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1.
张辉  危起伟  杨德国  杜浩  张慧杰  陈细华 《生态学报》2007,27(10):3945-3955
根据1981年葛洲坝截流至1998年对葛洲坝坝下河床研究的历史资料,结合1999~2006年间获得的中华鲟产卵场所在江段河床的5次地形数据,采用ArcGIS 9.0软件,对中华鲟产卵场河床的高程、坡度、坡向等地形因子进行了详细分析。结果表明:葛洲坝至磨基山江段中华鲟产卵场与历史产卵场相比具有极其相似的特征,临江溪至虎牙滩江段中华鲟自然繁殖频率不高可能主要是因为地形不符合要求,从而造成相关的水文因子也不能满足需要。中华鲟自然繁殖前期的迁徙分布和产卵后受精卵的散播与河床地形都有一定的关系,葛洲坝水利枢纽下游河势调整工程较大地改变了葛洲坝至庙咀江段河床的地形,地形复杂度的增加可能对中华鲟自然繁殖前期的栖息有利,而河床坡度、底质的改变则可能会对中华鲟受精卵的散播和发育产生不利影响。有必要结合中华鲟历史产卵场精确的地形数据,对“中华鲟产卵场功能分区模型假说”进行验证,并针对产卵场地形对中华鲟自然繁殖的影响,做出进一步探讨。  相似文献   

2.
葛洲坝下游中华鲟(Acipenser sinensis)产卵场地形分析   总被引:1,自引:0,他引:1  
张辉  危起伟  杨德国  杜浩  张慧杰  陈细华 《生态学报》2007,27(10):3945-3955
根据1981年葛洲坝截流至1998年对葛洲坝坝下河床研究的历史资料,结合1999~2006年间获得的中华鲟产卵场所在江段河床的5次地形数据,采用ArcGIS9.0软件,对中华鲟产卵场河床的高程、坡度、坡向等地形因子进行了详细分析。结果表明:葛洲坝至磨基山江段中华鲟产卵场与历史产卵场相比具有极其相似的特征,临江溪至虎牙滩江段中华鲟自然繁殖频率不高可能主要是因为地形不符合要求,从而造成相关的水文因子也不能满足需要。中华鲟自然繁殖前期的迁徙分布和产卵后受精卵的散播与河床地形都有一定的关系,葛洲坝水利枢纽下游河势调整工程较大地改变了葛洲坝至庙咀江段河床的地形,地形复杂度的增加可能对中华鲟自然繁殖前期的栖息有利,而河床坡度、底质的改变则可能会对中华鲟受精卵的散播和发育产生不利影响。有必要结合中华鲟历史产卵场精确的地形数据,对"中华鲟产卵场功能分区模型假说"进行验证,并针对产卵场地形对中华鲟自然繁殖的影响,做出进一步探讨。  相似文献   

3.
繁殖群体数量是中华鲟能否成功繁殖的重要影响因子, 建议作为长江生态考核的重要评价指标。根据重要种群参数和历史数据, 基于稳态转换理论和方法, 确定中华鲟繁殖群体数量指标的评估基准值和等级, 670尾以上为“优”、400—670尾为“良”、200—400尾为“中”、50—200尾为“差”、50尾以下为“极差”。水声学探测结果显示, 1998—2001年中华鲟繁殖群体数量指标评级为“良”; 2004—2012年三峡工程蓄水后至向家坝蓄水前评级为“中”; 2013—2020年评级为“极差”。为了复壮中华鲟野生种群, 建议修复葛洲坝下中华鲟产卵场功能, 大规模放流性成熟亲鱼和大规格个体, 建立国家级中华鲟保育中心。  相似文献   

