首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
描记纹胸Zhao属鱼类1新种,珠江纹胸ZhaoGlyptothorax zhujiangensis sp.nov.,采自广东新会市崖西镇白水带溪(属珠江水系)。新种与四斑纹胸ZhaoG.quadriocellatus较相近,但胸吸着器呈心形而不是楔形,腹鳍起点近吻端而不是近尾鳍基,头部无斑而不是在两眼后方各有1个黄色亮斑,尾鳍长大于而不是小于头长,鳃耙数、脊椎骨数较多,脂鳍基较短,与后者明显不同。  相似文献   

2.
截至1985年止,我国共记载被认为有效的纹胸(鱼兆)属鱼类18种(亚种)。通过对采自全国各地的4000余尾标本的整理,18种中仅14种真正有效。加上本文描述的2个新种,报道的3个新纪录,我国共有纹胸(鱼兆)属鱼类19种(亚种)。纹胸(鱼兆)属鱼类的皮肤表面突起分化明显,该性状在种内稳定,可以分为6种类型。某些骨骼的分化,如复合椎体、髓棘、胸带、背骨等,也很有分类价值。本文以皮肤突起类型及骨骼特征为主,辅以一些稳定可靠的体色型、腹鳍的相对位置等,对19种做了分类检索表。  相似文献   

3.
中国鮡属鱼类二新种记述(鲇形目:鮡科)   总被引:1,自引:0,他引:1  
本文报道在四川西部收集的鮡科鱼类标本中,发现有鮡属(Pareuchiloglanis)的壮体鮡,新种P.robusta sp.nov.和四川鮡,新种P.sichuanensis sp.nov.,对二新种的形态特征作了详细描述,并与相近种的主要性状列表进行比较。  相似文献   

4.
中华鮡与前臀鮡的形态差异和物种有效性   总被引:7,自引:2,他引:5  
采用主成分分析方法研究中华与前臀物种的有效性问题,并利用主成分分析结果中起主要作用的性状作差异性的统计分析,为分类性状的相关性提供了数学依据。结果表明:1)中华与前臀的主要鉴别特征在于前者之臀鳍起点至尾鳍基的距离小于至腹鳍起点的距离,后者反之;2)前者尾柄高大于前鼻孔至眼前缘距离后者反之;3)前者脂鳍基末端至尾鳍背侧起点的距离小于尾柄高,后者反之。据主成分分析及显著性t值检验结果。笔者观点与原文献作者观点完全一致,中华与前臀应是两个不同独立种。两物种形态上的差异主要表现在与游泳等行为有关的性状特征上,而且也是对不同小生境长期适应的结果。  相似文献   

5.
本文报道采自云南省的黑属鱼类一新种,长丝黑Gagatadolichonemasp.nov,本种与G.gagata(Hamilton)近似。模式标本保存于中国科学院水生生物研究所淡水鱼类博物馆。  相似文献   

6.
Jin J  Liu MD  Yin SY  Wang DQ  Liu SP  Chen DQ 《遗传》2011,33(3):255-261
老挝纹胸鮡是分布于澜沧江流域的一种特有鱼类,喜激流底栖生活。为了解其各地理种群间的遗传结构与遗传变异,文章分析了129尾采自澜沧江8条支流水系的老挝纹胸鮡mtDNA细胞色素b基因1 138 bp的序列变异,共发现16个多态性位点,定义了15个单倍型。澜沧江老挝纹胸鮡遗传变异较低,平均单倍型多样性指数和核苷酸多样性指数分别是h=0.299,π=0.299,有3个种群甚至没有变异,分子变异方差分析结果表明各种群内变异大于各种群间变异,种群间没有差异。对老挝纹胸鮡所有种群进行的单倍型错配分布呈现单峰型,中性检验结果均为负值(Tajima’s D=?2.36965,P<0.02;Fu’s Fs=?20.975,P<0.05)表明,澜沧江老挝纹胸鮡自然种群可能经历过近期的种群扩张事件。  相似文献   

