| 摘要: |
| 作者对太平洋牡蛎(Crassostrea gigas)人工培育群体的繁殖习性进行了初步探讨。经室内升温人工育苗培育的牡蛎性成熟年龄缩短,受精135d后性腺发育成熟;雌雄性比随着年龄而变 化,4.5月龄的牡蛎群体中,雄性占优势(68.93%),雌雄性比为1∶2.73;1龄群体中,雌雄两性比例接近,性比为1∶1.07;2龄群体中雌性 (63.69%)明显多于雄性,雌雄性比为1∶0.599。群体中存在雌雄同体现象,雌雄同体率随着年龄的增长而降低,4.5月龄的牡蛎群体中,雌雄同体 高达1.94%,1龄群体中雌雄同体比例降低为0.35%,而2龄牡蛎群体中,雌雄同体率仅为0.12%;雌雄同体者能够自体受精。怀卵量随年龄的增长而 增大,1龄牡蛎的平均怀卵量在800万粒～856.8万粒,而2龄牡蛎的平均怀卵量在2333.80万粒～2900万粒之间,明显多于1龄群体;怀卵量的 多少也与亲贝的营养条件和性腺的发育程度有关。雌体的壳高、壳宽、体质量和软体部质量都明显大于雄体(P<0.05),但雌雄两性在壳长方面差异不 显著。 |
| 关键词: 太平洋牡蛎(Crassostrea gigas) 人工培育群体 繁殖习性 |
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| 基金项目:国家863计划资助项目(2006AA10A401);国家科技基础条件平台建设资助项目(2005DKA30470) |
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| A primary study on reproductive characteristics of cultivated groups of Pacific oyster (Crassostrea gigas) |
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| Abstract: |
| The reproductive characteristics of cultured Pacific oysters (Crassostrea gigas) were discussed in this study. The time for sex maturation shortened in oysters that were artificially breeded inside the door by promoting the sea water temperature. The gonad matured only 135 days after fertilization in these oysters. Sex ratio of female to male varied greatly with ages, was 1:2.73 in a 4.5-month-old group, 1:1.07 in 1-year-old group and 1:0.599 in 2-year-old group. Hermaphrodites exist in oyster groups and the rate of hermaphrodites reduced with the increase of ages. The proportion of hermaphrodites was up to 1.94% in 4.5-month-old group and lowed to 0.35% in 1-year-old oyster, only 0.12% of hermaphrodites were observed in 2-year-old group. Self-fertilization was realizable in hermaphrodites. The fecundity increases with the increase of ages, the mean amount of eggs in each femle ranges from 23.338～290.0 million in 2-year-old oyster which were significantly more than that in 1-year-old group (ranged from 80.0～85.68million). Beside ages, fecundity also depended on nutrition and extent of gonad development. The females were larger than males in shell height, shell width, whole weight and tissue weight（P<0.05), but no significant differences were noticed in shell length between males and females. |
| Key words: Pacific oyster, Crassostrea gigas cultivated groups reproductive characteristics |
