This paper studied the effects of some ecological factors (temperature,pH,hatching method and ammonia) on the embryonic development of ricefield eel.The results indicated that the optimum hatching temperature of ricef...This paper studied the effects of some ecological factors (temperature,pH,hatching method and ammonia) on the embryonic development of ricefield eel.The results indicated that the optimum hatching temperature of ricefield eel was 25～28 ℃,and no significant difference was found about the effects of pH within the range of pH 5.5～9.5 on the hatching rate of oosperm.Dripping water incubation had a higher hatching rate of oosperm than staticing water incubation,and the hatching rate of oosperm decreased with increasing ammonia content.The present study provided an available suggestion for the all-artificial and half-artificial breeding of ricefield eel.展开更多
The eggs of Pelteobagrus vachelli were fertilized artificially at 23℃,from parental fish collected in the Jialing River,on May 23,2004.The embryonic development was observed at nine experimental temperatures,i.e.eigh...The eggs of Pelteobagrus vachelli were fertilized artificially at 23℃,from parental fish collected in the Jialing River,on May 23,2004.The embryonic development was observed at nine experimental temperatures,i.e.eight constant temperatures(17,19,21,23,25,27,29 and 31℃)and a varying temperature(from the blastoderm to the blastula stage at 23℃,from gastrulae to the neural plate stage at 25℃,from organogenesis to hatching at 27℃).The results showed that the hatching rate,incubation duration and survival rate in each developmental stage changed significantly with temperature.At 17℃,the fertilized eggs did not develop,and all of them died.Hatching rate increased with temperature from 19 to 25℃,then decreased with as temperatures rose further from 27 to 31℃.Hatching rate was highest(76.92%±1.07%)at 25℃.At the different constant temperatures,the best survival rates in the three stages of blastodem-blastula,gastrulae-neural plate and organogenesis-hatching were obtained at 23,25 and 27℃,respectively.The hatching rate(93.69%±0.57%)with the varying temperature regime was significantly higher than those at each constant temperature,while its incubation duration and accumulated temperature were close to those at the constant 25℃.The results showed that the embryos could develop adequately with temperature of 21-29℃ and optimally at 25℃ in constant temperature regimes.展开更多
文摘This paper studied the effects of some ecological factors (temperature,pH,hatching method and ammonia) on the embryonic development of ricefield eel.The results indicated that the optimum hatching temperature of ricefield eel was 25～28 ℃,and no significant difference was found about the effects of pH within the range of pH 5.5～9.5 on the hatching rate of oosperm.Dripping water incubation had a higher hatching rate of oosperm than staticing water incubation,and the hatching rate of oosperm decreased with increasing ammonia content.The present study provided an available suggestion for the all-artificial and half-artificial breeding of ricefield eel.
文摘The eggs of Pelteobagrus vachelli were fertilized artificially at 23℃,from parental fish collected in the Jialing River,on May 23,2004.The embryonic development was observed at nine experimental temperatures,i.e.eight constant temperatures(17,19,21,23,25,27,29 and 31℃)and a varying temperature(from the blastoderm to the blastula stage at 23℃,from gastrulae to the neural plate stage at 25℃,from organogenesis to hatching at 27℃).The results showed that the hatching rate,incubation duration and survival rate in each developmental stage changed significantly with temperature.At 17℃,the fertilized eggs did not develop,and all of them died.Hatching rate increased with temperature from 19 to 25℃,then decreased with as temperatures rose further from 27 to 31℃.Hatching rate was highest(76.92%±1.07%)at 25℃.At the different constant temperatures,the best survival rates in the three stages of blastodem-blastula,gastrulae-neural plate and organogenesis-hatching were obtained at 23,25 and 27℃,respectively.The hatching rate(93.69%±0.57%)with the varying temperature regime was significantly higher than those at each constant temperature,while its incubation duration and accumulated temperature were close to those at the constant 25℃.The results showed that the embryos could develop adequately with temperature of 21-29℃ and optimally at 25℃ in constant temperature regimes.
