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近几年我国北方地区的精养池塘,在封冰前后陆续出现了鲤成鱼,鲤鱼种死亡现象。其现象是: 在封冰前,于不同区域发现少数鲤鱼单一游动或集群游动,群内并混有极少数鲢鳙鱼。鲤鱼先在池塘四周扎边,后在草根下,注水口处游动。当人靠近时,鱼即游开或下沉,但人离开后仍回原处游动,并出现个别鲤鱼死亡,随后陆续死亡。如把游动无力的鱼移到清新水域则立即恢复正常。封冰后,单个鲤鱼或鱼群仍在冰层下的不同区域游动,有时在1～2月内于冰下水中群游,把局部区域的冰层融化开,并出现大批死鱼,甚至全军覆灭。有的池塘虽在封冰前后鲤鱼死亡50～60％,而池中存活下来的鱼,在春季冰融后散群,活动正常。
In recent years, intensive ponds in the northern part of our country have witnessed the death of common carp and carp species before and after the ice closure. The phenomenon is: before the ice seal, in a few areas found in a small number of carp swimming or swimming in a group, the group mixed with very few silver carp and bighead carp. Carp first barn around the pond, after the grassroots, water inlet swimming. When people approached, the fish swam or sank. However, after leaving, people still walked back and forth and some carps died. They died one after another. If the swimming weak swimming fish into fresh water immediately returned to normal. After ice is sealed, individual carps or fish groups are still swimming in different areas under the ice layer, sometimes swirling in ice water in January to February, melting the ice layer in some areas and leaving a large number of dead fish, or even The army vanished. Although some ponds kill 50 to 60% of the carps before and after sealing the ice, the fish surviving in the pond are clustered in the ice after the spring melt, and the activities are normal.