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5 December 2013 11:26 am ,
Vol. 342 ,
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...
Snake venoms are remarkably complex mixtures that can stun or kill prey within minutes. But more and more researchers...
At age 30, Dutch biologist Freek Vonk has built up a respectable career as a snake scientist. But in his home country,...
- 5 December 2013 11:26 am , Vol. 342 , #6163
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Listening to Fish Ears
14 August 2000 5:00 pm
SNOWBIRD, UTAH--Ask most biologists and you'll hear that salmon, trout, and many fish species make one round trip between fresh water and the ocean over their lifetime. But by looking in, of all places, their ear bones, scientists have learned that the European brown trout doesn't stick to such a simple itinerary: The fish seem to do whatever they please.
European brown trout start their life ranging through the rivers of Europe and Asia. Ecologists believed the fish first spent a year in fresh water, then moved to the ocean to mature and finally came home to reproduce. To test that scenario's accuracy, fisheries ecologist Karin Limburg of the State University of New York, Syracuse, studied the animals' otolith, a little bone under the brain that is part of its hearing and balance system. Because the otolith keeps growing throughout the animal's life, its chemical composition mirrors a fish's journey: Parts grown at sea have a higher strontium to calcium ratio than parts grown while the fish was in fresh water.
When they examined otoliths from adult brown trout caught near the Swedish island of Gotland in the Baltic Sea, Limburg and her colleagues found that most trout don't lead textbook lives. Some spend all their lives in fresh water, while others shoot out to sea immediately, only to come back later; yet others seem never to go back at all, Limburg reported on 9 August at the Ecological Society of America's annual meeting. In other work, Limburg found that eels and blueback herring in the Hudson River, too, have all sorts of travel patterns. "The otoliths are telling us that they're doing these things--but we don't know why yet," Limburg says.
Knowing precisely where fish travel over their lifetime is important for conservation, she says. It's certainly not a simple picture anymore. "The diversity of movements is more complex than anybody thought," comments John Musick, a vertebrate marine biologist from the Virginia Institute of Marine Science in Gloucester Point.