initiative.
Some of these fungal species have been discovered using DNA analysis to clarify the relationship between species. This has led scientists to split some species into two, or to increase the species numbers from 14 to 31, as was the case for coral fungi.
New marine species Norway’s rich marine environment supplied 157 new species, including sponges, snails, slime worms, bristle worms, fish parasites, molluscs and starfish. Another 16 new species were discovered in brackish and fresh water, primarily fish parasites and small crustaceans.
Marine species are not as accessible as terrestrial species for researchers. As a result, 48 per cent of the species found as part of the taxonomy initiative are completely new to the scientific world and have never before been described scientifically.
In comparison, 18 per cent of the new terrestrial species are what scientists call undescribed species. In some of the very poorly known marine species groups such as the worm-like (aplacophoran) molluscs that live on the ocean floor, Aplacophora/shell less molluscs, the proportion of undescribed species may be as high as 90 per cent.
New knowledge about better-known species groups Norway’s landscape varies greatly in its topography, climate and habitats, which are home to a rich lichen and moss flora, with more than 2000 species of lichens and about 11 000 species of mosses.
“Even though we believe that the flora of both lichens and mosses are relatively well known, we have learned a great deal about the incidence and prevalence of both groups as a result of the initiative” says Ingrid Salvesen, senior adviser at the Norwegian Biodiversity Information Centre and coordinator of the Norwegian Taxonomy Initiative.
This is partly because much of the current knowledge and species descriptions are based on very old data. DNA analyses, combined with surveys in little explored areas, have proven to be very useful.
Salvesen also says that the initiative has given scientists a better understanding of where better-known species are found and the relationships of these species to different habitats. This is an important cornerstone for knowledge-based management.
“Geo-referenced information records of species give us new knowledge of the habitat that these species live in, and the organisms that they live with,” Salvesen says. “That gives us the ability to better understand the complex interactions of nature.”
DNA reveals new species DNA barcoding is a method for identifying species using differences in genetic material. The method involves comparing a short DNA sequence of an unknown organism to known sequences in a reference library.
The DNA barcodes can identify species from just tiny tissue samples, such as from an insect leg or a drop of blood.
A selection of the material collected by the Taxonomy Initiative has been made available for DNA barcoding in collaboration with the Norwegian Barcode of Life network (NorBOL).
To date, NorBOL has registered barcodes from approximately 3800 species in Norway, over half of which have come via the Taxonomy Initiative. NorBOL is part of a global effort to build up the reference library of DNA barcodes for more and more of the Earth’s species.
The Research Council of Norway has provided funding for the country’s national infrastructure for DNA barcoding up to and including 2018, which will allow for a great number of Norwegian species to be registered in the library.
Facilitator and catalyst The major activity that has been generated by the Norwegian Taxonomy Initiative has revitalized the country’s biosystematics research. A large number of academics, experts, technicians and students from most natural science research institutions in Norway are involved in the survey work.
The project has also led to the establishment of solid, professional networks across national boundaries. Norwegian researchers have established working relationships with their colleagues in Sweden, Denmark, Finland, Estonia, the UK, Ireland, the Netherlands, Belgium, Poland, Germany, Austria, Hungary, Georgia Spain, Canada and Japan.
42 projects in five years The Norwegian Taxonomy Initiative has started 42 inventory projects for mapping and identifying species in Norway since its inception in 2009. About half of these projects are completed or will be completed during 2013. Another eight new projects will be initiated in 2014.
Originally published here: http://www.alphagalileo.org/ViewItem.aspx?ItemId=137581&CultureCode=en
The species that historically was quoted as the most abundant of coral algae that forms rodoliths at the Gulf of California in Mexico, is in reality a compound of five different species. This finding was made by Jazmín Hernández Kantun, marine biologist at the Autonomous University of South Baja California (UABCS), resulting in a change of paradigm in the study of the species known as Lithophyllum margaritae.
In fact, this Mexican research has reached Europe, where Hernández Kantun continues the project and her studies at Ireland’s National University with the support of the Mexican National Council of Science and Technology (Conacyt).
