| In this paper,7kinds of initial feed, including egg yolk, rotifers, soybean milk, skimmed milk powder, eel feed, fishmeal and yeast powder were used to study the effects on growth and survival for early cultivation of Misgurnus anguillicaudatus fry; and8commonly fish drugs, including Chlorine dioxide, CuSO4, KMnO4, Povidone iodine, Trichlorfon, Symclosene, Bromine chlorine hydantoin and Deltamethrin were used to test the acute toxicity of M. anguillicaudatus fry. The main results are as follows:Test1:The effects of different initial feed on growth and survival for early cultivation of Misgurnus anguillicaudatus fryThe effects of different initial feed on growth and survival for early cultivation of M. anguillicaudatus fry was observed in the small bodies water of laboratory. Each test container stocking200fry and begin the test when95%fry can horizontally swim. Feeding in daily timing, determinating water temperature and dissolved oxygen during the test. The test temperature was between25℃to29.5℃, dissolved oxygen was between5.0mg/L to7.0mg/L during the test, Changing water100%every day1times and at the same time to count the survival fry and remove the dead seedling,bait and feces.The results showed that after feeding for21d, there were significant differences in body length and survival rate of M. anguillicaudatus larval (P<0.05), the group of rotifer had the highest growth rate, the average daily length gain was0.31mm, also had the highest final survival rate, up to39.5%; followed by egg yolk group reached25.5%, the final survival rate of other groups were very low. In conclusion, the best diet of M. anguillicaudatus larval was rotifers under the conditions of this experiment. The growth curve models of the early larvae by fitting with Bertalanffy, Gompertz and Logisyic model, correlation index of the moels (R2) were all up to1.000, and the growth inflection point occured between6-8days of age.Test2:Acute toxicity test of8fish drugs to M. anguillicaudatus fry8commonly fish drugs, including Chlorine dioxide, CUSO4, KMnO4, Povidone iodine, Trichlorfon, Symclosene, Bromine chlorine hydantoin and Deltamethrin were used to test the acute toxicity of M. anguillicaudatus fry, which average body length and weight were (2.9±0.6) cm and (0.165±0.2) g, respectively. Each test group for9tail fry and test time is96h.The test temperature was25±1.5℃, dissolved oxygen was between5.0mg/L to7.0mg/L, pH was7.1±0.1during the test. No fed, no oxygen during the test, replace1times test solution every2days, regular observation daily, clean up the dead individual timely, and records the death number of24h,48h,72h,96h. Calculation and analysis the median lethal concentration (LC5o) of24h,48h,72h and96h and safe concentration (SC). The main results are as follows:Respectively, the sensitivity in order of8kinds of fish drugs were Deltamethrin>CuSO4>Povidone iodine>KMnO4>Trichlorfon>Symclosene>Chlorine dioxide>Bromine chlorine hydantoin.After testing for24h,48h,72h and96h in the use of Chlorine dioxide, the lethal concentration (LC50) were17.42mg/L,17.419mg/L,16.899mg/L,16.899mg/L respectively, the safe concentration (SC) was1.69mg/LAfter testing for24h,48h,72h and96h in the use of CuSO4, the lethal concentration (LC50) were0.107mg/L,0.088mg/L,0.062mg/L,0.055mg/L respectively, the safety concentration (SC) was0.005mg/L.After testing for24h,48h,72h and96h in the use of KMnO4, the lethal concentration (LC50) were3.964mg/L,3.768mg/L,2.85mg/L,2.85mg/L respectively, the safety concentration (SC) was0.28mg/LAfter testing for24h,48h,72h and96h in the use of Povidone iodine, the lethal concentration (LC50) were3.564mg/L,3.357mg/L,3.036mg/L,2.74mg/L respectively, the safety concentration (SC) was0.27mg/LAfter testing for24h,48h,72h and96h in the use of Trichlorfon, the lethal concentration (LC50) were16.684mg/L,16.298mg/L,12.812mg/L,11.973mg/L respectively, the safety concentration (SC) was1.19mg/LAfter testing for24h,48h,72h and96h in the use of Symclosene, the lethal concentration (LC50) were16.005mg/L,16.005mg/L,15.077mg/L,15.077mg/L respectively, the safety concentration (SC) was1.5mg/L.After testing for24h,48h,72h and96h in the use of Bromine chlorine hydantoin, the lethal concentration (LC50) were41.666mg/L,40.06mg/L,40.06mg/L,40.06mg/L respectively, the safety concentration (SC) was4mg/L,After testing for24h,48h,72h and96h in the use of Deltamethrin, the lethal concentration (LC50) were0.006ml/L,0.006ml/L,0.005ml/L,0.003ml/L respectively, the safety concentration (SC) was0.0003mg/L... |
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