根据鲶鱼的听觉特性和夜间活动习性,研制了鲶鱼活动性超声波自动观测系统。观测结果表明,该系统不仅可灵敏地自动记录鲶鱼的活动性,并对其正常活动性无影响,环境声响对该系统无干扰。同时可应用于其他水生动物活动性的自动观测。初步的观测资料表明,1982年1—6月的观测期间,唐山地区发生的两次强余震(M_L5.2和M_L5.5)前48小时内,自动观测到的鲶鱼活动性出现明显增高。 According to the auditory characteristics of catfish and nocturnal activity habits, an automatic catfish ultrasonic observation system was developed. Observations show that the system can not only automatically and sensitively record the activity of catfish, but also has no influence on the normal activity of the catfish. The environmental sound has no interference to the system. At the same time can be applied to other aquatic animal activity automatic observation. Preliminary observations show that during the observation period from January to June 1982, catfish activity was observed in the first 48 hours before the occurrence of two strong aftershocks (M_L5.2 and M_L5.5) in Tangshan.