蜂桶寨自然保护区中华姬鼠和社鼠肥满度的研究

我们于2008年4~11月对四川蜂桶寨自然保护区内中华姬鼠(Apodemus draco)和社鼠(Niviventer confucianus)肥满度在各年龄组及不同季节中的变化进行了研究,并初步分析了影响因素。结果显示：中华姬鼠肥满度在各年龄组中的性别差异不明显;在各年龄组间的差异显著,其变化趋势为老年组＞成年组＞亚成年组＞幼年组,亚成年组及老年组肥满度在各季节间无显著差异,而成年组则差异明显。社鼠肥满度在各年龄组间无显著性差异,亚成年组肥满度在各季节间差异显著,同时成年组及老年组肥满度在季节间无显著差异;二物种,亚成年组、成年组及老年组肥满度与海拔无明显的线性关系。分析认为,繁殖期能量的消耗的增加可能导致中华姬鼠肥满度在繁殖期下降,而社鼠成年及老年个体面对食物资源、能量需求等方面的季节变化,能够通过相应的调节,维持肥满度的稳定。     

洞庭湖区社鼠的繁殖生态

在洞庭湖区域,社鼠（Niviventer confucianus）种群主要栖息在山区和丘陵地带的林地内.总体而言,其种群雌性比基本维持在50%左右,但在季节间和年龄组间有一定的差别,雌性比在冬、春季较低,夏、秋季的雌性比都超过50%.年龄组间,雌性比最高的为幼年组66.7%,亚成年和成年组的雌性比接近50%,而老年组的雌性比为最低,为33.3%.所有雌鼠全年的怀孕率为31.1%,平均胎仔数为3.7只,繁殖指数为0.58.春、夏季怀孕率较高,冬季没有捕获到怀孕的雌鼠,仅捕获到有怀孕经历（有宫斑）的雌鼠.繁殖指数在夏、秋季维持高峰水平.雌性社鼠总的参产率为53.3%,各季间呈现从春、夏到秋逐渐增加的趋势,冬季停止怀孕.可见夏、秋季为雌鼠的繁殖高峰期.随着年龄组增长,平均胎仔数有明显增加的趋势,老年组胎仔数最高,而繁殖指数以成年组最高,说明成年组是种群中繁殖的主体.雄性社鼠的睾丸下位率全年总计为75.6%,分四季平均为86.0%,夏、秋季维持在较高水平,冬、春季稍低,低谷在春季.下位睾丸的重量与大小有明显的季节变化,呈现春、夏、秋、冬逐渐下降的规律,春季与冬季相比,有显著性差异,说明开春后,雄性社鼠在生殖潜能上已有明显变化.这些特征与雌鼠的繁殖高峰基本吻合.说明社鼠主要在春、夏、秋季繁殖,繁殖盛期在夏秋季.从不同年龄组看,幼年组个体不参与繁殖,亚成年组个体开始参与繁殖,繁殖主体是成年组个体.     

年龄、性别及季节因素对千岛湖岛屿社鼠最大活动距离的影响

2009年7-11月及2010年3-11月,在千岛湖2个岛屿上进行社鼠(Niviventer confucianus)的标志重捕,根据春、夏、秋3个季节将重捕4次以上的社鼠进行最大活动距离计算,分析年龄、性别及季节对岛屿社鼠最大活动距离的影响.结果显示,岛屿间无显著差异;将2岛数据合并后,幼年、亚成年、成年及老年4个年龄组社鼠最大活动距离之间差异极显著;雄性社鼠最大活动距离极显著地大于雌性,4个年龄组雌雄之间的最大活动距离均表现为雄性＞雌性,但仅成年组雌雄之间存在极显著差异;春、夏、秋3个季节之间的最大活动距离差异极显著,而仅亚成年组在3个季节之间存在极显著差异,雌性和雄性社鼠均表现春季＜夏季＜秋季,但只在春季表现出雌雄个体之间差异极显著,与以往巢区研究结果不一致,可能反映了岛屿环境下社鼠巢区活动的特殊性.显示岛屿隔离环境对小型哺乳动物巢区活动有影响,但这种岛屿效应仍有待深入研究.     

