Survival and metamorphosis of the larvae Portunus trituberculatus treated by the short-period fasting

Taking the Portunus trituberculatus larvas as testing animal,the research of the effects of the short-period fasting on survival and metamorphosis of Portunus trituberculatus larvas was carried out in Huaxing marine fry Ltd1 of Zhoushan city,Zhejiang province in April,2005.The results showed that: the average complete lethal time of Portunus trituberculatus larvas juvenile(Z₁,Z₂,Z₃,Z₄ to M)was 81, 120,141,162 and 200 h respectively,and the median lethal time was 39,66,90,64 and 174 h respectively. The displaying time of metamorphosis point was 33,57,69,54 and 150 h respectively under the condition of re-feeding recovering after the short-fasting.When the single fasting time was inside of the displaying time of metamorphosis point,the survival rate and metamorphosis rate were both declined,the larva metamor-phosis time prolonged and the death rate of anomalism was increased as the fasting time extending.There was no difference between the Z₁(group of starving for 3 h and the group of the recurring mode of/feeding for 3 h then fasting for 3 h0).The results of Z₂,Z₂,Z₄,M is same as the Z₁(Z₂ is between the group of fasting for 4 h and the group of recurring mode of/feeding for 4 h then fasting for 4 h0,Z₃ is between the group of fasting for 4.5 h and the group of recurring mode of/feeding for 4.5 h then fasting for 4.5 h0, Z₄ is between the group of fasting for 6 h and the group of recurring mode of/feeding for 6 h then fasting for 6 h,M is be ween the group of fasting for 7.5 h,fasting 15 h and the group of recurring mode of/feeding for 6 h then fasting for 6 h0).Finally,the thesis discussed the definition of fasting limit value and the total restricted disposing time,and the survival and metamorphosis character under short-period starvation of different period of Portunus trituberculatus larvas.