Differences in the Activities of Serum Antioxidant and Immune Factors between Wild and Captive Spotted Seal ( Phoca largha ) Pups from the Liaodong Bay Colony

The innate immune system plays a vital role to resist the environmental stresses and infectious pathogens in marine mammal pups. To get a baseline level of innate immune capacity in spotted seals, the concentrations of several antioxidant and immune-related factors in the serum of wild and captive spotted seal ( Phoca largha ) pups from the Liaodong Bay colony were measured and compared. Cu/Zn superoxide dismutase and peroxidase were mainly responsible for the antioxidant system of spotted seal pups, and wild pups possessed stronger antioxidant capacity than captive ones. Against infectious pathogens, wild spotted seal pups also had an advantage over the captive counterparts. Specifically, the activities of acid phosphatase, phenoloxidase, and lysozyme in the serum of wild spotted seal pups were significantly higher than those in captive animals. The present study provides the normal activities of several serum immune enzymes for wild and captive spotted seal pups from the Liaodong Bay colony, which is benefit to the conservation of this species.