小纹背鼩鼱肥满度的研究

对从四川和云南野外捕获的小纹背鼩鼱标本肥满度进行研究。结果表明,雌雄小纹背鼩鼱肥满度之间总体上无显著差异;不同年龄组间肥满度差异显著,未成年个体肥满度明显高于成年个体和老年个体;而不同地区和不同季节的小纹背鼩鼱的肥满度也呈现显著差异。     

安徽淮北农区三种鼠的种群数量动态与年龄结构的关系

本文对安徽省淮北农业区的黑线姬鼠、大仓鼠和黑线仓鼠的种群数量及与年龄组成变化的关系进行探讨。结果表明,其各鼠的年龄组成在每年的不同时段内的变化有一定的规律:各鼠主要繁殖群体的年龄组也是有区别的,如黑线姬鼠和黑线仓鼠主要是成年Ⅱ组,大仓鼠主要是成年Ⅰ组。如果种群中幼年组+亚成年组+成年Ⅰ组的比例高时,则当年数量就可能较高,如果种群中成年Ⅱ组和老年组的比例较高时,当年数量则低。     

四川短尾鼩种群年龄鉴定的研究

为给四川短尾鼩年龄鉴定提供科学合理的鉴定方法,对1996～2012年贵州省大方县捕获的134只四川短尾鼩(雌性86只,雄性48只)体重统计分析。结果表明:四川短尾鼩平均体重为(31.12±6.48)g。根据体重的频次分配特征,参照其繁殖状况,将四川短尾鼩划分为5个年龄组,制定了各年龄组的体重划分标准:幼年组(Ⅰ)体重≤23.0g,亚成年组(Ⅱ)23.1～28.0g,成年Ⅰ组(Ⅲ)28.1～33.0g,成年Ⅱ组(Ⅳ)33.1～38.0g,老年组(Ⅴ)>38.0g。体重与胴体重、体长之间具有极显著的正相关关系,依据体重与胴体重的回归方程,制定了各年龄组的胴体重划分标准:幼年组(Ⅰ)胴体重≤15.0g,亚成年组(Ⅱ)15.1～19.0g,成年Ⅰ组(Ⅲ)19.1～23.0g,成年Ⅱ组(Ⅳ)23.1～27.0g,老年组(Ⅴ)>27.0g。不同年龄组体重、胴体重之间具有显著差异,随着种群年龄的增长而不断增加。不同年龄组种群繁殖力存在显著差异,随着种群年龄的增长,种群繁殖力不断增加,参与种群繁殖的主要群体为成年Ⅰ组、成年Ⅱ组和老年组,平均怀孕率为37.10%,平均睾丸下降率为72.00%,平均繁殖指数为1.39。种群年龄组成具有明显的季节变化。     

微尾鼩冬季肥满度的初步研究

对野外捕获 2 2 2号微尾标本进行肥满度研究。结果表明 ,不同生境肥满度差异不显著 ,雌雄微尾肥满度之间无显著差异 ,不同年龄组间肥满度差异显著 ,未成年个体肥满度明显高于成年个体 ;冬季各月份肥满度与种群数量呈负相关 ,r =- 0 96 4 6 <0 ,P <0 0 1,差异极显著     

臭鼠的种群年龄结构研究

１９８６年１月至１９９３年１２月,作者在浙江萧山围垦农区采用体重法将臭　种群分为５个年龄组。雄体：Ⅰ．幼年组（体重≤３０８）、Ⅱ．亚成年组（体重＞３０９,≤４０ｇ）、Ⅲ．成年１组（体重＞４０ｇ,≤５２ｇ）、Ⅳ．成年ＩＩ组（体重＞５２８,≤６４８）、Ⅴ．老年组（体重＞６４ｇ）;雌体：幼年组（体重≤２４ｇ）,Ⅱ．亚成年组（体重＞２４ｇ;≤３６ｇ）．Ⅲ．成年Ⅰ组（体重＞３６９,≤４６ｇ）,Ⅳ．成年Ⅱ组（体重＞４６８,≤５４ｇ）,Ⅴ．老年组（体重＞５４ｇ）。各年龄组的繁殖特性存在差异。种群以成年Ⅰ组为主,但其种群的年龄结构存在有性别差异,雄性种群以成年Ⅰ组、成年Ⅱ组和老年组为主,雌性种群以亚成年组和成年Ⅰ组为主。种群的年龄结构存在季节性变化。在室内,雄性在春季和冬季以成年Ⅱ组为主,夏季和秋季以老年组为主;在室外春季、秋季和冬季均以成年Ⅰ组为主,夏季则以成年Ⅱ组为主。室内雌性在各季节均以成年Ⅰ组为主,而在室外春季和冬季以亚成年组为主,夏季和秋季以成年Ⅰ组为主。其种群年龄结构存在有年变化。     

