四大家鱼群体结构中低龄鱼比重上升，高龄鱼比重下降；

The proportion of the low age groups of Chinese carps increased and the advanced age group decreased;

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四大家鱼群体结构中低龄鱼比重上升，高龄鱼比重下降；

The proportion of the low age groups of Chinese carps increased and the advanced age group decreased;

youdao