Institute of Hydrobiology, Chinese Academy Of Sciences
Not a member yet
20118 research outputs found
Sort by
Gene Flow and Individual Relatedness Suggest Population Spatial Connectivity of Sinogastromyzon sichangensis (Cypriniformes: Balitoridae) in the Chishui River, China
No full textSinogastromyzon sichangensis is a hillstream loach endemic to the upper Yangtze River, China. It is unclear whether this fish lives in a very restricted area or may be dispersed over a long distance. In the present study spatial connectivity of populations of S. sichangensis was investigated based on 343 individuals collected from 12 sites of Chishui River and employing 22 microsatellite loci. The results of genetic diversity analysis showed that observed heterozygosity (H-O) and polymorphism information content (PIC) ranged from 0.5653 to 0.6999 and 0.8513 to 0.8819, respectively. Population structure analysis suggested that S. sichangensis had an unclear genetic structure. AMOVA showed that 69.36% of genetic variation was attributed to differentiation within individuals and all the pairwise genetic differentiation indices (F-ST) were low (mean F-ST = 0.0344), indicating weak differentiation among these populations. Estimation of gene flow showed frequent flow among populations, and contemporary levels (mean contemporary migration rate, m(c) = 0.0131) were approximately equal to historical levels (mean historical migration rate, m(h) = 0.0147). Individual relatedness analysis revealed a high level of sibship within and among different populations. The frequent gene flow and widespread sibship were due to S. sichangensis laying drifting eggs which travel for a long distance until hatching, after which the juveniles or adults migrate upstream. The results of unclear geographic structure and frequent exchange also indicate that it is necessary to decrease the negative impacts of anthropogenic activities on the connectivity of rivers to protect the migration routes of S. sichangensis
Diversity and community composition of ichthyofauna at Konhaye Stream, district Dir Lower, Pakistan
No full textThis study was undertaken to investigate the diversity, abundance ratio, and distribution of the fish species and to record the water quality of Konhaye Stream, district Dir Lower, Pakistan. A total of 16 fish species were recorded, belonging to 4 orders (Cypriniformes, Channiformes, Siluriformes and Mastacebilformes), and 5 families including Cyprinidae (Schizopyge esocinus, Racoma labiata, Cyprinion watsoni, Cyprinus carpio, Barilius pakistanicus, B. vagra, B. modestus, Crossocheilus diplocheilus, Garra gotyla, Puntius ticto, and P. sophore), Channidae (Channa punctatus and Channa gachua), Nemacheilidae (Schistura macrolepis), Sisoidae (Glyptothorax punjabensis), and Mastacembelidae (Mastacembelus armatus). Different ichthyo-diversity indices [Simpson's biodiversity index (D=0.918), Simpson's reciprocal index (1/D=1.088), Simpson's evenness index (E-1/D=0.068), species richness (S), Shannon-Weiner's index (H'=3.775), Menhinick's index (D-mn=0.804), and Margalef's index (D-mg=2.510)] were calculated for the stream. The physicochemical parameters [temperature (23.125 +/- 3.514 degrees C), dissolved Oxygen (9.003 +/- 0.627 mg L-1), pH (7.333 +/- 0.201), turbidity (76.5 +/- 6.403 NTU), electric conductivity (201.68 +/- 11.31 mu s cm(-1)), free CO2 (124.75 +/- 9.912 ppm), total dissolved solids (126.1 +/- 9.477 ppm), total