Unique university lecture held 18 metres underwater
Students at the University of Essex have taken their lectures to a whole new level – 18 metres under the sea in remote Indonesia to be precise.
The ground-breaking underwater marine biology lectures were the first of their kind, revolutionising the teaching, educational and learning experience during dives on tropical coral reef systems.
The lectures were held during the annual field trip to the Wakatobi Marine National Park in Indonesia, organised by the University’s School of Biological Sciences for its students.
The serious challenges threatening the future of the world’s coral reefs are the backbone of major research being carried out by the University’s internationally-recognised Coral Reef Research Unit (CRRU). Its on-going research, focused in this area of Indonesia, looks at the impact of climate change on coral reefs and how to work with nature to find a solution. More than half a billion people depend on coral reefs for food and income.
For the underwater lectures, Professor David Smith used specialised audio equipment so he could talk to students underwater, explaining exactly what they were seeing as they were seeing it. This was a world away from usual underwater communication involving basic slates to write on and hand signals.
“It was a fantastic experience as I was able to use the power of observation like never before,” explained Professor Smith. “I have been on thousands of dives over the years but this was a totally new experience as I was able to explain to students exactly what they were seeing and inject more passion and feeling into the whole lecture. It was very special and transformed the whole experience both for me and our students.”
Using a University of Essex special teaching grant, Professor Smith was able to buy an audio system which, to date, has never been used for formal lecturing and is only used by TV presenters and some professional divers. Professor Smith wore a full face mask which included a microphone and the students wore headsets so they could hear him talk. A hydrophone – an underwater microphone − was then positioned in the water which was linked to a control box and recorder on a boat.
With over 1,000 videos taken during the underwater lectures, adding up to 15 hours of footage, these will prove to be a valuable virtual field course resource for students who are not able to travel to Indonesia but can still get an insight into the experience whilst also providing a great “listen again” opportunity for participating students.
Second-year marine and freshwater biology student Tilly James said: “The underwater lectures were an invaluable part of the course as they enabled us to get a much better understanding of how all the components of the reef system were interacting with each other.
“It was an experience you simply cannot get with traditional lectures. Professor Smith was able to ask us questions throughout the dives, encouraging us as students to apply our theoretical knowledge in a much more practical setting.”
New research has revealed that the evolution of the complex, weight-bearing hips of walking animals from the basic hips of fish was a much simpler process than previously thought.
Tetrapods, or four-legged animals, first stepped onto land about 395 million years ago. This significant change was made possible by strong hipbones and a connection through the spine via an ilium – features that were not present in the fish ancestors of tetrapods.
In a study published in the journal Evolution and Development, Dr Catherine Boisvert of the Australian Regenerative Medicine Institute at Monash University, MacQuarie University’s Professor Jean Joss and Professor Per Ahlberg of Uppsala University examined the hip structures of some of human’s closest fish cousins.
They found the differences between us and them are not as great as they appear – most of the key elements necessary for the transformation to human hips were actually already present in our fish ancestors.
Dr Boisvert and her collaborators compared the hip development – bones and musculature – of the Australian lung fish and the Axolotl, commonly known as the Mexican Walking Fish. The results showed that, surprisingly, the transition from simple fish hip to complex weight-bearing hip could be done in a few evolutionary steps.
“Many of the muscles thought to be ‘new’ in tetrapods evolved from muscles already present in lungfish. We also found evidence of a new, more simple path by which skeletal structures would have evolved,” Dr Boisvert said.
The researchers found that the sitting bones would have evolved by the extension of the already existing pubis. The connection to the vertebral column could have evolved from an illiac process already present in fish.
“The transition from ocean-dwelling to land-dwelling animals was a major event in the evolution of terrestrial animals, including humans, and an altered hip was an essential enabling step,” Dr Boisvert said.
“Our research shows that what initially appeared to be a large change in morphology could be done with relatively few developmental steps.”
Aquarists at ZSL London Zoo are launching an urgent worldwide appeal to find a female mate for the last remaining males of a critically endangered fish species.
