温度和pH值对斜带髭鲷蛋白酶、淀粉酶活性的影响

研究了温度和pH值对斜带髭鲷Hapalogenys nitens蛋白酶、淀粉酶活力的影响。结果表明,斜带髭鲷胃内pH值范围为4.9～5.4;肝胰脏pH值为5.8～6.2;肠道pH值为6.5～6.9。蛋白酶活性随温度的上升而增加,在40℃达最大,40℃以上酶活性随温度的上升而下降。在不同消化器官中,蛋白酶活性大小顺序为：胃〉前肠〉幽门盲囊〉后肠〉肝胰脏。在15～50℃范围内,斜带髭鲷消化道不同部位淀粉酶活性的最适温度均为35℃,淀粉酶活性由高到低顺序为：肝胰脏〉幽门盲囊〉前肠〉后肠〉胃。在pH值为2.2～7.6范围内,胃蛋白酶活性的最适pH值为2.8;在pH值为4.8～8.0范围内,其他消化器官蛋白酶的最适pH值均为7.2;在最适pH值下,各消化器官中的蛋白酶活性由高到低顺序为：前肠〉幽门盲囊〉后肠〉肝胰脏。在pH值为4.8～8.0范围内,胃淀粉酶活性的最适pH值为6.0,肠、肝胰脏与幽门盲囊淀粉酶的最适pH值均为6.8,活性由高到低顺序为：肝胰脏〉幽门盲囊〉前肠〉后肠〉胃。在最适温度和pH值下,蛋白酶活性由高到低顺序为：胃〉前肠〉幽门盲囊〉后肠〉肝胰脏;淀粉酶活性由高到低顺序为：肝胰脏〉幽门盲囊〉前肠〉后肠〉胃。     

斜带髭鲷感染鱼肠道弧菌的分离及分析

[目的]对患病斜带髭鲷(Hapalogenys nitens)幼鱼进行病原菌的分离及鉴定。[方法]对2013年1月福州罗源湾某海水网箱养殖场斜带髭鲷幼鱼死亡病例进行了发病情况、临床表现及病原学方面的检验;对其中5尾患病斜带紫鲷的肝脏、脾脏、肾脏及鳃丝进行细菌分离与纯培养,对病原菌进行形态、生理生化测定和16S rRNA基因序列测定及系统发育学分析,并用30种抗菌类药物对5株菌进行了药敏试验。[结果]斜带髭鲷幼鱼死亡病例为细菌性感染症,分离纯培养的菌株(fzlyw201301071和fzlyw201301072)与弧菌属(Vibrio)的鱼肠道弧菌(Vibrio ichthyoenteri)可认定为同一种属。药敏试验结果显示,在不同菌株间无明显的敏感与耐药性差异。[结论]为水产养殖动物的疾病防治提供了理论依据。     

斜带髭鲷室内产卵的研究

本文报道了斜带髭鲷在室内大量自然产卵的试验结果。实验表明:3龄亲鱼采用加强饵料营养,结合使用适当剂量的激素(TRHR-A_2、TRHR-A_3和HCG)进行催熟和催产,亲鱼产卵量大,产卵集中,卵质较好。使用57尾亲鱼(27尾雌鱼,30尾雄鱼),总产卵量6256.5×10~4粒,受精卵4504.5×10~4粒,平均每尾雌鱼产卵231.7×10~4粒,平均受精率66.7％,仔鱼孵化率 79.2％。     

海湾网箱养殖斜带髭鲷的生长特性

2002～2005年期间在广东省饶平柘林湾海上网箱采集斜带髭鲷Hapalogenys nitens标本共515尾,以鳞片的年轮作为年龄鉴定依据,对其生长特性进行研究。结果表明,1～5龄鱼体长与鳞长的关系式为L=175·17r 227·22,体长与体重关系式为W=0·0001L2·8677,体长与全长的关系式为Lt=1·1736Lb 3·6206,应用von Berta-lanffy生长曲线拟合生长规律,求得斜带髭鲷的各项生长参数为渐进体长L∞=452·418mm,W∞=4315·455g,体重生长曲线的曲率k=0·2799,理论上体长和体重为零时的年龄t0=-1·1869龄,体重生长拐点年龄t0=2·738龄。     

