运输胁迫对银鲳血清皮质醇、血糖、组织中糖元及乳酸含量的影响

摘要

研究分析了运输胁迫2、4、8和12h后银鲳血清皮质醇、血糖、组织中糖元及乳酸含量的变化.选取平均体质量为(10.05±0.23)g的银鲳幼鱼为试验对象,共设3组运输密度,分别为4、8和16g/L.每个时间段的运输结束后,将取样后剩余的鱼转入1m3水体的圆形玻璃钢桶中观察24h,以统计各自的累计死亡率.研究结果显示,16gL密度组在运输12h后成活率为91.25%,其余均为100%;运输胁迫导致皮质醇含量显著升高(P<0.05),运输4h后,血清皮质醇含量均达到最高值,12h后皮质醇含量虽较运输4h后有所降低,但仍显著高于试验初的水平,且此时16g/L密度组的皮质醇含量均显著高于4和8/L密度组(P<0.05):血糖、血清与肌肉中乳酸含量在运输胁迫后均显著升高(P<0.05):肝脏与肌肉中糖元含量在运输胁迫后均显著降低(P<0.05),但在整个运输胁迫过程中,肝脏组织中糖元含量的降低程度明显高于肌肉组织.统计分析得出,较高的运输密度会加重银鲳的应激性反应,并推测在小水体开放式运输的情况下,规格为10 g左右的银鲳幼鱼,其运输密度不宜超过16g/L.此外,在运输胁迫下,银鲳机体的能量供给主要来自肝脏糖元的动员.%The effects of 2,4,8 and 12 h transportation stress on serum cortisol,glucose,tissue glycogen and lactate of juvenile silver pomfret (Pampus argenteus) with an average weight of (10. 05 ±0. 23) g were' evaluated at densities of 4,8 and 16 g/L. After transportation, fish from each density were moved into separate 1 m3 tanks for 24 h, and the 24 h cumulative mortality was monitored. The results showed that, the survival rate of fish at density of 16 g/L after 12 h transportation was 91.25% ,and the others were 100% ; Serum cortisol contents increased significantly after transportation (P ＜ 0. 05), and the maximum was observed after 4 h transportation. At all densities, the serum cortisol contents after 12 h transportation were lower than those after 4 h transportation, but significantly higher than that of 0 h transportation. After 12 h transportation, the cortisol content of fish at density of 16 g/L was significantly higher than those at densities of 4 g/L and 8 g/L,respectively(P＜0.05). Serum glucose,serum lactate and muscle lactate contents were all significantly increased after transportation (P ＜ 0. 05). On the contrary, liver and muscle glycogen contents were all significantly reduced after transportation(P ＜0. 05). However, during the transportation, more glycogen mobilization occurred in the liver instead of the muscle. In conclusion, higher transportation density could increase the stress response of silver pomfret, the transportation density of silver pomfret with an average weight of 10 g should not exceeded 16 g/L in the open system and small water volume conditions. Additionally, liver glycogen makes the most potential contribution to total energy expenditure during the whole transportation.