4.
为对青海湖裸鲤(Gymnocypris przewalskii)的自然繁殖需求条件进行定量研究, 实验结合青海湖裸鲤自然产卵场原位生境调查, 通过室内人工模拟构建产卵环境诱发野生亲鱼自然繁殖, 解答可控环境中青海湖裸鲤自然繁殖的环境需求。结果表明, 青海湖裸鲤自然繁殖发生与水温、水深、流速、光照及底质因素密切相关, 其中卵石河床质较细砂等底质环境可显著提升自然交配诱导率及繁殖效果; 在合适的底质条件下, 青海湖裸鲤自然繁殖的适宜条件: 水深为0.15—0.2 m、流速为0.2—0.4 m/s、水温为10.8—14.3℃; 15D﹕9L比例的光周期有利于促进青海湖裸鲤自然繁殖的发生。在人工模拟环境中, 水深≥0.45 m、流速≥0.8 m/s、温度≥17℃或≤6℃、全光照等环境中未观测到自然繁殖活动的发生, 这些被认为是其自然繁殖环境的限制条件。研究阐明了可控环境中青海湖裸鲤野生亲鱼自发产卵繁殖的环境需求, 构建人工模拟产卵环境技术, 为自然产卵场生境调查评估、改进人工繁育模式提供技术支撑和新思路。  相似文献   

5.
自然产卵场是维持物种延续最关键的栖息地,青海湖裸鲤(Gymnocypris przewalskii)的自然繁殖栖息地状况和生境特征尚缺乏详细的定量研究。以青海湖入湖河流泉吉河为例,在平水期采用现场调查和无人机遥测的方法对青海湖裸鲤的自然产卵场分布及生境状况进行调查,确定其产卵场生境特征参数,建立基于无人机遥测识别产卵场的方法并进行复核验证。结果表明:泉吉河河道形态可分为弯曲型、分汊型和顺直型等三种典型河型,青海湖裸鲤自然产卵场主要分布在弯曲型和分汊型河道中,分汊型河道几乎100%都有产卵场分布,弯曲型河道有70%为产卵场;产卵场河道平均长度(135.13±61.13) m,平均宽度(30.01±17.51) m,平均曲折度1.09±0.07;平均面积(4586.6±4201.61) m2;产卵场常位于缓水浅滩处,平均水深(0.19±0.10) m (范围:0.03-0.44m),平均流速(0.24±0.20) m/s (范围:0.01-0.81m/s),河床质为含有沙粒的卵石(粒径:163-256mm)底质。河道形态、沙洲分布、水深特征等特征参数可作为无人机遥测识别产卵场的判断条件,并实现验证成功。研究结果可为开展整个流域的青海湖裸鲤自然产卵场现状评估及保护对策制定提供技术支撑。  相似文献   

6.
王远坤  夏自强  王栋  李帆  李建 《生态学报》2009,29(12):6359-6365
通过对鱼类产卵场地形分析,认为水流能量损失是鱼类产卵场形成的重要原因之一,这种能量损失主要是由于特殊河道地貌形成的水流紊动而产生的.在此基础上探索性地推导了考虑这种河道水流能量损失的明渠非恒定流方程.以中华鲟为例,对产卵场河段进行了三维水流数值模拟,计算了产卵河段紊动能的分布,探讨了中华鲟产卵行为与水流紊动之间的关系,结果表明产卵区因紊动产生的能量损失明显大于非产卵区.以期为保护中华鲟和其他鱼类产卵场水力学环境提供参考.  相似文献   

7.
[目的] 为研究添加饲用益生菌对肉牛生长性能、血液生理生化指标及肠道微生物区系的影响。[方法] 在青海地区选取西门塔尔牛与荷斯坦牛的杂交1代18头,按每组平均体重相近的原则随机分为2组,每组9头,试验组饮食添加地衣芽孢杆菌、枯草芽孢杆菌和酿酒酵母的复合饲用益生菌。[结果] 试验结果表明:试验组显著地提高了胸围日增长量(P=0.029);试验组皮质醇浓度显著(P<0.05)高于对照组,高密度胆固醇脂蛋白、低密度胆固醇脂蛋白与总胆固醇浓度显著(P<0.05)低于对照组;进一步分析肠道微生物发现,两组之间Alpha多样性没有显著差异(P>0.05),Beta多样性差异显著(P<0.05);TenericutesAlistipesRuminococcaceae的相对丰度在试验组显著高于对照组(P<0.05),而Alloprevotella相对丰度显著低于对照组(P<0.05);检测到的芽孢杆菌种没有显著的差异,有趣的是,试验组降低了肠道中的大肠杆菌丰度。[结论] 综上,饲喂复合饲用益生菌能够有效降低血清胆固醇的合成、抑制有害微生物的繁殖。该研究为益生菌干预肉牛健康养殖提供了理论依据。  相似文献   

