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Categories: Biology: Marine, Engineering: Biometric

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Researchers investigated how the jaw shape of sharks has changed over the course of evolution. Their conclusion: in the most widespread shark species, the jaws show relatively little variation in shape over millions of years; most variable jaws were found for deep-sea sharks.

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Inspired by clam fishermen reports, researchers used passive acoustic telemetry to gauge the interactions between two highly mobile rays. They monitored the tagged rays in the wild over two years to see how often and when they visited clam leases, designated underwater locations used to produce hard clams of all sizes from littlenecks to chowders. Results provide both good news and bad news for clammers. Rays spent even more time in these clam lease sites than clammers reported or suspected, but it's not necessarily where they prefer hanging out.

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A new study has found humpback whales sing louder when the wind is noisy, but don't have the same reaction to boat engines.

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In the autumn, when right whales swim towards the coasts of South Africa, they ought to be fat and stuffed full. But in recent years, they have become thinner because their food is disappearing with the melting sea ice.

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Throughout the ocean, billions upon billions of plant-like microbes make up an invisible floating forest. As they drift, the tiny organisms use sunlight to suck up carbon dioxide from the atmosphere. Collectively, these photosynthesizing plankton, or phytoplankton, absorb almost as much CO2 as the world’s terrestrial forests. A measurable fraction of their carbon-capturing muscle comes from Prochlorococcus — an emerald-tinged free-floater that is the most abundant phytoplankton in the oceans today. New research suggests the microbe's ancient coastal ancestors colonized the ocean by rafting out on chitin particles.

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Scalloped hammerhead sharks hold their breath to keep their bodies warm during deep dives into cold water where they hunt prey such as deep sea squids. This discovery provides important new insights into the physiology and ecology of a species that serves as an important link between the deep and shallow water habitats.

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There have been heated debates over the size of Jurassic animals. The speculation was set to continue, but now a chance discovery in an Oxfordshire museum has led to palaeontologists publishing a paper on a Jurassic species potentially reaching a whopping 14.4 meters -- twice the size of a killer whale.

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Surveying the body sizes of Earth's living organisms, researchers found that the planet's biomass -- the material that makes up all living organisms -- is concentrated in organisms at either end of the size spectrum.

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Around 500 million years ago life in the oceans rapidly diversified. In the blink of an eye -- at least in geological terms -- life transformed from simple, soft-bodied creatures to complex multicellular organisms with shells and skeletons. Now, research has shown that the diversification of life at this time also led to a drastic change in the chemistry of Earth's crust -- the uppermost layer we walk on and, crucially, the layer which provides many of the nutrients essential to life.

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One of the basic and crucial embryonic processes to unfold in virtually every living organism is the formation of hollow, tubular structures that go on to form blood vessels or a digestive tract, and through branching and differentiation, complex organs including the heart and kidneys. This study illuminates fundamental design principles of tubulogenesis for all chordates, including mammals.

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Even without body parts that allowed for movement, new research shows -- for the first time -- that some of Earth's earliest animals managed to be picky about where they lived.

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Phytosterols are good for your health, but humans and other animals are not able to make them themselves, only plants can. To acquire phytosterols, humans are increasingly turning to supplements, green smoothies, or a Mediterranean diet with plenty of plant-based foods. Researchers have now discovered that tiny gutless worms from the Mediterranean can synthesize phytosterols on their own. Their study provides evidence that many other animals also have the genes needed to make their own phytosterols.

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For decades, scientists have used the amount of seaweed at the ocean's surface as a proxy for the health of coral reefs below. However, a new global study of more than 1,200 marine locations over a 16-year period reveals that this approach has been misleading -- and may even have hidden signs of reef stress.

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In the face of global warming and other environmental changes, corals in the Atlantic Ocean have declined precipitously in recent years, while corals in the Pacific and Indian Oceans are faring better. By describing several species of symbiotic algae that these corals need to grow, an international team has found that these mutualistic relationships from the Indo-Pacific may be more flexible and ultimately resilient to higher ocean temperatures than those in the Atlantic.

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California sea lions have managed to maintain -- and, in the case of males, increase -- their average body size as their population grows and competition for food becomes fiercer. This is in contrast to other marine mammals, whose average body size tends to decrease as their numbers increase. Researchers report that sexual selection was a strong driving force for males to grow bigger and to strengthen muscles in their neck and jaw that help them fight for mates. Both male and female sea lions evaded food shortages by diversifying their diets and, in some cases, foraging further from the shore.

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Life in the ocean's 'twilight zone' could decline dramatically due to climate change, new research suggests.

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Scientists found parallels between the neural circuitry that guides locomotion in sea slugs and in more complex animals like mammals.

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Researchers have identified a previously unknown group of bacteria, called UBA868, as key players in the energy cycle of the deep ocean. They are significantly involved in the biogeochemical cycle in the marine layer between 200 and 1000 meters.

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Roboticists have developed a jellyfish-inspired underwater robot with which they hope one day to collect waste from the bottom of the ocean. The almost noise-free prototype can trap objects underneath its body without physical contact, thereby enabling safe interactions in delicate environments such as coral reefs. Jellyfish-Bot could become an important tool for environmental remediation.

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A new Griffith University study has found that humpback whales will use sandy, shallow bay areas to 'roll' around in sandy substrates to remove dead skin cells on their return journeys south to cooler waters. Using data and footage collected from the tags, whales were observed performing full and side rolls in up to 49m water depth on the sea floor that was lined with fine sand or rubble.