EFFECTS OF TRANSPORTATION DENSITY AND TIME ON CORTISOL, LACTATE AND GLYCOGEN OF ANCHERYTHROCULTER NIGROCAUDA

To determine the suitable transport density of Ancherythroculter nigrocauda Yih et Wu, Ancherythroculter nigrocauda with the average body mass of (0.11±0.04) g and average body length of (27.08±3.09) mm were conducted with three density (20, 40 and 80 g/L) and five transport times (2, 4, 6, 8 and 10h) to measure cortisol, lactate, glycogen content of Ancherythroculter nigrocauda and the water quality in the oxygen bag. The results showed that the average survival rate of Ancherythroculter nigrocauda in each group was above 99% after transportation, but the difference between densities was significant (P<0.05). The total ammonia nitrogen concentration of each group increased significantly with the transportation time and the pH decreased significantly with the transportation time, and the differences between different transport densities were significant (P<0.05). The concentration of DO in the low-density group of 14.20—20.93 mg/L was significantly higher than that in the high-density group of (2.42—2.88 mg/L; P<0.05). The cortisol content of each treatment group increased first and then decreased, the cortisol contents at 4h and 6h were significantly higher than other transport times, and the difference between different transport densities was significant (P<0.05). The lactate content of each group increased significantly with the increased transportation time (P<0.05), but there was no significant difference between different densities (P>0.05). The glycogen content of each group was significantly reduced after 2h of transportation (P<0.05), and then remained stable. These results indicated that there was a significant interaction between transport density and time on cortisol, survival rate, total ammonia nitrogen and dissolved oxygen of Ancherythroculter nigrocauda, and the optimal transport density of Ancherythroculter nigrocauda was 40 g/L.