8.
目的 探讨全程无缝隙护理模式对肿瘤科护理工作质量的影响。方法 2013年1月-12月我院肿瘤科采用无缝隙护理模式的患者120例为观察组,2012年1月-12月采用常规护理的120例肿瘤科患者为对照组,对比两组患者的心理舒适度、患者对护理工作的满意度。结果 观察组患者的安全感、满足感、尊重感所占比例均高于对照组,差异均有统计学意义(P<0.05)。观察组患者对护士的工作能力、关爱与沟通、服务热情主动、病区管理、健康教育满意度均高于对照组,差异均有统计学意义(P<0.05)。结论 全程无缝隙护理模式应用于肿瘤科护理,能够有效改善患者不良情绪,提高护理工作质量及患者满意度。  相似文献   

9.
125I-EGF与人多形成胶质细胞瘤BT325细胞系膜上EGF受体的饱和结合实验, 竞争抑制实验研究GM3,BBG(bovine brain gangliosides)对EGF受体最大结合量, 亲和常数及受体数目的影响; 放射受体法观察EGF-EGFR复合物内吞过程, 测定胞质和培养基中EGF含量.结果表明: BT325细胞质膜上存在高亲和力EGF结合位点,GM3对EGF与其受体的亲和力无明显抑制作用(P>0.05),但能明显减少其受体的数目(P<0.05); GM3能明显延长EGF-EGFR复合物内吞过程; GM3处理的胞质中EGF浓度比对照组显著升高(P<0.05), 培养液中无明显差异,这可能是由于GM3抑制EGF分泌所致.  相似文献   

10.
于2016年6月20日至8月10日在四川马尔康林麝繁育场开展,采用基于量表的个性评价法对172头(雌麝59头,雄麝113头)圈养林麝进行了个性评价,建立了圈养林麝个性维度,并探索了个性维度与其麝香分泌和繁殖成效的关系。结果表明:因子分析各项载荷值均大于0.4,Cronbach''s α分析结果为0.648,表明个性量表具有较好的一致性信度和结构效度。此外,特征根大于1时,圈养林麝的侵略性、活跃性、刻板性、胆怯性及社会性五大个性维度可解释70.77%的个性信息,并通过聚类分析,进一步验证了维度划分的合理性;雄性林麝的社会性维度和麝香分泌量存在显著正相关(r=0.234,P < 0.05),社会性越强(展现出更多的互饰接触、共同摄食等亲和行为的个体),其泌香量越高;侵略性(r=0.463,P < 0.05)、活跃性(r=0.440,P < 0.05)、刻板性(r=0.595,P < 0.05)与雌性分娩时间存在显著正相关关系,即个性越强,分娩时间越晚,此外,刻板性与产仔数呈显著负相关(r=-0.341,P < 0.05),表明圈养林麝的繁殖成效主要受刻板性维度影响,刻板性强的个体对繁殖成效会有一个负面的效应。  相似文献   