alkalinity (4.325 +/- 0.171 mg L-1), total suspended solids (127.1 +/- 6.864 ppm), total hardness (5.225 +/- 0.341 mg L-1), salinity (42.25 +/- 6.292 ppt), calcium hardness (2.975 +/- 0.670 mg L-1), magnesium hardness (105 +/- 9.954 mg L-1), potassium (0.0145 +/- 0.001 mg L-1), sodium (16.55 +/- 3.861 mg L-1), chloride (1.825 +/- 0.727 mg L-1), and nitrate (0.053 +/- 0.006 mg L-1) level] were monitored and found to be in varying but permissible ranges. The stream was found to be harboring a number of economically valuable fish species. An exotic fish species, C. carpio, was found well flourished, indicating the potential of the stream to be used for mitigating the declining ichthyofaunal diversity in the main nearby rivers. Two species, P. sophore and P. ticto, were recorded for the first time from the district. Proper management, appropriate fish stocking, and implementing environmental/fishing laws are suggested for the maintenance of the diversity and alleviating anthropogenic stress/threats
Enhanced Microalgal Harvesting Using Microalgae-Derived Extracellular Polymeric Substance as Flocculation Aid
No full textCoagulation-based harvesting has been widely used in microalgal biomass harvesting. However, the coagulant contamination in the harvested biomass may negatively affect the applications in feedstock processing for food, feed, and fuel. In this study, extracellular polymeric substances (EPSs) were derived from microalgae, Scenedesmus acuminatus, and then used as a bioflocculant to aid the flocculation of the same algae. The results show that the alum coagulant (Al3+) usage was significantly reduced from 77.6 to 4.5 mg g(-1) when adding this EPS bioflocculant at a dose of 3.2 mg g(-1), which potentially reduces the chemical cost from 71 per metric ton dry biomass that is harvested. To analyze the compositions of this bioflocculant, molecular fractionation was performed. The functional fractions such as protein-like and humic-like organic substances were characterized by fluorescence excitation-emission, followed by polysaccharide analysis. Low-MW (<3 kDa) EPS contributed to the flocculation process more than the large-MW fractions. Low-MW EPS contained higher contents of glucose and mannose in the polysaccharide that influence the interactions of the algae and the alum coagulant. Microalgal-derived bioflocculants may open up new avenue toward the low-cost and sustainable bioflocculation processes for algal and other biomass separation
Almond Shell-Derived, Biochar-Supported, Nano-Zero-Valent Iron Composite for Aqueous Hexavalent Chromium Removal: Performance and Mechanisms
No full textNano-zero-valent iron biochar derived from almond shell (nZVI-ASBC) was used for hexavalent chromium (CR) removal. Experiments showed that pH was the main factor (p < 0.01) that affected the experimental results. At a dosage of 10 mg.L-1 and pH of 2-6, in the first 60 min, nZVI-ASBC exhibited a removal efficiency of 99.8%, which was approximately 20% higher than the removal yield at pH 7-11. Fourier transform infrared spectroscopy results indicated N-H was the main functional group that influenced the chemisorption process. The pseudo second-order dynamics and Langmuir isotherm models proved to be the most suitable. Thermodynamic studies showed that the reaction was exothermic and spontaneous at low temperatures (T < 317 K). Various interaction mechanisms, including adsorption and reduction, were adopted for the removal of Cr(VI) using the nZVI-ASBC composite. The findings showed that the BC-modified nZVI prepared with almond shell exerts a good effect and could be used for the removal of Cr(VI)
