The scavenging effect of polysaccharide extracts of Ulva pertusa on O2and OH·, inhibiting lipid peroxidation effect and its antioxidant effect on grease were studied, the results showed that polysaccharide extracts of Ulva pertusa had scavenging effect on O2and OH·, and the effect improved with the increase of polysaccharide concentration, markedly increased scavenging effect in a dose dependent manner. The conclusion was that polysaccharides from Ulva pertusa had certain antioxidant activity, and the added concentration was positively correlated with antioxidant activity.
Ten trace elements,Pb,Cd,As,Se,Cu,Cr,Mn,Ni,Co and Sn in the muscle of Paralichthys olivaceus were determined by graphite furnace atomic absorption spectrometry.Muscle samples were digested by microwave technique.The results showed that Graphite furnace method has good precision and accuracy.The content of Cr、Cu、Mn and Se in the muscle of Paralichthys olivaceus was 1.096 μg/g、0.613μg/g、0.347 μg/g and 0.199μg/g respectively,indicating Paralichthys olivaceus contained a lot of beneficial trace elements.On the contrast,those harmful trace elements,such as As,Pb and Cd were in low levels,0.083μg/g、0.097μg/g and 0.010μg/g respectively.Those data suggested that Paralichthys olivaceus was a good source of trace elements for human being.
Based on fishery resources investigation in the Gezhou(1998～2007),Chongqing(2006～2007),Hejiang(1998～2005)reaches of the middle and upper Yangtze River,population mortalities of Coreius guichenoti were estimated and the rational utilization of its resources in the middle and upper Yangtze River was approached by using the catchper recruit theory of Beverton-Holt mode1.The results revealed that:1)The exploration level and fishing mortality coefficient of Coreius guichenoti of each year in three reaches were respectively far higher than the allowable maximum exploration level and reference point of the corresponding year and the resources of Coreius guichenoti were over-fishing in all three reaches;2)The optimum first capture age was 4 age in the Gezhouba Reach(body length 330 mm)and the first capture age was 5 age at least(body length 375 mm).To protect the resources of Coreius guichenoti,it could be available to properly increase the mesh size(2a)to larger than 75mm in the Gezhouba Reach while larger than 90 mm.The decrease of the catching frequency of different net styles in the other two reaches aims to protect the resources of Coreius guichenoti.
Juvenile of Paralichthys olivaceus was under short time exposure to different ammonia concentrations to study the effects of ammonia on the activity of superoxide dismutase(SOD) and content of malondialdehyde(MDA) in liver of the fish.The results indicated that SOD activities were activated to significant level at higher concentrations or with the delay of exposure time under the condition of this experiment,as compared with control,but no changes were observed in MDA contents in liver with ammonia exposure.
Several strains of bacteria were isolated from the intestines of the diseased Kareius bicoloratus supplied by the Fish Farm of Xunshan Fisheries Group Company of Rongcheng City in July, 1998. One of these strains was proved to be a pathogen by challenge tests. It was a Gram-negative short rod bacterium. It could not move and could not grow when the temperature exceeded 32℃. It produced acid but no gas from glucose. It was identified to be Pasteurella anatipestifer by BIOLOG MICROSTATION SYSTEM. It was sensitive to the following antibiotics: furazo lidone, furantoin, norfloxacin amikacin and ciprofloxacin.
Juvenile ofparalichthys olivaceus under short time exposure to different ammonia concentrations were used to study the effects of ammonis on the activety of superoxide dismutase(SOD) and content of malondialdehyde(MDA) in liver of the fish.The results indicated that SOD activeties were activated to significant level at higher concentrations or with the delay of exposure time under the condition of this experiment,as compared with control,but no changes were observed in MD contents in liver with ammonia exposure.