11.
The Chinese sturgeon (Acipenser sinensis), a kind of maricolous anadromous migratory fish species, is endangered and protected in China. Historical spawning habitats were distributed in the lower reaches of Jinsha River and the upper reaches of Yangtze River. Since the establishment of the Gezhouba water conservancy pivot in 1981, the migratory route of Chinese sturgeon spawning was blocked. Therefore, the fish was forced to propagate in a new spawning ground which was mainly distributed in the 4-km-long mainstream from Gezhouba Dam to Miaozui in the middle Yangtze River. After water storage and power generation of the Three Gorges reservoir (TGR) in 2003, the propagation of Chinese sturgeon has been impacted gradually. According to field surveys, the fish used to spawn twice a year before TGR impoundment, but only once happened after that. Besides, the spawning scale is also declining with each passing year.In order to simulate and evaluate the effect of TGR impoundment on spawning habitats of Chinese sturgeon, with consideration of their reproductive characteristics, an eco-hydrodynamic model was established by coupling a two-dimensional hydrodynamic model and a fuzzy fish habitat module based on fuzzy logic inference. Flow fields at the studied site in an impoundment scenario and an assumed no impoundment scenario were simulated with the 2D hydrodynamic model. Afterwards, by linking hydrodynamic conditions to the expert knowledge base, the fuzzy habitat model used fuzzy logic inference to compute habitat suitability of the Chinese sturgeon. In addition, the approach was used to propose a suitable instream flow range during the propagation period for Chinese sturgeon. The results indicated that the suitable instream flow needed for Chinese sturgeon spawning in middle Yangtze River should be between 10,000 m3/s and 17,000 m3/s and it also showed that after TGR was put into pilot impoundment operation at the designed water level of 175 m, the habitat suitability has decreased significantly in October. Besides, the water temperature of spawning habitat increased to a higher level in propagation period due to the impoundment of the TGR. All these alterations have had imposed tremendous impacts on the propagation of Chinese sturgeon. Therefore, adjusting impoundment schedule of the TGR to recover the water flow over spawning habitat in October is a crucial way to improve the habitat suitability. Furthermore, the presented method also provides a theoretical basis for further research on the assessment of habitat suitability of aquatic species at a micro-habitat scale.  相似文献   

12.
A bedform morphology hypothesis for spawning areas of Chinese sturgeon   总被引:1,自引:0,他引:1  
Results from previous research suggested that geomorphic characteristics may be important controlling factors among other microhabitat variables for spawning fish. We investigated the bedform morphology of seven spawning areas (five historic and two present spawning areas) of Chinese sturgeon (Acipenser sinensis) by analysis of relief maps of the riverbed and by field surveys. We conclude that the topographic characteristics of the spawning areas include rocky or gravelly substrate river bend, large variations in water depth and river width and a slope with moderate length and slope. The turning structure and the adverse slope may be the most important topographic characteristics for the spawning areas. Combined with the reproductive occurrence of the fish in these spawning areas, we tentatively propose a bedform morphology hypothesis for the spawning areas. We consider that a spawning area of A. sinensis should consist of three functional areas: Mating area (M), Dispersal area (D) and Incubation area (I). M, D and I are distributed along the water current and their bedform characteristics are clearly different. M is the place for mature fish to mate and spawn. It is usually below a riffle with rolling terrain. D is the place for fertilizing and dispersing fertilized eggs. It is usually in a river bend with sharp variations in terrain, such as deep pools or steep slopes. I is the place for dispersal of fertilized eggs. It is usually in long point bars or broad shallow areas with rocky substrate. This hypothesis could serve as a guideline for improving the present spawning areas or constructing new spawning areas, so as to rehabilitate the wild stock of the sturgeon.  相似文献   

13.
For effective conservation, it is important to explore the environmental cues initiating the spawning activities of a fish species. Based on monitoring data gathered between 1998 and 2011, the relationships between spawning activities of the Chinese sturgeon, Acipenser sinensis, and several environmental cues were analyzed using the rare events logistic regression ‘Relogit’ method, which indicated that water temperature, 1‐day ?‐discharge, and atmospheric pressure were among the key spawning cues for Asinensis (P < 0.05). It is suggested that Chinese sturgeon might have an optimal environment window of 17–20°C water temperature, high day‐to‐day discharge increase, and low atmospheric pressure for spawning. In support of Chinese sturgeon reproduction, suggested modifications to the operational procedures for the Three Gorges Reservoir (TGR) to trigger spawning are: lowering the downstream water temperature to below 20°C before mid‐October and expanding the period with water temperatures of between 17 and 20°C; to create a day‐to‐day intermittent increase in the discharge to an optimal spawning water temperature; and to regulate flow at nights with a low atmospheric pressure.  相似文献   

