Dive Pacific Iss 171 Oct- Nov 2019

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Provided by ABC SOUNDINGS INTERNATIONAL NEWS Newly discovered electric eel has the most powerful shock After years thinking there was only the one species in the genus Electrophorus, researchers now characterise the electric eel, Electrophorus electricus, as three species. And a recent addition, Electrophorus voltaic, has been recorded generating 860 volts, far above the previous record of 650 volts, reports ABC Science in Australia. E.voltai is now thought to be the most powerful electricity generating animal in the world, say the authors of a report in Nature Communications. Their research aims to identify and describe the electric fishes of the Amazon rainforest, said zoologist and lead author of the paper Dr David de Santana of the Smithsonian’s National Museum of Natural History. Though their discharge is high voltage its low amperage and wouldn’t necessarily be dangerous to humans. The electric eel is not actually an eel at all but a type of knifefish that grow up to 2.5 metres in length. It was first described by Swedish scientist Carl Linnaeus in 1766. Electric Electric fishes are said to be electrogenic (produces electricity) as opposed to others described as electroreceptic, or able to detect electric fields, with some species both. Other electric fish include electric rays and electric catfish. Electrophorus voltai has the most powerful electric discharge of any known animal. (Supplied: L. Sousa) Dr de Santana and his colleagues collected 107 electric eel specimens over six years from across the Amazon basin. Though they look very similar, differences in their DNA showed they were made up of three different species with each of the species living in different parts of the Amazon basin. “The discovery of hidden species diversity and of such an eye-catching and long-known organism as electric eels indicates that an enormous amount of species are still waiting to be discovered in the Amazon rainforest,” Dr de Santana said. “Many may harbour cures for diseases or inspire technological innovations, reinforcing the critical need to protect Earth’s hotspots of biodiversity.” Electric fish use three electric organs to generate electricity made of modified muscle cells called electrocytes which can produce strong electrical discharges as well as weaker ones, and they typically use them arranged like batteries in series fired by entire-body muscle contractions caused by the direct stimulation of spinal motor neurons. The ancient Egyptians, Greeks and Romans all used electric fish for their medicine to numb people or treat conditions like gout and headache. Dr de Santana said electric eels inspired the design of Italian physicist Alessandro Volta’s first electric battery, and an enzyme extracted from their electric organs has been used as a target for drugs to treat Alzheimer’s disease. More recently electrical eels have promoted the advance of hydrogel batteries (made of a substance similar to gelatin) that might be used to power medical implants. An electric ray residing in Sydney Harbour called the coffin ray (Hypnos monopterygius) can grow to 40 cm. Biomedical engineer Professor Alistair McEwan of the University of Sydney said they use electrical sensing like a shark to see around them, not just passively by listening into the electricity, but also by sending out their own electric field to map the world around them”. Researchers have looked at how to emulate this system to monitor internal cardiac surgery, and in the brain. Professor McEwan and his colleagues are also looking at how they might be able to use Sydney Harbour’s coffin ray (Hypnos monopterygius) the electroreception abilities of Australia’s platypus and the echidna. “We thought the electroreception would only work well with water. It’s amazing the platypus works well in fresh water without conductive salt, but even more amazing that the echidna can electrically sense in the dry desert,” he said. Provided by ABC 28 Dive New Zealand | Dive Pacific
SOUNDINGS INTERNATIONAL NEWS AUT signs up for 10 year international ocean research Auckland University of Technology (AUT) has joined 45 national and international partners on a 10-year research programme exploring how to utilise the oceans for aquaculture and energy production. The Blue Economy CRC is an Australian A$329 million project combining expertise on seafood production, renewable energy and offshore engineering. Australia's Cooperative Research Centres undertake joint programmes between research institutes, industry and government aimed at finding solutions to major issues; in this case sustainable food production and renewable energy sources. The 'Blue Economy' is an emerging concept to encourage better stewardship of our ocean or 'blue' resources. AUT is New Zealand's core research partner in the programme with Associate Professor, Dr Lindsey White co-leader for the seafood and marine products programme. New Zealand King Salmon, Plant and Food Research and the Cawthron Institute are the other New Zealand-based research partners. White says the funding will be used to innovate and transform how we utilise our oceans for sustainable food and energy production. Australia and New Zealand combined have the second largest exclusive economic zone on the planet behind the EU. Involvement in the CRC allows the opportunity to integrate aquaculture of numerous species, including fish and seaweed, with marine-based renewable energy generation, that is to partner aquaculture with energy production, a world first. Associate Professor White says energy generated from solar, wind, wave and tidal sources could be harnessed and used to run aquaculture operations with excess energy used to split water into hydrogen, and oxygen for use in aquaculture operations. Fish farm operators worldwide are moving their farms offshore to take advantage of larger spaces, better water quality to produce healthier fish and lower water temperatures in the face of warming temperatures. https://blueeconomycrc.com.au New whale species identified off Japan coast Japanese scientists have confirmed a new whale species has been identified off Japan’s coast after carrying out DNA testing, Science News reports. The new species has often been previously spotted by whalers in the north Pacific Ocean but never before officially recognised as it continued to elude researchers. With carcasses of several unidentified whales washing up on Hokkaido, Japan's northernmost island, while others caught by fishing vessels, researchers carried out DNA testing to find a complete new species now named Black Baird's beaked whale (Berardius minimus). Six specimens were studied in terms of their morphology, osteology, and molecular phylogeny. The results published in the journal Scientific Reports showed that the body length of physically mature individuals is distinctively smaller than B. bairdii (6.2-6.9m versus 10.0m). Detailed cranial measurements and DNA analyses further emphasized the significant difference from the other two known species in the genus Berardius. Due to it having the smallest body size in the genus, the researchers named the new species B. minimus. The new species while similar to the Baird's beaked whale is also darker in colour and with a shorter beak. All beaked whale species prove hard to document since they prefer deep ocean waters and have a long diving capacity. Takashi Matsuishi of Hokkaido University who led the research team said "There are still many things we don't know about B. minimus. We still don't know what adult females look like, and there are still many questions related to species distribution. We hope to continue expanding what we know." Local Hokkaido whalers also refer to some whales in the region as Karasu (crow). It is still unclear whether B. minimus (or Kurotsuchikujira) and Karasu are the same species or not, and the research team speculate that it is possible Karasu could be yet another different species. Black Baird’s beaked whale Photo by Associated Newspapers Limited www.dive-pacific.com 29
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