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5 December 2013 11:26 am ,
Vol. 342 ,
At age 30, Dutch biologist Freek Vonk has built up a respectable career as a snake scientist. But in his home country,...
Since arriving on the island of Guam in the 1940s, the brown tree snake ( Boiga irregularis ) has extirpated native...
An animal rights group known as the Nonhuman Rights Project filed lawsuits in three New York courts this week in an...
Researchers have been hot on the trail of the elusive Denisovans, a type of ancient human known only by their DNA and...
Thousands of scientists in the Russian Academy of Sciences (RAS) are about to lose their jobs as a result of the...
Dyslexia, a learning disability that hinders reading, hasn't been associated with deficits in vision, hearing, or...
Exotic, elusive, and dangerous, snakes have fascinated humankind for millennia. They can be hard to find, yet their...
Researchers have sequenced and analyzed the first two snake genomes, which represent two evolutionary extremes. The...
- 5 December 2013 11:26 am , Vol. 342 , #6163
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Video: How Jellyfish Make It Look Easy
7 October 2013 3:00 pm
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Jellyfish, as their name implies, aren’t exactly the hulks of the sea. Despite their relative lack of muscles, however, they still appear to glide effortlessly through dense and churning waters. The trick? Their bodies get an extra push from pressure that builds up in the water around them as they move. High-speed video of moon jellyfish (Aurelia aurita), reported online today in the Proceedings of the National Academy of Sciences, reveals that the animals don’t just speed up when their bell-shaped bodies are contracting, as others had observed, but also for a brief time after they have relaxed. Up to 32% of the jellyfish’s movement can be attributed to this phase of motion. To figure out how this happens, the researchers measured the pressure around a jellyfish’s body at each point in a thrust. As water rushes into the bell of the jellyfish after a muscle-driven contraction, they found, a large region of positive pressure forms in a ring shape under the jellyfish bell. The resulting motion of the water is enough to give the jellyfish an extra boost of propulsion. The finding helps explain how jellyfish, some species of which are considered invasive species, have adapted to compete with other, more muscle-filled fish to take over an ecosystem and compete for resources.