长江刀鲚生殖洄游过程中血清能量指标变动

为探究刀鲚(Coilia nasus)生殖洄游过程中血清能量指标的变动情况，于2019年4月15日 ~ 6月5日，在长江崇明段、镇江段和安庆段使用刺网采集刀鲚，对49尾刀鲚血清样本的能量指标进行测定分析。结果显示，自崇明至安庆的洄游过程中血糖、总胆固醇、低密度脂蛋白含量均无显著差异(P>0.05)，血清总蛋白、甘油三酯、高密度脂蛋白和游离脂肪酸含量在镇江至安庆段均无显著差异(P>0.05)，出现显著差异的过程主要集中在崇明至镇江段，总蛋白和甘油三酯含量显著降低(P<0.05)，分别下降19.36%和29.29%；高密度脂蛋白和游离脂肪酸含量显著升高(P<0.05)，分别上升60.38%和23.65%；安庆段卵巢发育至不同时期的刀鲚样本中，Ⅳ期样本的甘油三酯含量于Ⅱ期和Ⅲ期样本均存在显著差异(P<0.05)，分别上升67.24%和53.75%，其余指标在各发育期样本间均无显著性差异(P>0.05)。综上所述，自崇明至镇江段，刀鲚血清样本甘油三酯、高密度脂蛋白和游离脂肪酸等血脂相关指标出现显著性变化(P<0.05)，表明刀鲚在洄游前期脂质代谢活跃，脂肪应是其洄游及发育的主要供能物质；自镇江至安庆段，其代谢水平对洄游及性腺发育的能量需求逐渐适应，因此洄游后期刀鲚血清能量指标总体趋于平稳。

Changes of serum energy metabolism indices of Coilia nasus in Yangtze River during spawning migration

In order to explore the changes of serum energy indexes of Coilia nasus during spawning migration, 49 serum samples of Coilia nasus were collected from Chongming, Zhenjiang and Anqing sections of the Yangtze River from April 15 to June 5, 2019. The results illustrated that there was no significant difference in the contents of serum glucose, total cholesterol and low-density lipoprotein during the migration from Chongming to Anqing (P>0.05). No significant differences in the contents of serum total protein, triglyceride, high density lipoprotein and free fatty acid was observed from Zhenjiang to Anqing (P>0.05). The significant differences were mainly concentrated in Chongming to Zhenjiang, in which the contents of total protein and triglyceride showed a significant downward trend, decreased by 19.36% and 29.29% respectively; while the contents of high- density lipoprotein and free fatty acid showed a significant upward trend (P<0.05), increased by 60.38% and 23.65% respectively. Aamong the Coilia nasus samples from different stages of ovarian development in Anqing section, the triglyceride contents of stage IV samples was significantly different from that of stage II and stage III samples (P < 0.05), increased by 67.24% and 53.75% respectively, and other indexes had no significant difference among the samples from different stages (P > 0.05). In summary, from Chongming to Zhenjiang, the serum triglyceride, high density lipoprotein and free fatty acid of Coilia nasus showed significant changes (P < 0.05), which indicated that the lipid metabolism of Coilia nasus was active in the early stage of migration, and fat should be the main energy source for its migration and development. From Zhenjiang to Anqing, the metabolic level gradually adapted to the energy requirements of migration and gonadal development, so the serum energy index of Coilia nasus tended to be stable in the later stage of migration.