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本实验利用现行主流分类衍征,重新对荆州碘泡虫(Myxobolus kinchowensis)进行了详细描述,其分类特征如下:包囊圆形,寄生于鲫肌肉与肾脏,肌肉包囊大小(126.7±1.8)μm,肾脏包囊直径为94.2μm;两寄生部位各形态参数无显著差异,成熟孢子正面观呈梨形,缝面观呈纺锤形,含一大一小两梨形极囊;无明显囊间突起,孢子后端无褶皱,无粘液膜。组织病理显示在两寄生部位均未引起严重的炎性反应,且感染强度不高,推测该种对宿主无显著影响。基于18S r DNA进化分析发现荆州碘泡虫与寄生在肌肉部位的碘泡虫属种类聚为一个大枝,然后该大枝又根据地理位置远近分为北美枝、欧洲枝以及亚洲枝。通过形态比较研究以及分子分析可确定荆州碘泡虫为有效种,其寄主为鲫,寄生部位为肌纤维间和肾小囊。此外,两组织差异明显的寄生部位出现说明荆州碘泡虫相应的放射孢子虫在宿主鲫体内存在不同的发育与移行途径,而肌肉可能为其常规寄生部位,肾脏为其异常寄生部位,这种寄生部位的转移与宿主转变可能是粘孢子虫物种多样性形成的机制。 相似文献
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为了鉴定感染鲤鳃的病原并分析其鳃部严重受损的病因,本研究运用形态计量学、分子生物学、系统发育学和组织病理学方法,对其进行了详细研究。结果显示,该致病黏孢子虫寄生于鲤鳃弓,孢子壳面观呈椭圆形或近圆形,缝面观呈柠檬形,顶面观呈橄榄形;孢子长9.2～11.8μm,宽8.3～10.5μm,厚4.4μm;拥有2个大小不等的水滴形极囊,2个极囊前端略微靠拢,大极囊长3.5～4.7μm、宽2.4～3.1μm,小极囊长2.8～3.8μm、宽1.8～2.6μm,大、小极囊极丝分别缠绕5圈和3圈;部分孢子后端可以见"V"形褶皱,但未观察到囊间突起、黏液被膜和嗜碘泡。18S rDNA与已报道的鳃基碘泡虫相似度达99.69%.因此,该寄生虫的形态学与分子生物学数据以及宿主信息表明,该种为鳃基碘泡虫,属中国新记录。孢囊发生在病鲤鳃部传入和传出动脉之间。由于孢囊体积增大,传入和传出动脉受到压迫而变形、堵塞;鳃丝基部也因此发生机械性断裂;部分孢囊周围结缔组织受到破坏。孢囊破裂后,孢子浸润到周围组织。研究表明,鳃基碘泡虫的孢囊压迫主血管,破坏鳃丝,致使鳃丝血流不畅、供血不足,进而导致鳃呼吸功能丧失,是病鲤致死的主要原因。本研究提供的鳃基碘泡虫的形态、分子和病理数据可为水产养殖中鳃基碘泡虫病的防控提供理论依据。 相似文献
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为了完善瓶囊碘泡虫的分类学特征及厘清其与洪湖碘泡虫的分类关系,实验采用形态学、组织学和分子生物学方法对瓶囊碘泡虫进行了重描述,并与洪湖碘泡虫的分子标记进行了系统比较。结果显示,瓶囊碘泡虫寄生于异育银鲫的鳃,形成乳白色的圆形或椭圆形孢囊,直径为1.2～1.4 mm。成熟孢子壳面观呈梨形,前端较尖,后端钝圆,孢子长17.3～19.6 μm,孢子宽7.4～9.9 μm。两个极囊呈瓶状,大小不等。大极囊长6.4～9.7 μm,大极囊宽2.1～3.3 μm;小极囊长5.3～8.9 μm,小极囊宽2.0～3.3 μm。极丝圈数为8～11圈。组织学分析显示,瓶囊碘泡虫寄生于鳃小片间的上皮组织。BLAST分析显示,本研究获得的瓶囊碘泡虫的SSU rDNA序列与GenBank中瓶囊碘泡虫序列的相似性为99.5%～99.8% （KC425223-KC425225,MH329620,JQ690361,JQ690373,KJ725082,MN227351,DQ339482）。系统发育分析表明,瓶囊碘泡虫与洪湖碘泡虫形成姐妹支。瓶囊碘泡虫与洪湖碘泡虫分子标记序列的比较显示,这两种碘泡虫的序列相似性为98.2%～98.8% ,遗传距离为0.014～0.018,存在27个碱基差异。SSU rRNA二级结构分析显示,瓶囊碘泡虫和洪湖碘泡虫不同群体间的二级结构一致,两个物种间的二级结构存在明显差异,表明SSU rRNA二级结构可以作为鉴别瓶囊碘泡虫和洪湖碘泡虫的分子特征。本研究完善了瓶囊碘泡虫在异育银鲫鳃部的详细寄生部位,提出SSU rRNA二级结构可以作为有效鉴别瓶囊碘泡虫和洪湖碘泡虫的分子标记。 相似文献
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引起池养异育银鲫高死亡率的粘孢子虫新种咽碘泡虫形态和分子分析 总被引：1，自引：0，他引：1
对近几年发生在江苏省盐城地区引起池养异育银鲫大批死亡的粘孢子虫进行了形态和分子等方面分析研究,发现该粘孢子虫主要特点是:孢子梨形,部分孢子后部外周包围有透明无色的膜状鞘和壳瓣底部内侧呈现1～6个"V"形缺刻,两个极囊大小不等,孢子前端内侧两个极囊间有一个细长的囊间突起,胚质中无嗜碘泡,孢囊大小10～25 mm,孢子长16.82±0.43(16.03～17.69)μm,孢子宽10.26±0.43(9.12～10.88)μm,孢子厚8.09±0.29(7.50～8.75)μm,孢子长宽比1.64±0.09(1.50～1.93);大极囊长8.66±0.25(8.25～9.16)μm、宽3.65±0.25(3.01～4.19)μm,小极囊长8.35±0.28(7.60～8.85)μm、宽3.58±0.23(3.09～4.11)μm,囊间突起长1.80±0.12(1.59～2.00)μm。特异性地寄生在异育银鲫的口咽腔上颚的咽组织内、具有寄主和寄生在咽部的专一性,PCR扩增得到1 576 bp的18S rDNA序列,GenBank登录号为JQ726700。该粘孢子虫与相近的其它粘孢子虫比较,孢子长分别与白鲟碘泡虫(Myxobolus psephurusi)和扭曲碘泡虫(M.twistus)无显著差异(P>0.05),与M.ampullicapsulatus、M.wulii和鳙碘泡虫(M.aristichthydis)分别有显著差异(P<0.05);孢子宽和厚、极囊长和宽分别与M.ampullicapsulatus、M.wulii、白鲟碘孢虫(M.psephurusi)、鳙碘泡虫(M.twistus)和扭曲碘孢虫(M.aristichthydis)有显著差异(P<0.05);分子系统树分析结果显示,与M.ampullicapsulatus在同一个分支中,亲缘关系最近。从孢子形态学、寄主的特异性、寄生部位的专一性以及18SrDNA序列等特点综合比较分析,表明该粘孢子虫为一新种,命名为咽碘泡虫Myxobolus pharynae n.sp.。 相似文献
