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1.
草兔的年龄鉴定和种群结构分析   总被引:3,自引:0,他引:3  
根据1991年2-10月猎自晋东南的212只和1990-1992年狩猎季节猎自山西和陕西省各地的1510只草兔眼晶体重的分布规律并参照繁殖资料,确定225毫克为区别1年以下及其以上个体的临界重量。秋-冬季种群中,当年兔占86.3(72.2-93.5)%;随着繁殖季节的推移,当年兔的比例逐渐增加。在4011只标本中,雌性占52.3%;其中1226只幼体和195只成体中分别有雌性52.4%和54.4%。在2-9月所获的91只当年兔有雌性50.5%,而成体中雌性则有58.2%。  相似文献   

2.
草兔的年龄鉴定和种群的结构分析   总被引:1,自引:1,他引:0  
卢欣  申守义 《兽类学报》1994,14(3):176-183
根据1991年2-10月猎自晋东南的212只的1990-1992年狩猎季节猎自山西和陕西省各地的1510只草兔眼晶体重的分布规律并参照繁殖资料,确定225毫克为区别1年以下及其以上个体的临界重量,秋-冬季种群中,当年兔占86.3(72.2-93.5)%;随着繁殖季了的推移,当年兔的比例逐渐增加,在4011只标本中,雌性占52.3%;其中1226只幼体和195只成体中分别在雌性52.4%和54.4%  相似文献   

3.
洞庭平原黑线姬鼠繁殖特性研究   总被引:18,自引:4,他引:14  
王勇  陈安国 《兽类学报》1994,14(2):138-146
1986年10月-1990年10月在湖南省桃源县和汉寿县的稻作区逐月调查,夹捕黑线姬鼠长江亚种2768只,雌性占45。6%。主要繁殖期3-11月,研究期内的月平均怀孕率为48.6±4.0%、平均胎仔数为5.3±0.2只。繁殖指数为2.36±0.29。以上3个参数及种群性性比有季节性变化,4-5月和7-10月为2个妊娠高峰;雄性睾丸下位率和雌性怀孕率有同步变动的趋势。5年龄组之间,其性比、怀孕率和繁  相似文献   

4.
丁平  鲍毅新 《兽类学报》1994,14(4):294-298
1985年4月1992年12月,作者采用夹日法对萧山围垦农区臭Qu种群动态进行了连续逐月定点定时的研究。结果表明:臭Qu种群相对数量的季节消长呈后峰型双峰曲线,5月和10月各出现一次高,怀孕率在2月和7月各出现一次高峰,平均胎仔数在5-6月和8-9月相对较多。室外群种相对数量高峰在4月和9-10月;室内种群在5月和10月,前峰不及室外种群明显。室内种群雌体怀孕率明显于室外种群。种群相对数量的季节变  相似文献   

5.
洞庭湖区东方田鼠繁殖特性研究   总被引:44,自引:10,他引:34  
武正军  陈安国 《兽类学报》1996,16(2):142-150
1992年1月~1994年12月,作者在东洞庭湖区岳阳县麻塘区调查,3年捕获并剖检东方田鼠1392只,其中雌鼠599只,雌性比♀/(♂+♀)=43.0%。该鼠全年繁殖,盛夏5~7月怀孕率较低,冬季12~2月怀孕率比同域其它鼠种显著偏高。3年合计总怀孕率为29.2%.平均胎仔数(x±SE)为5.13±0.12只,平均窝仔数4.60±0.27只,雌鼠和雄鼠的繁殖强度随年龄增长而递增。室内饲养的东方田鼠妊娠期约20天,窝仔数4.33±0.33只,雌鼠50~60天成熟,雄鼠稍迟。枯水期(11月~翌年4月)东方田鼠主要栖息于湖洲草地,汛期(5~10月)主要栖息于过垸内稻田。在不同栖息地其繁殖力差别较大,湖洲的繁殖强度最高,稻田区次之,岗地最低,反映它在各栖息地生态适合度不同。文中还对全国4个亚种的繁殖参数作了比较。  相似文献   

