Growth And Reproductive Traits Of Monopterus Albus And Application Of Stoyer Additives Under Artifical Rearing Condition

The growth and reproductive traits of Monopterus albus under artifical rearing condition were investigated from March 2007 to October 2008, and the growth and reproductive traits of different body color Monopterus albus were compared; The influences of different additives on growth and reproductive traits and digestive enzyme activities of Monopterus albus were studied. The studies could offer theoretical directions for cultivation, artificial propagation and variety selection of Monopterus albus. The results are as follows:1. The growth rate of Monopterus albus increased with decreasing of stocking density in cages, but the fishing harvest per unit space was the best when the stocking density was 0.6 kg/m2; 1 and 2 years old Monopterus albus grew quickly, the growth velocity decreased significantly after 3 years old.2. Under artifical rearing condition, spawning was not observed of the parent fish which were reared in high desity cages at earlier period, separated stocking in low density at earlier period and separated stocking at earlier sexual maturity and separated stocking at late sexual maturity were 3 different rearing modes of parent fish, their spawning period, spawning rate, productivity of parent fish and growth of larvae were all differential. The spawning period were from late May to mid July, from mid July to late August and from early August to early September, correspondly; The spawning rate were 53.5%, 54.1% and 24.5%, correspondly; and average number of larvae per group were 45.1, 69.4 and 60.7, respectively; The growth velocity of larvae which were hatched at different period was differential; The spawning rate and mean productivity declined while the relative productivity rised as the weight decreasing of female parent fish, but the variation of absolute productivity was not obvious; When the sex ratio of parent fish was 1:1, the spawning rate was significant higher than 2:1.3. The heredity of the 3 body color of Monopterus albus was stable at the stage of first filial generation; At the stage of larva, the growth velocity and feedstuff utilization rate of big-flower were all the best, but the variability of growth performance among 3 body color Monopterus albus was not significant. The gravidity rate of big-flower was at the top of the 3 body color Monopterus albus, the absolute fecundity and the relative fecundity of crypt-flower were all at the top; Reproducted in the condition of "eco-like", the spawning rate of crypt-flower was the best, reached 60%.4. According to the orthogonal design L₈ (2⁷), dihydropyridine,V_E,HUFA and betaine were added into the feedingstuff and feeded Monopterus albus for 60 days, and then detected the growth velocity, ovary coefficient, fecundity and digestive enzyme activities. The results were as follows, there were promotion for growh, reproduction and digestive enzyme activities when the 4 additives were suitable matched, the optimum additive amount of dihydropyridine, Ve, HUFA and betaine (with the optimal level) in the feedingstuff were 0.12% , 0.04%, 3.00% and 1.00%, respectively.5. The cultivation experiment of adding barm compounds into the feedstuff indicated, Some influences on growth and digestive enzyme activities of Monopterus albus were caused by the barm compounds, the optimal additive amount of barm compounds was 1.8% for 2 years old and 5.0% for 3 years old, respectively.