鰤鱼诺卡氏菌对乌鳢血液指标的影响

应用浓度为106cfu/mL的鰤鱼诺卡氏菌(Nocardia seriolea)菌悬液腹腔注射乌鳢,人工感染诺卡氏菌病。在感染后3d、6d、9d、12d、18d和24d时抽取乌鳢血液,检测乌鳢的血细胞数、血细胞脆性、溶菌酶、血清总蛋白、碱性磷酸酶、乳酸脱氢酶和尿素氮等指标。结果表明,与对照组相比,感染鰤鱼诺卡氏菌后乌鳢血细胞数呈先升高后降低的趋势,而血细胞脆性在各实验时间点均高于对照组;血清碱性磷酸酶呈先降低后升高趋势,血清溶菌酶、血清总蛋白和血清尿素氮等均呈先降低后增高再降低的趋势,血清乳酸脱氢酶活力显著增加。说明鰤鱼诺卡氏菌感染会引起乌鳢血液指标明显变化。     

Evidence of geographical structuring in the Malaysian Snakehead, Channa striata based on partial segment of the CO1 gene

Channa striata, locally known as "haruan", is economically important in fisheries and aquaculture industries in several Asian countries. DNA sequencing, based on a partial segment of the Cytochrome oxidase c subunit 1 (CO1) gene, was used to determine genetic variation in C. striata samples from four different populations on the west coast of Peninsular Malaysia. The highest nucleotide and haplotype diversities were observed in the Linggi population (π = 0.0067, h = 0.835), and the lowest in the Timah Tasoh population (π = 0.0008, h = 0.286). Apart from Kajang-Linggi, which was insignificant, F(ST) values were significant (p < 0.05) in all pairwise-population comparisons. Consequently, it is inferred that genetic structuring C. striata populations in this region was largely shaped by a common origin, with secondary influences from geographical factors and isolation.     

Genetic structure of the snakehead murrel, Channa striata (channidae) based on the cytochrome c oxidase subunit I gene: Influence of historical and geomorphological factors

Nucleotide sequences of a partial cytochrome c oxidase subunit I gene were used to assess the manner in which historical processes and geomorphological effects may have influenced genetic structuring and phylogeographic patterns in Channa striata. Assaying was based on individuals from twelve populations in four river systems, which were separated into two regions, the eastern and western, of the biodiversely rich state of Perak in central Peninsular Malaysia. In 238 specimens, a total of 368-bp sequences with ten polymorphic sites and eleven unique haplotypes were detected. Data on all the twelve populations revealed incomplete divergence due to past historical coalescence and the short period of separation. Nevertheless, SAMOVA and F(ST) revealed geographical structuring existed to a certain extent in both regions. For the eastern region, the data also showed that the upstream populations were genetically significantly different compared to the mid- and downstream ones. It is inferred that physical barriers and historical processes played a dominant role in structuring the genetic dispersal of the species. A further inference is that the Grik, Tanjung Rambutan and Sungkai are potential candidates for conservation and aquaculture programmes since they contained most of the total diversity in this area.     

海南岛宽额鳢(Channa gachua)群体遗传变异与生物地理过程

为了解海南岛宽额鳢(Channa gachua)的群体遗传分化和亲缘生物地理过程,采集了云南元江和海南岛5个水系(昌化江、陵水河、藤桥河、万泉河及南渡江)共6个种群168个宽额鳢个体,基于线粒体细胞色素b(Cyt b)基因全序列(1142 bp)对其遗传多样性和遗传分化程度进行了评估,并探讨了地质和气候等因素如何塑造了这一物种的亲缘地理结构及演化历史。基于Cyt b序列构建的系统树结果将所有个体分成两个主要谱系(A和B),谱系A包括海南岛所有种群,其中,部分昌化江个体形成独立的亚支(A2),其余个体聚为另一亚支(A1),谱系B为云南元江的全部个体,各谱系间的遗传分化指数均较高。种群历史动态分析表明,各谱系均没有发生种群扩张,但A1亚支与谱系B曾在约1万年前发生过有效种群数量减小的事件。根据研究结果推测,更新世冰期期间,北部湾因海平面下降而暴露,大陆和海南岛的水系发生接触,越南北部水系(包括元江/红河)通过一条联系雷州半岛和海南岛的古河道流入南海,因而冰期期间宽额鳢有机会从元江(红河)扩散至海南岛西南部,随后在海南岛内部,宽额鳢进一步扩散,并以五指山为种群间基因交流的重要地理障碍,各水系间种群发生基因交流和遗传分化。     

Structure and composition of teleost scales from snakehead Channa argus (Cantor) (Perciformes: Channidae)