洞庭平原黄胸鼠种群年龄组的划分

根据胴体重的频次分布和每５ｇ胴体重组的鼠所对应的发育与繁殖状况,将黄胸鼠分为５个年龄组,Ⅰ,幼年组：胴体重≤３５ｇ;Ⅱ。亚成年组,３６－６５ｇ;Ⅲ。成年一组：６６－１００ｇ;Ⅳ．成年二组：１０１－１３５ｇ;Ⅴ．老年组;〉１３５ｇ。经ｔ检验,各组间的胴体重,体重,体长尾长都有显著性的差异。各年龄组间的体重与胴体重存在显著的正相关前３个年龄组的体长和尾长与胴体重之间有极显著相关性。各年龄组的雌性比变化     

千岛湖岛屿社鼠的种群年龄结构和性比

2009年7月至11月以及2010年3月至11月在千岛湖地区2个岛屿上对社鼠(Niviventer confucianus)种群进行标志重捕,通过对社鼠种群年龄结构和性比的研究,探讨陆桥岛屿环境下生境片段化对社鼠种群结构的影响。结果显示:社鼠种群年龄结构整体上均表现为由上半年幼年组和亚成年组占优势逐渐过渡到下半年成年组和老年组占绝对优势,岛屿环境对社鼠年龄结构变化的影响与陆地环境有所不同;两岛社鼠种群数量与性比(♀:♂)之间均存在显著的负相关性(B岛2010年7-11月除外),当种群数量处于高峰期时,雌性少于雄性,而种群数量处于低潮期时,雌性多于雄性,这可能是社鼠种群数量变动内部调节机制的一种表现;由于9-10月和2-3月的繁殖高峰以及高的胎仔数,翌年上半年种群数量就能恢复并达到全年最高峰。     

The effect of cold-acclimation on energy strategies of Apodemus draco in Hengduan Mountain region

Environmental factors play an important role in the seasonal adaptation of body mass and thermogenesis in small mammals. The purpose of the present study was to test the hypothesis that ambient temperature triggers adjustments in body mass, body temperature, energy intake, digestible energy intake, metabolic energy intake, and the length and weight of the digestive tract, in Apodemus draco during 42 days of cold exposure. Body mass and body temperature of the cold-acclimated group decreased during the first 28 days and then stabilized at the lower levels. After 14 days of cold acclimation, the body mass of the cold-exposed group was significantly lower and the energy intake, digestible energy intake, and metabolic energy intake were significantly elevated relative to control animals. The differences were maximal after 21 days. The length and weight of the digestive tract (both wet and dry mass of the stomach, small intestine, large intestine, and cecum) changed significantly in response to decreasing temperature. During cold exposure, A. draco was able to maintain physiological functions and reduce its absolute energy demands by reducing the body mass, increasing energy intake, and adjusting the length of the digestive tract.     

Laboratory evaluation of the chemosterilant lufenuron against the fruit flies Ceratitis capitata, Bactrocera dorsalis, B. cucurbitae, and B. latifrons

Four species of tephritid fruit flies, Ceratitis capitata, Bactrocera dorsalis, B. cucurbitae, and B. latifrons were evaluated for toxic, developmental, and physiological responses to the chemosterilant lufenuron. No significant mortality of laboratory strains of the first three species was observed after their exposure up to 50 μg/mL of lufenuron in agar adult diet, whereas B. latifrons adults fed with 50 μg/mL of lufenuron in the diet caused significant mortality compared to the control. Fertility of C. capitata adults fed on 50 μg/mL lufenuron-fortified diet between 7 and 12 days of age was approximately 46% of the no lufenuron control. Fertility of B. dorsalis and B. latifrons adults fed on 50 μg/mL lufenuron-incorporated diet was about 45% and 62% of the control, respectively. Lufenuron did not significantly affect fertility of B. cucurbitae adults. Lufenuron did not affect fecundity of C. capitata and B. dorsalis. Fecundity of B. cucurbitae and B. latifrons was not evaluated due to difficulty to count the eggs laid deep in the agar diet. Larvae fed on a liquid larval diet with ≤ 0.1 μg/mL of lufenuron were also evaluated. Pupal recovery, adult emergence, adult fliers, mating, egg hatch, and egg production of C. capitata were significantly decreased, while for B. dorsalis, pupal recovery, larval duration and adult emergence were affected. No effect of lufenuron on B. cucurbitae larvae was observed. B. latifrons was not performed because shortage of eggs at the time of this research. Lufenuron is a potential agent for management and control of C. capitata and B. dorsalis.     

