暗纹东方鲀线粒体COI及其侧翼tRNA基因的克隆与序列分析

以暗纹东方鲀(Takifugu fasciatus)肝脏的线粒体DNA为模板,按照红鳍东方鲀线粒体DNA序列设计合成特异引物进行PCR扩增,克隆并测定了线粒体细胞色素氧化酶I亚基（COI）及其侧翼tRNA基因的全序列,结果显示,克隆了暗纹东方鲀COI基因1546bp及其5′端上游的tRNATyr基因和3′端下游的tRNASer基因序列共1766bp。用DNA分析软件对暗纹东方鲀与GenBank中10个目13种鱼类的COI序列进行比较分析,显示暗纹东方鲀与这些鱼类的COI基因具有较高的同源性,与同属红鳍东方鲀的同源性最高为97.6%,与同目不同科的矛尾翻车鲀和翻车鲀的同源性为76.5%和75.4%。根据暗纹东方鲀与其他13种鱼的COI基因序列同源性所建立的进化树,与传统的分类地位基本吻合。推定的这二种tRNA的二级结构都具有典型的三叶草型结构。     

菊黄东方鲀、暗纹东方鲀及其杂交F1代肌肉营养成分的比较分析

为了了解菊黄东方鲀(Takifugu flavidus)、暗纹东方鲀(T.obscurus)及其杂交F1代的肌肉营养特征,利用生物化学方法,从每类实验样本中取9尾对其肌肉中的粗蛋白、粗脂肪、水分、粗灰分和氨基酸成分进行了测定和分析。结果显示:(1)杂交F1代在生长方面具有明显的杂交优势,与亲本之间存在着显著差异(P0.05),杂交F1代的体重为其亲本的1.48~1.77倍;(2)杂交F1代肌肉水分含量与其母本含量相近,但粗脂肪含量均较亲本少(P0.05),粗蛋白含量则与亲本差异不显著(P0.05);(3)除色氨酸和胱氨酸外,16种氨基酸均在肌肉样本中被检测到,除甲硫氨酸外,其余15种氨基酸间含量均存在着显著性差异(P0.05)。菊黄东方鲀(♀)×暗纹东方鲀(♂)杂交F1代的总氨基酸含量最高,而暗纹东方鲀(♀)×菊黄东方鲀(♂)F1代总氨基酸含量则介于两亲本之间。对其必需氨基酸总量进行分析发现,菊黄东方鲀与其正反杂交F1代之间均存在显著性差异(P0.05),而暗纹东方鲀与其正反杂交F1代之间差异不显著(P0.05);(4)肌肉营养品质评价结果表明,菊黄东方鲀(♀)×暗纹东方鲀(♂)杂交F1代的鲜味氨基酸含量为26.68%,明显高于双亲样本(菊黄东方鲀22.28%、暗纹东方鲀25.20%),而暗纹东方鲀(♀)×菊黄东方鲀(♂)F1代的鲜味氨基酸总量(23.30%)较其父本偏高,但低于其母本。研究结果表明,杂交东方鲀的肌肉营养综合了双亲的优良特性,特别是是菊黄东方鲀(♀)×暗纹东方鲀(♂)杂交F1代,拥有最高的鲜味氨基酸含量,具有推广价值。     

野生和人工养殖的暗纹东方鲀毒性的比较

长江的鲀形目鱼类资源主要有两种,暗纹东方(Fugu obscurus Abe)和弓斑东方Fugu ocellatus(Linnaeus.研究结果表明 :与野生的弓斑东方鲀相比较,野生的暗纹东方鲀的毒性比较低。现在已有人工养殖的暗纹东方鲀,那么它们的毒性是否也像红鳍东方鲀一样,经过人工养殖后毒性有所下降,甚至变为无毒,因此食用更加安全了呢 ?为此,作者进行了研究。       