The structure of teleost scales from snakehead Channa argus was investigated using thermogravimetric analysis (TG), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive analysis of X-rays (EDAX), Fourier transform infra-red spectroscopy (FTIR) and X-ray diffraction (XRD). Thermal treatment of fish scales indicates that the fibrillary plate is partially calcified. SEM shows two kinds of scale denticles, arranged along the circuli in the anterior field and the lateral fields, respectively. TEM indicates the stratum laxum with abundant fibrils, chromatophores and capillary blood vessels within the scale covering, and shows the fibrillary plate as an 'orthogonal plywood structure' of stratified lamellae, consisting of 80–100 nm diameter collagen fibres co-aligned in individual lamellae and alternated by c. 90° of the fibre alignment between adjacent lamellae. EDAX, FTIR and XRD show that the mineral phase of the scales is a carbonated hydroxyapatite with a Ca:P molar ratio of 1·85.     

鳜和乌鳢最适温度的研究

研究了体重47.2-540.2g的鳜和45.0-546.2g的乌鳢的最适摄食和生长温度。结果表明,鳜的最大摄食率随温度的上升而增大,在25-35℃之间形成“最适温度平台”,低温（10-25℃）时,乌鳢的最大摄食率随温度的上升而增加,在25-30℃之间形成“最适温度平台”,之后随温度的增加而下降,鳜的特定生长率随温度的增加而加快,在25-35℃“最适温度平台”,乌鳢的特定生长率受体重和温度的交互影响。     

胡子鲇、月鳢、泥鳅具气呼吸作用器官呼吸上皮的电镜观察

应用扫描电子显微镜与透射电子显微镜技术观察了具气呼吸作用的胡子鲇树枝状鳃上器、月鳢耳片状鳃上器和泥鳅的肠等器官 ,证实 3种淡水鱼类具气呼吸作用的器官表面均被覆一层高度毛细血管化的呼吸上皮。胡子鲇的呼吸上皮表面形态呈玉米棒状 ,月鳢的鳃上器表面为半圆形鹅卵石状 ,泥鳅肠内壁表面如云朵状。这 3种器官的呼吸上皮细胞均为同一种类型 ,是一类特化的扁平上皮细胞 ,兼有哺乳类肺泡Ⅰ型和Ⅱ型上皮细胞的细微结构特征。同时 ,构成气血屏障的三部分即呼吸上皮细胞、毛细血管内皮细胞胞质薄层和两者之间的基底膜与其他脊椎动物的呼吸器官极为相似。     

斑鳢血细胞初步研究

对斑鳢的外周血细胞用常规Wright’s法染色并进行显微观察。结果显示,斑鳢外周血中具有红细胞、幼稚红细胞、小淋巴细胞、大淋巴细胞、血栓细胞、单核细胞和嗜中性粒细胞,未发现嗜酸性粒细胞和嗜碱性粒细胞。分别对各种血细胞的显微结构进行了描述。     

The effects of calcitonin on plasma calcium levels and bone metabolism in the fresh water teleost Channa punctatus

Administration of salmon calcitonin (sCT) caused significant reduction in total and ultrafiltrable plasma calcium content in the plasma of a fresh water female teleost Channa punctatus. A time-bound analysis on the effect of sCT showed a highly significant short duration reduction in total and ultrafiltrable plasma calcium content in fish kept in normal tap water and low-calcium water and a moderate hypocalcemia in fish kept in high-calcium water. Sexually immature adult fish showed a greater response than the sexually mature ones. Using tartrate-resistant acid phosphatase (TRACP) and alkaline phosphatase (ALP) activities in plasma and hydroxyproline (HYP) excretion in urine, the effect of sCT on the inhibition of bone calcium resorption were examined. In both sexually mature and immature adult fish, kept in normal tap water, sCT significantly suppressed TRACP and ALP activities in plasma and excretion of HYP in urine within 2-6 h with a maximum at 4 h after injection. Salmon CT treatment to sexually immature adult fish caused significant increase in skeletal bone calcium concentration. Taken together, all this information indicates that CT in a fresh water female teleost is an effective regulator of plasma calcium levels, and its action, at least in part, operates through inhibition of bone calcium resorption.     

乌鳢组织内三种同工酶的研究

本研究对乌鳢９种组织内的ＬＤＨ、ＭＤＨ和ＡＴＰａｓｅ同工酶作了分析，结果表明，乌鳢各组织内的ＬＤＨ、ＭＤＨ有明显的组织特异性，ＬＤＨ由两个基因编码。骨骼肌中的ｓ－ＭＤＨ也有两个基因编码。ＡＴＰａｓｅ同工酶存在于乌鳢的多种组织中，其基因编码数有待进一步探讨。