14.
The Chinese sturgeon (Acipenser sinensis) is an anadromous fish inhabiting the Yangtze River. Migration of Chinese sturgeon from the estuary to upper Yangtze River was blocked by Gezhou Dam, completed in 1981, and a new, much smaller, spawning ground was established below the dam. However, Three Gorges Dam began operating in 2003, altering hydrological conditions in the new spawning grounds and the impact on Chinese sturgeon reproduction was severe. The annual survey of Chinese sturgeon shows that both spawning scale and breeding population decreased during this period. To illustrate the impact of Three Gorges Dam on the spawning grounds and reproduction of Chinese sturgeon, the habitat suitability of spawning grounds on spawning day was simulated using River2D. Results show that the area of suitable spawning grounds positively correlates with the scale of reproduction and both have decreased sharply since 2003.  相似文献   

15.
The anadromous Chinese sturgeon (Acipenser sinensis), mainly endemic to the Yangtze River in China, is an endangered fish species. The natural population has declined since the Gezhouba Dam blocked its migratory route to the spawning grounds in 1981. In the near future, the completion of the Three Gorges Dam, the world's largest hydroelectric project, may further impact this species by altering the water flow of the Yangtze River. Little is currently known about the population genetic structure of the Chinese sturgeon. In this study, DNA sequence data were determined from the control region (D-loop) of the mitochondrial genome of adult sturgeons (n = 106) that were collected between 1995–2000. The molecular data were used to investigate genetic variation, effective female population size and population history of the Chinese sturgeon in the Yangtze River. Our results indicate that the reduction in abundance did not change genetic variation of the Chinese sturgeon, and that the population underwent an expansion in the past. AMOVA analysis indicated that 98.7% of the genetic variability occurred within each year's spawning populations, the year of collection had little influence on the diversity of annual temporary samples. The relative large effective female population size (N ef) indicates that good potential exists for the recovery of this species in the future. Strikingly, the ratio of N ef to the census female population size (N f) is unusually high (0.77–0.93). This may be the result of a current bottleneck in the population of the Chinese sturgeon that is likely caused by human intervention. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

16.
Lake sturgeon, Acipenser fulvescens, are one of a few species of cartilaginous fishes that complete their life cycle entirely in freshwater. Sturgeons maintain very low concentrations of circulating calcium (Ca2+) compared with other vertebrates, and therefore, face unique challenges in regard to Ca2+ regulation, which are likely to be magnified during vitellogenic stages of the reproductive cycle. In the present study, Ca2+ concentrations and associated hormones of female and male lake sturgeon were examined in two wild populations, and were related to reproductive stage. In both populations, free, bound and total Ca2+ were low, peaking in mid-late vitellogenic females. Internal Ca2+ and phosphate (PO43−) concentrations were inversely related to environmental concentrations, suggesting that these ions are preferentially retained and that mechanisms for mobilization are up-regulated under diminished environmental concentrations. Plasma 17β-estradiol, 11-ketotestosterone and testosterone, peaked in mid-late vitellogenic females, while the androgens peaked in spawning males. Urine Ca2+ was more tightly regulated than other divalent ions and decreased in spawning fish. Therefore, the increases in free plasma Ca2+, the very low circulating concentrations of free and total Ca2+, and the increase in PO43− and bound Ca2+ in low Ca2+ environments indicate unique adaptations to Ca2+ regulation in the lake sturgeon.  相似文献   

17.
We have investigated the effects of three current velocities and three substrate sizes (gravel to cobble) on the spawning behavior of Japanese dace, Tribolodon hakonensis, in spawning-induction and habitat-selection experiments. In the spawning-induction experiment under laboratory conditions the number of females induced to spawn was significantly fewer at low current velocity (ca. 5 cm s–1) than at medium (ca. 30 cm s–1) or high (ca. 50 cm s–1) current velocity. Females spawned independently of substrate size in the experimental tank, and did not bury their eggs in the substrate bed. In the habitat-selection experiment under field conditions, females selected the substrate microhabitat and spawned more frequently at a site with medium substrate size (very coarse gravel; major axis ca. 40 mm) than at sites with small (fine gravel; ca. 8 mm) or large (cobble; ca. 70 mm) substrate size. We conclude that Japanese dace select spawning sites at least partly on the basis of current velocity and substrate size, which affects the survival rate of eggs.  相似文献   

