MICROHABITAT DISTRIBUTION OF METAZOAN PARASITES ON GILLS OF SILURUS ASOTUS IN JIANGKOU RESERVOIR, JIANGXI PROVINCE, CHINA

ＩＮＴＲＯＤＵＣＴＩＯＮＩｎｔｅｓｔｉｎａｌｐａｒａｓｉｔｅｃｏｍｍｕｎｉｔｉｅｓｉｎｆｉｓｈａｒｅｆｏｕｎｄｎｏｒｍａｌｌｙｔｏｂｅｐｏｏｒｉｎｔｅｒｍｓｏｆｓｐｅｃｉｅｓｃｏｍｐｏ ｓｉｔｉｏｎｓｗｈｅｎｃｏｍｐａｒｅｄｗｉｔｈｔｈｏｓｅｉｎｂｉｒｄｓａｎｄｓｏｍｅｏｔｈｅｒｈｉｇｈｅｒｖｅｒｔｅｂｒａｔｅｓ (Ｋｅｎｎｅｄｙｅｔａｌ.,1 986;Ｅｓｃｈｅｔａｌ.,1 990 ) .Ｈｏｗｅｖｅｒ,ｅｃｔｏｐａｒａｓｉｔｅｃｏｍｐｏｓｉｔｉｏｎｓｏｎｇｉｌｌｓｏｆｆｉｓｈａｒｅｃｏｎｓｉｄｅｒｅｄａｓｓｐｅｃ…     

突降盐度胁迫对大黄鱼(Pseudosciaena crocea)血清生理生化及鳃丝Na+/K+-ATP 酶活性的影响

采用海水盐度由25突降至21、17和13胁迫大黄鱼(Pseudosciaena crocea)的方法,研究了48h内血清生理生化和鳃丝Na+/K+-ATP酶活性的变化。结果表明,实验过程中三个盐度突降组的血清Na+、Ca2+离子浓度均未发生显著变化(P>0.05),血清K+浓度均显著升高(P<0.05),且升高幅度与盐度突降幅度呈正相关,最大值达14.03mmol/L(盐度13组,48h);血清Cl浓度在盐度21组未发生显著变化(P>0.05),17和13组则在48h时显著降低(P<0.05);三个盐度突降组的血清酶ALT、AST、LDH、CK-MB活性均显著高于对照组(P<0.05),随胁迫时间的延长呈先升后降的趋势,且变化幅度均与盐度突降幅度呈正相关;三个盐度突降组的鳃丝Na+/K+-ATP酶活力均呈先升后降的变化趋势,除盐度21组在12h时高于对照组外,活力均显著低于对照组(P<0.05),且降低幅度与盐度突降幅度呈正相关;到实验15天时,死亡率随盐度突降幅度增大而升高。     

Resistance of Lophelia pertusa to coverage by sediment and petroleum drill cuttings

In laboratory experiments, the cold-water coral Lophelia pertusa was exposed to settling particles. The effects of reef sediment, petroleum drill cuttings and a mix of both, on the development of anoxia at the coral surface were studied using O₂, pH and H₂S microsensors and by assessing coral polyp mortality. Due to the branching morphology of L. pertusa and the release of coral mucus, accumulation rates of settling material on coral branches were low. Microsensors detected H₂S production in only a few samples, and sulfate reduction rates of natural reef sediment slurries were low (<0.3 nmol S cm⁻³ d⁻¹). While the exposure to sediment clearly reduced the coral’s accessibility to oxygen, L. pertusa tolerated both partial low-oxygen and anoxic conditions without any visible detrimental short-term effect, such as tissue damage or death. However, complete burial of coral branches for >24 h in reef sediment resulted in suffocation.     

鲈鱼苗烂鳃、烂尾病病原菌的研究

１９９７年４～５月,对花鲈（Ｌａｔｅｏｌａｂｒａｘｊａｐｏｎｉｃｕｓ）鱼苗期细菌性烂鳃和烂尾病的病原菌进行了研究。从具有明显症状的病鱼的病灶组织分离到２株致病菌Ｃ－１和Ｗ－１,经人工感染及从人工感染发病鱼体再分离的Ｗ－４和Ｗ－５菌株的再感染试验结果表明,所分离的细菌为鲈鱼苗烂尾,烂鳃病的致病菌。经６４项生物学特性,生理生化特征测试结果表明,这４株菌可归为一类,同属于鳗弧菌（Ｖｉｂｒｉｏａｎｇｕｉｌａｒｕｍ）。药敏试验结果表明,痢特灵、ＣＩＮ１００、ＭＥＬ２５、呋喃妥因、氯霉素、磺胺药＋ＴＭＰ和美洛西林等７种药物对病原菌有显著的抑制作用。     