According with the Mexican researcher, the objective now is to determine the number of species of coral algae in Europe and Mexico trough molecular tests.
“Coral algae in Mexico and trough out the world are usually identified only by their shape and color. However, is necessary to investigate the species in depth, given that bigger biodiversity exists in this organism than previously thought” said the researcher.
About the importance of her discoveries, the researcher exposed that since 1992 the Habitats Directive of the European Union protects two rodoliths forming species: Lithothamnion corallioides and Phymatolithon calcareum; considering them the most abundant and important, giving them relevance as a marine ecosystem and using them as rich mineral fertilizers.
The specialist found that at least other two species: L. glaciale and L. tophiforme, should be considered in the protected group having the same characteristics.
The environmental value of coral algae lies in the fact that when detached during tides and accumulate in specific areas, they form mantles of rodoliths which are rich in calcium and used by corals, clams, larvae and mollusks as “foundation” to start their development.
However, global warming is changing the natural chemistry of ocean ecosystems, increasing the absorption of carbon dioxide and modifying its acidification levels (pH).
Hernández Kantun warned that the acidification could remove the mantles of rodoliths from the ecosystem, directly affecting the mollusks, corals and any other organism found in them.
The marine biologist insisted that the coral’s biological diversity must be considered. She assured that the negative effects of climate change and the level of repercussion that come with them are different for each species.
“A lot of research is missing in this field, we haven’t quite understood the diversity of this algae, is like saying that all dogs are alike when each breed has different genetics and response to environmental factors. Is not the same to protect one than five different species!” she highlighted.
After four years of studying for her PhD in Ireland and collaborating with researchers from the United Kingdom, Spain, France and Italy, Jazmín Hernández Kantun is waiting for her grade exam to return to Mexico where she plans to found a laboratory to continue with her research and use it for the conservation of this marine organisms.
Tridacna maxima, a close relative of the newly discovered giant clam. Image credit: Karelj.
The yet-to-be-named species belongs to Tridacna, a genus of large saltwater clams.
“Giant clams can grow up to 230 kg and are some of the most recognizable animals on coral reefs, coming in a spectrum of vibrant colors including blues, greens, browns and yellow hues,” explained Jude Keyse, a postgraduate student at the University of Queensland, Australia.
Giant clams are beloved by divers and snorkelers but also prized as a source of meat and shells. Overconsumption by humans has depleted giant clams populations in many areas and most giant clam species are on the International Union for Conservation of Nature Red List of Threatened Species.
Ms Keyse, who is a co-author of the paper published in the open-access journalPLoS ONE, with colleagues non-lethally collected samples of tissues from giant clams at 0 – 20 m depth in the waters near the Solomon Islands and at Ningaloo Reef in Western Australia.
“DNA sequences strongly suggest that a distinct and unnamed species of giant clam has been hiding literally in plain sight, looking almost the same as the relatively common Tridacna maxima,” Ms Keyse said.
“To correctly describe the new species now becomes critical as the effects of getting it wrong can be profound for fisheries, ecology and conservation,” said co-author Shane Penny, a postgraduate student at Charles Darwin University.
Published from materials found here: http://www.sci-news.com/biology/science-tridacna-new-species-giant-clam-01569.html
Posted December 9th, 2013. Add a comment
A male Pacific leaping blenny on the island of Guam. Photo: Courtney Morgans/UNSW.
One of the world’s strangest animals – a legless, leaping fish that lives on land – uses camouflage to avoid attacks by predators such as birds, lizards and crabs, new research shows.
UNSW researchers, Dr Terry Ord and Courtney Morgans, of the Evolution and Ecology Research Centre, studied the unique fish – Pacific leaping blennies – in their natural habitat on the tropical island of Guam.
Their study will be published in the journal Animal Behaviour.
“This terrestrial fish spends all of its adult life living on the rocks in the splash zone, hopping around defending its territory, feeding and courting mates. They offer a unique opportunity to discover in a living animal how the transition from water to the land has taken place,” says Dr Ord, of the UNSW School of Biological, Earth and Environmental Sciences.
