华贵栉孔扇贝不同壳色后代早期发育阶段性状比较

Comparison of Traits among Offspring Deriving from Different Shell Colors in Noble Scallop Chlamys nobilis Reeve at Early Developmental Stage

为了提高华贵栉孔扇贝的产量以及通过人工选择培育新品种,利用同一养殖群体中的橙色、褐色、橙褐色个体为亲本,采用个体间随即交配的方法,于2008年10月14日、16日和18日分批建立了橙色、褐色、橙褐色三个不同群体。为了减少环境效应,自受精卵孵化开始,三个群体一直被培养在相同的环境条件下。结果发现,三个群体在受精卵孵化率、幼虫存活率、幼虫及稚贝生长等方面都存在显著差异。就孵化率而言,橙色的最高、褐色的次之、橙褐色的最低,分别为97.5%、92.6%和91.3%;就幼虫存活率而言,橙褐色的最高、褐色的次之、橙色的最低,10日龄时分别为67.0%、43.8%和16.0%;就幼虫期生长而言,褐色生长最快、橙褐色次之、橙色生长最慢,壳长的日增量分别为9.49μm、8.30μm和7.73μm,壳高的日增量分别为8.18μm、7.17μm和6.61μm,且壳长比壳高生长得快;就稚贝期生长而言,橙褐色生长最快、橙色次之、褐色生长最慢,壳长的日增量分别为64.6μm、58.6μm和49.0μm,壳高的日增量分别为78.6μm、70.5μm和59.5μm,但壳高比壳常生长得快。很明显,华贵栉孔扇贝的壳色与其生长、存活有密切的联系,这为其选择育种提供了理论依据。

In order to improve production and get new strains of noble scallop Chlamys nobilis Reeve by selec- tion breeding, three populations of orange, brown and orange-brown were established using the method of ran- dom mating among individuals on 14, 16 and 18 October 2008, respectively, whose parents derived from the same cultured population. Since fertilization, the three populations were always cultured under the same condi- tions in order to minimize environmental effects. The results showed that there were significant differences among the three populations in the hatching rate, larval survival, and growth at larvae and juvenile stage. The hatching rate was 97.5%, 92.6% and 91.3% for orange, brown and orange-brown population, respectively, and the former were higher than the later two. The survival rate from high to low was always in order of or- ange-brown, brown and orange population at whole larvae stage, which was 67.0%, 43.8% and 16.0% at age of day 10, respectively. At larvae stage, the brown population grew the fastest, the orange-brown population grew slower than the brown population, and the orange population grew the slowest, whose growth rate was 9.49 μm/ d, 8.30 μm/d, and 7.73 μm/d in shell length and 8.18 μm/d, 7.17 μm/d, and 6.61μm/d in shell height, respeetively; at juveniles stage, the orange-brown population grew the fastest, the orange population grew slower than the orange-brown population, and the brown population grew the slowest, whose growth rate was 64.6 μm/d, 58.6 μm/d, and 49.0μm/d in shell length and 78.6 μm/d, 70.5μm/d, and 59.5 μm/d in shell height, respective- ly. Furthermore, the shell length grew faster than shell height at larvae stage, whereas shell height grew faster than shell length at juvenile stage. The present results suggested that there was a close connection between shell color and traits in the noble scallop, which provided a theoretical basis for selective breeding of this species.