Just before the 1855 earthquake, a fisherman reported nervous catfish. They swam to and from in the water as though they were restless or anxious. The fisherman saw this as sign of an oncoming quake. He hurried ้home and managed to save his family minutes before the tremor struck. Catfish were also said to have acted in the same restless way just before 1923 Tokyo earthquake. So the scientists got busy. In the 1930' s, Professor Hatai at Tohoku University set an experiment. He watched the behaviour of catfish in the laboratory tanks. Day after day, the catfish remained calm. They did not even react to finger tapping on the table that held their tank. Hatai noticed, however, that in 80 percent of the cases they became jumpy six to eight hours before an earthquake. Hatai believes that catfish are somehow sensitive to electric currents in the earth. These currents change before earthquake activity.