The Effect Of Several Diets On Litopenaeus Vannamei Broodstock Reproduction Performance

The safety problem of broodstock diets closely related to issues of SPF litopenaeus vannamei larva production is still a great problem, which is badly restricting the cultivation of litopenaeus vannamei developing forward so far.This article provided "silver carp meat","silver carp meat mixed with limnodrilus and silver carp ovary","limnodrilus" as trial diets, and seted a kind of "broodstock feed","crassostrea meat mixed with neathes" as the control, to investigate the trial diets effect on the body length, body weight, gonad development, spawn and zygote quality of litopenaeus vannamei broodstocks, expecting that this research could provide us some proof for exploring or developing ideal broodstock diets suitable for the application of SPF litopenaeus vannamei larva production.The result showed that, the "limnodrilus" was perfect for the body length, body weight, gonad development, spawn and zygote quality of broodstock; the effect of "silver carp meat mixed with limnodrilus and silver carp ovary" was similar but inferior to the "limnodrilus"; the "silver carp meat" was the worst one.(1)On broodstock body length, body weight side: There was no significant difference among the groups. The "limnodrilus" was the first one on body length increase, body weight increase, body length an body weight increase rate.The "silver carp meat mixed with limnodrilus and silver carp ovary" was just behind. The body length increase and increase rate of the "limnodrilus" was0.93cm and6.73%; and body weight increase and increase rate was6.6g and19.42%.(2)On the gonad development side:The gonad weight increase rate of the "limnodrilus" was1475%, significantly larger than the "broodstock feed" and "silver carp meat" group (P<0.05).There was no significant difference (P>0.05) on the ultimate gonad index among the groups, yet the ultimate gonad index and gonad index increase of the "limnodrilus" was5.12%and4.50%separately, took up the best.The first spawning time of the "limnodrilus" was113.67h, was serious significantly shorter than the "silver carp meat" group (P<0.01), while was not significantly different from the "broodstock feed" group and the "crassostrea meat mixed with neathes" group (P>0.05)The mature rate of the "limnodrilus" was10.45%. Each group was of no significant difference (P>0.05).(3)On the spawn side:The continuous spawning rate of the "limnodrilus"group was72.08%, being the largest, which was no significant difference with the "crassostrea meat mixed with neathes" group(P>0.05). While the two groups were both serious significantly larger than the "broodstock feed" or "silver carp meat" group (P<0.01).The spawning interval among each group was of no significant difFerence(P>0.05).The one of the "crassostrea meat mixed with neathes" was117h,being shortest; and the one of the "limnodrilus" was134h,just following behind. The egg amount of the "silver carp meat" group was serious significantly smaller than the other(P<0.01), while the other were of no significant difference (P>0.05). The largest one was the "crassostrea meat mixed with neathes", achieving125.9thousand.The average spawning time of the "limnodrilus" was2.33times, obviously less than the "crassostrea meat mixed with neathes"(P<0.05), and was significantly more than the "broodstock feed" or "silver carp meat" group (P<0.01).(4)On the zygote quality side:The "crassostrea meat mixed with neathes" group was the best. Its egg size, nauplius hatch rate, nauplius metamorphism rate, were all the largest, were0.2700mm,61.90%,66.16%separately. Meantime, its nauplius and zoea survival time tested by immerging lower salty water abruptly, were the longest, were365.50S、341.67S separately, both significantly more than the other (P<0.01).The nauplius and zoea survival time tested by immerging lower salty water abruptly of the "limnodrilus" were significantly (P<0.05) and serious sifnificantly (P<0.01) more than the other separately.Throughtout the results, we considered that the trial diet "limnodrilus" was more useful in improving broodstock grow and gonad development; and was evenly matched with the "crassostrea meat mixed with neathes" in improving the zygote quality.Therefore, the work of developing limnodrilus as broodstock diet for the SPF litopenaeus vannamei larva production should be of great value.