Productivity and cost of whole‑tree harvesting without debarking in a Eucalyptus nitens plantation in Tasmania,Australia

There is increasing interest worldwide in using tree harvesting biomass as an energy source. Bark retained on logs is commonly used as an energy source, but is generally removed from eucalypt logs during harvest. In order to evaluate the potential use of eucalypt bark as fuel, there is a need for information on the productivity and cost implications of retaining eucalypt bark during harvest operations. The study examined the impact of retaining bark on logs on the productivity and costs of a whole?tree to roadside harvesting system in a short?rotation Eucalyptus nitens plantation in Australia being harvested for pulp logs. Trees were felled and bunched with a feller?buncher in spring, then left infield for four weeks to promote bark adhesion and reduce bark loss. A skidder extracted the trees to roadside where a processor processed them to predominantly 10?m logs. Machine productivities were calculated from estimated tree and log volumes and cycle times recorded from video recordings. The feller?buncher's productivity (65 m3 PMH₀^?1) was less than expected as it appeared to be underpowered to handle the larger trees on the study site. The skidder's productivity (56 m3 PMH₀^?1) was comparable to those reported in studies under similar conditions and with bark retained. The roadside processor's productivity (25 m3 PMH₀^?1) was lower than expected. This was believed to result from the operator separately stacking 10?m and 5?m logs, and the lower feed speed resulting from slippage due to the reduced feed roller pressure used in the study to reduce bark loss. Future research could identify feed rollers that increase feed speed while retaining bark. Harvest system costs (AUD18 GMt^?1) were similar to those reported for a eucalypt roadside processing trial where bark was removed. These results suggest that retaining bark on the logs at roadside did not affect the harvesting system's productivity or costs.     

Genetic characterisation of a Eucalyptus nitens base breeding population in South Africa

The measurement and statistical analysis of data from eight Eucalyptus nitens trials, established in the summer rainfall forestry region of South Africa during the 1980s and 1990s, have enabled the characterisation of the Institute for Commercial Forestry Research's breeding population. Provenance testing showed that the more northerly New South Wales (Australia) Eucalyptus nitens provenances of Barren Mountain and Barrington Tops are distinctly better suited to the summer rainfall areas of South Africa than the southern New South Wales provenances and the Victorian provenance, Penny Saddle. Generally, the species was not badly affected by Coniothyrium canker. High type B genetic correlations for all site pairs, except one comparison, ranged from 0.75 to 0.99 for diameter at breast height (dbh), indicating very little or no genotype × environment interaction for dbh for the genotypes tested in this study. Narrow-sense heritability coefficients ranged from 0.01 to 0.34, indicating that the species generally exhibited sufficient breeding opportunity for improvement of diameter growth. High genetic correlations of greater than 0.90 between diameter measurements at 52 to 62 months after establishment and diameter measurements at 94 or 113 months were found, indicating that selections can be reliably made at five or six years. Predicted genetic gains were highest in the trials at Goedehoop and Arthur's Seat, with increases in dbh of 3.07 cm (17.1%) and 3.17 cm (20.7%), respectively, at full rotation.     

斜带髭鲷线粒体DNA 控制区序列的结构分析

采用PCR技术获得我国南海斜带髭鲷(Hapalogenys nitens)养殖及野生群体共50尾样品的mtDNA控制区全序列,长度范围788 ～790 bp;测得序列与GenBank下载的其他鲈形目鱼类D-loop全序列利用CLUSTAL X进行排序后,对控制区结构进行分析.识别了其终止结合序列区、中央保守区和保守序列区,指出了终止相关序列的主体是TACAT与其反向互补序列ATGTA以及一系列保守序列(CSB-F、CSB-E、CSB-D和CSB-1、CSB-2、CSB-3),并给出了其一般形式;此外,基于斜带髭鲷D-Loop全长序列,利用贝叶斯法构建了分子系统进化树.结果显示,斜带髭鲷养殖群体与野生群体部分样品各自紧密聚成一小支,而在整棵进化树上,养殖样品与野生样品相互交错聚集在一起,可见本研究海区斜带髭鲷养殖群体与野生群体之间的遗传差异分化不显著.     