The researchers first measured the colour of five different populations of the fish around the island and compared this with the colour of the rocks they lived on. “They were virtually identical in each case. The fish’s body colour is camouflaged to match the rocks, presumably so they aren’t obvious to predators,” says Dr Ord.
To see if background matching reduced predation, the researchers created realistic-looking models of blennies out of plasticine. “We put lots of these model blennies on the rocks where the fish live, as well as on an adjacent beach where their body colour against the sand made them much more conspicuous to predators,” says Dr Ord.
“After several days we collected the models and recorded how often birds, lizards and crabs had attacked them from the marks in the plasticine. We found the models on the sand were attacked far more frequently than those on the rocks.
“This means the fish are uniquely camouflaged to their rocky environments and this helps them avoid being eaten by land predators.”
The researchers then studied the body colour of closely related species of fish, some of which lived in the water and some of which were amphibious, sharing their time between land and sea.
“These species provide an evolutionary snapshot of each stage of the land invasion by fish,” says Dr Ord.
The similarities in colour between these species and the land-dwelling fish suggest the ancestors of the land-dwelling fish already had a colouration that matched the rocky shoreline before they moved out of the water, which would have made it easier for them to survive in their new habitat.
The Pacific leaping blenny, Alticus arnoldorum, is about four to eight centimetres long and leaps using a tail-twisting behaviour. It remains on land all its adult life but has to stay moist to be able to breathe through its gills and skin.
Originally published here: http://newsroom.unsw.edu.au/news/science/secrets-legless-leaping-land-fish
Posted December 3rd, 2013. Add a comment
The new species, a flasher wrasse, was named Parcheilinus rennyae in honor of ichthyologist Renny Hadiaty of the Indonesian Institute of Sciences (LIPI). (Photo courtesy of Conservation International)
By Jakarta Globe
Indonesian scientists working together with counterparts from the University of California have announced the discovery of a new species of fish in East Nusa Tenggara.
The new species was named Parcheilinus rennyae in honor of ichthyologist Renny Hadiaty of the Indonesian Institute of Sciences (LIPI).
“I’m deeply honored by this recognition, not only because it is such a beautiful fish species, but also because the lead author on the description is my close colleague and internationally renowned ichthyologist Gerald Allen,” said Hadiaty, the curator of fish collections at the Museum Zoologicum Bogoriense (MZB), in a statement released by Conservation International on Wednesday.
The description of the species — a flasher wrasse — was published in the year-end edition of aqua, International Journal of Ichthyology, the statement said.
Conservation International (CI) said that Hadiaty, in her 27-year career, has focused primarily on the taxonomy of freshwater fish in Indonesia, and has coauthored many papers with Allen, who now works for CI as a consultant.
The wrasse — a striking and colorful fish — is adding further conservation value to Komodo National Park and the surrounding reefs of southwest Flores, according to CI.
Tiene Gunawan, marine program director at Conservation International Indonesia, said that the new species therefore must be protected.
Although it is the seventeenth known species of flasher wrasse, CI said that the fish is unique in both its colors and the rounded shape of its dorsal and anal fins and tail.
“We’re delighted that one of our young local scientists, Ni Luh Astria Yusmalinda, was able to publish her first international journal paper based on her genetic analysis of this new species and its closest relatives,” Ngurah Mahardika, the hosting laboratory director of the Indonesian Biodiversity Research Center at Udayana University, said.
He also said that he deemed it particularly fitting that the new species be named after Renny and added that he hoped “this will highlight the spirit of strong scientific collaboration between Indonesian universities, conservation NGOs like Conservation International and the Indonesian Institute of Sciences.”
Flasher wrasses are popular among divers and underwater photographers because of their neon color patterns displayed as part of a daily mating ritual about one hour before sundown. Wrasses are brownish in hue the remainder of the day.
“We’re also hopeful that this new species will add to the tourism value of Komodo National Park and the surrounding reefs of southwest Flores,” Tiene Gunawan, marine program director at Conservation International Indonesia, said.