7.
系统整理了中国刺鳅属鱼类Mastacembelus,记述2新种,腹纹刺鳅M.strigiventus Zhouet Yang,sp.nov.和三叶刺鳅M.triolobus Zhouet Yang,sp.nov.及中国1新纪录种,云斑刺鳅M.oatesii(Boulenger)。新种模式标本分别保存于中国科学院昆明动物研究所(KIZ)鱼类标本库和西南林业大学(SWFC)。腹纹刺鳅与三叶刺鳅、大刺鳅的区别在于:背鳍、臀鳍与尾鳍基部大部愈合,但具缺刻相区分;体侧前部具4~5条褐色纵条纹,最下1条常断续,全部纵纹至肛门前方渐成网格交叉或断续;腹面亦具1条明显褐色纵纹,有时分歧形成小网格。三叶刺鳅区别于腹纹刺鳅及大刺鳅的主要特征包括:背鳍条、臀鳍条和尾鳍条数目均少;背鳍、臀鳍与尾鳍仅在基部相连,在端部分开,能明显区分;除背部的黑色大斑块外,体无六角状环纹或锯齿状纹,腹面亦无斑纹;头长为头宽3.5倍以下,为吻长2.8倍以下。云斑刺鳅以下面组合特征区别于三叶刺鳅和腹纹刺鳅:背鳍条,臀鳍条数目均少,尾鳍条数目相对较多;背鳍、臀鳍与尾鳍仅基部愈合;体侧具云状斑,背部具14~15个褐色斑块,腹面无纵纹或网眼斑;头长为头宽4.0倍以上,为吻长3.0倍以上。  相似文献   

8.
丁锦华 《昆虫学报》1985,(4):430-434
在我国云南、广东两省采集的同翅目、飞虱科Delphacidae标本中,经鉴定发现分隶于三个属的三个新种,现描述如下。 新种模式标本存放在南京农业大学植保系。 1.元江扁角飞虱 Perkinsiella yuanjiangensis 新种(图1—7) 头顶黄褐色,基宽为中长的1.3倍;额褐色,其间夹杂数对淡色小圆斑,中长为中部最宽处宽的1.6倍;颊黄褐,中域具“人”字形暗褐纹,端角两边沿脊亦具暗褐条纹;触角第一节背面和腹面近端缘及第二节基部黑褐,其余部分暗褐色;前、中胸背板中部污黄,侧区在  相似文献   

9.
怒江扎那纹胸鮡的遗传多样性和遗传分化   总被引:2,自引:1,他引:1  
怒江水电开发将对扎那纹胸鮡产生不利的影响。为了解扎那纹胸鮡遗传多样性和遗传分化情况,文章测定了采自怒江中下游怒江州地区的贡山、古登和泸水及保山市地区的道街、勐糯和木城6个扎那纹胸鮡群体共102个个体的线粒体Cyt b基因序列。结果显示,在1137bp序列中共检测到87个变异位点,定义了36个单元型。总样品的单元型多样性(h)和核苷酸多样性(π)分别为0.851±0.028和0.01356±0.0008。扎那纹胸鮡的遗传多样性相对较低,但怒江州种群遗传多样性显著高于保山市种群。群体间分化指数(FST)(0.475~0.846)明显高于群体内分化指数(0.002~0.108),且各群体间分化指数和地理距离呈线性正相关。利用AMOVA(Analysis of molecular variance)对遗传分化进行分割,群体间和群体内分别占53.65%和46.35%,群体间遗传分化指数(FST)为0.5365(P0.01),扎那纹胸鮡在怒江州和保山种群分化显著。单元型分子系统树和简约网络图显示,扎那纹胸鮡单元型聚为两个独立的支系:怒江州支系和保山市支系。这些鱼类至少代表一个管理单位,但也可能是一个进化显著单位。因此,建议保护扎那纹胸鮡种群,在水电工程建设时应充分考虑扎那纹胸鮡种群结构现状,避免不同区域的种群之间发生基因交流。  相似文献   

10.
记述采自中国内蒙古的直斑蝇属(双翅目,斑蝇科)1新种,并编制了中国直斑蝇属分种检索表。内蒙直斑蝇,新种Tetanops neimonggolica sp.nov.(图1~8)新种头部特征与T.myopina Fallén近似,但翅几乎完全透明,仅在翅基径室内有非常模糊的小斑;新种的翅特征与T.sintenisi Becker近似,但头黄色且额的大部分覆有灰色粉被。词源:新种以采集地命名。模式标本保存于中国科学院动物研究所。  相似文献   

11.
The goal of this article was to establish reference ranges of the concentration of trace elements in human serum and to compare these results with those reported by other authors. We describe the sample preparation and measurement conditions that allow the rapid, precise, and accurate determination of Al, As, B, Be, Cd, Co, Cu, Fe, Li, Mn, Mo, Ni, Rb, Se, Sr, and Zn in human serum samples (n=110) by inductively coupled plasma-mass spectrometry (ICP-MS). Accuracy and precision were determined by analyzing three reconstituted reference serum samples by comparison with other methods and by the standard addition procedure. The advantages of the ICP-MS method include short time of analysis of the elements mentioned, low detection limit, high precision, and high accuracy. Disadventages include a high risk of contamination due to the presence of some of the elements of interest in the environment, the relatively delicate sample handling, and the high cost of the equipment.  相似文献   