Adsorptive removal of anionic dyes by graphene impregnated with MnO2 from aqueous solution
No full textGraphene nanosheet-manganese dioxide (GN-MnO2) composite was synthesized by a microwave-assisted method. The physico-chemical properties of modified graphene (GN) were characterized by different techniques, such as scanning electron microscopes (SEM), Fourier-transform infrared spectrometers (FTIR), X-ray diffraction (XRD) and Raman spectroscopy. The effects of contact time, pH, concentration, temperature, and the dose of adsorbent on the adsorption attributes of Congo red (CR) and Acid green 25 (AG25) on GN-MnO2 composite was studied. The experimental facts of the isotherm were found to be more fitted with the Langmuir isotherm rather than the Freundlich one, while the pseudo-second-order kinetic model/curve was found to be fitted with experimental data, giving an indication that the experiment was controlled by chemical processes. The maximum adsorption capacities is derived from the Langmuir model equation at 303 K were 270.06 and 324.26 mg/g for CR and AG25, respectively. The thermodynamic study revealed that the adsorption of CR and AG25 dyes onto the GN-MnO2 was pretty much spontaneous in nature and showed that the GN-MnO2 was a decent adsorbent for the elimination of CR and AG25 ions in aqueous conditions. The column studies were conducted in varying flowrates (4-12 mL/min), and bed heights (0.5-1.5 cm), with a concentration of 100 mg/L, while at pH of 3 and 4 for CR and AG25, respectively. The adsorption capability increased with the increasing influent level and column depth while it was reduced by upturn in flow-rate. The results obtained were fitted well with the Bed Depth Service Time BDST and Thomas models
A stable simultaneous anammox, denitrifying anaerobic methane oxidation and denitrification process in integrated vertical constructed wetlands for slightly polluted wastewater
No full textAnaerobic ammonium oxidation (anammox), denitrifying anaerobic methane oxidation bacteria (DAMO) have received great attention for their excellent performance in nitrogen removal. However, not much study focused on the co-existence of anammox, DAMO, and denitrification in constructed wetlands, not to mention the advantage of their application in mitigating the necessary byproduct nitrous oxide (N2O), methane (CH4) from the biodegradation process. In this study, the result indicated the construction of integrated vertical constructed wetlands (IVCWs) contributed to the high-efficient stable simultaneous anammox, DAMO and denitrification (SADD) process for the nutrients removal, with denitrification being the least contributor to nitrogen reduction. Besides the succession of SADD process was largely the driver for the variation of N2O, CH4 emission. The structural equation method (SEM) further suggested that the three biological pathways of qnorB/bacteria, archaea/qnorB, and anammox/nirK accounted for the N2O production, as were top-controlled by mcrA/DAMO in IVCWs. Besides the anammox-associated nitrifier denitrification was the main source for N2O production. And that the trade-off effect between the CH4 and N2O production was exerted by the DAMO, while the influence was far from satisfactory under the methane constraints. (C) 2020 Elsevier Ltd. All rights reserved