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【目的】研究米氏碘泡虫（Myxobolus miyairii Kudo, 1919）不同寄生部位和不同地理分布的株系差异和遗传分化情况。【方法】基于形态特征、组织向性、地理分布、18S rDNA序列相似度、遗传距离、系统发育,对米氏碘泡虫各株系进行比较分析。【结果】米氏碘泡虫各株系孢子形态特征基本一致;米氏碘泡虫重庆株系1（鲶鳃腔膜寄生）,重庆株系2（鲶肠寄生）和江西株系（鲶肠寄生）间相似度为98.6%~99.9%,遗传距离为0.000~0.013;系统发育分析显示,米氏碘泡虫重庆株系2先与江西株系聚支,其形成的进化支再与重庆株系1形成姐妹群关系。【结论】序列比较和系统发育分析结果表明,米氏碘泡虫并没有形成地理种群特有的单系,而是依据寄生部位形成肠寄生支系和鳃腔膜寄生支系。宿主种类相同的条件下,较之于地理隔离,寄生部位差异对于米氏碘泡虫种群分化的影响更大。【意义】本文米氏碘泡虫各株系的比较研究及其结果,为人们进一步了解该寄生虫的进化生物学特征积累基础资料。 相似文献
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为探究洪湖碘泡虫在被感染异育银鲫不同组织器官中的分布及不同感染阶段的差异，实验采用显微镜镜检、PCR检测及组织病理切片相结合手段，对发病及隐性感染异育银鲫的肌肉、伪鳃、鳃、头肾等11个组织器官进行了广泛检测分析。显微镜镜检发现，在发病鱼的咽、伪鳃和鳃能观察到孢囊或成熟孢子；在隐性感染异育银鲫的咽上壁与副蝶骨间结缔组织、伪鳃及其血管周边观察到大量棕黄色结节，并含有洪湖碘泡虫的成熟孢子。不同组织器官DNA样品PCR检测发现，在发病鱼除肌肉外的其他10个组织器官中均检测到洪湖碘泡虫存在，其中伪鳃检出率最高(100%)；隐性感染异育银鲫在咽上壁组织、伪鳃、头肾、体肾、脾脏及卵巢中检出洪湖碘泡虫，伪鳃检出率也为最高(26.7%)。组织病理切片显示，发病鱼咽上壁内分布着大量蜂巢状孢囊及成熟孢子，伪鳃被严重侵占和破坏；残存伪鳃鳃丝周边能观察到增殖和发育阶段的孢子生成细胞。综上所述，本研究首次报道了洪湖碘泡虫在发病和隐性感染异育银鲫不同组织器官中的分布差异，发现伪鳃可能是洪湖碘泡虫寄生和发育成熟的重要器官。结果为洪湖碘泡虫病的准确检验检疫和进一步开展致病机制研究奠定基础。 相似文献
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<正> 饼形碘泡虫主要寄生在草鱼的肠组织中,其大小只有几微米,碘泡虫的多数孢子由肠组织分泌的结缔组织包围形成孢囊,比较难分离和提纯。在研究该孢子虫的形态特征、生物学特性及防治方法等试验中,必须备有大量纯净的孢子.为了满足上述的需要,作者试验得出一种简单易行的方法。此种方法不需任何 相似文献
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洪湖碘泡虫(Myxobolus honghuensis)是引起异育银鲫(Carassius auratus gibelio Bloch)“喉孢子病”的重要病原, 每年导致养殖苗种和成鱼大量死亡。本研究通过隐性感染异育银鲫母本人工受精、实验室条件下受精卵孵化和幼鱼培育, 采用单管半巢式 PCR、荧光定量 PCR 和寡核苷酸荧光原位杂交等检测手段进行亲本、卵和幼鱼等环节的检测分析, 探究异育银鲫寄生洪湖碘泡虫是否存在经卵传播途径。结果表明, 所采用的 34 尾异育银鲫母本(A1~A22, B1~B12)的洪湖碘泡虫隐性感染率达 50%~75%, 其中, 卵和伪鳃检出率高于卵巢组织样品; 特异性寡核苷酸探针荧光原位杂交在隐性感染母本的卵巢、伪鳃、肾、脾组织检测到洪湖碘泡虫前孢子生成阶段营养体; 实验室条件下阳性母本所产的卵经孵化和培育出的幼鱼 15 dph 和 30 dph 样品可以检出阳性(A1、A18、B8 和 B9); 荧光原位杂交显示 15 dph 幼鱼在伪鳃、鳃和肾脏组织检测出阳性信号。本研究进一步揭示了异育银鲫寄生洪湖碘泡虫存在经鱼卵传播途径; 研究结果可为相关疾病制定防控措施奠定重要的理论基础。 相似文献
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Association between the interannual variation in the oceanic environment and catch rates of bigeye tuna (Thunnus obesus) in the Atlantic Ocean 
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下载免费PDF全文 The environmental processes associated with variability in the catch rates of bigeye tuna in the Atlantic Ocean are largely unexplored. This study used generalized additive models (GAMs) fitted to Taiwanese longline fishery data from 1990 to 2009 and investigated the association between environmental variables and catch rates to identify the processes influencing bigeye tuna distribution in the Atlantic Ocean. The present findings