Study Of Diets Choose And Compensatory Growth On Juvenile Oxyeleotris Marmoratus

1. Effect of different diets on the feeding，growth and digestion of juvenileoxyeleotris marmoratusA8-week feeding trial was conducted to evaluate the effects of different diets(freshwater shrimp, grass carp, ruditapes variegate and tubificidae) on growthperformance, body composition and digestive enzymes activities of juvenileoxyeleotris marmoratus. Each diet was randomly allocated to four treatments of20fish, and fish were fed second daily to apparent satiation. The results showed that theweight growth rate(WGR)，specific growth rate(SGR）, feed efficiency ratio(FER）and protein efficiency ratio(PER) of the fish fed tubificidae were significantlyhigher(P<0.05) than other groups, and the fish fed grass carp were significantlylower(P<0.05) than other groups. Crude protein content of the fish fed tubificidae wassignificantly higher(P<0.05) than other groups and the crude protein of fish fed grasscarp was the lowest, however, no significant difference was found between the fishfed freshwater shrimp and ruditapes variegate. Crude Lipid content of the fish fedtubificidae was significantly higher(P<0.05) than other groups, but ash content wassignificantly lower (P<0.05) than other groups. Pepsin activity of the fish fedtubificidae was significantly higher than other groups, and the fish fed grass carp wassignificantly lower than other groups. No significant difference of lipase and amylaseactivities was observed in the gastrointestinal tract. Hence, tubificidae is fairly betterthan other three kinds of diets for the juvenile oxyeleotris marmoratus, but the fishwhich has been widely used is the worst.2. Effect of starvation and compensatory growth on juvenile OxyeleotrismarmoratusThis study is about the effects of starvation and compensatory growth on growthperformance, body composition, glycogen content and digestive enzymes activities of juvenile Oxyeleotris marmoratus, which initial body weight4.58±0.02g,full length8.02±0.14cm. The fish were divided into4experimental groups and another samplinggroup. The fish of experimental groups were starved for0d(controlgroup,S0),7d(S7),14d(S14),21d(S21),then were refed for51d,44d,37d,30d. Theresults showed that the body weight keep decrease during starvation, the weight lostrate of S14and S21were significantly higher(P<0.05) than S7. After refeeding andcompensatory growth, the body weight of experimental groups were still significantlylower(P<0.05) than control group, it indicated Oxyeleotris marmoratus is patiallycompensatory growth. The content of glycogen in liver and muscle decreased duringstarvation, then the content of crude protein and crude lipid decreased. This indicatedthe glycogen in liver and muscle were used first during starvation, then lipid andprotein in the body. After compensatory growth, the body composition ofexperimental groups were return to normal except S21. After starvation, the digestiveenzymes activities decreased significantly(P<0.05),while they can return to normalexcept pepsin activity in S21. Hence, starvation and compensatory growth strategy isnot applicable for juvenile Oxyeleotris marmoratus.3. Effect of alternately feeding on the feeding，growth and body composition ofjuvenile Oxyeleotris marmoratusThis study is about the effects of growth performance, body composition ofjuvenile Oxyeleotris marmoratus, which initial body weight3.67±0.09g, full length7.32±0.23cm, by alternately feeding tubificidae and grass carp. The fish were dividedinto5experimental groups, which were groupA(fed tubificidae)，B(fed grass carp)，C(fed grass carp1d+tubificidae1d)，D(fed grass carp2d+tubificidae1d)，E(fed grasscarp1d+tubificidae2d). After8-week feeding, the results showed that there were nosignificant difference(P>0.05) between experimental groups on feed efficiency ratio,Protein efficiency ratio and the content of crude lipid and ash, while the specificgrowth rate(SGR), feeding rate(FR) and the content of crude protein of group E wassignificantly higher(P<0.05) than other groups. It indicated that the feeding strategyof alternate feeding grass carp1d and tubificidae2d is beneficial for juvenile Oxyeleotris marmoratus growth and increasing the content of crude protein.