不同群落中米氏冰草和羊草的年龄结构动态

米氏冰草和羊草都是根茎型禾草,是典型的无性系植物。采取单位面积挖掘取样法,对呼伦贝尔沙地植被次生演替过程中的米氏冰草和羊草种群分株年龄结构进行调查。结果表明,在单生和混合群落中,米氏冰草分株分别由3和4个年龄级组成,羊草均由2个年龄级组成;米氏冰草分株数量和生物量年龄结构变化基本一致,即随着生长年限的延长,呈减少低龄级和增加高龄级比例的趋势,使单生群落中始终为增长型,但接近于稳定型,混生群落中由增长型变为稳定型。羊草分株数量和生物量年龄结构在连续2a均为明显的增长型。羊草各龄级平均单株生产力均高于米氏冰草,平均是米氏冰草的5.2倍。米氏冰草和羊草种群分株年龄结构的变化,蕴含着米氏冰草种群的优势地位将被羊草种群取代的趋势。     

Genetic detection and quantification of Nosema apis and N. ceranae in the honey bee

The incidence of nosemosis has increased in recent years due to an emerging infestation of Nosema ceranae in managed honey bee populations in much of the world. A real-time PCR assay was developed to facilitate detection and quantification of both Nosema apis and N. ceranae in both single bee and pooled samples. The assay is a multiplexed reaction in which both species are detected and quantified in a single reaction. The assay is highly sensitive and can detect single copies of the target sequence. Real-time PCR results were calibrated to spore counts generated by standard microscopy procedures. The assay was used to assess bees from commercial apiaries sampled in November 2008 and March 2009. Bees from each colony were pooled. A large amount of variation among colonies was evident, signifying the need to examine large numbers of colonies. Due to sampling constraints, a subset of colonies (from five apiaries) was sampled in both seasons. In November, N. apis levels were 1212 ± 148 spores/bee and N. ceranae levels were 51,073 ± 31,155 spores/bee. In March, no N. apis was detected, N. ceranae levels were 11,824 ± 6304 spores/bee. Changes in N. ceranae levels were evident among apiaries, some increasing and other decreasing. This demonstrates the need for thorough sampling of apiaries and the need for a rapid test for both detection and quantification of both Nosema spp. This assay provides the opportunity for detailed study of disease resistance, infection kinetics, and improvement of disease management practices for honey bees.     

The influence of bioturbation by the sandprawn Callianassa kraussi on feeding and survival of the bivalve Eumarcia paupercula and the gastropod Nassarius kraussianus

Field observations and experimental evidence have shown that bioturbation by the southern African sandprawn Callianassa kraussi may significantly influence the abundance and distribution of the filter-feeding bivalve Eumarcia paupercula and the grazing gastropod Nassarius kraussianus. It was hypothesized that (1) sediment reworking by C. kraussi negatively affects microalgal growth on the sediment surface, leading to a reduction in food intake by N. kraussianus, (2) sediment deposited by C. kraussi will also diminish the food uptake of E. paupercula by interfering with its filtration mechanism. To test these hypotheses, manipulative field and laboratory experiments were undertaken in which N. kraussianus and E. paupercula were added to treatments with and without C. kraussi, and their survival and gut chlorophyll-a content measured. The effects of C. kraussi on sediment erodability and on condition of E. paupercula (tissue mass/shell length) were determined in a second experiment. In the presence of C. kraussi, (1) microalgal consumption by both N. kraussianus and E. paupercula was halved; (2) condition and survival of E. paupercula were significantly reduced but survival of N. kraussianus was unaffected; and (3) sediment erodability was increased. A significant negative relationship was established between sediment erodability and condition of E. paupercula. Evidently C. kraussi exerts a strongly negative influence on the feeding of E. paupercula and N. kraussianus, and this may explain the scarcity of these organisms in areas containing high densities of C. kraussi.     

