流速对拟穴青蟹生长、应激压力和糖代谢的影响

本文研究了0、1和2倍体长每秒(BL·s^-1)的3个流速对拟穴青蟹幼蟹的生长、应激压力和糖代谢的影响.结果发现尽管30 d的流水养殖导致了蜕壳相关基因EcR和MIH表达的显著提高,但未对青蟹的生长产生显著影响.在应激压力方面,流水养殖导致了青蟹血清中的皮质醇和肝胰腺中丙二醛水平的显著降低,同时1 BL·s^-1流速显著提高了肝胰腺的总抗氧化能力,显著降低了抗氧化酶活性水平,但2 BL·s^-1流速对这些指标的影响弱于1 BL·s^-1流速.此外,在糖代谢方面流水养殖导致了青蟹肝胰腺中丙酮酸激酶活性的显著降低,未引起肌肉中乳酸水平的显著变化,但2 BL·s^-1流速导致了肌糖原水平的显著升高.这些研究结果表明,适度的流水养殖虽然对生长没有显著促进作用,但可降低青蟹的生理压力,增强青蟹的抗氧化能力,提高肌肉中的能量储存研究结果可为完善青蟹的循环水养殖技术提供新的思路.

Effects of flow velocity on growth,stress and glucose metabolism of mud crab Scylla paramamosain

The current study was designed to examine the effect of flow velocity on growth performance, stress, and glucose metabolism of mud crab Scylla paramamosain. Juvenile crabs were subjected to recirculating water at different velocities including 0, 1, and 2 body length (BL).s^-1 for 30 days. The results showed that flow velocity had no significant effect on crab growth despite the significantly increased expression of molting-related genes including ecdysteroid receptor gene and molt-inhibiting hormone gene. Further, flow velocity produced a significant decrease in the levels of serum cortisol and hepatopancreas malonaldehyde. Especially, the 1 BL.s^-1 velocity significantly improved hepatopancreas total antioxidative capacity and inhibited the antioxidative enzymes, as compared with the 2 BL.s^-1 velocity. In addition, flow velocity resulted in a depressed activity of hepatopancreas pyruvate kinase and had no major effect on muscle lactate level. The 2 BL.s^-1 velocity led to a highly elevated level of muscle glycogen. These findings suggest that the moderate flow velocity reduces the physiological and oxidative stress, enhances antioxidative capacity, and increases muscle energy storage without the alteration of mud crab growth performance.