Abstract: An experiment was conducted to investigate serum’s biochemical indexes and activities of metabolic enzymes in juvenile Epinephelus moara in three temperature treatments (9, 13, 17 ℃; the latter as control). At the beginning of the trial, the water temperature rapidly dropped to 13 ℃ or 9 ℃ and maintained for 7 days. The results indicated that the contents of total protein (TP) and glucose (GLU) changed with the decrease of temperature, but there was no significant difference (P>0.05). At the end of the trial, there was a significant difference in the content of either triglyceride (TG) or creatinine (CREA) (P<0.05) compared with the control. The activities of the alkaline phosphatase (AKP), glutamic oxalacetic transaminase (GOT), glutamicpyruvic transaminase (GPT) and lactic dehydrogenase (LDH) increased with the increase of stress strength and stress time (P<0.05). At the end of this trial, there was a significant difference in slactate dehydrogenase activity between treatments (P<0.05). Results suggest that the stress of low temperature had no significant effect on the serum biochemical indexes in a short period. Juvenile fish can increase the activities of serum metabolic enzymes in response to the low temperature stress to improve the antistress ability. However, starvation at low temperature can lead to decreases in immunity and antioxidation capacity, so it is needed to reduce the stress strength and time of low temperature in the production process.

Key words: tea plant, soil microbial community, phospholipid fatty acid., microbial utilization rate of carbon source, ratooning continuous cropping