Abstract:

The response of Superoxide Dismutase (SOD), Acid Phosphatase (ACP), and Phenoloxidase (PO) in Penaeus monodonfamilies to normal growth, low temperature stress and high ammonia stress was studied under laboratory condition. Growth in terms of specific growth rate (SGR) was significant difference among the selected families (p<0.05). The activities of ACP were significant difference among family 077, 017 and 661. The activities of SOD were significant difference between family 4612 and family 017. When the rearing temperature decreased from 27 ℃ to 20 ℃, the activities of ACP and SOD first increased and then decreased, the activities of PO reduced prolonged according to the low temperature stress, and the minor changes of control trial were not regular. Under the high ammonia stress, the activities of ACP increased prolonged, the activities of SOD increased in 0-8 h, then rapidly decreased in 8-48 h, the activities of PO reduced in 0-48 h, and the minor changes of control trial were not regular. The activities of immune enzymes of some families were significant differences, and three immune enzymes activities of family 4612 higher than that of other families under the high ammonia stress. A negative correlation was found between the specific growth rate and the activities of ACP, SOD and PO of ten families in three trials.

Key words: Penaeus monodon, family, low temperature, ammonia, immunity enzymes activity