暗纹东方鲀线粒体基因组核苷酸全序列测定与分析

以暗纹东方鲀(Takifugu fasciatus)肝的线粒体DNA为模板,参照红鳍东方鲀(T.rubripes)等近源鱼类的线粒体基因组DNA序列,设计合成14对特异引物,进行PCR扩增并测序,首次获得了暗纹东方鲀线粒体基因组全序列。结果表明,暗纹东方鲀线粒体基因组序列全长16 444 bp(GenBank登录号为GQ409967),A+T含量为55.8%,其mtDNA结构与其他脊椎动物相似,由22个tRNA基因、2个rRNA基因、13个蛋白质编码基因和1段819 bp非编码的控制区(D-loop)所组成。蛋白质基因除COⅠ和ND6的起始密码子为GTG、CCT以外,均为典型的起始密码子ATG。ND1、ATPase8、COⅢ、ND4L、ND5、Cyt b使用典型的终止密码子TAA,其他的使用不完全终止密码子。除ND6和tRNAGln、tRNAAla、tRNAAsn、tRNACys、tRNATyr、tRNASer、tRNAGlu、tRNAPro在L-链上编码之外,其余基因均在H-链编码。基因排列顺序与已测定的鲀类一致,这显示了鲀类线粒体基因排列顺序上的保守性。tRNA基因核苷酸长度为64～73nt,预测了22个tRNA基因的二级结构,均呈较为典型的三叶草状。基于19种鲀类mtDNA全序列构建的进化树表明,暗纹东方鲀与红鳍东方鲀、中华东方鲀(T.chinensis)聚成一个姊妹群。结果还支持东方鲀属鱼类为一单系类群。     

薄层色谱和高效液相色谱联用测定暗纹东方鲀肌肉中肌肽和谷胱甘肽的含量

通过薄层色谱(TLC)与高效液相色谱(HPLC)联用技术鉴定了暗纹东方鲀(Takifugu obscurus)肌肉中存在肌肽和谷胱甘肽,同时利用高效液相色谱法测定了肌肽和谷胱甘肽(GSH)的含量。薄层层析采用的展开剂为正丁醇:乙酸:水(4∶2∶1),层析板为硅胶板。高效液相色谱利用Kromasil C18反相柱分析,流动相为10%的纯乙腈和90%含有0.05%三氟乙酸的超纯水。结果表明:通过薄层色谱和高效液相色谱鉴定了暗纹东方鲀肌肉中肌肽和谷胱甘肽,其中暗纹东方鲀肌肉中肌肽含量约213μg/g(鲜重),还原性谷胱甘肽含量约211μg/g(鲜重)。本法样品无需衍生,操作简便,适合于暗纹东方鲀肌肉中肌肽和谷胱甘肽的测定。本文为生物体内肌肽和谷胱甘肽的研究提供借鉴意义。     

暗纹东方鲀应激胀气行为功能形态学观察

该文以四齿鲀科(Tetraodontidae)的暗纹东方鲀(Takifugu obscurus)为对象,采用形态学解剖、X光透视和骨骼神经染色等方法,对其胀气行为的功能形态学进行研究。其结果发现,暗纹东方鲀腹部受到刺激后,口腔小幅高频将水或空气吞咽进入由食道腹壁特化成的气囊里,气囊与消化道的前后结合处由括约肌控制,腹壁肌呈束状,与此同时,高弹性的皮肤、脊柱和神经都会发生相应的位移变化,以保证胀气行为的快速完成。通过对暗纹东方鲀胀气行为及其吸、排水机制的深入了解,为进一步研究胀气行为的神经机理奠定基础,也将会丰富动物警戒逃避行为的理论。     

暗纹东方鲀年龄鉴定的研究

用耳石、脊椎骨、鳃盖骨等识别和鉴定暗纹东方鲀(Takifugu obscurusAbe)的年龄,在描述其轮纹特征基础上,比较其在判读暗纹东方鲀年龄和生长特征上的异同与准确性。结果表明,耳石磨片上的轮纹特征明显、清晰且规律性强,是最好的年龄鉴定材料;脊椎骨轮纹也很清晰,但测量时有一定难度,也是较好的年龄鉴定材料;鳃盖骨上年轮较难判定,只能作为辅助材料。本文还对牙齿能否作为年龄鉴定材料进行了观测。       

暗纹东方鲀侧线系统早期形态和生长发育

通过光镜和扫描电镜对暗纹东方鲀(Takifugu obscurus)的侧线系统进行形态学及组织学的研究。研究结果首次揭示了暗纹东方鲀侧线系统除了主侧线外还包括辅助侧线和辅助神经丘。主侧线分布主要包括眶上线、眶下线、耳后侧线、下颌线、前鳃盖线、上颞线、背侧线、腹侧线。辅助侧线和辅助神经丘分布主要包括口部辅助侧线、眶下辅助侧线、下颌前辅助侧线、下颌后辅助侧线、眶上后辅助侧线、上颞腹辅助神经丘、上颞背辅助神经丘、前鳃盖后辅助神经丘、背部辅助神经丘、尾部辅助神经丘。暗纹东方鲀侧线器官为接受机械刺激的神经丘,数目上千,神经丘分布在体表的凹槽里,且位于高低不同突起顶端。神经丘由套细胞、支持细胞和感觉毛细胞组成。感觉毛细胞呈圆形排列,并且每个细胞的游离面均有一根动纤毛和几十根静纤毛。据本研究对暗纹东方鲀侧线分布特征和神经丘的生长特征等的观察结果,认为尽管暗纹东方鲀侧线系统没有如其他真骨鱼类的管道系统,但是依然具有两套不同生理机能的机械感受系统,符合"七管模式"的主侧线神经丘与管道神经丘同源,而辅助侧线和辅助神经丘才是真正的表面神经丘。     

