Physiological and immunological conditions of the sea cucumber Isostichopus badionotus (Selenka, 1867) during dormancy

Dormancy is a state of reduced metabolic activity adopted by organisms during periods of environmental stress, including physiological and biochemical adaptations. In this study, the physiological and immunological statuses of two populations of Isostichopus badionotus with different times of dormancy (B12 = 12 months and B24 = 24 months) are compared with a physiologically active population (BC = control). The coelomic liquid (CL) of 18 organisms from each batch (B24, B12, and BC) was used to perform the biochemical analysis. The body volume of dormant L badionotus decreased exponentially as time passed under stable conditions. The total protein of B24 (9.26 mg/ml) was lower than that of B12 (15.64 mg/ml) and BC (13.21 mg/ml). Carbohydrate content was similar in both groups (824 and B12) of dormant I. badionotus but lower than that of the control (6.93 mg/ml). The cholesterol content of B12 (0.40 mg/ml) was significantly higher than the similar cholesterol levels of B24 and the control. Activities of superoxide dismutase CT-SOD), catalase (CAT), and glutathione peroxidase (GPx) were higher in B12 than in B24 and BC. Phenoloxidase was lower in dormant sea cucumbers than the control (37.3 U/ml). Dormancy for the B12 organisms appears to be a fairly light state, involving no physiological changes that cannot be rapidly reversed. In contrast, the B24 organisms showed deterioration of their antioxidant complex and low lipid and protein reserves after 48 months, suggesting that the return to an active state would be impossible. (C) 2013 Elsevier B.V. All rights reserved.