海水鱼类寄生虫刺激隐核虫(Cryptocaryon irritans)趋化性研究

应用本实验室建立的趋化模型对海水鱼类寄生虫刺激隐核虫(Cryptocaryon irritans)的趋化特性进行研究。结果显示, 刺激隐核虫幼虫在30min时趋化达到饱和, 在温度28℃时趋化率达到最高; 多种硬骨鱼的血清与粘液对刺激隐核虫的幼虫都有着强烈的吸引作用, 刺激隐核虫幼虫对碳水化合物、氨基酸等小分子物质没有趋化作用; 在组织匀浆液中, 刺激隐核虫幼虫对肌肉匀浆液有一定的趋化作用, 对肝、肠、胃的匀浆液都没有趋化作用; 感染后鱼类血清对刺激隐核虫的幼虫有着更加强烈的吸引作用(P<0.01); 18种中草药中的五倍子、大黄、槟榔、苦楝、虎杖、贯众等6种中药草对刺激隐核虫的幼虫有一定的驱虫作用。本文的研究结果有助于深化对刺激隐核虫致病性的认识并对“白点病”的防治有一定的参考价值。     

Preliminary evidence for human fecal contamination in corals of the Florida Keys,USA

Corals and reef environments are under increased stress from anthropogenic activities, particularly those in the vicinity of heavily populated areas such as the Florida Keys. The potential adverse impacts of wastewater can affect both the environment and human health; however, because of the high decay rate of bacterial indicators in coral reef waters it has been difficult to document the presence of microbial contaminants and to assign risks in these environments. Here we show initial evidence that microorganisms associated with human feces are concentrated along the surface of coral heads relative to the overlying water column in the Florida Keys. Bacterial indicators (fecal coliform bacteria, enterococci or Clostridium perfringens) were detected in 66.7% of the coral surface microlayer (CSM) samples at levels between five and 1000 CFU/100 ml, but were found infrequently and at low numbers in the overlying water column ( < or = 2.5 CFU/100 ml). Similarly, enterovirus nucleic acid sequences, an indicator of human-specific waste, were detected in 93.3% of the CSM samples and only once in the water column by cell culture. Results show that coral mucus may accumulate enteric microorganisms in reef environments, and may indicate a risk to public and environmental health despite low indicator levels in the surrounding water.     

河流弧菌(Vibrio fluvialis)对大黄鱼( Pseudosciaena crocea ) 鳃粘液粘附特性研究

采用间接ELISA法(最低检测值约104cfu)研究不同培养条件、不同培养阶段、抗体处理、营养饥饿等对河流弧菌粘附作用的影响。结果表明,经TSB培养的菌体的粘附作用极显著强于TSA培养的菌体的粘附作用(P<0.01);河流弧菌能很好地粘附于大黄鱼粘液,粘附量随菌浓度升高而增大并符合饱和粘附动力学:y=0.1782ln(x)1.6923(R2=0.9810);不同生长阶段河流弧菌的粘附能力不同,在培养初期阶段细菌的粘附量先是随着培养时间的延长而增大,并在培养24h后粘附量达到最大,而后随着培养时间的延长其粘附量急剧下降;抗体处理后河流弧菌的粘附量显著低于对照组(P<0.05);营养饥饿菌体的粘附量明显降低。以上结果表明:海水中的河流弧菌能很好地粘附于大黄鱼鳃粘液,其粘附作用受细菌培养条件、营养状况等自身因素的显著影响。本研究结果有助于了解河流弧菌的流行病学和致病机理。     

鲈鱼的鳃寄生车轮虫病及扫描电镜观察

报道鲈鱼的鳃寄生车轮虫病及病理组织的扫描电镜观察。病原鉴定为 :直钩车轮虫、杜氏车轮虫、日本车轮虫、劳牧小车轮虫及简单两分虫 5种车轮虫科纤毛虫 ,其中数量上占优势的为直钩车轮虫。扫描电镜观察结果表明 ,鳃寄生车轮虫可对宿主的上皮组织产生明显的机械性损伤并造成鳃丝粘液分泌增多及炎症反应。文中就海水养殖鱼类及野生鱼类由车轮虫寄生造成的危害及防治途径做了探讨。     

褐牙鲆鳃丝Na+-K+-ATPase性质的研究

研究了褐牙鲆 (Paralichthysolivaceus)鳃丝Na K ATPase的性质。结果表明 :褐牙鲆鳃丝Na K ATPase活力随着反应温度、pH的增加均呈现峰值变化 ,其最适反应温度为 3 0～ 3 5℃ ,高于 40℃酶活力急剧下降 ,至 5 0℃酶失活 ,而最适pH为 7.5～ 8.0之间 ,pH <7.5或 >8.0时酶活力急剧下降 ,低于 6.0酶活则被完全抑制 ;在本试验设计的反应时间和底物浓度范围内 ,随着时间和底物浓度的增大 ,酶活力的变化均为逐渐升高 ,且上升趋势逐渐变缓 ;反应介质中Na ,K ,Mg2 的最适浓度分别为 180 ,3 0 ,6mmol/L ,并且当K 或Mg2 浓度为 0时 ,酶活力均接近于 0。抑制剂乌本苷对鳃丝Na K ATPase活力表现为显著性抑制 ,在乌本苷浓度为 2mmol/L时 ,酶活力完全被抑制。