孵化后温度调控对虹鳟全雌家系早期生长性能的影响

Effect of rearing temperatures post hatching on growth of the all female family in rainbow trout(Oncorhynchus mykiss)

本研究以建立的虹鳟(Oncorhynchus mykiss)全雌全同胞家系为研究对象,受精卵在12℃避光孵化至上浮,上浮后设置了四个温度处理组进行饲育,分别为12℃、15℃、18℃、20℃和水温4～7℃之间(平均水温约为6℃)常规涌泉水流水养殖对照组。30d后,所有处理组均转入与对照组相同条件的流水养殖。生长性能数据采集于上浮后的30d、60d、90d、120d,测量各实验组以及对照组稚鱼体重、体长等生长性状,对测量数量进行单因素方差分析(One WayANOVA),并采用Tukey-Kramer HSD检验(P<0.05)进行各实验组均值间的多重比较。方差分析结果表明30日龄,体重性状单因素方差均值18℃组的最高,依次为15℃、20℃、12℃,对照组最低。体长性状15℃组的最高,依次为12℃、18℃、20℃,对照组最低。多重比较结果显示,对于体重性状,18℃、15℃组,处于最高水平;对于体长性状,15℃组处于最高水平。在60d时,12℃、15℃、18℃、20℃四个处理组的体重性状均仍然显著高于对照组(P<0.001),此时15℃组的单因素方差均值仍处于最高,90d和120d时仍保持这种状态。上述结果显示,15℃可能是虹鳟全雌家系初浮稚鱼的最适生长温度,只需在稚鱼上浮后给予30d15℃的水温调控,虹鳟全雌家系即可在之后持续的3个月中保持显著的生长优势。

An experiment was carried out to study the effect of temperature of 12℃,15℃,18℃.20℃ and a running water control（range 4 to 7℃,average 6℃） on growth for 30 days（starting on the day fry floating in 12℃） in a full-sib all female rainbow trout（Oncorhynchus mykiss） family.Further,all the treatment groups were moved to the same condition as the control group in running water for another 90 days.On the day of 30,60,90,120 post fry floating,the growth traits,such as weight and length of the juvenile trout were measured for the treatment and control groups.Analyses of variance and Tukey-Kramer HSD test were used to determine if significant（P0.05） differences existed between the groups.The results of variance analysis showed that,for the body weight on the age of 30 day,the largest mean was 18℃ group,in turn,the 15℃,20℃,12℃ and the lowest was the control;for the body length,the largest mean was the 15℃ group,in turn,the 12℃,18℃,20℃ and the lowest was also the control.The results of Tukey-Kramer HSD test showed that the highest order for the body weight on the age of 30 day was 18℃ and 15℃ groups and the highest order for the body length on the age of 30 day was 15℃ group.On the age of 60 days,12 ℃,15 ℃,18 ℃,20 ℃,the body weight of all the four treatment groups were still significant higher than the control group（P 0.001）,the largest mean was still the 15℃ group,,this state remained on the age of 90 and 120 days.The above results showed that 15 ℃ was probably the optimal growth temperature of juvenile fish for the all female rainbow trout family.Just giving a 15 ℃ temperature control for 30 days,the all female juvenile fish could continuous remain significantly growth advantage during the next three months.