性成熟年龄 meaning in Chinese

age at sexual maturity

The reasons of small resource are 1st , the fish eggs is lack of sticky and most spawning ground is not comfortable for spawning ; 2nd , the fish matures about 5 years old and fecundity is in low level on absolute or relative eggs amount ; 3rd , the shape is easier for catching with tall width and thin body
黑龙江鲂资源量少的原因为：黑龙江鲂为产弱黏性卵的鱼类，对产卵场的要求较高。黑龙江鲂的性成熟年龄较大( 5龄) ，而且无论是绝对怀卵量还是相对怀卵量都较低，因此生殖力较低。黑龙江鲂由于体形高而侧扁，极易被捕捞。