| 来源类型 | Monograph (IIASA Interim Report) |
| 规范类型 | 报告 |
| Phenotypic and Genetic Consequences of Size Selection at the Larval Stage in the Pacific Oyster (Crassostrea gigas). | |
| Taris N; Ernande B; McCombie H; Boudry P | |
| 发表日期 | 2006 |
| 出版者 | IIASA, Laxenburg, Austria: IR-06-064 |
| 出版年 | 2006 |
| 语种 | 英语 |
| 摘要 | The life histories of oysters in the genus "Crassostrea", like those of most marine bivalves, are typified by high fecundity and low survival in nature. Rearing conditions in hatcheries however ensure optimized density, diet, and temperature. Hatcheries are becoming increasingly important for the production of juveniles in aquaculture, and their culture practices often include culling of slow growing larvae to reduce and synchronize the time taken to reach settlement. Because previous studies have found substantial genetic variation for early life developmental traits in "Crassostrea gigas", these culling practices are likely to cause highly different selective pressures in hatcheries from those in the natural environment. We studied the phenotypic and genetic impact of such culling practices in a factorial cross between 10 males and 3 females subjected to progressive culling of the smallest 50% of larvae, compared with a non-culled control. Measurements were made on larval growth, survival, time taken to attain pediveliger stage and settlement success. Culling had a larger effect on the variance of these larval traits than on their means. The larvae in culled cultures were approximately 10% larger than those in controls, whereas the coefficient of variation was reduced by 30 -40%. Culling also reduced the mean time to settlement by 12% and its variance by 55%. Using a multiplexed set of microsatellite markers to trace parentage, we also estimated the variance in reproductive success in a controlled experiment to quantify the consequences of intensive hatchery rearing practices. We also focused on changes in effective population size and genetic structure over time (and developmental stages). Our results show a loss of genetic diversity following removal of the smallest larvae by culling, as well as temporally varying genetic structure of the larval population. This supports the existence of genetic variability in early life developmental traits in C. gigas. Culling in hatcheries, like size-related selective pressures in the wild, are likely to have a significant genetic impact, through their effects on the timing of settlement. |
| 主题 | Evolution and Ecology (EEP) |
| URL | http://pure.iiasa.ac.at/id/eprint/8035/ |
| 来源智库 | International Institute for Applied Systems Analysis (Austria) |
| 资源类型 | 智库出版物 |
| 条目标识符 | http://119.78.100.153/handle/2XGU8XDN/125494 |
| 推荐引用方式 GB/T 7714 | Taris N,Ernande B,McCombie H,et al. Phenotypic and Genetic Consequences of Size Selection at the Larval Stage in the Pacific Oyster (Crassostrea gigas).. 2006. |
| 条目包含的文件 | ||||||
| 文件名称/大小 | 资源类型 | 版本类型 | 开放类型 | 使用许可 | ||
| IR-06-064.pdf（225KB） | 智库出版物 | 限制开放 | CC BY-NC-SA | 浏览 | ||
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