reveal that the year (temporal factor), latitude and longitude (spatial factors), and major regular longline target species of albacore catches are significant for the standardization of bigeye tuna catch rates in the Atlantic Ocean. The standardized catch rates and distribution of bigeye tuna were found to be related to environmental and climatic variation. The model selection processes showed that the selected GAMs explained 70% of the cumulative deviance in the entire Atlantic Ocean. Regarding environmental factors, the depth of the 20 degree isotherm (D20) substantially contributed to the explained deviance; other important factors were sea surface temperature (SST) and sea surface height deviation (SSHD). The potential fishing grounds were observed with SSTs of 22–28°C, a D20 shallower than 150 m and negative SSHDs in the Atlantic Ocean. The higher predicted catch rates were increased in the positive northern tropical Atlantic and negative North Atlantic Oscillation events with a higher SST and shallow D20, suggesting that climatic oscillations affect the population abundance and distribution of bigeye tuna. 相似文献
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Liping Li Rui Wang Wanwen Liang Xi Gan Ting Huang Yan Huang Jian Li Yunliang Shi Honglin Luo Ming Chen 《广西水产科技》2014,(1)
Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae(GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the ?rst time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in ?ve provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding36.9%(62/168), 37.5%(63/168) and 19.6%(33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia(95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010,but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during2007–2011, III onlyoccurred in 2012. 14 different PFGE types, including 4 new types(N, O,P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9%(141/168) of the total GBS strains. Ia corresponded to 11 PFGE types(A–H, N–P), in which type D predominated(51%). Ib represented 3 genotypes(I, J and Q) and III harbored only 2genotypes(N and F). Type N and Fsynchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years.Although Iastillpredominated, new rareserotypeIII alreadyoccurred in China. 相似文献
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In this experiment, a feeding trial was performed to determine the effects of fructooligosaccharide (FOS) on growth performance, digestive enzyme activity and immune response of Japanese sea bass, Lateolabrax japonicus juveniles (initial weight 38.3 ± 0.5 g), and the fish were examined following feeding with six levels of FOS (0, 0.5, 1, 2, 4 and 6 