团头鲂消化道发育的组织学观察

团头鲂是一种优良的淡水鱼类，为提高鱼苗饲养成活率，对其早期消化顺官的发育进行了观察。鱼苗孵出后第１天至第３天，消化道呈直管形，管壁由单列细胞组成，口裂未形成，肛管不与外界相通，营养靠自身的卵黄囊。从孵出后第３天起，口腔开始形成，消化道呈现弯曲，细胞层次增加，前肠中肠后肠三段组织学结构区分逐渐明显，卵黄囊缩小，肛门形成，可以摄取外界细小的食物。此时将鱼苗由孵化容器中移入池塘饲养比较适时，过早过晚不利     

团头鲂3个选育群体的选择压力分析

团头鲂选育群体基因组选择信号的检测有助于研究人工选育条件下基因组的进化机制,为团头鲂的进一步遗传改良提供依据。以团头鲂"浦江1号"选育奠基群体(F0)为对照组,以3个团头鲂选育群体为试验组,采用经典的Ewens-Watterson中性检验和基于3种算法(岛屿模型、分级岛屿模型、贝叶斯似然法)的FST-离群值点检验,在14个转录组微卫星位点上进行选择信号检测。结果显示,F0群体中所有位点均为中性位点,选育群体A在Mac927位点和Mac158位点受到了正向选择压力,选育群体B在Mac158位点受到了正向选择压力,选育群体C在Mac927位点和Mac158位点受到了正向选择压力。由此可见,自1985年起的连续世代人工选育已在团头鲂基因组中留下了可检测到的选择信号。3个选育群体均在Mac158位点检测到选择信号,表明3个选育群体受到的人工选择方向比较接近。     

Optimizing the Proportions of Plant Protein Ingredients in the Diet of Juvenile Blunt Snout Bream,Megalobrama amblycephala

An 8‐wk feeding trial was conducted to evaluate the influence of different proportions of dietary plant ingredients on the growth of juvenile blunt snout bream, Megalobrama amblycephala. A 2 × 3 factorial arrangement was set for this trial with three ratios of cottonseed meal (CSM) and canola meal (CM) (2:1, 1:1, or 1:2) and three proportions of soybean meal (SBM) (2, 1, or 0). The results showed that the specific growth rate and protein efficiency ratio both significantly decreased with decreasing amounts of SBM in the diets of blunt snout bream (P < 0.05), while the feed efficiency ratio and feed intake increased significantly (P < 0.05). Meanwhile, the growth performance and feed utilization were shown to improve with increasing amounts of CSM, although the effects were not significant (P > 0.05). The interaction of these two factors had no effect on either growth or feed utilization (P > 0.05). Diet composition was not seen to affect body composition (P > 0.05). The ratio of CSM to CM significantly affected gut amylase activity, liver alanine aminotransferase content, and plasma cholesterol levels (P < 0.05). The interaction between the two main effects significantly influenced the plasma glucose level (P < 0.05). Therefore, the suitable proportion of plant feed for blunt snout bream should include high levels of SBM and CSM, with a SBM : CSM : CM ratio of 2:2:1.     

生物絮团对团头鲂(Megalobrama amblycephala)生长、消化酶和免疫相关酶活性的影响

为了研究零换水条件下团头鲂(Megalobrama amblycephala)养殖水体生物絮团形成所需的适合的碳氮比(C/N),以及不同C/N形成的生物絮团对团头鲂生长、消化酶活性和非特异性免疫力的影响,本实验设计4个不同C/N实验组,包括投喂基础饲料(C/N=8∶1)的对照组,在基础饲料上添加葡萄糖的处理组,其中将处理组的C/N分别调整为12∶1(C/N12)、16∶1(C/N16)和20∶1(C/N20).结果显示,C/N16和C/N20处理组中团头鲂的增重率和特定生长率显著高于对照组(P＜0.05),而饲料系数显著低于对照组(P＜0.05);C/N16和C/N20处理组中团头鲂肠道的蛋白酶活性和淀粉酶活性显著高于对照组(P＜0.05);而各实验组中团头鲂肠道的脂肪酶活性没有显著性差异;C/N16和C/N20处理组中团头鲂肝脏超氧化物歧化酶、碱性磷酸酶和溶菌酶活性显著高于对照组(P＜0.05).研究表明,生物絮团技术应用于团头鲂养殖适宜的C/N应不低于16,该条件下形成的生物絮团能有效提高团头鲂生长、消化酶和免疫相关酶活性.     