6.
宋策 《动物学杂志》1997,32(1):29-31
1993-1995年,连续三年在辽宁凤城地区对戴胜繁殖习性进行 观察。结果发现,戴胜每年3月中旬迁来,9月下旬迁离。每年繁殖两次,繁殖期在4月中旬至7月末。窝卵量:第一窝9-10枚,第二窝5-7枚。雌鸟边产卵边卵卵。孵卵期;第一窝18d,第二窝15d。  相似文献   

7.
鲁西南甘薯天蛾发生规律及防治研究   总被引:2,自引:0,他引:2  
甘薯天蛾在鲁西南一年发生3-4代,以蛹在土中7-15cm深处越冬。各代幼虫发生期:第1代发生在5月下旬至6月下旬,第2代于7月上旬至下旬,第3代8月上旬至9月上旬,而第4代则于9月上旬至10月下旬。发育起点温度15.6±1.3℃,有效积温370.6±13日度。温度、天敌、降水是影响此虫发生的重要因素。采用高效低毒农药、点灯诱杀、保护利用天敌等措施综合防治甘薯天蛾,有较好的防治效果。  相似文献   

8.
1985-1994年的3-11月,在山西省代县对小PiTi的繁殖生物学进行了研究。该鸟在山西省为夏候鸟,每年最虫3月6日迁来,最晚11月24日迁离,居留期为255天左右。种群密度在繁殖前的4月为1.37,繁殖后的9月为1.95(只/ha)。产卵始期为5月27日,日产1枚,窝卵数5-8枚,产出第二枚卵时开始孵卵。观察到最早孵卵期为5月28日,孵卵期为20-22d。雏鸟出壳先后顺序与产卵先后顺序相一致  相似文献   

9.
990-1994年3-10月,在山西庞泉沟国家级自然保护区,对白繁殖生态进行了研究。研究表明,该鸟在本区为夏候鸟,3月底迁来,10月上旬迁离,多在山涧溪流、池塘、水沟边活动。种群密度遇见数在繁殖前为170只/km,繁殖后177只/km,繁殖后比繁殖前增长412%。食物以昆虫为主,最早产卵于5月11日,每窝卵数3-6枚,孵卵期12-14d,孵化率80%-100%。  相似文献   

10.
瓣结鱼的繁殖习性以及精子的活力与寿命   总被引:5,自引:0,他引:5  
经组织学观察,研究了性成熟瓣结鱼的性腺发育的周期性变化,并初步分析了瓣结鱼的和。其繁殖盛期在4月下旬到5月上旬,繁殖群体♀:♂=1:9.1,繁殖季节具有雌雄二态性,雄鱼绝大多数在2龄性成熟,雌鱼多在3性成熟。不同浓度的NaCl溶液对精子活力和寿命有较大影响,成熟精子在0.45-0.55%的NaCl溶液中剧烈运动时间最长,平均为172.5秒。  相似文献   

11.
Ca-Cd interaction in the prymnesiophyte Cricosphaera elongata   总被引:1,自引:1,他引:0  
Abstract. 45Ca and 109Cd uptake were followed in Criscosphaera elongata Prymnesiophyceae. In both cases, after a rapid increase for the first 5 min, the incorporation rate slowed during the hour of observation. Verapamil, a blocker of voltage-dependent slow calcium channels, inhibited 45Ca uptake except during the first rapid phase when adsorption should predominate. Cadmium also decreased 45Ca labelling, suggesting that the two metals are antagonistic. However, verapamil was shown to augment 109Cd incorporation, contrary to what occurs in animals cells; this effect is detectable in continuous labelling as well as in pulse experiments. The data support the presence of calcium channels in the alga and suggest several processes in Cd accumulation: adsorption on peripheral envelopes and diffusion of uncharged Cd.  相似文献   

