熊本牡蛎壳金品系与壳黑品系的生长、存活、性腺发育及生化成分的周期性变化

CHARACTERISTICS OF GROWTH, SURVIVAL, GONADAL DEVELOPMENT AND BIOCHEMICAL COMPONENT BETWEEN THE GOLDEN SHELL AND BLACK SHELL LINES OF CRASSOSTREA SIKAMEA

熊本牡蛎(Crassostrea sikamea)壳金品系与壳黑品系分别是壳颜色为金色与黑色的选育群体,为了评估选育效果与选育差异,分析了F3群体的生长、存活、性腺发育和生化成分(糖元、甘油三酯、总蛋白)含量的周期性变化特征。结果表明:浮游幼虫与稚贝期(9-40 dph)壳黑品系的壳高显著大于壳金品系(P<0.05),而幼贝与成贝期(180-450 dph)壳金品系的壳高、壳长、总重、总体积、软体重大于壳黑品系,并且总重呈显著性差异(P<0.05),表明成贝期壳金品系具有较全面的生长优势。15-450 dph壳金品系的存活率均高于壳黑品系,360与450 dph(6月与10月)壳金品系的成活率分别为55.35%与42.22%,是同时期壳黑品系成活率(25.27%与12.12%)的2.19倍与3.49倍(P<0.05),成贝期壳金品系具有较高的存活率优势。成贝期壳金品系与壳黑品系雌雄比接近1﹕1,性腺发育同步,6-9月(360-450 dph)为配子排放盛期。180-450 dph(12月至次年10月)壳金品系闭壳肌、外套膜、鳃和性腺中的糖元与甘油三酯含量均高于壳黑品系(P>0.05),随着卵子发育成熟,性腺中糖元含量逐渐升高,而甘油三酯含量逐渐降低;两个品系总蛋白含量无组织与时间差异。研究表明熊本牡蛎的生长、存活以及生化成分含量与壳色相关联。研究为经济性状与壳色的协同选择提供了参考依据。

The golden shell line and black shell line are the colored selection strains for Crassostrea sikamea. The F3 population were used to evaluate their growth, survival, gonadal development, and biochemical component(glycogen,triglyceride, total protein). The results suggested that the shell height of black shell line was significant higher than that of golden shell line at larvae and juvenile stages(9-40 days;P<0.05), while the golden shell line had higher growth in the shell height, shell length, total weight, total volume, and body weight compared to the black shell line, with a significant difference for the total weight(P<0.05). The golden shell line had a growth advantage over the black shell line at adult stage. The survival rate was higher in the golden shell line than that in the black shell line during the period of15-450 days. The survival rates were 55.35% and 42.22% in the golden shell line at 360 days(June) and 450 days(October), respectively, which were 2.19 times and 3.49 times higher than that of the black shell line(25.27% and12.12%, respectively). The sex ratio(female: male) was close to 1﹕1 both in the golden shell and black shell lines, and their gonadal development was synchronous, with the highest spawning during the period of June to September(360-450 days). Moreover, the golden shell line had a higher reproduction compared to the black shell line. The glycogen and triglyceride contents were higher in the adductor muscle, mantle, gill, and gonad of the golden shell line than those of the black shell line(P>0.05). Furthermore, the glycogen content gradually increased with the gametogenesis in the golden shell and black shell lines, in contrast, the triglyceride content gradually decreased in the same period. The total protein content was indifferent between two groups. The present study displays that there is a close relationship between the shell color and growth, survival, and biochemical content, which provides a basic reference for the synergistic selection of phenotypes and shell color in C. sikamea.