Analysis of Multiplicity of Hypoxia-Inducible Factors in the Evolution of Triplophysa Fish (Osteichthyes: Nemacheilinae) Reveals Hypoxic Environments Adaptation to Tibetan Plateau
No full textHIF (Hypoxia-inducible factor) gene family members function as master regulators of cellular and systemic oxygen homeostasis during changes in oxygen availability. Qinghai-Tibet Plateau is a natural laboratory for for long-term hypoxia and cold adaptation. In this context, T. scleroptera that is restricted to >3500 m high-altitude freshwater rivers was selected as the model to compare with a representative species from the plain, P. dabryanus. We cloned different HIF-alpha and carried out a phylogenetic analysis from invertebrates to vertebrates for identifying HIF-alpha genes and analyzing their evolutionary history. Intriguingly, the HIF-alpha has undergone gene duplications might be due to whole-genome duplication (WGD) events during evolution. PAML analysis indicated that HIF-1 alpha A was subjected to positive selection acted on specific sites in Triplophysa lineages. To investigate the relationship between hypoxia adaptation and the regulation of HIF-alpha stability by pVHL in plateau and plain fish, a series of experiments were carried out. Comparison the luciferase transcriptional activity and protein levels of HIF-alpha s and the differing interactions of HIF-alpha s with pVHL, show clear differences between plateau and plain fish. T. scleroptera pVHL could enhance HIF-alpha transcriptional activity under hypoxia, and functional validation through pVHL protein mutagenesis showed that these mutations increased the stability of HIF-alpha and its hetero dimerization affinity to ARNT. Our research shows that missense mutations of pVHL induced evolutionary molecular adaptation in Triplophysa fishes living in high altitude hypoxic environments
天体生物学研究进展和发展趋势
No full text天体生物学旨在研究宇宙演化背景下生命的起源、演化、分布和未来.天体生物学研究始于20世纪中期,已在生命起源、生命与环境协同演化、宜居环境、地外生命探测、生命星际传输、行星开发和保护等方面获得了一系列新发现和新认识,深刻改变了人们对生命和宜居环境的理解.天体生物学是一门交叉性和探索性很强的学科,其发展不仅推动了生命科学、地球科学、行星科学、空间科学、天文学等不同学科的交叉融合,也增强了科研人员与工程技术人员、科学家与公众之间的对话和沟通.近年来,我国探月工程取得了举世瞩目的成就,酝酿中的火星、木星等深空探测旨在探索浩瀚宇宙,给我国的天体生物学研究提出了更高要求.本文综述了国内外天体生物学的研究现状、主要方向、关键科学问题和研究进展等,并对我国的天体生物学研究提出了若干建议.</p
左炔诺孕酮对稀有鮈鲫脂质代谢的干扰效应
No full text为探究孕激素左炔诺孕酮(LNG)对鱼类脂质代谢的影响,将刚孵化的稀有鮑鲫仔鱼置于0.8和6.5ng/L LNG暴露6个月至性成熟,考察其生长指标、肝脏组织病理学变化、脂质和脂蛋白含量及脂质代谢相关基因的表达情况.结果显示:(1)0.8,6.5ng/L LNG暴露显著降低70dph稀有鮈鲫的体重和肥满度,且6.5ng/L LNG暴露显著降低180dph雌、雄鱼的体长或体重;(2) 0.8,6.5ng/L LNG暴露导致180dph成鱼肝脏出现细胞空泡、肝细胞肿胀等损伤;(3) 0.8,6.5ng/L LNG暴露显著降低180dph雌鱼肝脏中甘油三酯、胆固醇的含量,且6.5ng/L LNG暴露显著降低雌鱼血浆中甘油三酯的含量,但对雄鱼肝脏及血浆的脂质含量无显著影响;(4) 0.8,6.5ng/L LNG暴露显著降低180dph雌鱼肝脏中脂肪酸合成酶基因(fasn)mRNA的表达水平,且6.5ng/L LNG暴露显著降低180dph雄鱼肝脏中fasn及乙酰辅酶A羧化酶基因(acaca)mRNA的表达水平.由此可见,LNG长期低剂量暴露可抑制稀有鮈鲫的生长、诱导肝细胞损伤、引起肝脏和血浆脂质含量发生性别差异性变化,并影响肝脏中脂质代谢相关基因的表达,表明LNG在低浓度下可干扰稀有鮈鲫的脂质代谢,提示LNG对鱼类种群具有较高的潜在生态风险
基于回声探测监测沉水植物盖度的插值方法研究以杭州西湖沉水植物盖度监测为例
No full text沉水植物作为水生态系统的重要组成成分,在水生态系统物质循环和能量流动中发挥着重要作用,其覆盖度和生物量是评价湖泊等浅水水体系统稳定性的关键参数.随着高效和无损伤监测的回声探测仪在沉水植物盖度监测中的应用,其精确度算法也受到了越来越多的关注.本研究以成功恢复沉水植物的浅水湖泊杭州西湖为研究对象,利用Bio-Sonics便携型回声探测仪---MX采集沉水植物回声样本.同时结合人工样方设置,采集与回声探测对应位点的沉水植物样本,验证回声探测结果的精确性.通过建立回归模型分析回声探测得到的沉水植物体积百分比(PVI)与人工样方获得的对应平均鲜重关系,结果表明二者具有较好的相关性.分别采用普通克里金法、反距离权重法、径向基函数法3种插值方法对同一季节的不同湖泊和同一湖泊的不同季节未采集区域沉水植物的盖度数据进行插值分析,并对插值结果进行交叉验证,以确定方法的精确度.交叉验证结果表明,插值精确度反距离权重法>径向基函数法>普通克里金法.研究结果为回声探测与插值分析方法结合在大尺度浅水水体中沉水植物监测应用提供了技术支撑.</p