Estimates of Heritabilities and Genetic Correlations for Growth and Gonad Traits in Blunt Snout Bream,Megalobrama amblycephala

Blunt snout bream, Megalobrama amblycephala, is an herbivorous freshwater fish and has been recognized as a main aquaculture species in the Chinese freshwater polyculture system. The objective of the study is to estimate the genetic parameters for growth, body shape, and gonad traits for M. amblycephala at 1 yr of age. The phenotypic analysis showed that coefficients of variation for gonad traits had large variation relative to the other traits analyzed, and there was no sexual dimorphism by comparing growth and body shape in M. amblycephala. Based on restricted maximum likelihood and Markov chain Monte Carlo Bayesian methods using the animal model, the heritabilities of body weight (0.423–0.504), body length (0.309–0.678), body height (0.408–0.599), and dressed weight (0.359–0.643) were moderate and high, while the other traits, including conditional factor (0.029–0.199), body shape coefficient (0.095–0.405), edible ratio (0.073–0.207), gonad weight (0.018–0.170), and gonadosomatic index (0.050–0.222), had moderate or low heritabilities. High genetic and phenotypic correlations were found among growth traits, but not between growth traits and body shape or gonad traits except dressed weight. Based on our results, it could be efficient to combine the selection on body weight for fast growth and nonearly sexual maturity varieties of M. amblycephala breeding.     

Single Intravascular and Oral Dose Pharmacokinetics of Mebendazole in Blunt Snout Bream,Megalobrama amblycephala

Mebendazole (MBZ) is a broad‐spectrum benzimidazole methylcarbamate anthelmintic used widely in animal husbandry and aquaculture. However, there is no information available on the pharmacokinetic behavior of MBZ in blunt snout bream, Megalobrama amblycephala. In this study, pharmacokinetic parameters of MBZ were estimated in blunt snout bream after intravascular (3 mg/kg body weight [BW]) and oral (20 mg/kg BW) administration. The analyses of plasma samples were performed using ultra performance liquid chromatography with ultraviolet detector. After intravascular administration, plasma concentration–time curves were best described by a two‐compartment open model. The distribution half‐life (t_1/2α), elimination half‐life (t_1/2β), and area under the concentration–time curve (AUC) of blunt snout bream were 0.1 h, 27.9 h, and 56666.0 h.µg/L, respectively. After oral administration, a one‐compartment open model with first‐order absorption best fit the plasma data. The absorption half‐life (t_1/2Ka), elimination half‐life (t_1/2Ke), peak concentration (C_max), time‐to‐peak concentration (T_max), and AUC of blunt snout bream were estimated to be 1.9 h, 34.6 h, 918.1 µg/L, 8.4 h, and 54201.4 h.µg/L, respectively. The oral bioavailability (F) was 14.3 %. The pharmacokinetics of MBZ in blunt snout bream displayed low bioavailability, relatively rapid absorption, and relatively rapid elimination.     

饲料中添加纤维素酶对团头鲂生长的影响

在 A、B、C、C0 和 D五组团头鲂鱼种 (体均重 2 .35± 0 .2 0 g)的配合饲料中分别加 0、6 0 0、2 4 0 0、2 4 0 0和 4 2 0 0 U/ kg纤维素酶。其中 B、C、D组中加入的纤维素酶都经过适当的预处理 ,而 C0 组饲料则直接添加 2 4 0 0 U/ kg的纤维素酶。经 56天喂养试验 ,结果显示 :投喂 B、C两组饲料的鱼体增重率分别比 A组提高了 14 .59%和 34.18% ,饲料效率也分别提高 6 .0 6 %和13.6 4 % ;而 C0 和 D组的生长性能则与 A组之间没有显著性差异。     

