随着分子生物学技术的不断发展，其在鱼类研究中已得到广泛应用。目前，达氏鳇分子研究基础薄弱，只对其DNA含量比较分析及总DNA提取、线粒体控制区异质性和系统发育分析、遗传多样性分析、达氏鳇及其杂交子代的分子鉴定做了初步研究。今后，在继续加深以往研究的同时，还应积极开展达氏鳇种质资源遗传多样性保护、遗传图谱构建、功能基因克隆与表达、功能基因的分离提纯和基因功能验证研究，以保证达氏鳇产业的健康持续发展和这一珍贵濒危物种的资源恢复。

A feeding trial was conducted to evaluate effects of dietary ascorbic acid(vitamin C) on growth and some immune indexes in the juvenile Hemibarbus maculates.The juveniles with 14.84 g in initial body weight were stocked into 12 net cages of each 60 cm ×60 cm×120 cm placed in two flowing water concrete tanks of each 6.0 m×2.0 m×1.2 m at a rate of 25 individuals per cage and fed semi-purified formulated feed containing 37.0% of crude protein and 11.0% of crude lipid,and supplemented with four levels(0,1 000,2 000,3 000 mg/kg diet) of 95% coated-ascorbic acid with triplication for each diet at a water temperature of(25.0±3.0)℃ for 125 days.The survival of the juveniles ranged from 93.33% to 98.67% during the experiment,without significant differences among the groups(P>0.05).The specific growth rate(SGR) of the fish increased with increase in dietary vitamin C levels first,and then decreased.The fish fed the diets containing the vitamin C levels of 1 415.78 mg/kg and 1 451.74 mg/kg had the maximal SGR and the minimal feed conversion ratio(FCR).The maximal serurm γ-globulin level,and activities of lysozyme and superoxide dismutase(SOD),very significantly different from the control group(P<0.01),were found in the fish fed the diets containing the vitamin C levels of 973.00,2 857.00 and 1 882.00 mg/kg,respectively.There were very significantly higher activities of protease,amylase and lipase in the hepatopancreas of Hemibarbus maculates fed the diets supplemented with vitamin C than those in the fish fed the diets without vitamin C supplementation(P<0.01).

The experiment was conducted to evaluate the effects of dietary lipid levels on growth performance in Hemibarbus maculates. The juveniles (14.38 g body weight) were stocked into 18 net cages, 60 cm × 60 cm × 120 cm per cage, which were placed in two concrete ponds of each 6.0 m×2.0 m×1.2 m with flowing water. The water temperature was at 23±5 ℃. The juveniles were fed isonitrogenous semi-purified diets for 100 days containing with fish meal, corn protein, soybean meal, cottonseed meal and soybean oil. The dietary lipid levels were as follows: 5.20%, 7.21%, 9.23%, 11.18%, 13.21% and 15.20%. The results showed that the specific growth rate, feed conversion ratio and protein efficiency ratio were directly proportional to the dietary fat levels in the juveniles fed the diets containing fat less than 11.18%, whereas, there were an inverse correlation at the dietary fat levels over 11.18%. The treatments were no significant difference in crude fat content in the hepatopancreas and muscles (P>0.05) within fat levels from 5.20% to 11.18%. The maximum specific growth rate, protein efficiency ratio and minimum feed conversion ratio were observed in the juveniles fed the diets containing 11.18% of fat, significantly different from those fed the diets containing 5.20% and 15.20% of fat (P<0.05). With the increase in dietary fat, the fish had high hepatopancreas somatic indices (HSI) and muscular exudative losses. The optimal dietary fat level was suggested to be 9.23%-11.18% for the juveniles.

本文采用聚丙烯酰胺垂直板电泳法研究了狗鱼肌肉、心脏、肝脏、脑和眼睛等5种组织的超氧化物脱氢酶(SOD)、苹果酸脱氢酶(MDH)和乳酸脱氢酶(LDH)酶谱.试验结果表明:狗鱼不同组织的SOD酶谱具有明显的组织特异性,每种组织的酶带4～7条不等;狗鱼不同组织的苹果酸脱氢酶共检测到4条酶带;狗鱼不同组织的乳酸脱氢酶共检测到8条酶带.

The experiment was conducted to evaluate the effects of dietary lipid levels on growth performance in Hemibarbus maculates. The juveniles (14.38 g body weight) were stocked into 18 net cages, 60 cm × 60 cm × 120 cm per cage, which were placed in two concrete ponds of each 6.0 m×2.0 m×1.2 m with flowing water. The water temperature was at 23±5 ℃. The juveniles were fed isonitrogenous semi-purified diets for 100 days containing with fish meal, corn protein, soybean meal, cottonseed meal and soybean oil. The dietary lipid levels were as follows: 5.20%, 7.21%, 9.23%, 11.18%, 13.21% and 15.20%. The results showed that the specific growth rate, feed conversion ratio and protein efficiency ratio were directly proportional to the dietary fat levels in the juveniles fed the diets containing fat less than 11.18%, whereas, there were an inverse correlation at the dietary fat levels over 11.18%. The treatments were no significant difference in crude fat content in the hepatopancreas and muscles (P0.05) within fat levels from 5.20% to 11.18%. The maximum specific growth rate, protein efficiency ratio and minimum feed conversion ratio were observed in the juveniles fed the diets containing 11.18% of fat, significantly different from those fed the diets containing 5.20% and 15.20% of fat (P0.05). With the increase in dietary fat, the fish had high hepatopancreas somatic indices (HSI) and muscular exudative losses. The optimal dietary fat level was suggested to be 9.23%-11.18% for the juveniles.