12.
俞发宏  彭燕章 《兽类学报》1992,12(2):96-104
对懒猴、猕猴、叶猴和长臂猿的肘关节形态与功能和前臂伸、屈肌肌肉电生理的研究结果表明,随着上肢运动功能的加强,肘关节的灵活性亦相应增大。猕猴各肌的肌电活动相对较弱,肘关节的结构明显不同于其它3个种,表现出对四足型运动和维持关节稳定性的适应特点。叶猴肘关节的形态结构和前臂各肌的肌电活动类似于长臂猿,表现出与臂摆荡有关的活动特点。对前臂伸、屈肌有关指数的判别分析表明,与骨骼相比,4个种的前臂各肌的形态差异明显较大。肱肌的近侧起点指数。肱桡肌的止点指数和肱三头肌内侧头的起点指数可作为4个种的鉴定特征。  相似文献   

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17.
The kinetics of cyanide binding to chloroperoxidase were studied using a high-pressure stopped-flow technique at 25 degrees C and pH 4.7 in a pressure range from 1 to 1000 bar. The activation volume change for the association reaction is delta V not equal to + = -2.5 +/- 0.5 ml/mol. The total reaction volume change, determined from the pressure dependence of the equilibrium constant, is delta V degrees = -17.8 +/- 1.3 ml/mol. The effect of temperature was studied at 1 bar yielding delta H not equal to + = 29 +/- 1 kJ/mol, delta S not equal to + = -58 +/- 4 J/mol per K. Equilibrium studies give delta H degrees = -41 +/- 3 kJ/mol and delta S degrees = -59 +/- 10 J/mol per K. Possible contributions to the binding process are discussed: changes in spin state, bond formation and conformation changes in the protein. An activation volume analog of the Hammond postulate is considered.  相似文献   

18.
Association reactions between water and N-methylated adenines (M), occurring under field-ionization conditions in a mass spectrometer at the tungsten point emitter surface, were studied at a number of temperatures. The origin of the peaks observed in the mass spectra at m/e ratios corresponding to MH+ was assigned to M X H2O monohydrates , of those corresponding to (MH X H2O)+ and (MH2)2+ to double hydrates M(H2O)3. Measurements of the relative peak intensities allowed calculation of apparent equilibrium constants, Kass, for successive hydration steps, and hence the respective van't Hoff enthalpies of hydration. Both the equilibrium and the energy parameters obtained support the available quantum-mechanical single-layer hydration schemes of adenine and of its N-methylated derivatives.  相似文献   

19.
本文报导了以棉花751为母本与鸡脚叶棉、乌干达棉、红叶棉、汉寿大桃、草棉等5个父本的混合花粉进行杂交。授粉后,观察了751大小孢子和雌雄配子体的发生、发育及其受精过程。切片观察表明在大小孢子的发生、发育与花蕾大小成正相关。大小孢子的发生在减数分裂前是不同步的。小孢子的发生早于大孢子发生1 ̄2个时期。减数分裂后它们的发育逐渐趋向同步。开花时达到同步成熟。用多父本的混合花粉授粉,其受精过程仍为单精入卵  相似文献   

20.
The UTEX 2193 strain of Scenedesmus armatus (Chod.) Chod, when cultured in any of several media (whether natural or artificial, concentrated or dilute) produced a variety of colonial morphologies as well as a unicell population. Morphological expression was related to culture ape. When the initial cell density was just a feu1 hundred cells per mL. the culture first produced a unicell population, then spiny colonies, and as stationary phase was approached, spine-less colonies. Two classes of spiny colonies were detected. Type I colonies had elongate cells with the terminal cells shorter than median cells. Spines were longer than cell length. The wider, oval, grainy cells of Type II colonies were uniform m length. Spines were shorter and thicker than those on Type I colonies. Only Type I colonies produced unicells: the latter appeared as two morphs. The smaller unicell was obovoid with four delicate spines: the larger had ovate cells bearing four thicker spines. Control of unicell development in all media was achieved by carefully monitoring colony type and cell number used for the inoculum. A unicellular population developed in batch culture in defined media, both concentrated and dilute, when the initial cell density (either Type I or Type II colonies) was low (below 1000 cells-mL?1), as well as in synchronous cultures. With higher initial cell densities, e.g. 2 × 104 cells·mL?1, the inoculum had to contain Type I colonies to produce unicells. Unicells were also produced in water from Agronomy Pond, where the strain originated. We discuss the role of unicell populations in the distribution of Scenedesmus.  相似文献   

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