团头鲂,鲫鱼出血性败血病的研究

最近几年,出血性败血病已成了上海地区池养鲤科鱼类的一种流行病。我们对团头鲂和鲫鱼等的这种出血性败血病作了调查并进行了综合防治试验。我们从患病的团头鲂、鲫、鲢、鳙鱼体内分离出了致病菌。对致病菌和组织病理研究所取得的材料表明,此种鱼病系由点状产气单胞菌和非霍乱孤菌所引起。根据致病菌对药物的敏感性及综合防治试验的结果,提出了一套可行的综合防治方法。     

Growth Performance,Fatty Acid Composition,Peroxisome Proliferator‐activated Receptors Gene Expressions,and Antioxidant Abilities of Blunt Snout Bream,Megalobrama amblycephala,Fingerlings Fed Different Dietary Oil Sources

A 60‐d feeding trial was conducted to evaluate the effects of different dietary oil sources on growth, fatty acid composition, peroxisome proliferator‐activated receptor (PPAR) gene expression levels, and antioxidant responses of blunt snout bream, Megalobrama amblycephala, fingerlings. Fish (average initial weight, 0.35 ± 0.01 g) were fed five experimental diets respectively containing fish oil (FO), soybean oil, canola oil, peanut oil, and palm oil (PaO). Results showed that body weight gain, specific growth rate, and feed conversion ratio did not significantly differ among treatments. Fish fed PaO diet showed significantly higher hepatosomatic index value and liver lipid content than those fed FO diet. The FO group showed significantly higher liver eicosapentaenoic acid (20:5n‐3) + docosahexaenoic acid (22:6n‐3) concentrations than other groups in both neutral lipid and polar lipid fractions. The mRNA expression levels of PPAR‐α and PPAR‐γ in the liver were significantly increased by feeding vegetable oil diets compared to FO. The activities of catalase, superoxide dismutase, and glutathione peroxidase in livers of fish fed PaO diet were lower than those fed FO diet. Meanwhile, PaO group had significantly lower malondialdehyde value than other groups. In conclusion, we suggested that a combination of FO and vegetable oil diet should be used in feed formulations for blunt snout bream fingerlings.     

团头鲂胚胎及仔稚鱼发育观察

团头鲂(Megalobrama amblycephala Yih)是鳊鲌亚科中的重要经济鱼类,现已成为国内淡水养鱼业的主要养殖对象之一。为提高团头鲂人工繁殖中的孵化出苗率和下塘成活率,本研究对其胚胎及胚后发育作了连续观察。根据形态和生态特点,作者认为当仔鱼发育至鳔雏形期就应及时下塘,孵化适温控制在18℃～27℃为宜。     

放养密度对虹鳟稚鱼生长的影响

虹鳟稚鱼伞长、体重生长速度随着放养密度的增大而降低,而这种差异随着生长时问的延长,表现更为显著稚鱼体重持定生长率随着放养密度的增大而降低,两者间存在着显著的负相关关系;Y=-5．0979X＋36．727（R2=0．9844）,Y代表体重特定生长率,X代表放养密度.日增重、饵料转化丰随着放养密度的增大而降低．净增重随着放养密度的增大而增加.     

养殖密度对地图鱼幼鱼生长发育的影响

在室内水族箱中养殖地图鱼的幼鱼,密度分别为50、100、200、400尾/m2,共养殖28d。试验结果表明,各密度组地图鱼幼鱼的生长速度存在明显差异,增重率、增长率、特定生长率和平均日增重都随养殖密度的增加而降低;高密度组(400、200尾/m2)地图鱼的幼鱼个体生长速度离散度明显加大。     

淤泥湖团头鲂与梁子湖团头鲂杂交子一代的性状研究

团头鲂(Megalobrama amblycephala Yih)是一种优良的淡水养殖鱼类,但在家养条件下连续传代会引起经济性状指标下降。本试验通过原种选优,以优配优的杂交组合,得出淤泥湖团头鲂与梁子湖团头鲂杂交子一代和回交子代。经饲养观察,证明杂交子一代和回交子代都有良好的生长优势,含肉率和粗蛋白含量相对增高,经济性状较亲本更好。血清蛋白电泳分析结果表明,杂交子代与亲本存在着质的差异。     