暗纹东方鲀耐寒相关基因CIRBP、HMGB1和AFP-Ⅳ的分子特征和对低温胁迫的响应

为了探索暗纹东方鲀(Takifugu obscurus)对低温环境的响应机制,克隆了暗纹东方鲀耐寒相关基因CIRBP、HMGB1和AFP-Ⅳ的cDNA序列,并进行了基因的分子特征和功能分析。组织分布检测显示CIRBP和HMGB1在下丘脑、肝脏和肌肉中具有高表达,而AFP-Ⅳ则主要在肝脏中表达。在受到低温胁迫后, 3种基因在肝脏和下丘脑中的表达呈现不同的变化趋势,其中CIRBP基因在肝脏中于48h表达量显著增加,在下丘脑中于12h和48h有上调表达; HMGB1基因在肝脏中呈现逐渐上升的趋势,于48h达到最大值,而在下丘脑中呈现先上升后下降的趋势,处理后2h达到最大, 2—8h下降,于8h下降至最低,随后恢复至初始水平;肝脏中的AFP-Ⅳ在0—24h无显著变化,在48h上升至最大值。进一步通过大肠杆菌原核表达系统研究了AFP-Ⅳ的抗冻功能,发现AFP-Ⅳ融合蛋白在–80℃下具有抗冻活性,并且抗冻活性随着浓度的增加而提高。研究结果表明3种基因都参与了暗纹东方鲀对低温胁迫的应答过程,为深入探索暗纹东方鲀的耐低温机制奠定了基础。     

聚乙二醇-4000对暗纹东方鲀肠上皮电生理的影响

以暗纹东方鲀(Takifugu obscurus)为研究对象,采用Ussing chamber技术研究了聚乙二醇-4000(PEG-4000)对肠上皮开路电压、短路电流(Isc)、短路电流变化("Isc)、电导(G)、跨膜电位(TEP)的影响。结果表明:PEG-4000在肠道中6 h残留浓度为1.83 g·L-1,显著高于其在水中浓度(P0.05),残留率达184%; PEG处理组暗纹东方鲀离体肠上皮Isc为69.20μA·cm~(-2),显著低于对照组(P0.05);ΔIsc显著低于对照组(P0.05),仅为对照组的68.57%; PEG处理组暗纹东方鲀离体肠上皮电导为24.97 m S·cm~(-2),显著低于对照组(36.22 m S·cm~(-2))(P0.05); PEG-4000在暗纹东方鲀肠道中极易残留、不易渗透,使得肠道上皮的转运蛋白或者离子通道受阻,从而显著影响肠上皮Isc、"Isc以及电导,降低了离子的主动流动量。本研究结果为鱼类肠道电生理平台的构建提供了技术参数,该平台不仅能用于评估PEG等污染物对鱼类肠道的影响,还能用于鱼类肠道上皮细胞离子转运机制的研究。     

Schooling Increases Risk Exposure for Fish Navigating Past Artificial Barriers

Artificial barriers have become ubiquitous features in freshwater ecosystems and they can significantly impact a region''s biodiversity. Assessing the risk faced by fish forced to navigate their way around artificial barriers is largely based on assays of individual swimming behavior. However, social interactions can significantly influence fish movement patterns and alter their risk exposure. Using an experimental flume, we assessed the effects of social interactions on the amount of time required for juvenile palmetto bass (Morone chrysops × M. saxatilis) to navigate downstream past an artificial barrier. Fish were released either individually or in groups into the flume using flow conditions that approached the limit of their expected swimming stamina. We compared fish swimming behaviors under solitary and schooling conditions and measured risk as the time individuals spent exposed to the barrier. Solitary fish generally turned with the current and moved quickly downstream past the barrier, while fish in groups swam against the current and displayed a 23-fold increase in exposure time. Solitary individuals also showed greater signs of skittish behavior than those released in groups, which was reflected by larger changes in their accelerations and turning profiles. While groups displayed fission-fusion dynamics, inter-individual positions were highly structured and remained steady over time. These spatial patterns align with theoretical positions necessary to reduce swimming exertion through either wake capturing or velocity sheltering, but diverge from any potential gains from channeling effects between adjacent neighbors. We conclude that isolated performance trials and projections based on individual behaviors can lead to erroneous predictions of risk exposure along engineered structures. Our results also suggest that risk perception and behavior may be more important than a fish''s swimming stamina in artificially modified systems.     

