杂色鲍的胚胎发育

EMBRYONIC DEVELOPMENT OF ABALONE (HALIOTIS DIVERSICOLOR REEVE)

杂色鲍 (HaliotisdiversicolorReeve)的胚胎发育分为 4个阶段共 32个发育期 ,其中 ,卵裂阶段有 13个时期 :受精期、第 1极体放出期、第 2极体放出期、 2细胞分裂早期、 2细胞期、 4细胞期、 8细胞期、 16细胞期、 32细胞期、 6 4细胞期、 12 8细胞期、桑椹期和囊胚期。胚胎发育阶段有 4个时期 :原肠期、担轮幼体早期、担轮幼体晚期和担轮幼体孵化瞬期。胚后发育阶段有 13个时期 :担轮幼体期、面盘幼虫早期、面盘幼体中期、面盘幼体后期、匍匐幼体早期、匍匐幼体中期、匍匐幼体后期、围口壳幼体早期、围口壳幼体中期、围口壳幼体后期、上足分化幼体早期、上足分化幼体中期和上足分化幼体后期。幼鲍阶段有 2个时期 :第 1呼吸孔出现早期 ,第 1呼吸孔出现期。在适宜水温范围内 ,随着水温升高 ,孵化期相应缩短。在水温 18～ 34℃条件下 ,受精卵不同程度都能孵化 ,但孵化率和孵化时间则有很大差别。在水温 18℃时 ,鲍卵从受精至开始孵化需经历 11hr 32min ,孵化率占 2 5‰ ,平均孵化期为 2 6hr 15min ,孵化速率为 0 0 381,周限增长率为 1 0 0 10 /hr;而在水温 2 2℃条件下 ,经过 7hr 30min才开始孵化 ,平均孵化期为 2 3hr 5min ,孵化速率为 0 0 415 ,周限增长率为1 0 2 0 2 /hr。鲍卵受精后 ,在水温为 2

The embryonic development in Abalone ( Haliotis diversicolor Reeve), was divided into four periods, including 32 stages (Table 1). (1) Cleavage period containing 13 stages: artificial fertilization, the first polar body stage, the second polar body stage, early 2 cell stage, 2 cell stage, 4 cell stage, 8 cell stage, 16 cell stage, 32 cell stage, 64 cell stage, 128 cell stage, morula stage and blastula stage; (2) Embryonic development period including 4 stages: gastrula stage, early trochophore stage in egg membrane, late trochophore stage in egg membrane and at the moment of hatching stage;(3) Postembryonic development composed of 13 stages: trochophore, early veliger stage, mid veliger stage, late veliger stage, early creeping larva stage, mid creeping larva stage, late creeping larva stage, early peristomial shell larva stage, mid peristomial shell larva stage, late peristomial shell larva stage, early differentiation epipodes stage, mid differentiation epipodes stage and late differentiation epipodes stage;(4) Juvenile period made up of 2 stages: early emergence stage of the first breathing pore and emergence stage of the first breathing pore. Although the fertilized eggs of the Abalone may were incubated under the range of temperature from 18℃ to 34℃, the instantaneous incubation rate and hatching time are veried.The incubative duration of fertilized egg needed eleven hours and thirty two minutes after the artificial fertilization under the temperature of 18℃, the instantaneous incubation rate was 2 5‰, the average incubation period was twenty six hours and fifteen minutes. The speed of hatching rate was 0 0381, the finite rate of increase was 1 0010 per hour. But under the water temperature of 22℃, the beginning of hatching time was seven hours and thirty minutes, the average incubation period was twenty three and five minutes, the speed of hatching rate was 0 0415, the finite rate of increase was 1 0202 per hour. Water temperature showed a marked influence upon the incubation period of the fertilization egg. Within the range of 20～28℃, the higher the water temperature, the shorter the incubation time and the higher the incubation rate (Table 2). The time that an embryonic egg developed into a juvenile(emergence of the 1st breathing pore)was 23～24 days under water temperature 23 7～28 5℃ and salinity 32 8‰～34 5‰(specific gravity 1 0223～1 0229).