团头鲂水库网箱养殖试验

在网箱中进行团头鲂（Megalobrama amblyocephala)鱼种，成鱼养殖，鱼种箱平均产量470kg,平均尾重81．5g，个体净增重12．19倍，平均饲料系数2．22，成鱼箱平均产量828.65kg,平均尾重435g，个体净增重7．53倍，平均饲料系数2．25。     

淤泥湖团头鲂的引进与养植试验

１９９１年对淤泥湖四头鲂和本地团头鲂进行了对比养殖试验。经１５７天养殖，淤泥湖四头鲂平均增重２．０５倍，本地团头鲂平均增重０．８３倍。同年１１月，专家鉴定认为，本研究在山东省属首次，其技术为省内先进水平。     

乳化剂对团头鲂生产性能、脂肪酶活性及血液生化指标的影响

在基础日粮中添加乳化剂研究其对团头鲂生产性能、肌肉组织成分、肠道和肝胰脏脂肪酶活性及血浆生化指标的影响,并初步探讨乳化剂在团头鲂养殖中的应用效果。用初始体质量约70g团头鲂480尾,随机分成4组,每组4重复,每重复30尾,分别饲喂不添加乳化剂的基础日粮(对照组)和添加复合乳化剂250、500、1000g/t的试验日粮。试验结果表明,添加乳化剂1000g/t,能显著提高团头鲂的质量增加率及特定生长率(P0.05)。3个处理组的肌肉粗蛋白含量极显著提高(P0.01),但肌肉粗脂肪、肝胰脏的粗蛋白和粗脂肪含量均无显著差异(P0.05)。添加乳化剂250g/t,团头鲂肠道脂肪酶活力和血浆总胆固醇含量均显著提高(P0.05),而甘油三酯含量随乳化剂添加量的提高而降低(P0.05);各试验组的低密度脂蛋白胆固醇含量均显著低于对照组(P0.05),但高密度脂蛋白胆固醇和极低密度脂蛋白胆固醇无显著变化(P0.05)。添加乳化剂能提高团头鲂的生长速度,使肌肉蛋白质沉积增加、脂肪沉积减少,并能降低血浆低密度脂蛋白胆固醇含量,其中以添加乳化剂1000g/t的使用效果最佳。     

养殖密度对厚颌鲂幼鱼生长、饲料利用及肠道抗氧化应激性能的影响

本研究拟通过养殖实验确定厚颌鲂(Megalobrama pellegrini)幼鱼最适养殖密度;同时,利用酶学和分子生物学手段分析养殖密度对厚颌鲂幼鱼肠道抗氧化酶活性及氧化应激相关基因表达的影响。实验设计5个密度处理组,分别为0.15 kg/m³ (50尾/桶)、0.24 kg/m³ (80尾/桶)、0.34 kg/m³ (110尾/桶)、0.42 kg/m³ (140尾/桶)和0.50 kg/m³ (170尾/桶),每组设置3个平行,实验周期为42 d。结果显示,当养殖密度从0.15 kg/m³ 逐渐升高到0.50 kg/m³ 时,厚颌鲂幼鱼生长(增重率和特定生长率)呈先上升后下降的趋势,且在最大密度时(0.50 kg/m³ )增重率和特定生长率显著低于0.34 kg/m³ 密度实验组(P<0.05)。同时,最高养殖密度处理组(0.50 kg/m³ )饲料系数显著高于中低密度实验组(0.15、0.24和0.34 kg/m³ )(P<0.05),说明过高养殖密度不利于厚颌鲂幼鱼的生长和饲料利用。实验表明,提高养殖密度并未影响厚颌鲂幼鱼成活率(P>0.05),各组存活率均较高(>97%)。当养殖密度为0.34 kg/m³ 时,厚颌鲂幼鱼全鱼粗蛋白和粗脂肪含量显著高于其他各密度实验组(P<0.05)。厚颌鲂幼鱼肠道抗氧化应激相关指标受到养殖密度的显著影响,其中,0.24和0.34 kg/m³ 密度处理组鱼体肠道总抗氧化能力显著高于最低密度组(0.15 kg/m³ )和高密度组(0.42、0.50 kg/m³ )(P<0.05);最高密度实验组(0.50 kg/m³ )肠道超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性最低,而丙二醛(MDA)含量最高(P<0.05);谷胱甘肽(GSH)含量最高值出现在0.34 kg/m³ 处理组,显著高于其他各实验组(P<0.05)。最低密度实验组(0.15 kg/m³ )厚颌鲂幼鱼肠道细胞色素P450(CYP1 A)基因相对表达量显著低于较高密度实验组(0.42 kg/m³ )(P<0.05);最高养殖密度组(0.50 kg/m³ )鱼体肠道转录因子NF-E2相关因子2(Nrf2)基因相对表达量最高,而锰超氧化物歧化酶基因(MnSOD)相对表达量最低,与0.34 kg/m³ 密度处理组间有显著性差异(P<0.05),说明养殖密度过高时能引起鱼体的氧化应激反应。研究表明,体重为0.45~1.36 g的厚颌鲂幼鱼最适养殖密度为0.34 kg/m³ ,该结果可为提高厚颌鲂苗种培育效率,促进其种质资源恢复提供理论基础。     

