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1.
Schizopygopsis younghusbandi is an endemic fish of Tibet characterized by slow growth. Artificial stock enhancement was applied to rebuild the natural population of S. younghusbandi in recent years. However, the optimal growth temperature and thermal tolerance of S. younghusbandi has not been studied, which restricts the production of S. younghusbandi fingerling for stock enhancement. The purpose of this paper is to determine the growth, critical thermal maximum (CTMax), lethal thermal maximum (LTMax) and acclimation response ratio (ARR) of S. younghusbandi juveniles (body weight 5.7 ± 1.2 g) at three acclimation temperature levels (10, 15, 20°C). The results showed that acclimation temperature significantly affected the growth, CTMax, LTMax and ARR of the experimental fish. Largest final weight (7.5 ± 2.3 g) was recorded in 15°C group. At a heating rate of 1°C/30 min, CTMax ranged from 30.98 to 32.01°C and LTMax ranged from 31.76 to 32.31°C in the three acclimation temperatures. Schizopygopsis younghusbandi had lower ARR value (0.097) than most other fish species. Low ARR value indicates that S. younghusbandi may have narrower thermal tolerance range and weaker acclimation ability to global warming. For successful aquaculture of S. younghusbandi juveniles, temperature should be maintained around 15°C.  相似文献   
2.
嘉陵裸裂尻鱼为青藏高原特有鱼类,近年来随自然地理气候的变迁和人类活动的影响,种群数量急剧减少。为了解嘉陵裸裂尻鱼的遗传背景以便更好的保护其遗传资源,本研究采用线粒体控制区部分序列变异,分析了嘉陵裸裂尻鱼6个地理种群的遗传结构和分布动态。在147尾个体中共发现17个变异位点,定义了14种单倍型,群体总的单倍型多样性较高为0.810,核苷酸多样性低为0.00698。AMOVA分析显示,44.29%的分子差异源于群体间,55.71%的分子差异源于群体内,群体间遗传分化极显著。Fst值统计检验表明,除宕昌群体和舟曲群体之间差异不显著外,其余两两群体之间Fst值统计检验均显著。基因流估计显示各群体间的基因流水平较高,遗传交流较频繁。Mantel test检验表明,嘉陵裸裂尻鱼种群之间遗传分化程度与地理距离存在显著相关。系统树和单倍型网络进化图显示,6个地理群体的单倍型按照嘉陵江水系和渭河水系形成两个大的类群。错配分布和中性检验表明嘉陵裸裂尻鱼群体在近期历史上群体大小保持稳定,未出现显著的种群扩张。根据本文所揭示的嘉陵裸裂尻鱼种群遗传结构特征,建议将分布在嘉陵江水系的嘉陵裸裂尻鱼作为一个整体进行保护,嘉陵裸裂尻鱼渭河种群属高度分化的单倍型类群,且遗传多样性极低,需对该种群进行优先保护。  相似文献   
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4.
1. Complete sequences of 1140 base pair of the cytochrome b gene from 133 specimens were obtained from nine localities including the inflow drainage system, isolated lakes and outflow drainage system in Qinghai–Tibetan Plateau to assess genetic diversity and to infer population histories of the freshwater fish Schizopygopsis pylzovi. 2. Nucleotide diversities (π) were moderate (0.0024–0.0045) in populations from the outflow drainage system and Tuosuo Lake, but low (0.0018–0.0021) in populations from Qiadam Basin. It is probable that the low intra‐population variability is related with the paleoenvironmental fluctuation in Qiadam Basin, suggesting that the populations from Qiadam Basin have experienced severe bottleneck events in history. 3. Phylogenetic tree topologies indicate that the individuals from different populations did not form reciprocal monophyly, but the populations from the adjacent drainages cluster geographically. Most population pairwise FST tests were significant, with non‐significant pairwise tests between Tuosu Lake and Tuosuo Lake in the north‐west of the Qinghai–Tibetan Plateau. Analysis of molecular variance (amova ) indicates that the significant genetic variation was explained at the levels of catchments within and among, not among specific boundaries or inflow and outflow drainage systems. 4. The nested clade phylogeographical analysis indicates that historical processes are very important in the observed geographical structuring of S. pylzovi, and the contemporary population structure and differentiation of S. pylzovi may be consistent with the historical tectonic events occurred in the course of uplifts of the Qinghai–Tibetan Plateau. Fluctuations of the ecogeographical environment and major hydrographic formation might have promoted contiguous range expansion of freshwater fish populations, whereas the geological barriers among drainages have resulted in the fragmentation of population and restricted the gene flow among populations. 5. The significantly large negative Fs‐value (−24.91, P < 0.01) of Fu's Fs‐test and the unimodal mismatch distribution indicate that the species S. pylzovi underwent a sudden population expansion after the historical tectonic event of the Gonghe Movement. 6. The results of this study indicate that each population from the Qinghai–Tibetan Plateau should be managed and conserved separately and that efforts should be directed towards preserving the genetic integrity of each group.  相似文献   
5.
