2个凡纳滨对虾群体仔虾的生长比较

Comparison of Growth between Two Populations of Pacific White Leg Shrimp Litopenaeus vannamei

以凡纳滨对虾二代群体自交、选育家系（♀）×引进SPF（♂）群体杂交,通过自然交配和人工培育获得2个仔虾群体,待仔虾长至体长0.8~1.0 cm时,随机选取60万尾放养于3口0.133 hm2的对虾养殖高位塘中,密度150万尾/hm2,其中二代仔虾2口塘,杂交仔虾1口塘。投喂＂恒兴＂牌饲料,相同的养殖环境和管理措施,养殖30 d后,每隔10 d进行一次生长测定。结果表明,杂交仔虾的生长速度和成活率高于二代仔虾,体质量和体长的总生长率高于二代仔虾,抗应激能力强于二代仔虾,较二代仔虾均匀;在40 d的观测期内杂交仔虾体长的绝对增长量为4.49 cm,二代仔虾为3.66 cm,提高22.68%,杂交仔虾体质量的绝对增长量为3.73 g,二代仔虾为2.20 g,提高69.55%,杂交仔虾生长优势明显。

The F2 generations from self-crossing lines of SPF broodstock of Pacific white leg shrimp Litopenaeus vannamei from Ocean Institute of Hawaii were established,and the hybrid generation（SPF♂×family♀）was acquired by crossing introduced SPF white leg shrimp with healthy family broodstock which had been selective bred 5 years in Zhanjiang.A total of 400 thousand F2 postlarvae and 200 thousand hybrid postlarvae were cultivated in 3 ponds at a stocking density of 1.5 million per square meter.One month later,the body length and body weight of the shrimp were measured every ten days.The hybrids were found to have better growth,higher survival rate,and greater anti-stress ability than the F2.During 40 days,there were 22.68% higher growth in Absolute body length（4.49 cm）and 69.55% higher growth in body weight（3.73 g）in the hybird generation than those in the F2（3.66 cm and 2.20 g）.