The Mangarahara cichlid (Ptychochromis insolitus) is believed to be extinct in the wild, due to the introduction of dams drying up its habitat of the Mangarahara River in Madagascar, and two of the last known individuals are residing in ZSL London Zoo’s Aquarium.
And as if the situation wasn’t dire enough for this tropical fish species, the individuals at ZSL London Zoo are unfortunately both male.
The Curator of the Aquarium at ZSL London Zoo, Brian Zimmerman, along with colleagues at Zurich Zoo in Switzerland set about trying to find other Mangaraharan cichlids in zoos around the world – using international zoo and aquarium associations to reach as many experts and aquarists as possible, but had no luck finding surviving females.
The team at ZSL London Zoo are now launching a desperate appeal for private aquarium owners, fish collectors, and hobbyists to come forward if they have or know of any females in existence, so that a vital conservation breeding programme can be started for the species.
Launching the appeal, ZSL London Zoo’s Brian Zimmerman said: “The Mangarahara cichlid is shockingly and devastatingly facing extinction; its wild habitat no longer exists and as far as we can tell, only three males remain of this entire species.
“It might be too late for their wild counterparts, but if we can find a female, it’s not too late for the species. Here at ZSL London Zoo we have two healthy males, as well as the facilities and expertise to make a real difference.
“We are urgently appealing to anyone who owns or knows someone who may own these critically endangered fish, which are silver in colour with an orange-tipped tail, so that we can start a breeding programme here at the Zoo to bring them back from the brink of extinction.”
ZSL London Zoo is asking anyone with information about the cichlids to email the team at fishappeal@zsl.org
When predicting the outcome of a fight, the big guy doesn’t always win, suggests new research on fish.
Scientists at the University of Exeter and Texas A&M University found that when fish fight over food, it is personality, rather than size, that determines whether they will be victorious.
The findings suggest that when resources are in short supply personality traits such as aggression could be more important than strength when it comes to survival. The study, published in the journal Behavioral Ecology and Sociobiology, found that small fish were able to do well in contests for food against larger fish provided they were aggressive. Regardless of their initial size, it was the fish that tended to have consistently aggressive behaviour – or personalities – that repeatedly won food and as a result put on weight.
Dr Alastair Wilson from Biosciences at the University of Exeter said: “We wondered if we were witnessing a form of Napoleon, or small man, syndrome. Certainly our study indicates that small fish with an aggressive personality are capable of defeating their larger, more passive, counterparts when it comes to fights over food. The research suggests that personality can have far reaching implications for life and survival.”
The sheepshead swordtail fish (Xiphophorus birchmanni) fish were placed in pairs in a fish tank, food was added and their behaviour was captured on film. The feeding contest trials were carried out with both male and female fish. The researchers found that while males regularly attacked their opponent to win the food, females were much less aggressive and rarely attacked.
In animals, personality is considered to be behaviour that is repeatedly observed under certain conditions. Major aspects of personality such as shyness or aggressiveness have previously been characterised and are thought to have important ecological significance. There is also evidence to suggest that certain aspects of personality can be inherited. Further work on whether winning food through aggression could ultimately improve reproductive success will shed light on the heritability of personality traits.
This work was funded by a Biotechnology and Biological Sciences Research Council (BBSRC) David Phillips Fellowship. No fish were distressed or received physical injury during these experiments.
Scientists from the Hebrew University of Jerusalem and the Technion-Israel Institute of Technology have discovered why Heteroxenia corals pulsate. Their work, which resolves an old scientific mystery, appears in the current issue of PNAS.
One of the most fascinating and spectacular sights in the coral reef of Eilat is the perpetual motion of the tentacles of a coral called Heteroxenia (Heteroxeniafuscescens). Heteroxenia is a soft coral from the family Xeniidae, which looks like a small bunch of flowers, settled in the reef walls and on rocky areas on the bottom of the reef. Each “flower” is actually a living polyp, the basic unit which comprises a coral colony. Apparently, the motion of these polyps, resembling flowers that are elegantly spreading out and closing up their petals, is unique in the animal kingdom.