g/kg) for 28 days. Significant enhancement of weight gain (WG) and specific growth rate (SGR) was found in fish fed 1 g/kg FOS incorporated diets (p < .05), while the feed conversion ratio (FCR) in the 1, 2 g/kg FOS groups reduced significantly compared with the control (p < .05). Besides, the crude lipid in the 4, 6 g/kg FOS groups increased significantly compared with the control (p < .05). On the other hand, the erepsin and lipase activities significantly elevated in intestine of fish fed 2 g/kg FOS (p < .05) and the lysozyme activity in serum of fish fed 2 g/kg FOS were significantly higher than that in the control (p < .05). Moreover, the alkaline phosphatase activities in serum of fish fed 0.5, 1, 2 g/kg FOS were significantly higher than in control (p < .05). Regression analysis showed that the relationships between dietary FOS levels and either SGR, FCR, erepsin or lysozyme activities were best expressed by regression equations, and the optimal inclusion levels are 1.37, 1.80, 3.06, 3.11, 1.93 and 1.80 g/kg for SGR, FCR, erepsin, lipase, lysozyme and total superoxide dismutase activities, respectively. Overall, this study revealed that FOS incorporated diets could beneficial for L. japonicus culture in terms of increasing the growth, digestion and immune activities. Under the present experimental condition, the optimal supplementary level of FOS in the diet of L. japonicus is 1–3 g/kg. 相似文献
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Growth hormone (GH) and reproduction: a review 总被引：5，自引：0，他引：5
Florence Le Gac Odile Blaise Alex Fostier Pierre-Yves Le Bail Maurice Loir Brigitte Mourot Claudine Weil 《Fish physiology and biochemistry》1993,11(1-6):219-232
Interaction between growth and reproduction occurs in many vertebrates and is particularly obvious at certain stages of the life cycle in fish. Endocrine interactions between the gonadotropic axis and the somatotropic axis are described, the potential role of GH being emphasised. A comparative analysis of these phenomena in mammals, amphibians and fish, suggests a specific role of GH in the physiology of puberty, gametogenesis and fertility. It also shows the original contribution made by studies on the fish model in this field of investigations. 相似文献
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Two gonadotropins (GtH; Qa and Qb) were purified by gel filtration and ion exchange chromatography from the pituitaries of Indian walking catfish (Clarias batrachus). The presence of GtH during purification was assessed by in vitro oocyte maturation and in vivo steroidogenic activity, and their identities were determined by elution profiles, molecular weight, biological