本研究建立中国刺参(♂)与日本红刺参(♀)杂交组合,通过对杂交子代的胚胎发育进行观察,详细描述其胚胎及幼体各个阶段的发育时序和形态特征,并比较在幼参培育期间杂交苗与中国刺参自交苗的生长和成活。结果表明,在20~22℃时,杂交子代发育至初耳幼体的时间为受精后24h38min,发育至中耳幼体的时间为72h8min,然后经过167h 8min(约7d)发育至大耳幼体,到受精后第9天发育至樽形幼体。樽形幼体后期,纤毛环逐渐退化,浮游能力减弱,幼虫由浮游转至底栖生活。在幼参培育期间,受精后第38~51天,平均水温为25.2℃,杂交幼参的体重特定生长率(SGR)为2.58%,而自交幼参的SGR略高,为3.03%;从受精后第51~80天,平均水温达到27.17℃,杂交幼参的生长速度减慢,SGR减小至0.66%,但平均体质量明显增加,到第80天达到(0.34±0.035)g,而自交幼参活动能力减弱,摄食量明显减少,SGR减小至0.08%,生长近于停滞,到第80天平均体质量为(0.19±0.034)g。自交苗和杂交苗的成活率相差不显著,分别为82.2%和73.9%。这表明,在高温条件下杂交苗种比自交苗种生长优势明显。
In present study, intraspecific hybridization was carried out between Green sea cucumber (♂) and Red sea cucumber (♀), Apostichopus japonicus. The embryonic development of hybrids was observed and the morphological characteristics of each period were described detailedly. Moreover, the growth rates and survival between hybrid juveniles and inbred Green juveniles were compared. At 20-22 ℃, the hybrid larvae required 24 h 38 min to develop to early auricularia, 72 h 8 min to develop to mid-auricularia, and 167 h 8 min to develop to late auricularia. Furthermore, the hybrid larvae required 9 to develop to doliolaria. During the late stage of doliolaria, with the loss of cilia band, the larvae sank and became to settle on the bottom. F/om 38 to 51 after hatching, the average water temperature was 25.17 ℃, specific growth rate for weight (SGR) in the hybrid juveniles was 2. 58%, while inbred juveniles grew at slightly higher SGR (3.03%). When the average water temperature rose to 27.17 ℃ from 51 to 80 d, despite the growth rate of hybrid juveniles slowed down with SGR decreased by 0. 66%, the average weight increased to (0. 34±0. 035) g at 80 d after hatching. However, with the decreased food intake of inbred juveniles, the SGR dropped Sharply to a extremely low value (0.08%), with the average weight of (0. 19 ±0. 034) g at 80 d. There was no significant difference on survival between hybrid and inbred juveniles (82. 2% and 73.9%). This indicated that the advantages of growth characteristics in the hybrid juveniles under the higher water temperature were obvious.