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.
