Eels lack magnetic compass.The discovery of magnetic bacteria led scientists to wonder whether other organisms might have built-in magnetic compasses. Many species of birds and fish migrate long distances with uncanny precision of navigation, and it seems an attractive suggestion that they use the earth's magnetic field Earth's magnetic field (and the surface magnetic field) is approximately a magnetic dipole, with one pole near the north pole (see Magnetic North Pole) and the other near the geographic south pole (see Magnetic South Pole). for direction. One such species is the European eel The European eel, Anguilla anguilla,[1] is a snake-like, facultatively catadromous fish, which can reach in exceptional cases a length of 1½ m, but is normally much smaller, about 60–80 cm, and rarely more than 1 m. , Anguilla anguilla L. Researchers from Chalmers University of Technology (body, education) Chalmers University of Technology - A Swedish university founded in 1829 offering master of science and doctoral degrees. Research is carried out in the main engineering sciences as well as in technology related mathematical and natural sciences. in Gothenburg, Sweden, and the University of Gothenburg dissected European eels (using nonmagnetic tools) in search of magnetic materials Magnetic materials Materials exhibiting ferromagnetism. The magnetic properties of all materials make them respond in some way to a magnetic field, but most materials are diamagnetic or paramagnetic and show almost no response. . Although they found materials in several parts of the eel's anatomy that show a magnetic susceptibility, none of these could be lined up in chains of single magnetic domains all oriented in the same direction, as is the magnetic material in magnetotaxic bacteria. So the researchers conclude that they have been unable to find any evidence for a magnetic compass in European eels. |
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