Except for the familiar swimming motion of jellyfish, no other bottom-attached aquatic animal is known to perform such motions. Pulsation is energetically costly, and hence there must be a reasonable benefit to justify this motion.
The perpetual motions of jellyfish serve them for swimming, predation and feeding. The natural explanation would be that that the Heteroxenia’s spectacular motions are used for predation and feeding, however several studies indicate that these corals do not predate on other animals at all. If predation is not the reason for pulsating, there must be another explanation to justify the substantial energetic expense by the Heteroxenia.
Maya Kremien found the answers to these questions, while working on her master’s research at the Interuniversity institute for Marine Sciences in Eilat under the supervision of Prof. Amatzia Genin from the Hebrew University and Prof. Uri Shavit from the Technion in a joint research funded by the National Science Foundation.
After watching several coral colonies with an underwater infrared-sensitive camera night and day, the researchers found their first surprising discovery: Heteroxenia corals cease to pulsate and take a half-hour break every single day in the afternoon hours. At this stage, the afternoon “siestas” remained unexplained.
The labs of Prof. Genin and Prof. Shavit conduct work on the interaction between biological processes of aquatic creatures and the water motions which surround them. Apparently aquatic animals affect the flow and at the same time are absolutely dependent on that flow. In order to solve the mystery of the Heteroxenia coral, the research team developed (as part of Ph.D. work by Tali Mass) an underwater measuring device called PIV (particle imaging velocimetry), which allows measurement of the flow field just around the coral very accurately. The system consists of two powerful lasers, an image capturing system and computation ability. A special set of lenses releases a sheet of light in short, powerful pulses so that the imaging system can capture pairs of snapshots of natural particles moving with the flow. The computational system then performs a mathematical analysis of the pairs of photos, producing a huge database of flow field maps, from which the flow speed, characteristics of solutes transport, and turbulent mixing intensity are calculated.
The measurements were performed at night with the support of divers who volunteered to assist the research team. It was found that if a diver lightly touched the coral, the polyps “close” and remain motionless for a few minutes, after which the coral returns to its normal pulsation activity. The researchers used this behavior in order to repeatedly measure the flow field around the Heteroxenia during pulsation and rest.
These measurements led to the research group’s next discovery. Analysis of the direction of water flow indicated that the motion of the polyps effectively sweeps water up and away from the coral tissues into the ambient water. Corals need carbon-dioxide during daytime and oxygen during nighttime, as well as nutrients (such as phosphate and nitrogen) during day and night. One of the challenges for coral colonies is to render their surrounding waters rich in essential commodities by efficiently mixing the water around them.
By using the sophisticated measuring system, the researchers calculated the mixing intensity of the water as a result of the coral’s pulsation. The unexpected discovery was that even though the polyps’ motions are uncoordinated (i.e. each polyp starts its period of motion at a different time), the accumulated effect of the polyps’ activity is a significant enhancement of the flow around the colony, particularly in the upward direction which sweeps water away from the coral, hence reducing the probability of re-filtration of the same water.
However, these findings still did not yet answer the question of why a coral would invest so much energy to move its tentacles. After receiving a permit from the Israel Nature and Parks Authority, the research team collected a few Heteroxenia colonies from the sea in order to run a series of laboratory experiments. All corals were returned back to their original location after the experiment terminated. The Hypothesis was that the pulsation motions enhance the coral’s photosynthesis rate.
Corals are among the most ancient creatures surviving on our planet. One of the “secrets” of their amazing survival abilities is that they “host” photosynthetic algae in their tissues. The symbiotic algae provides the coral with essential nutrients and lives off the waste of the coral.
In a previous study of the same research team (which the results of were also published in PNAS) it was found that the motion of water around corals is essential in order to enhance the efflux of oxygen from the coral tissues. Without water motion, the oxygen concentration in the coral tissues would rise and the photosynthesis rate would drop.