12.
Summary Concentration of N, P, K, Ca, Mg and S in summer groundnut crop was higher than in kharif while Zn, Fe, Mn and Cu contents were higher in summer crop. Kernel's N, P and Zn; Leaflet's Ca and Mn; Stem's K and Fe; Root's S and Cu and Petiole's Mg contents were highest. Shell's N, P, K, Mg, S, Zn and Cu; Kernel's Ca, Fe and Mn contents were the least. N, P, K, S, Zn and Cu concentrations decreased linearly as the crop grew. Ca, Mg, Fe and Mn concentrations did not display any distinct pattern. Ca concentration was positively correlated with pod yield in both the seasons.  相似文献   

13.
14.
The variation with age of the 18 trace element mass fractions and some histological characteristics of intact prostate glands of 50 subjects aged 0–30 years was investigated by instrumental neutron activation analysis, inductively coupled plasma atomic emission spectrometry, and a quantitative morphometric analysis. Mean values ± standard error of the mean (M ± SΕΜ) for the mass fractions (in milligrams per kilogram wet tissue) of these trace elements in pre-puberty were: Al 28.5 ± 9.0, B 0.40 ± 0.11, Ba 1.48 ± 0.44, Br 10.5 ± 1.5, Ca 241 ± 30, Cl 3,203 ± 278, Cu 3.51 ± 0.89, Fe 33.7 ± 4.1, K 2,364 ± 145, Li 0.020 ± 0.004, Mg 153 ± 23, Mn 0.46 ± 0.06, Na 2,286 ± 130, P 1,391 ± 100, S 1,698 ± 132, Si 62 ± 11, Sr 0.38 ± 0.08, and Zn 27.6 ± 2.3. During puberty and postpuberty, when there is a significant increase in circulating androgens, the mean values were: Al 7.2 ± 1.4, B 0.21 ± 0.05, Ba 0.25 ± 0.06, Br 5.8 ± 1.0, Ca 433 ± 81, Cl 2,314 ± 201, Cu 1.77 ± 0.13, Fe 20.9 ± 1.6, K 2,585 ± 118, Li 0.0088 ± 0.0014, Mg 232 ± 27, Mn 0.34 ± 0.04, Na 1,875 ± 107, P 1,403 ± 98, S 1,673 ± 73, Si 22.2 ± 3.1, Sr 0.22 ± 0.03, and Zn 93.3 ± 8.9. Mean values (M ± SΕΜ) of percent volumes (%) of the stroma, epithelium and lumen in the prostate before puberty were 73.4 ± 2.6, 20.4 ± 1.7, and 4.45 ± 0.94, respectively, versus 46.5 ± 2.5, 38.5 ± 1.9, and 14.9 ± 1.2 during puberty and postpuberty. This work’s results confirm that the Zn mass fraction in prostate tissue is an androgen-dependent parameter. For the first time it has been demonstrated that the glandular lumen is a main pool of Ca, Mg, and Zn accumulation and that the stroma is a main pool of Al, B, Ba, Br, Cl, Cu, Fe, Mn, Na, and Si accumulation in the normal human prostate, for the age range 0–30 years. It was concluded that the Ca, Mg, and Zn binds tightly within the prostatic fluid, because the volume of glandular lumen reflects the volume of prostatic fluid.  相似文献   

15.
This report attempts to formulate reference ranges of elemental concentrations for 15 trace elements in selected human tissues and body fluids. A set of samples consisting of whole blood, blood serum, urine, milk, liver, and hair were chosen and considered for 15 elements of biological significance: As, Cd, Co, Cr, Cu, F, Fe, I, Hg, Mn, Mo, Ni, Pb, Se, and Zn. The results represent wholly or partially data received from 40 countries of the global regions of Africa, Asia, Europe, North, South, and Central America, Australia, and New Zealand. This survey, even if qualitative, has been useful in demonstrating certain trends of trace-element scenarios around the world. It is of course recognized that both diet and environment exert a strong influence on the distribution pattern of several elements, such as As, Cd, Mn, Pb, Se, and Zn. A limited comparison of the available information on soil status of different countries reflected some interesting associations for elements, such as Mn and Zn. Importantly, this study revealed that only a few countries were in a position to identify a reasonable amount of data on samples requested for this project. Regretably, for a number of countries, any dependable data for even such essential elements as Cu, Fe, and Zn were not available. In view of the nutritional importance of many elements, the time is ripe for concerted efforts by intergovernmental agencies to initiate investigations or commission task forces/projects to generate reliable reference data for selected global regions, which sadly lack data of any kind at present.  相似文献   