18.
The hypotheses of this study were (i) that shovelnose sturgeon would make upstream movements to spawn, (ii) movement of spawning fish would be greater in a year with higher discharge, and (iii) that spawning fish would have greater movements than reproductively inactive fish. Shovelnose sturgeon Scaphirhynchus platorynchus (Rafinesque, 1820) in five reproductive categories (e.g. males, confirmed spawning females, potentially spawning females, atretic females, and reproductively inactive females) were tracked in 2008 and 2009. All reproductive categories, except reproductively inactive females, exhibited large‐scale movements and had omnidirectional movements. No differences in movement rates were observed in confirmed spawning females between years despite a 45% higher peak discharge in 2008 (839 m3 s?1) than in 2009 (578 m3 s?1). A peak discharge was obtained at a faster rate in 2008 (165 m3 s?1 day?1) than in 2009 (39 m3 s?1 day?1), and high discharge was of greater duration in 2008. Reproductively inactive females did not exhibit large‐scale movements and their movement rate differed from other reproductive categories. Shovelnose sturgeon spawned in both years, despite highly varying hydrographs between years.  相似文献   

19.
Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus) experienced severe declines due to habitat destruction and overfishing beginning in the late 19th century. Subsequent to the boom and bust period of exploitation, there has been minimal fishing pressure and improving habitats. However, lack of recovery led to the 2012 listing of Atlantic sturgeon under the Endangered Species Act. Although habitats may be improving, the availability of high quality spawning habitat, essential for the survival and development of eggs and larvae may still be a limiting factor in the recovery of Atlantic sturgeon. To estimate adult Atlantic sturgeon spatial distributions during riverine occupancy in the Delaware River, we utilized a maximum entropy (MaxEnt) approach along with passive biotelemetry during the likely spawning season. We found that substrate composition and distance from the salt front significantly influenced the locations of adult Atlantic sturgeon in the Delaware River. To broaden the scope of this study we projected our model onto four scenarios depicting varying locations of the salt front in the Delaware River: the contemporary location of the salt front during the likely spawning season, the location of the salt front during the historic fishery in the late 19th century, an estimated shift in the salt front by the year 2100 due to climate change, and an extreme drought scenario, similar to that which occurred in the 1960’s. The movement of the salt front upstream as a result of dredging and climate change likely eliminated historic spawning habitats and currently threatens areas where Atlantic sturgeon spawning may be taking place. Identifying where suitable spawning substrate and water chemistry intersect with the likely occurrence of adult Atlantic sturgeon in the Delaware River highlights essential spawning habitats, enhancing recovery prospects for this imperiled species.  相似文献   

20.
Green sturgeon, Acipenser medirostris, are the most marine-oriented of North American sturgeons. However, their estuarine/marine distribution and the seasonality of estuarine use are largely unknown. We used acoustic telemetry to document the timing of green sturgeon use of Washington estuaries. In the summers of 2003 and 2004, uniquely coded acoustic transmitters were surgically implanted in green sturgeon captured using commercial gillnets. All sturgeon tagged were greater than 1.2 m total length. They were caught, tagged, and released in both Willapa Bay (n = 49) and Columbia River (n = 11) estuaries. We deployed an array of four fixed- site acoustic receivers in Willapa Bay to detect the estuarine entry and exit of these and any of over 100 additional green sturgeon tagged in other systems during 2003 and 2004. Green sturgeon occurred in Willapa Bay in summer when estuarine water temperatures exceeded coastal water temperatures by at least 2°C. They exhibited rapid and extensive intra- and inter- estuary movements and green sturgeon from all known spawning populations were detected in Willapa Bay. We hypothesize that green sturgeon optimize their growth potential in summer by foraging in the relatively warm, saline waters of Willapa Bay and we caution that altering the quality of estuarine habitats could negatively affect this species throughout its range.  相似文献   

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