斜带髭鲷血液生理和生化指标的研究

［目的］ 丰富斜带髭鲷血液生理生化指标的数据库。[方法］以60尾斜带髭鲷成鱼为材料,运用常规血液指标和血细胞涂片方法,测定了血液生理、生化指标。［结果］斜带髭鲷成鱼血液中,红细胞和白细胞数量分别为（215.25±14.33）万和（1.87±0.43）万个/mm^3;血红蛋白含量为（62.30±7.50）g/L;红细胞压积为（23.3±1.01）%;红细胞沉降率为（0.58±0.21） mm/h。血涂片经显微镜观察显示可以明显分出血红细胞、淋巴细胞、单核细胞、血栓细胞、嗜中性粒细胞。血液中的血清总蛋白、白蛋白和肌酐浓度分别为（32.13±8.61）、（26.46±2.75）和（16.15±3.86）μmol/L;乳酸脱氢酶活性为（1 446.30±523.58）IU/L;磷酸脱氢酶活性为（30.33±13.92）IU/L;甘油三酯为（1.80±0.46）mmol/L;总胆固醇为（2.68±0.51）mmol/L;Ca^2＋、Na^＋、Cl^-和K^＋浓度分别为（1.31±0.22）、（191.74±5.27）、（154.14±8.51）和（2.11±0.58） mmol/L。［结论］该试验为斜带髭鲷鱼的基础生物学研究提供血液学基础资料。     

斜带髭鲷和紫红笛鲷早期发育阶段的行为选择

采用实验生态学方法研究斜带髭鲷(Hapaologenys nitens)和紫红笛鲷(Lutianus argentimaculatus)幼鱼早期发育阶段的行为选择,旨在从行为学角度为优化种苗生产管理提供科学依据。结果显示,斜带髭鲷回避红色底质,对黑色底质的选择则是随着生长而逐渐增加,1 cm体长组的隐匿习性最强,为50.67%;2 cm和3 cm组的隐匿率分别为40.67%和35.33%;4 cm组仅25.00%。1 cm组的顶流率为3.35%,4 cm达71.65%。1 cm和2 cm组在1 760~2 210 lx照度下的分布率分别为41.67%和35.00%,在39~59 lx为8.33%和16.67%,4 cm组在38~53 lx的分布率达41.67%,在2 780~2 980 lx仅为8.33%。体长1 cm的紫红笛鲷喜栖息于白色底质,约占总群体的61.00%,随着生长,对黑色底质的喜好明显增强;4 cm组对白色底质无选择,而对黑色底质的选择达到63.67%。1 cm组的隐匿百分率为55.67%,4 cm组仅为25.00%。在流速1 cm/s的情况下,趋流率比较低,为50.00%左右,1 cm组在流速3 cm/s时的趋流率最高,达到98.67%;1 cm组的顶流率为96.65%,3 cm和4 cm组的顶流率仅为6.65%和3.35%。研究表明,斜带髭鲷和紫红笛鲷行为特征随着个体的发育而变化。     

斜带髭鲷室外水池仿生态系育苗研究

2001年至2002年,就斜带髭鲷(Hapalogenys n itens)室内人工育苗周期长、需求活饵多等问题,进行室外水池人工设置模仿自然生态条件的仿生态系育苗技术研究。即1号试验池接入6种生物饵料;2号对照池接入2种生物饵料。2001年仔鱼经108d培育,1号池、2号池分别获得幼鱼5.55万尾和3.03万尾,平均全长31mm和29mm,平均体重0.9g和0.75g,成活率达18.5%和10.1%;2002年仔鱼经60d培育,分别获得幼鱼4.98万尾和2.76万尾,平均全长36.7mm和30.8mm,平均体重1.48g和0.95g,成活率达16.6%和9.2%。试验结果:1号池的成活率、全长、体重明显好于2号对照池。表明在仔鱼培育期间,多种生物饵料有利于生物饵料的多样性以及开口仔鱼的摄食和营养,有利于鱼苗的生长发育和成活率的提高。