The scientists participating scientists were from the Indonesian Biodiversity Research Center, a collaborative initiative of Udayana University in Bali, the State University of Papua in Manokwari, Diponegoro University in Semarang, the University of California Los Angeles and Conservation International Indonesia.
Source: The Embassy of Indonesia
Posted November 22nd, 2013. Add a comment
Photograph by Jim Agronick/Shutterstock.
FORT LAUDERDALE-DAVIE, Fla. – The great white shark, a major apex predator made famous by the movie “Jaws,” is one of the world’s most iconic species capturing an extraordinary amount of public fascination. An intriguing question is what makes a white shark so distinctive? One way to address this is to explore the genetic makeup of this remarkable animal.
A new study by scientists from Nova Southeastern University’s (NSU) Save Our Seas Shark Research Centre and Cornell University published in final form today in the journal BMC Genomics now undertakes the first large-scale exploration of the great white shark’s genetic repertoire, and comes up with unexpected findings.
The researchers compared the transcriptome (i.e., the set of RNA sequences expressed by the organism’s genes) from the white shark heart to the transcriptomes from the best studied fish research model (the zebrafish) and humans to look for similarities and significant differences that might explain the distinctiveness of the white shark. So they had a common comparative base, the researchers compared gene products that had known functions in all three species.
Surprisingly, the researchers found that the proportion of white shark gene products associated with metabolism had fewer differences from humans than zebrafish (a bony fish).
Indeed, more broadly speaking, the researchers were also surprised to find that other aspects of the white shark heart transcriptome, including molecular functions as well as the cellular locations of these functions, also showed greater similarity to human than zebrafish. Like many first looks at complex scientific questions, the unexpected results of this study raises more questions than provides answers.
“It’s intriguing why there are these fewer differences in the proportion of gene products between white sharks and humans, than white sharks and zebrafish” said study co-author Mahmood Shivji, director of NSU’s Save Our Seas Shark Research Center and Guy Harvey Research Institute. “One possibility for the apparent greater similarity between white sharks and humans in the proportion of gene products associated with metabolism might be due partly to the fact that the white shark has a higher metabolism because it is not a true cold-bodied fish like bony fishes; however this explanation remains a hypothesis to be further tested.”
One of the notable biological properties of white sharks is that it is one of few fishes that is regionally warm-bodied, i.e., parts of its body (its viscera, locomotor muscles and cranium) are kept at a higher temperature than the surrounding water world – a property known as regional endothermy. This warm-body property is in turn associated with elevated metabolic rates compared to true cold-blooded bony fishes.
“Additional comparative data from other white shark tissues and/or from other endothermic shark species such as makos would be required to see if this general similarity in gene products holds”, said Michael Stanhope of Cornell, who co-led the study with Shivji. “Nevertheless, this preliminary finding opens the possibility that some aspects of white shark metabolism, as well as other aspects of its overall biochemistry, might be more similar to that of a mammal than to that of a bony fish.”
Another curious feature of the genetic repertoire of the white shark heart was that the transcriptome revealed a much lower abundance of a certain type of DNA sequence that occurs in repeated triplet form, than found in other vertebrates. Interestingly, in human genes that contain such repeated triplet sequences, an aberrant increase in their number has been linked to a variety of neurological disorders. It’s not known whether sharks are immune to neurological genetic diseases, but the fact that these DNA patterns occur in such low abundance in white shark genes may indicate a reduced chance of similar such disorders in this primitive vertebrate.
“Our results, along with other distinctive shark genome features reported by the very few studies in this area by others, are suggesting that we may be in for some surprises as we further explore sharks at their most fundamental level – their genes” said Shivji. “We’ve just scratched the surface in terms of investigating what makes these evolutionary marvels, and in many cases threatened species, tick.”
Originally published here: http://www.newswise.com/articles/great-white-shark-study-uncovers-unexpected-and-distinctive-features
The full study can be accessed from BMC Genomics:http://www.biomedcentral.com/1471-2164/14/697
Posted November 21st, 2013. Add a comment