高原裸裂尻鱼头部轮廓形状及其变异的几何形态测量分析   总被引:3,自引:0,他引:3  
为了明确描述高原裸裂尻鱼的表型多样性,运用现代几何形态测量法,基于高原裸裂尻鱼头部轮廓的形态坐标数据,对其5个地理种群的样本做了定量分析。结果主要如下:①主成分分析(PCA)和典型变量分析(CVA)显示,5个地理种群的样本的变异主要位于口型特征、下吻部形状、下颌骨形状、下颌锐利角质程度和头部形状等性状。②基于主成分分析、典型变量分析和聚类分析,高原裸裂尻鱼三个亚种(班公湖亚种、玛法木湖亚种和指名亚种)相互分开,在PC1轴上从负值到正值依次排列,从而确定了高原裸裂尻鱼亚种划分的有效性。③通过形态差异的显著性检验,基于马氏距离和普氏距离分析了高原裸裂尻鱼各地理种群之间的形态变异距离,根据差异显著性将该5个地理种群的高原裸裂尻鱼分为湖泊型亚种和河流型亚种,随后的聚类分析同样支持该结果。总之,通过几何形态测量法,准确描述了高原裸裂尻鱼头部轮廓的形态多样性,按照外形的差异,将5个地理种群分为两种生态型,并推测该差异主要是由于所生活的水体环境和食物差异所造成。对高原裸裂尻鱼形态差异的识别和研究,能为其生态学研究和物种多样性保护提供相应指导,丰富微进化理论。  相似文献   
6.
长期以来,柴达木裸裂尻鱼(Schizopygopsis kessleri)的分类学地位存在争议。为此,测定了柴达木裸裂尻鱼格尔木河及托素湖种群24个个体及黄河裸裂尻鱼(S.pylzovi)黄河及大通北川河种群12个个体的Cytb基因全序列。通过遗传距离和系统发育分析,探讨了柴达木裸裂尻鱼的分类学地位。结果显示,柴达木裸裂尻鱼与黄河裸裂尻鱼在系统进化树上并未形成相应的单系群;柴达木裸裂尻鱼与黄河裸裂尻鱼种间平均遗传距离为0.54%,明显低于裂腹鱼亚科其他属鱼类的种间遗传距离及本属其他种间遗传距离,表明来自柴达木盆地格尔木河和托素湖的裸裂尻鱼与黄河裸裂尻鱼之间没有达到种级水平的显著分化。综合地质学资料和柴达木水系与黄河水系现今的隔离格局,建议将柴达木裸裂尻鱼作为黄河裸裂尻鱼的一个亚种,即S.pylzovi kessleri。  相似文献   
7.
目的克隆黄河裸裂尻鱼肥胖基因(obese gene,ob),分析编码蛋白leptin的序列特征,检测ob mR-NA的组织特异性表达和不同环境温度下肝胰脏和白肌ob mRNA的相对表达水平,为探究黄河裸裂尻鱼在青藏高原季节性寒冷环境下的生态适应机制提供科学数据。方法利用RT-PCT、5’-RACE和3’-RACE法获得ob基因全长cDNA序列。通过已知cDNA序列设计半定量RT-PCR和real-time PCR引物,进行表达研究。结果黄河裸裂尻鱼ob基因序列全长为1 337 bp,其中开放阅读框(ORF)长513 bp,编码170个氨基酸。黄河裸裂尻鱼ob mRNA在心脏、肾脏、脂肪、肠、精巢、肝胰脏、鳃、脑和肌肉9个被检组织中均有表达,其中在心脏中表达最强,肌肉组织中表达最弱。栖息水域环境温度下降,将显著抑制黄河裸裂尻鱼肝胰脏和白肌ob mRNA的表达。结论黄河裸裂尻鱼ob基因特殊的组织表达特征可能与其特定组织的能量代谢及其特殊的生物学功能有关。Leptin在黄河裸裂尻鱼能量代谢调节和季节性环境适应方面发挥着重要作用。  相似文献   
8.