activities and yield. The molecular weights of Qa and Qb were 37 and 42 kDa, respectively, and composed of distinct subunits (Qa: 20 and 14 kDa and Qb: 26 and 18 kDa). Polyclonal antibodies raised against Qa immunostained Qa, Qb and pituitary GtH cells. A competitive Qa‐ELISA was developed whose sensitivity was 6.25 ng mL?1 (1.25 ng well?1) with intra‐ (3.5%) and inter‐ (12.4%) assay coefficients of variation. Displacement curves parallel to the standard were obtained with plasma and pituitary extracts of catfish, Qb and carp GtHII. The assay was validated by measuring the plasma Qa levels after LHRH treatment and in relation to ovarian growth in the female catfish during different reproductive phases. Based on the results, Qa and Qb corresponded to fish LH and FSH respectively. The findings will increase the knowledge of the mechanisms controlling fish reproduction and identification of sensitive phases in fish in captivity for hormonal manipulation. 相似文献
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Controlled infection of Poecilia reticulata Peters (guppy) with Tetrahymena by immersion and intraperitoneal injection 下载免费PDF全文
下载免费PDF全文 G Sharon M Pimenta‐Leibowitz M C L Vilchis N Isakov D Zilberg 《Journal of fish diseases》2015,38(1):67-74
Tetrahymena is a protozoan parasite, which infects guppy, Poecilia reticulata Peters, and causes substantial economical losses in commercial farms worldwide. Studies of guppy infected by Tetrahymena require standardized infection protocols. The LD50 for Tetrahymena infection of guppies by intraperitoneal (IP) injection was calibrated, and the level obtained was 946 parasites per fish. Guppy infection with Tetrahymena by immersion, imitating the natural route of infection via the integument, was studied under normal or stress conditions. Exposure to cold and netting (CNI) and to cold only (CI) followed by immersion exposure to 10 000 Tetrahymena per mL resulted in 22.5% and 19.2% mortality, respectively, as compared to 14.2% and 10% in groups that were netted only (NI) or non‐stressed (I). Histopathology revealed that immersion infection resulted in a systemic infection. Lysozyme levels, measured 3 weeks after infection, were significantly higher in the CNI group (288 μg per mg protein) compared with CI‐, NI‐ and I‐treated groups (94.5, 64 and 62.3 μg mg?1, respectively). There was no evident parasite immobilization activity in body homogenates, suggesting no development of acquired immunity. Re‐infection by IP injection revealed no increase in protection in any of the treatment groups, mortality range of 56.3–75%, higher than in the non‐exposed control (40.6% mortality). 相似文献
18.
