发头裸腹溞生长、生殖的研究

STUDY ON GROWTH, REPRODUCTION OF MOINA IRRASA (CLADOCERA)

发头裸腹MoinairrasaBrehm（Cladocera）在25±1℃下有3个幼龄、6个成龄，平均寿命为167．7h，平均最大体长为1．75mm，平均产仔量为117个，rm为1．358／d；在30±1℃下有3个幼龄、7个成龄，平均寿命为121．0h，平均最大体长为1．71mm，平均产仔量为106．6个，rm为1．650／d。在生命初期30±1℃下体重增长率（dW／dt）、相对体长增长率（dL／Ldt）、体长、体重均大于25±1℃，在生命中后期25±1℃各增长率、体长及体重反而超出30±1℃。体重增长率25±1℃下在0．862d有一最大值，30±1℃下在0．395d有一最大值。两温度下相对体长增长率在t＝0即刚出生时最大。

There are 3 juvenile instars and 6 adult instars of Moina irrasa (Cladocera)at 25 ± 1℃. The average life span is 167.7h, the average number of egg production per adult is 117, the mean maximum body length is 1.75 mm, and the intrinsic growth rate is 1.358 / d. There are 3 juvenile instars and 7 adult insane at 30±1℃. The average life span is 121.0h， the average number of egg production per adult is 106.6,the mean maximum body length is 1.71 mm. The intrinsic growth rate is 1.650/d.The growth of length and weight the instantaneous weight increment rate and instantaneous length relative increment rate equations of M. irrasa at 25 ±1℃ and 30 ±1℃ are as following in which the length (L) unite is mm, the weight (wet weight,w) is mg, and the bine (t) is the day.25±1℃, Lt = 1 .880[1 - e - 0.3185(t+1.8620)]W = 0.3728[1 - e-0.3185(t+1.8620)] 2.3814dW/dt = 0.15625·e -0.3185t(1-0.55264e-0.3185t)1.3814dL/Ldt = 0.3185/[e0.3185(t+ 1.8620) -1]30 ±1℃, Lt = 1.708[1-e-0.7428(t+0.7733)]W = 0.2966[1-e-0.7428(t+0.7733)2.3814dW/dt = 0.29542·e-0.7428t(1-0.56304e-0.7428t)1,3814dL/Let = 0.7428/[e0.7428(t+0.7733)-1]At the begining of life span the length. weight and their growth rates at 30 ±1℃ are bigger than those at 25±1℃. But after mid life span that the length, weight and theirs growth rates at 25 ±1℃ are bigger than that at 30 ±1℃ instead. The instantaneous weight increment rates at 25±1℃ and 30±1℃ have a maximum value when t = 0.862d and 0.395d respectively. When t = 0 or just be born, the instantaneous length relative increment the at 2 temperatures each has a maximum value.