Aspects of reproduction in ruffed lemurs (Lemur variegatus).

Results of breeding of ruffed lemurs (Lemur variegatus) at the Duke Primate Facility provide information concerning estrous cycle, sexual behavior, age of first conception, gestation period, parturition, litter size. L. variegatus differs from other Lemur species in these respects.     

鲢幼鱼通过水流速度障碍的模拟

鱼类能否通过水流速度障碍直接影响过鱼设施的过鱼效果。利用计算机技术,综合水力因素、鱼类行为、地理特征及环境因子,展开鱼类通过水流速度障碍的模拟,有助于过鱼设施的优化设计。以国外涵洞式鱼道模拟软件Fish Xing为切入点,结合主要模块和关键因子,对我国特有鱼类鲢幼鱼进行模拟,得到鲢通过不同水流速度障碍的成功率;对比鲢在物理模型中的游泳表现,从模型主要模块和影响鱼类游泳表现的关键因子角度,分析影响鱼类通过水流速度障碍模拟的因素。结果表明,Fish Xing软件不能精确模拟鲢通过水流速度障碍的表现。分析表明,该软件在地理要素、管道特征和水力信息等参数方面具备独特的优势,但对我国鱼类有一定局限性,主要体现在鱼类的生物学信息如鱼类游泳特征等方面存在不足;进行鱼过障碍的模拟需要深入研究目标鱼类的生理特征、游泳能力及其与水力环境因子的响应关系。     

DIFFERENTIAL SURVIVAL OF SEXUAL AND ASEXUAL POECILIOPSIS DURING ENVIRONMENTAL STRESS

According to the Frozen Niche-Variation model, coexisting clones of an asexual species can freeze and faithfully replicate ecologically relevant genetic variability that segregates in the sexual ancestors. The present experiments with fish of the genus Poeciliopsis provide further evidence in support of this model. Sexual and clonal forms of Poeciliopsis live in the desert streams of Sonora, Mexico, and are exposed to environmental extremes ranging from flash floods to hot, desiccating, residual pools. We examined coexisting members of the monacha complex to see whether the fish types differed with respect to survival during stress and swimming endurance in an artificial flume. The two coexisting clones of the triploid gynogenetic fish P. 2 monacha–lucida differed dramatically: clone MML/II had the best survival during heat and cold stress and the worst survival during hypoxic stress, whereas clone MML/I had the best survival during hypoxic stress and the worst during heat stress. Poeciliopsis monacha, the sexual species with which these clones coexist, had intermediate survival during heat and hypoxic stress and very poor swimming endurance in the flume. The physiological differences seen in this study are consistent with the Frozen Niche-Variation model and provide some insights into environmental factors that affect the distribution and abundance of these fish.     

中华鲟人工繁殖放流现状评价

1984-1998年,在长江葛洲坝水利枢纽下游江段,中国集团公司中华鲟研究所共捕捞663尾中华鲟亲鱼用于人工繁殖。各年的捕捞量变动在31—60尾之间。实际用于人工催产的亲鱼年利用率变动在3.1—91.7％之间。平均28.4％。催产卵的年受精率变动在0—85.0％之间,平均66.5％。年人工孵化鲟苗量变动在5—151.9万尾之间,平均54.3万尾。历年合计向长江放流初孵鲟苗4258万尾、幼鲟6.28万尾。经过多年的实践,中华鲟的人工催产,幼鲟孵化、培育和放流等方面的技术已经发展成熟。     

Diurnal changes of behavior and respiration of Yangtze finless porpoises (Neophocaena phocaenoides asiaeorientalis) in captivity

A preliminary study was carried out to investigate diurnal changes of behavior of three, one adult male, one adult female, and one juvenile female, Yangtze finless porpoises (Neophocaena phocaenoides asiaeorientalis) in captivity. The respiration and behavior of the porpoises were recorded for 222 hr across 42 days. Behavioral data were recorded for eight general categories: aerial display and fast swimming, begging for fish, playing, nonsexual socializing, sexual behavior, resting, rubbing, and miscellaneous (i.e., other behaviors not included in the above categories). Each behavioral category was scored using one‐zero sampling with 10‐min intervals. The adult male showed shorter mean respiratory intervals at night (19:00–7:00 h), whereas the mean respiratory intervals of the females were shorter during the day (7:00–19:00 h). Begging for fish of all individuals, playing of the juvenile female, nonsexual socializing, and miscellaneous behavior of the adult female and resting of the male were observed more easily in the day, and aerial display and fast swimming of the adults and resting of the females were observed more easily at night. No significant diurnal difference was found, however, in the remaining categories of each individual. Each of the three porpoises therefore showed a distinct diurnal pattern, but none was obviously more active in the daytime than during the nighttime. Results suggest that daytime‐only feeding schedules may be insufficient to meet the energetic needs of marine mammals that show a 24‐hr activity cycle, and that nighttime feeding may be a worthwhile addition to husbandry routines. Zoo Biol 0:1–11, 2005. © 2005 Wiley‐Liss, Inc.     

