Feed the Future Innovation Lab for Collaborative Research on Aquaculture & Fisheries

Survival and physiological response of Labeo victorianus juveniles under varying salinity gradients were studied during a 6 h transport. Salinity ranges were: 0, 0.25, 0.5, 1, 2, 4, 8 and 10 psu. To each transport bag, 100 juvenile L. victorianus (mean weight = 8.0 ± 1.1 g, stocking biomass = 16 kg m^{− 3}) were transferred. Water temperature, dissolved oxygen (DO), pH, total ammonia nitrogen (TAN) and carbon dioxide (CO₂) were measured before and after transport. Plasma cortisol, blood glucose, plasma sodium, plasma chloride and blood ammonia were also determined. No juvenile mortalities occurred in salinity ranges of 1 to 4 psu. After transport, survival and parameters of physiological response in the juvenile of L. victorianus were significantly different among different salinity treatments (p < 0.05). Low survival, of less than 70% occurred in control treatments (0 psu) and in salinities 0.25, 0.5 psu and at 10 psu. Increased salinity correlated negatively with TAN and CO₂ in water after transport. Plasma cortisol in salinities of 0.5 to 8 psu, blood glucose and blood ammonia in salinities ranging from 1 to 4 psu as well as plasma sodium and plasma chloride in salinity ranging from 1 to 8 psu were similar before and after transport. This study recommends salinity ranges of 1 to 4 psu for minimizing the physiological effects associated with both the primary and secondary physiological response induced by transport stress in juvenile L. victorianus.

NOP 11-A03 (English)