16.
A new polynitro cage compound 2, 4, 6, 8, 10, 12, 13, 14, 15-nonanitro-2, 4, 6, 8, 10, 12, 13, 14, 15-nonaazaheptcyclo [5.5.1.1(3,11).1(5,9)] pentadecane (NNNAHP) was designed in the present work. Its molecular structure was optimized at the B3LYP/6-31 G(d,p) level of density functional theory (DFT) and crystal structure was predicted using the Compass and Dreiding force fields and refined by DFT GGA-RPBE method. The obtained crystal structure of NNNAHP belongs to the P-1 space group and the lattice parameters are a = 9.99 ?, b = 10.78 ?, c = 9.99 ?, α = 90.01°, β = 120.01°, γ = 90.00°, and Z = 2, respectively. Based on the optimized crystal structure, the band gap, density of state, thermodynamic properties, infrared spectrum, strain energy, detonation characteristics, and thermal stability were predicted. Calculation results show that NNNAHP has detonation properties close to those of CL-20 and is a high energy density compound with moderate stability.  相似文献   

17.
The effect of age and gender on major, minor, and trace element contents in the intact rib bone of 80 relatively healthy 15–55-year-old women and men was investigated. Contents or upper limit of contents of 16 chemical elements in the rib bone were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Mean values (M?±?SΕΜ) for the mass fraction of Ba, Ca, Cu, Fe, K, Li, Mg, Na, P, S, Sr, and Zn (milligram per kilogram of dry bone) were as follows: 2.54?±?0.16, 171,400?±?4,050, 1.35?±?0.22, 140?±?11, 1,874?±?71, 0.049?±?0.011, 2,139?±?38, 5,378?±?88, 75,140?±?1,660, 1,881?±?51, 291?±?20, and 92.8?±?1.5, respectively. The upper limits of contents of Al, B, Mn, and V were <7.20, <0.65, <0.36, and <0.03, respectively. Statistically significant tendency for the Ca, Mg, and P content to decrease with age was found in the human rib bone, regardless of gender. The mass fraction of Fe in the male rib bone increases with age. It was shown that higher Ca, Mg, Na, P, and Sr mass fractions as well as lower Fe content were typical of female ribs as compared to those in male ribs.  相似文献   

18.
《Ibis》1894,36(3):447-460
  相似文献   

19.
The unitary conductances and permeability sequences of the rat connexin40 (rCx40) gap junction channels to seven monovalent cations and anions were studied in rCx40-transfected neuroblastoma 2A (N2A) cell pairs using the dual whole cell recording technique. Chloride salt cation substitutions (115 mM principal salt) resulted in the following junctional maximal single channel current-voltage relationship slope conductances (γj in pS): CsCl (153), RbCl (148), KCl (142), NaCl (115), LiCl (86), TMACl (71), TEACl (63). Reversible block of the rCx40 channel was observed with TBA. Potassium anion salt γj are: Kglutamate (160), Kacetate (160), Kaspartate (158), KNO3 (157), KF (148), KCl (142), and KBr (132). Ion selectivity was verified by measuring reversal potentials for current in rCx40 gap junction channels with asymmetric salt solutions in the two electrodes and using the Goldman-Hodgkin-Katz equation to calculate relative permeabilities. The permeabilities relative to Li+ are: Cs+ (1.38), Rb+ (1.32), K+ (1.31), Na+ (1.16), TMA+ (0.53), TEA+ (0.45), TBA+ (0.03), Cl (0.19), glutamate (0.04), and NO3− (0.14), assuming that the monovalent anions permeate the channel by forming ion pairs with permeant monovalent cations within the pore thereby causing proportionate decreases in the channel conductance. This hypothesis can account for why the predicted increasing conductances with increasing ion mobilities in an essentially aqueous channel were not observed for anions in the rCx40 channel. The rCx40 effective channel radius is estimated to be 6.6 Å from a theoretical fit of the relationship of relative permeability and cation radius.  相似文献   

20.
We investigated the uptake of inorganic elements (Be, Na, Mg, K, Ca, Sc, Mn, Co, Zn, Se, Rb, Sr, Y, Zr, Ce, Pm, Gd, and Hf) and the effect of Ca on their uptake in carrots (Daucus carota cv. U.S. harumakigosun) by the radioactive multitracer technique. The experimental results suggested that Na, Mg, K, and Rb competed for the functional groups outside the cells in roots with Ca but not for the transporter-binding sites on the plasma membrrane of the root cortex cells. In contrast, Y, Ce, Pm, and Gd competed with Ca for the transporters on the plasma membrane. The selectivity, which was defined as the value obtained by dividing the concentration ratio of an elemental pair, K/Na, Rb/Na, Be/Sr, and Mg/Sr, in the presence of 0.2 and 2 ppm Ca by that of the corresponding elemental pair in the absence of Ca in the solution was estimated. The selectivity of K and Rb in roots was increased in the presence of Ca. The selectivity of Be in roots was not affected, whereas the selectivity of Mg was increased by Ca. These observations suggest that the presence of Ca in the uptake solution enhances the selectivity in the uptake of metabolically important elements against unwanted elements.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号