| China is vast with a long coastline. The distance between producing areas and consumption areas of aquatic products are always very far. Live transportation is an effective solution to keep the freshness, meet the needs of consumers and increase interests for enterprises. During the live transportation, the fish always affect by many factors, which lead to the changes of physiological and biochemical characteristics even death. Mandarin fish, siniperca chuatsi, is an rare fresh water fish with rich nutrients and tender meat, which is favorite among people. The research object in this thesis is Mandarin fish. The effects of vibration frequency and water temperature on physiological and biochemical characteristics of Mandarin fish during live transportation were studied. Based on these changes of physiological and biochemical indexes, we resulted in the optimal vibration frequency and water temperature. What’s more, the anesthesia of eugenol to Mandarin fish was researched, and the effective concentration was summarized. The main research reports are:Firstly, the effects of vibration frequency on physiological and biochemical indexes were studied. Using a transport-simulation shaking tester, we simulated 0Hz, 50 H, 100 Hz, 150 Hz and 200 Hz and measured the respiratory rate, indexes in meat and blood and water after vibrating for 3h at the five frequencies. The results revealed that the stronger of vibration frequency were, the more s ignificant the effects on mandarin fish became. The respiratory rate, the content of protein, meat glycogen, ATP and blood glucose decreased significantly, while the ammonia nitrogen and Ph in water, the content of lactic acid in meat, the AST and LDH in blood increased. We also found that the level of UREA in blood fell first and rose later. It turned out that the mutat ional points located between 50 H and 100 Hz by analyzing the change trends of all the indexes. So it can summarize that when the water is 15℃, the optimal vibration frequency to Mandarin fish during live transportation is at most 50 Hz.Secondly, we studied the effects of water temperature on siniperca chuatsi during live transportation by measuring the respiratory rates, the contents of ammonia nitrogen in water, glycogen and lactic acid in meat and blood biochemical indexes at 20℃, 15℃, 10℃ and 5℃ after transported for 0h, 3h, 10 h and 24 h. The results showed that the respiratory rates declined as the temperature decreased and transportation time passed by; the ammonia nitrogen in water increased with the water temperature falling and lapse of time; the level of glycogen dropped as time went by and 24 h after declined with the temperature falling; but lactic acid had a completely opposite trend. The cortisol decreased with the temperature declining, and rose first and then fell with the time; AST had a negative correlation with water temperature but GLU had a positive correlation; UREA decreased significantly with the declined temperature from 20℃ to 10℃, and the level of it at 5℃ was close to that at 20℃. All these results showed 10-15℃ was the best choice for live transportation.Thirdly, the effective concentration of eugenol to Mandarin fish was figured out. The effects of six different concentrations of eugenol on behaviors of Mandarin fish were studied, and the six concentrations were 5 mg/L, 10 mg/L, 20 mg/L, 30 mg/L,40 mg/L and 50 mg/L. According to the bahaviors, it can distinguish anesthes ia stages; According to characteristic behaviors of anesthetized fish in water, it can distinguish resuscitation stages. By testing the anesthesia time and resuscitation time, we found the effective concentration of eugenol to Mandarin fish is 20mg/ml-30mg/ml when the water temperature is 15℃. |
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