Preliminary studies on the effects of the temperature and shaking on transport and survival of juvenile black seabream(Acanthopagrus schlegelii)

Abstract:

In order to investigate the influences of water temperature and vehicle swaying on the survival rate of juvenile fish for stock enhancement during the process of transportation, the changes of environmental water ammonia nitrogen mass concentration, the changes of muscular lactic acid concentration and glycogen mass fraction of juvenile Acanthopagrus schlegelii, at different water temperature and different levels of swaying simulation. When the environmental water temperature was elevated, increased ammonia nitrogen concentration in water was observed, while the muscular lactic acid concentration of juvenile fish increased at early stage and then decreased later, whereas the muscular glycogen mass fraction of juvenile fish varied in the opposite way, decreased at early stage and then increased later. The survival rate of juvenile fish dropped significantly with the increase of environmental water temperature, and 21 to 25℃ were regarded as optimal water temperature. In the swaying simulation experiments, when the swaying frequency of environmental water was enhanced, increased ammonia nitrogen mass concentration in water was observed, while the juvenile fish was observed with increased muscular lactic acid concentration and decreased muscular glycogen mass fraction. The survival rate of juvenile fish dropped significantly with the enhancement of environmental water swaying. It is recommended that the black sea bream juveniles with a size of about 5 cm should be trained for the black sea bream juveniles before transport, and the stress factors such as water temperature and shaking should be trained. The water temperature during transportation should not exceed the water temperature under the indoor cultivation conditions. 21-25℃ are appropriate, and can be lower than the water temperature under its indoor cultivation conditions, but the temperature difference should not exceed 4℃, while the shaking frequency during transportation should not exceed 105 r/min.