Assessing the ecological relevance of swimming performance traits: a case study of bluegill sunfish (<Emphasis Type="Italic">Lepomis macrochirus</Emphasis>)

A variety of fish species show habitat-related variation in traits associated with swimming performance and foraging behavior. This commonly manifests as a distinction between open water and shallow water littoral ecotypes. In bluegill sunfish (Lepomis macrochirus), open water fish exhibit greater energy economy and speed during sustained locomotion than those from the littoral, whereas littoral fish were more maneuverable than their open water counterparts. These distinctions are associated with variation in diet and foraging behavior and may represent a resource polyphenism that enhances fitness through more effective exploitation of particular habitat types. A lack of field data means that polyphenisms have not been placed in context with swimming behavior in the field. We have used 3D videography to quantify bluegill field swimming performance in open water and littoral habitats. This revealed patterns of performance variation that parallel the trait variation previously established in the laboratory. Open water fish utilized faster average swimming speeds than inshore fish, while indicators of nonlinearity and unsteadiness were greater in the littoral fish. There are, however, differences in propulsive behavior between the field and laboratory. Pectoral-fin-powered, median-paired fin swimming is rarely employed by open water fish. Field body-caudal fin swimming involves short sequences of propulsive tail beats interspersed with gliding, rather than the repeated propulsive cycles employed under steady-state conditions. This suggests a need to re-evaluate the applicability of steady-state performance traits to behavior and fitness in the field and highlights the general importance of obtaining field performance data.     

Use of a self-propelled,fish-shaped,computer model to study the effects of shape and tail-beat frequency on torque and velocity in salmon-shaped fish

The relationship between fish shape, swimming ability and energy consumption during swimming in fish is complex and not well understood. In this paper, we show how a self-propelled 3-D fish model can be used to examine the effect of controlled changes in some shape parameters. Parameters of the model fish are modified and the resulting fish activated for short swimming episodes during which swimming velocity, torque and energy expenditure are calculated in the computer environment. The effect of shape was determined for two different fish shapes swimming at three different tail-beat frequencies (1.43, 0.94 and 0.64?Hz). The simulation results indicate that fish model one (based on a salmon) has stronger swimming ability than fish model two (a modified salmon fish shape) even though energy expenditure of fish shape two is greater than that of fish shape one. In the same fish types, the fish-swimming velocity and energy expenditure are proportional to tail-beat frequency. This model has the potential to be useful, particularly for predicting fish behavior in fish swim ways and the tail-water of energy turbines.     

鱼类通过鱼道内水流速度障碍能力的评估方法

鱼类通过鱼道内水流速度障碍能力的量化对鱼道设计有重要理论和实际价值,其基础是鱼类游泳能力的测定.首先对鱼类游泳能力的研究方法进行了概述总结,指出了鱼类游泳能力经典测试方法存在测定流场与自然情况相差较大的不足;分析了关键要素如鱼类行为特征、生理耗能规律及水力特性对鱼类通过水流速度障碍能力的影响;提出了分析鱼类游泳行为和能力与特征流场的关系,探讨鱼类通过水流障碍行为规律和生理疲劳恢复特征,通过研究仿自然流态下的鱼类自由游泳行为、水力计算及生理耗能的关系,构建多因素鱼类游泳能力关系式,定量评价鱼类通过鱼道内水流速度障碍的发展方向.     

基于视频跟踪的竖缝式鱼道内鱼类运动行为分析

竖缝式鱼道过鱼对象运动行为与鱼道池室内水力条件是否相适应是进行鱼道设计的关键。研究通过视频跟踪法对竖缝式鱼道中目标鱼的运动轨迹进行实时跟踪, 获取鱼的运动加速度、运动速度, 并和人工手动跟踪的鱼类运动轨迹进行对比, 证明基于视频跟踪法的鱼类运动分析程序既能较好的应用于竖缝式鱼道中, 获取鱼类运动行为, 又可减少大量的人工操作, 有助于为竖缝式鱼道设计提供重要基础数据。