| 摘要: |
| 采用统计学方法研究大菱鲆幼鱼饲育密度对其生长、白化鱼色素改善及饲料转化率的影响。设计了5组不同养殖密度,初始养殖密度分别为0.28、0.87、1.12、1.16、2.75kg/m2,研究结束时养殖密度分别为1.91、6.31、8.86、11.97、17.67kg/m2。结果表明,在同等实验条件下,低密度养殖范围内,大菱鲆幼鱼生长与密度呈正相关,而当种群达到一定密度(即高密度)时,生长与密度呈负相关。各实验组的SGR值分别为3.189、3.304、3.447、3.341、3.087。各实验组体重分布的均匀性随密度增加而下降。不同实验组饲料转化率不同,饲料转化率与密度呈负相关,高密度影响大菱鲆的生长,也降低饲料的转化率。实验组1,饲料转化率最高,饲料系数为0.95;实验组5,饲料系数为1.25。高养殖密度抑制了大菱鲆的生长,也增加了饲料系数。在白化鱼色素改善方面,不同饲育密度对色素的改善也略有不同,改善程度与密度呈负相关。 |
| 关键词: 大菱鲆 饲育密度 生长 饲料系数 色素改善 |
| DOI： |
| 分类号: |
| 基金项目:农业部结构调整重大技术研究专项,041101B号;国家“863”项目资助,2004AA603320号、2004AA603330号 |
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| EFFECT OF STOCKING DENSITY ON GROWTH,FEED CONVERSION AND PIGMENTATION IMPROVEMENT OF TURBOT (SCOPHTHALMUS MAXIMUS L.) |
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MA Ai-Jun, CHEN Chao, LEI Ji-Lin, CHEN Si-Qing, ZHUANG Zhi-Meng, WANG Yin-Geng
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Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, 266071
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| Abstract: |
| Turbot Scophthalmus maximus L. is a flatfish species distributed along east and north coasts of Atlantic Ocean in nature. It was first introduced to China in 1992 by theYellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences. Since then many researches have been carried out for taming, seed breeding and culture. At present, turbot is an important culture species in China and contributes greatly to economy and society.
Higher density stocking could utilize water resource completely and promote product ion. However, high density would affect behavioral interact ions then consequently the growth rate showing up pigmentation abnormal. Very low density would waste water and energy. This study discusses the effect of stocking density on growth, pigmentation improvement and feed coefficient of turbot and search for the most suitable stocking density in turbot culture.
In our experiment, juvenile turbots were reared in five different experiment groups with initial stock density of 0.28, 0.87, 1.12, 1.16, and 2.75kg/m2 respect ively. At the experiment end 60 days later, the stock density was 1.91, 6.31, 8.86, 11.97, 17.67kg/m2 respectively.
Special growth rate are calculated using SGR (Special growth rate) =100×(lnWe-lnWi)/t. Coverage of the tank bottom in percentage at the ending time of the experiment is estimated for all the treatment groups as well as in growth variation, growth rate, survival rate and pigmentation improvement.
Results show that, under the same ambient condition, the stocking density has positive effect on growth at low density and negative at high density. SGR was 3.189, 3.304, 3.447, 3.341, and 3.087 respectively for each group. SGR is positively related to low stocking density but to high stocking density. SGR in early stage (0–30days) is higher than late stage SGR (30–60days), according with the law of growth in biology. The uniformity of weight distributing among the groups was decreased with increasing density. The highest density group corresponded to the largest weight range, and vise versa.
The stocking density is positively related to feed coefficient. For example, Group 1 that in the lowest density has the least feed coefficient 0.96. Similarly for Group 5, the highest 1.25. The other 3 groups were in between. High density inhibits the animal from growing and also increases the feed coefficient.
For survival rate, the result shows that the experiment condition satisfied the need for turbot surviving. No significant difference was shown among the groups.
For pigmentation improvement, turbots in albinism were chosen. They were fed with the same filtered quality synthetic feed. Pigment was shown first on the surface of the internal organs then spread over their body as they grow up. Best pigmentation improvement was found in Group 3 whose retrieval rate of complete natural pigmentation was 22%, comparing to the least one, 10% in Group 5. This result shows that pigmentation improvement was slightly affected by stocking density negatively. The suitable stocking density would be helpful to pigmentation improvement. However, the stock density is not the only one factor that affects pigmentation improvement. Other factors especially nutrition and seed quality are also important ones to which follow-up research needs to be done. |
| Key words: Turbot Scophthalmus maximus, Stocking density, Growth, Feed coefficient, Pigmentat ion improvement |