The answer to the question as to why the Heteroxenia pulsates was finally revealed through the lab experiments. First, the photosynthesis rate of a pulsating Heteroxenia was measured, and it was found to be on an order of magnitude higher than that of a non-pulsating colony. Next, in order to prove that the mechanism of pulsation is intended to sweep away oxygen, the researchers artificially increased the oxygen concentration in the measurement chamber so that even when the coral managed to mix water via pulsation, it was replacing oxygen-rich water with new water, which, unfortunately for the coral , was also rich in oxygen. And indeed it was found that the photosynthesis rate was low in this case, and even when the coral was constantly pulsating, the oxygen concentration remained high and photosynthesis remained low, as if the coral was at rest (i.e. not pulsating).
The elegant motion of Heteroxenia has been fascinating the scientific society and capturing the attention of researchers for nearly 200 years (Jean-Baptiste Lamarck, 1744-1829), yet it has not been explained. Now, in the study of Kremien, Genin and Shavit, it was found that the pulsation motions augment a significant enhancement in the binding of carbon dioxide to the photosynthetic enzyme RuBisCo, also leading to a decrease in photorespiration. This explanation justifies the investment of energy in pulsation — the benefit overcomes the cost. In fact, thanks to pulsation, the ratio between photosynthesis to respiration in Heteroxenia is the highest ever measured in stony and non-pulsating soft corals.
The findings of this study indicate that pulsation motions are a highly efficient means for sweeping away water from the pulsating body, and for an increased mixing of dissolved matter between the body and the surrounding medium. These two processes (expulsion of medium and mixing of solutes) may lead to future applications in engineering and medicine. Currently the research group is focusing on attempts to broaden the results of this study and on developing mathematical models which could serve various applicative purposes.
Newcastle Researchers Leapfrog Ahead in World-First
University of Newcastle researchers have successfully developed a method to freeze frog embryonic cells in a world-first breakthrough that could slow the threat of extinction to hundreds of frog species.
The researchers have separated, isolated and frozen the embryonic cells of an Australian Ground Frog (the Striped Marsh Frog, Limnodynastes peronii), using cryopreservation techniques that will now allow for cloning.
This is the first time anyone in the world has successfully used slow-freezing techniques on amphibian cells, project leader at the University of Newcastle, Professor Michael Mahony, said.
“Almost 200 frog species have been lost in the past 30 years due to disease and a further 200 species face imminent threat – this is the worst rate of extinction of any vertebrate group,” he said.
“Amphibian eggs and early embryos, unlike human eggs and embryos, are large in size and have traditionally presented a challenge to researchers attempting to cryo-preserve and store frog genomes, as they would shatter during the freezing process.
“The new technique, developed by our University of Newcastle researchers, will act as an insurance policy to buy us time for species on the edge of extinction, as we search for answers to diseases and other threats.”
Professor Mahony said the development would have wider implications for other species facing extinction.
“Not only will it help us preserve the genetic diversity of frogs, but this discovery could also help in the conservation of other species with large embryonic cells, such as fish.”
The University of Newcastle is leading the world on research into amphibian protection. This latest discovery follows on from recent work with other universities on the Lazarus project, which generated live embryos using cells from an extinct Australian frog.
The technical work was led by Dr John Clulow and Professor Michael Mahony, alongside Ms Bianca Lawson and Mr Simon Clulow.
Photograph courtesy of the Journal of Comparative Psychology.
Researchers Document Sea Lion’s Synchronized Head Bobbing to ‘Boogie Wonderland’
Newswise — WASHINGTON – Move over dancing bears, Ronan the sea lion really does know how to boogie to the beat.
Video Credit: Pinniped Lab
A California sea lion who bobs her head in time with music has given scientists the first empirical evidence of an animal that is not capable of vocal mimicry but can keep the beat, according to new research published by the American Psychological Association.
The study’s authors suggest that their findings challenge current scientific theories that an animal’s ability to synchronize its movements with sound are associated with the same brain mechanisms that allow for vocal mimicry in humans and some birds such as cockatoos, parrots, and budgerigars. The findings were published online April 1 in APA’s Journal of Comparative Psychology.