采用RT-PCR技术克隆获得了黄河裸裂尻鱼(Schizopygopsis pylzovi)COⅠ、Ⅱ、Ⅲ基因的编码序列,并对此进行了初步分析。结果表明,黄河裸裂尻鱼COⅠ基因全长为1 551 bp,开放阅读框(ORF)由基因全长组成,编码516个氨基酸;COⅡ基因全长为691 bp,开放阅读框为690 bp,编码230个氨基酸;COⅢ基因全长为786 bp,其开放阅读框也是由基因全长组成,编码261个氨基酸。序列同源性分析显示,黄河裸裂尻鱼与其他9种鲤科鱼类3个亚基在基因和氨基酸序列上均有较高的同源性,虽然不同物种亚基基因间存在序列差异,但是所编码的氨基酸序列却趋于一致,揭示了鲤科鱼类细胞色素C氧化酶在线粒体呼吸链电子传递中的功能稳定性。黄河裸裂尻鱼与滇池金线鲃(Sinocyclocheilus grahami)在COⅠ和COⅡ亚基上均存在相同位置、相同种类和相同数量的功能位点,而且在基于COⅠ亚基基因和氨基酸序列、COⅡ及COⅢ亚基基因序列的系统发育树中聚在同一支上,表明两者具有较近的亲缘关系,该结论与裂腹鱼亚科鱼类起源于晚第三纪广泛分布于青藏地区的喜温性原始鲃类的观点相一致。  相似文献   
9.
As a subspecies of Schizopygopsis chengi (Fang), Schizopygopsis chengi baoxingensis (Fu, Ding et Ye) occurs as a single population endemic to the Baoxing River in China. The influences from the construction of hydropower dams in its distribution area might result in its extinction in the future due to its very narrow habitat and small population size. In this study, we sequenced the mitochondrial DNA control region of 81 individuals to analyze the genetic variability of the subspecies, hoping to acquire basic genetic information. The results revealed a limited genetic diversity of the population. Total samples could only be defined as seven haplotypes based on nucleotide variations. The nucleotide diversity (0.0008), haplotype diversity (0.534), and overall mean genetic distance among individuals (0.00080 ± 0.00053) were very low. Therefore, it is very necessary and urgent to conserve the population of this subspecies, avoiding further genetic loss, or even extinction. Handling editor: Christian Sturmbauer  相似文献   
10.
黄河裸裂尻鱼五种群mtDNA控制区的遗传结构   总被引:1,自引:0,他引:1  
黄河裸裂尻鱼(Schizopygopsis pylzovi)主要分布于青藏高原东北部兰州以上黄河干支流水系和高原北部柴达木内流水系,由于其对高原特殊生境表现出独特的适应性而受研究者关注。本文采用聚合酶链式反应(PCR)和直接测序的方法获得了一个分布于柴达木内流水系种群和四个黄河支流种群共99条个体的线粒体DNA(mtDNA)控制区(D-100p)821bp核苷酸的序列,探讨了其种群遗传结构和分化。99条个体的序列经比对后,发现77个(9.37%)多态性位点,共定义了53个单倍型,其中有一个单倍型(DT12)为两个种群(大通种群和互助种群)所共享,其余52个单倍型均为某个种群所特有。遗传多样性分析表明,柴达木种群的单倍型多样度(h=0.79&#177;0.06)和核苷酸多样度(π=0.0027&#177;0.0017)均略低于黄河支流各种群。AMOVA分析结果显示,遗传差异主要发生在种群之内,占75.39%,而小同水系的种群间只有24.61%,各种群间成对的Fst及遗传距离均表明种群间出现了一定程度的种群分化,但系统进化树最示出一种混杂的单倍型分布格局,提示青藏高原东北部地质事件所造成的水系间的隔离形成较晚。单倍型歧点分布呈现为单峰以及中性检验Tajima的D(-1.497,P=0.058)和Fu的Fs(-24.741,P=0.001)结果综合表明,黄河裸裂尻鱼在青藏高原隆升过程中曾经历过近期的种群扩张事件[动物学报54(6):972—980,2008]。  相似文献   
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