Sandra García‐Garrido Ismael Hachero‐Cruzado Carlos Rosas Pedro Domingues 《Aquaculture Research》2013,44(11):1741-1751
Protein and amino acid composition of the mantle of juvenile O ctopus vulgaris (Cuvier, 1797) during fasting for 27 days were determined. Average protein content of octopus mantle was of 711.19 ± 46.80 g kg?1 DW, and it decreased with increasing fasting days. The non‐essential amino acids content was higher (486.18 ± 11.08 g kg?1 protein) than essential amino acids (425.82 ± 9.15 g kg?1 protein) at the start of the experiment (unstarved animals). The results suggest that the amino acid profile of the mantle where the most abundant amino acids are Arg, His, Lys, Gly, Leu and Pro could indicate a prolonged fasting condition (>20 days) or poor nutrition of O . vulgaris. This study supports the idea of using mantle for metabolic needs of starved O . vulgaris suggesting that the degradation pathway of amino acids to pyruvate and tricarboxylic acid cycle intermediates was favoured contrary to the degradation pathway of ketogenic amino acids. Special considerations should be taken concerning Thr, Ile, Ser, Ala, Asx (Asp, Asn), Glx (Glu, Gln) (because of their fast intake) and Lys and His (due to their stable contents) during a prolonged period of fasting. 相似文献
19.
The endemic, anadromous cyprinidChalcalburnus tarichi is the only fish species known to occur in alkaline Lake Van (Eastern Anatolia, Turkey). EightC. tarichi were maintained individually in Lake Van water (17 – 19°C; pH 9.8; 153 mEq·I–1 total alkalinity; 22 total salinity) and tank water samples analyzed for 24 h in 2 to 4 h intervals. At zero time, < 1µM ammonia was present and urea was undetectable in the tank water; at 24 h, total ammonia and urea made up 114±32 and 35±25µM, respectively. Over the experimental period, ammonia-N and urea-N excretion averaged 1041±494 and 607±169moles·kg–1 fish·h–1, respectively. The extent of urea excretion was highly variable between specimens. Uric acid excretion was not detectable.Urea was present at high concentrations in all tissues and plasma (25 – 35moles·g–1·ml–1) of freshly caughtC. tarichi; total ammonia content of the tissues was by a factor of 1.9 (liver) to 3.0 (brain) lower. High arginase activity (2.4±0.2 U·min–1·g–1) was detected in the liver ofC. tarichi but ornithine carbamoylphosphate transferase, a key enzyme of the ornithine-urea-cycle, was absent. Ureagenesis is likely through degradation of arginine and/or uricolysis. High glutamine synthetase activity (11±0.6 U·min–1·g–1) and low ammonia content in brain suggest that, like other teleosts,C. tarichi has an efficient ammonia detoxification in the brain, but in no other tissue.Nitrogenous waste excretion at alkaline pH is discussed. The ability ofC. tarichi to excrete high levels of ammonia at extremely alkaline pH is unique among teleosts studied so far. The mechanism of ammonia excretion under Lake Van conditions remains to be elucidated. 相似文献
20.
There has been growing concern about the overuse of antibiotics in the ornamental fish industry and its possible effect on the increasing drug resistance in both commensal and pathogenic organisms in these fish. The aim of this study was to carry out an assessment of the diversity of bacteria, including pathogens, in ornamental fish species imported into North America and to assess their antibiotic resistance. Kidney samples were collected from 32 freshwater ornamental fish of various species, which arrived to an importing facility in Portland, Oregon from Colombia, Singapore and Florida. Sixty‐four unique bacterial colonies were isolated and identified by PCR using bacterial 16S primers and DNA sequencing. Multiple isolates were identified as bacteria with potential to cause disease in both fish and humans. The antibiotic resistance profile of each isolate was performed for nine different antibiotics. Among them, cefotaxime (16% resistance among isolates) was the antibiotic associated with more activity, while the least active was tetracycline (77% resistant). Knowing information about the diversity of bacteria in imported ornamental fish, as well as the resistance profiles for the bacteria will be useful in more effectively treating clinical infected fish, and also potential zoonoses in the future. 相似文献