“Understanding the cognitive capabilities of animals requires carefully controlled, well-designed experiments,” said study co-author Colleen Reichmuth, PhD, with the Institute of Marine Sciences at the University of California at Santa Cruz. “This study is particularly rigorous because it examines, step-by-step, the learning conditions that supported the emergence of this complex behavior.”
Ronan, a 3-year-old sea lion, demonstrated her ability to bob to the beat in six experiments led by doctoral candidate Peter Cook at the Long Marine Lab at UCSC.
“Dancing is universal among humans, and until recently, it was thought to be unique to humans as well,” said Cook. “When some species of birds were found to have a similar capability for rhythmic movement, it was linked to their ability to mimic sound. Now we’re seeing that even mammals with limited vocal ability can move in time with a beat over a broad range of sounds and tempos.”
Ronan’s first musical “dance” lesson was to the tune of a simplified section of John Fogerty’s “Down on the Corner,” the study said. Once Ronan was trained to bob her head to music, the researchers tested her with two pop songs, “Everybody” by the Backstreet Boys, and “Boogie Wonderland” by Earth, Wind and Fire. Without any prior exposure to the songs, Ronan was able to bob to the beat of both songs over the course of multiple trials, according to the study. She then showed that she could follow along to five different tempos of “Boogie Wonderland.”
Ronan’s bobbing skills markedly improved over the course of the trials and apparently endured, the study found. The researchers gave her a follow-up test a few weeks after the final session and she was successful in keeping the beat with each of the sounds previously used, maintaining a minimum of 60 consecutive bobs to each of the various beats.
At the beginning of the experiments, Ronan was first trained to move in time to a hand signal, which was replaced by a simple non-musical sound signal. When she successfully completed tests by bobbing her head to various rhythmic sounds, she was rewarded with a fish, the study said.
The researchers varied the types and speed of the sounds to verify that she was actually following the rhythm by bobbing her head. To rule out that she wasn’t simply bobbing her head in response to the previous beat, they tested her using two computer-generated, metronome-like ticks – one that did not miss a beat and the other that did. Ronan kept the beat going even when the metronome missed a beat, according to the study.
Most kindergarteners can tell you that an animal eats with its mouth, not its butt. One species of sea cucumber, however, didn’t appear to get the memo: Scientists have discovered that the giant California sea cucumber (Parastichopus californicus) actually uses its anus as a second mouth. Scientists already knew that the marine invertebrate, which lives in the shallow ocean waters off the Pacific coast of North America, breathes with its butt. Because they don’t have lungs, sea cucumbers rely on respiratory trees, a set of long tubes running down either side of the body with a lot of different branches. P. californicus is shaped like a hollow tube, with a mouth at one end and its anus at the other.
Two weeks ago, a group of sailors off the coast of New Zealand leaned over the side of their boat, dropped a contraption into the Pacific Ocean and watched it disappear. Using an app they’d downloaded to a smartphone, they logged a reading from the underwater device, along with their GPS location and the water temperature. In just a few minutes’ time, they had become the first participants in a new program launched by the UK’s Plymouth University Marine Institute which allows citizen scientists to help climatologists study the effects of climate change on the oceans.
Researchers writing in the Proceedings of the Royal Society A say they have developed a new robotic fish that has lateral line sensing capabilities.
The FILOSE team members have spent four years investigating fish lateral line sensing, which is a sensing organ found in aquatic vertebrates used to detect movement and vibration in the surrounding water. This organ essentially helps a fish’s orientation in the water. The team set out to understanding how a fish detects and exploits flow features in water, and then use their findings to develop efficient underwater robots based on biological principles.
Flow can be measured and characterized on many salient features that do not change. This “flowscape” is a flow landscape that helps fish and robots orient themselves, navigate, and control their movements in water.
Source: redOrbit
Photo: Prof. Maarja Kruusmaa and FILOSE fish robot. Credit: Jelena Pijonkina