植物甾醇对团头鲂生长、血脂和肝胰脏抗氧化功能的影响

选取体质量(74.52±1.03)g的团头鲂480尾,随机分成4组,每组4个重复,每个重复30尾,分别投喂添加0(对照组)、20mg/kg(试验Ⅰ组)、40mg/kg(试验Ⅱ组)和80mg/kg(试验Ⅲ组)植物甾醇的配合饲料,进行为期81d的饲养试验。试验结果表明,40、80mg/kg植物甾醇可提高团头鲂质量增加率及特定生长率(P0.05),其中40mg/kg组效果更佳,对肌肉粗蛋白含量影响不显著,对肌肉粗脂肪含量有一定提高(P0.05);添加40mg/kg植物甾醇显著降低了81d血浆低密度脂蛋白胆固醇水平(P0.05)。在本试验条件下,添加40mg/kg植物甾醇效果最佳。     

Effect of Restricted Feeding Regimes on Compensatory Growth and Body Composition of Red Sea Bream, Pagrus major

Compensatory growth of red sea bream, Pagrus major, during feed deprivation and after refeeding was investigated. Groups of three fish each were allocated into 28 cages. Fish were fed by a commercial feed to satiation twice a day. Four feeding groups of fish were prepared: one group with continuous feeding (C) for 9 wk and three other groups with feed deprivation for 1 wk (F1) in Week 3, 2 wk (F2) from Week 2 to Week 3, and 3 wk (F3) from Week 1 to Week 3, respectively. All fish in the feed deprivation treatments resumed feeding in Week 4. The full compensatory growth was achieved in F1 and F2 fish after refeeding for the first 3 wk but in F3 fish after refeeding for the second 3 wk. Specific growth rate and feed conversion efficiency in all fish experiencing fasting were higher than those of control fish after first 3 wk of refeeding. At the end of feed deprivation in Week 3, crude protein, crude lipid, and energy content of all fish experiencing fasting were lower than those of the control fish. These results indicated that red sea bream experienced 1‐, 2‐, and 3‐wk fasting could achieve full compensatory growth in the 9‐wk feeding trial.     

放养密度和饵料种类对中国大鲵幼苗存活与生长的影响

研究了放养密度和饵料种类对幼中国大鲵（Andrias davidianus）生长发育的影响,跟踪分析了自胚胎孵化至一龄幼鲵的存活与生长发育状况。结果表明,自胚胎孵化至一龄幼鲵的养殖密度为每0.1m210～20尾时,其成活率可达到100%,投放密度每0.1m2自20尾增加到60尾,平均存活率、年体长增加和年体重增加均显著降低。投喂摇蚊幼虫、猪肉、牛肉、羊肉和小鱼虾,幼苗的存活率分别为100%、90%、95%、85%和95%,体长增加分别为8.09cm、5.45cm、5.28cm、4.57cm、6.82cm,体重增加分别为25.97g、12.68g、11.82g、10.86g和20.67g。可见,摇蚊幼虫和小鱼虾是一龄幼大鲵的适宜饵料。