[ Objective] This paper aimed to summarize the results of the lenok reproduction in a hatchery, including growth of the artificially bred lenok, artificial propagation and fry rearing. [ Method ] Lenok （ Brachymystax...[ Objective] This paper aimed to summarize the results of the lenok reproduction in a hatchery, including growth of the artificially bred lenok, artificial propagation and fry rearing. [ Method ] Lenok （ Brachymystax lenok） collected at wild were fed with pelleted feed and cultured to ma- turity in a flowing -water pond. The broodstocks were hormonally induced to spawn, and fry were reared from 2003 to 2010 in order to obtain a suit- able and reliable method for the mass production of lenok juveniles. The embryos were hatched at accumulative temperature of up to 180 -213 day degree at water temperature of 8 -10 ~C. [Result]The results showed that 68% -85% of success rate was obtained with the eyed rate （fertilizing rate） of 32.8% -83%, hatching rate of 56.5% -87%, and emerging rate of 59.9% -90%. The fry developed into swim-up stage 10-12 days post - hatching. There were no significant differences in growth rate, fecundity and the eyed rate in the cultured lenok from those of the wild lenok. [ Conclusion] Mass fry production of lenok could be achieved by hormonally induction.展开更多
We evaluated the effect of ration level(RL) on the growth and energy budget of lenok Brachymystax lenok. Juvenile lenok(initial mean body weight 3.06±0.13 g) were fed for 21 d at five different ration levels: sta...We evaluated the effect of ration level(RL) on the growth and energy budget of lenok Brachymystax lenok. Juvenile lenok(initial mean body weight 3.06±0.13 g) were fed for 21 d at five different ration levels: starvation,2%,3%,4% bwd(body weight per day,based on initial mean values),and apparent satiation. Feed consumption,apparent digestibility,and growth were directly measured. Specific growth rates in terms of wet weight,dry weight,protein,and energy increased logarithmically with an increase in ration levels. The relationship between specific growth rate in terms of wet weight(SGRw,%/d) and RL(%) was characterized by a decelerating curve: SGRw=-1.417+3.166ln(RL+1). The apparent digestibility coefficients of energy exhibited a decreasing pattern with increasing ration level,and there was a significant difference among different RLs. Body composition was significantly affected by ration size. The relationship between feed efficiency rate in terms of energy(FERe) and RL was: FERe=-14.167+23.793RL–3.367(RL)2,and the maximum FERe was observed at a 3.53% ration. The maintenance requirement for energy of juvenile lenok was 105.39 k J BW(kg)-0.80/d,the utilization efficiency of DE for growth was 0.496. The energy budget equation at satiation was: 100IE=29.03FE+5.78(ZE+UE)+39.56 HE+25.63 RE,where IE is feed energy,FE is fecal energy,ZE+UE is excretory energy,HE is heat production,and RE is recovered energy. Our results suggest that the most suitable feeding rate for juvenile lenok aquaculture for wet weight growth is 2.89% bwd,whereas for energy growth,the suggested rate is 3.53% bwd at this growth stage.展开更多
基金supported by Special Fund for Agro-scientific Research in the Public Interest(Grant no. 201003055)the National Science and Technology Supporting Plan(Grant no. 2012BAD25B10)National Science and Technology Plan of the Twelfth Five-Year for the Rural Development in China(Grant no. 2012BAD26B05)
文摘[ Objective] This paper aimed to summarize the results of the lenok reproduction in a hatchery, including growth of the artificially bred lenok, artificial propagation and fry rearing. [ Method ] Lenok （ Brachymystax lenok） collected at wild were fed with pelleted feed and cultured to ma- turity in a flowing -water pond. The broodstocks were hormonally induced to spawn, and fry were reared from 2003 to 2010 in order to obtain a suit- able and reliable method for the mass production of lenok juveniles. The embryos were hatched at accumulative temperature of up to 180 -213 day degree at water temperature of 8 -10 ~C. [Result]The results showed that 68% -85% of success rate was obtained with the eyed rate （fertilizing rate） of 32.8% -83%, hatching rate of 56.5% -87%, and emerging rate of 59.9% -90%. The fry developed into swim-up stage 10-12 days post - hatching. There were no significant differences in growth rate, fecundity and the eyed rate in the cultured lenok from those of the wild lenok. [ Conclusion] Mass fry production of lenok could be achieved by hormonally induction.
基金Supported by the Special Fund for Agro-Scientific Research in the Public Interest of China(No.201003055)the National Key Technology Research and Development Program of China(Nos.2012BAD25B10,2012BAD26B05)the Central-Level Non-Profit Scientific Research Institutes Special Funds of China(No.HSY201412)
文摘We evaluated the effect of ration level(RL) on the growth and energy budget of lenok Brachymystax lenok. Juvenile lenok(initial mean body weight 3.06±0.13 g) were fed for 21 d at five different ration levels: starvation,2%,3%,4% bwd(body weight per day,based on initial mean values),and apparent satiation. Feed consumption,apparent digestibility,and growth were directly measured. Specific growth rates in terms of wet weight,dry weight,protein,and energy increased logarithmically with an increase in ration levels. The relationship between specific growth rate in terms of wet weight(SGRw,%/d) and RL(%) was characterized by a decelerating curve: SGRw=-1.417+3.166ln(RL+1). The apparent digestibility coefficients of energy exhibited a decreasing pattern with increasing ration level,and there was a significant difference among different RLs. Body composition was significantly affected by ration size. The relationship between feed efficiency rate in terms of energy(FERe) and RL was: FERe=-14.167+23.793RL–3.367(RL)2,and the maximum FERe was observed at a 3.53% ration. The maintenance requirement for energy of juvenile lenok was 105.39 k J BW(kg)-0.80/d,the utilization efficiency of DE for growth was 0.496. The energy budget equation at satiation was: 100IE=29.03FE+5.78(ZE+UE)+39.56 HE+25.63 RE,where IE is feed energy,FE is fecal energy,ZE+UE is excretory energy,HE is heat production,and RE is recovered energy. Our results suggest that the most suitable feeding rate for juvenile lenok aquaculture for wet weight growth is 2.89% bwd,whereas for energy growth,the suggested rate is 3.53% bwd at this growth stage.
