杂交鲟 (西伯利亚鲟♀×施氏鲟♂) 全人工繁殖、胚胎发育及早期仔鱼生长发育研究

Study on total artificial reproduction, embryo development and early larva growth of hybrid sturgeon (Acipenser baerii♀×A. schrenckii♂)

  • 摘要: 为探明养殖杂交鲟 (西伯利亚鲟Acipenser baerii ♀×施氏鲟A. schrenckii ♂) 胚胎发育及早期仔鱼生长阶段的关键特征和规律,并为其人工催产和苗种培育提供基础数据和参考依据,采用注射外源激素 (LHRH-A2+DOM) 的方法,利用干法受精获得受精卵,对杂交鲟胚胎及早期仔鱼发育各时期的形态变化特征进行观察,同时测量其形态学指标。结果显示:人工繁殖的平均催产率为100%,受精率为 (80.08±8.57)%,孵化率为 (63.69±10.71)%。杂交鲟的受精卵为沉性卵、灰黑色、不透明,富含卵黄,卵膜3层,卵径为 (2.50±0.56) mm。根据对胚胎发育形态特征的观察与分析,将杂交鲟的胚胎发育过程分为受精卵、卵裂、囊胚、原肠胚、神经胚、器官形成、出膜共7个阶段、34个时期。水温16.30~17.10 ℃时,经124~134 h孵化出膜,发育总积温为2 083~2 251 (h·℃);初孵仔鱼全长 (10.61±0.58) mm,仔鱼在第7天开始有摄食行为,并进入混合营养期,此时全长为 (17.17±0.64) mm,到第10天时卵黄囊被完全吸收,进入外源营养期,混合营养期仅持续3 d。

     

    Abstract: To investigate the key characteristics and patterns of embryonic development and early larval stages of farmed hybrid sturgeon (Acipenser baerii♀×A. schrenckii♂) and to provide basic data and reference basis for its artificial spawning and nursery breeding, through injecting the exogenous hormone (LHRH-A2+DOM), we dissected and retrieved the eggs, carried out the artificial insemination, and finally obtained the fertilized eggs by dry fertilization. Then we observed the morphological change characteristics of the hybrid sturgeon embryos and larvae in each period of development, and measured their morphological indexes. The results show that the average catalysis rate of the artificial reproduction was 100%, the fertilization rate was (80.08±8.57)% and the hatching rate was (63.69±10.71)%. The fertilized eggs of the hybrid sturgeon were heavy, grey-black, opaque and rich in yolk, with three layers of egg membranes and an egg diameter of (2.50±0.56) mm. According to the observation and analysis of the morphological characteristics of embryonic development, the embryonic development process of hybrid sturgeon was divided into seven stages, including fertilized egg stage, egg cleavage stage, blastocyst stage, protozoa embryo stage, neuroembryo stage, organ formation stage, and emergence of membranes, which comprised 34 periods. The total cumulative temperature of development was 2 083–2 251 (h· ℃). The total length of the newly hatched larvae was (10.61±0.58) mm. The hatchlings began to feed on the 7th day and entered the mixed nutritional stage, with the total length being (17.17±0.64) mm. The yolk sac was completely absorbed by 10th day and entered the exogenous nutrient phase. The mixed nutrient period was only 3 d.

     

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