Frog egg smell of death


07/12/2008

Scientists have found that frogs learn to identify the smell of danger before the hatching of the eggs, tadpoles that gives some of the benefits in the future when it will be necessary to elude predators.

Animals are able to react to smells or sounds that accompany the danger remembering them as a warning that there is a threat to their lives. A team of scientists led by Maud Ferrari (Maud Ferrari) of the Canadian University of Saskatchewan in Saskatoon (University of Saskatchewan in Saskatoon, Canada) decided to test whether wood frog eggs "learn" to detect the scent of a predator.

Eggs are lowered into the water, which previously contained ognennobryuhih newts. Half the eggs were also given a "smell" danger in the form of crushed tadpoles, whose death was marked by chemical signals. After hatching from eggs, researchers gave a second time to smell the newt tadpoles. Tadpoles, who was accompanied by the smell of newt odor of dead tadpoles, still froze in place - a classic defense against predators. Those that do not pass this training, continued to swim as usual, not showing any signs of anxiety.

In the second study, a team Ferrari has shown that, without encountering the "smell of danger" at the age of eggs, frogs feel the smell of Triton safe and unable to associate it with danger in the future.

This is the first study showing that animals can learn the smell of predators, while still in the embryonic stage of development. Scientists already have some preliminary evidence that fish also can be trained to smell danger. That is, these abilities may be widespread in the animal kingdom. News First, download and upload news ticker on your page.

Original: Newscientist


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