摘要
为丰富细鳞鲑（Brachymystax lenok）早期幼鱼培育的基础生物学资料和规模化人工养殖提供理论指导,探究了不同温度（9、13、17、21、25℃）、不同盐度（0、3、6、9、12）及在不同盐度下温度变化对细鳞鲑仔、稚鱼存活和生长的影响。结果表明,温度25℃和盐度9、12条件下,细鳞鲑仔、稚鱼存活率显著低于其他各组（P〈0.05）,温度17℃对细鳞鲑仔、稚鱼末重和特定生长率显著高于其他温度水平（P〈0.05）;随着盐度的升高,细鳞鲑仔、稚鱼末重和特定生长率显著降低（P〈0.05）;在不同盐度的水体中,水温升至19℃时,盐度6、9、12时细鳞鲑仔、稚鱼开始死亡。试验显示,在细鳞鲑仔、稚鱼培育阶段,在9~17℃范围内可适当提高水温,增加其生长速度和增重效果,缩短养殖周期;在一定的盐度水环境中,细鳞鲑仔、稚鱼对温度的适应范围缩小,适应能力减弱。
Manchurian trout,Brachymystax lenok Pallas（ Salmoniformes,Salmonidae）,is an important freshwater salmonids species endemic to northeast and northwest China and of high nutritional and economic value. Cultivation of Manchurian trout in China has expanded rapidly during the last decade due to successful artificial propagation.However,further expansion is limited by the low survival rate,low quality and poor adaptability of fingerlings. Environmental conditions are vital to the survival,growth and metabolism of fish and larvae,juveniles and gravid females are especially sensitive to water temperature and salinity. To increase basic biological data on Manchurian trout larvae rearing and provide theoretical guidance for large-scale artificial breeding,we investigated the effect of temperature（ 9,13,17,21,25℃）,salinity（ 0,3,6,9,12 g / kg） and temperature change at different salinities on the survival and growth of larval and juvenile Manchurian trout. Manchurian trout with an average length of2. 17 cm and weight of 0. 103 g were selected for testing and acclimated at（ 18 ± 1） ℃,in triplicate,with 30 Manchurian trout in each trial. Test fish were placed in glass containers and the water temperature was increased or decreased 2℃ / d until the design temperature was attained. The water temperature test was run for 20 d after fingerlings acclimated for 5 days in the design temperature. The salinity experiment was conducted at（ 17 ± 1） ℃ and the salinity was increased from the initial salinity of 0 g / kg by 3 g / kg each day until the design salinity was attained.The test fish were acclimated for 5 d at each salinity level and each test lasted 20 d. After the salinity test,the water temperature of each group was increased by 1℃ / d up to 21℃ and the death rate of the test fish was recorded for each salinity treatment. Results show that the survival rate of larval and juvenile Manchurian trout at the temperature of 25℃ and salinity of 9 or 12 g / kg treatment was significantly lower than other groups（ P〈 0. 05）. The final weight and special growth rate（ SGR） of larval and juvenile Manchurian trout at 17℃ were significantly higher than at other temperature level（ P〈 0. 05）. The weight and SGR of larval and juvenile Manchurian trout significantly decreased with increased salinity（ P 〈0. 05）. When the water temperature at different salinity treatments rose to19℃,the larval and juvenile Manchurian trout of 6,9,12 g / kg groups began to die. The experiments indicate that the water temperature for the cultivation of larval and juvenile Manchurian trout can be increased appropriately in the range of 9- 17℃,which could help to increase the growth rate and SGR of Manchurian trout,and shorten the breeding cycle. In a high salinity environment,the upper limit of water temperature goes down. Based on the results of this study,we suggest that Manchurian trout larvae and juveniles could be cultivated at the salinity of no more than 6g / kg.
出处
《水生态学杂志》
CSCD
北大核心
2016年第5期87-91,共5页
Journal of Hydroecology
基金
国家自然科学基金(31260638
31360640
31460692)
内蒙古自治区高等学校"青年科技英才资助计划"项目(NJYT-14-B13)
关键词
细鳞鲑
温度
盐度
生长
Brachymystax lenok
temperature
salinity
growth