Asymmetrical coexistence of Nosema ceranae and Nosema apis in honey bees

Globalization has provided opportunities for parasites/pathogens to cross geographic boundaries and expand to new hosts. Recent studies showed that Nosema ceranae, originally considered a microsporidian parasite of Eastern honey bees, Apis cerana, is a disease agent of nosemosis in European honey bees, Apis mellifera, along with the resident species, Nosema apis. Further studies indicated that disease caused by N. ceranae in European honey bees is far more prevalent than that caused by N. apis. In order to gain more insight into the epidemiology of Nosema parasitism in honey bees, we conducted studies to investigate infection of Nosema in its original host, Eastern honey bees, using conventional PCR and duplex real time quantitative PCR methods. Our results showed that A. cerana was infected not only with N. ceranae as previously reported [Fries, I., Feng, F., Silva, A.D., Slemenda, S.B., Pieniazek, N.J., 1996. Nosema ceranae n. sp. (Microspora, Nosematidae), morphological and molecular characterization of a microsporidian parasite of the Asian honey bee Apis cerana (Hymenoptera, Apidae). Eur. J. Protistol. 32, 356-365], but also with N. apis. Both microsporidia produced single and mixed infections. Overall and at each location alone, the prevalence of N. ceranae was higher than that of N. apis. In all cases of mixed infections, the number of N. ceranae gene copies (corresponding to the parasite load) significantly out numbered those of N. apis. Phylogenetic analysis based on a variable region of small subunit ribosomal RNA (SSUrRNA) showed four distinct clades of N. apis and five clades of N. ceranae and that geographical distance does not appear to influence the genetic diversity of Nosema populations. The results from this study demonstrated that duplex real-time qPCR assay developed in this study is a valuable tool for quantitative measurement of Nosema and can be used to monitor the progression of microsprodian infections of honey bees in a timely and cost efficient manner.     

湖北石首麋鹿昼间活动时间分配

为探讨性别、年龄和季节对麋鹿(Elaphurus davidianus)行为的影响,2006年9月-2007年10月,作者采用焦点取样法和瞬时记录法,将麋鹿昼间活动归为采食、饮水、运动、休息、警觉、其他行为等六大类型,每月6-8 d对湖北石首麋鹿国家级自然保护区麋鹿种群的昼间活动时间分配进行了跟踪观察.结果表明:麋鹿有晨、昏两个采食高峰和一个午间休息期,各种行为类型所占比例依次是:休息53.40％(±5.59％)、采食22.36(±8.34％)、运动11.23％(±0.63％)、警觉5.03％(±1.76％)、其他行为4.42％(±2.06％),饮水2.65％(±0.74％).不同季节,时间分配变化明显.非参数Kruskal Wallis H检验结果显示(n=120),季节、年龄和性别显著影响麋鹿的活动时间分配.除运动行为(x2=16.856,df=3,P＞0.05)和饮水行为(x2=7.667,df=3,P＞0.05)无显著差异外,采食(x2=15.657,df=3,P＜0.01)、休息(x2=13.173,df=3,P＜0.01)、警觉(x2 =13.887,df=3,P＜0.01)和其他行为(x2=16.317,df=3,P＜0.01)在不同季节所占时间百分比均有极显著差异.对不同性别年龄组的活动时间分配采用两个独立样本的Mann-Whitney U检验,各性别-年龄组间的运动行为所占时间比例有极显著差异(P＜0.01),雄鹿与雌鹿之间的警觉行为有极显著差异(P＜0.01),雄鹿花较多时间用于警觉.幼鹿与成年鹿及亚成年鹿之间的采食行为时间有极显著差异(P＜0.01).不同性别、年龄组在不同季节的昼间活动时间分配的差异采用方差(ANOVA)分析后发现:所有年龄组,夏季与冬季饮水、春季与夏季警觉均存在显著性差异(P＜0.01);成体和亚成体麋鹿,春季与冬季警觉、夏季与冬季运动均存在显著性差异(P＜0.01).     

Flower removal increases rhizome mass in natural populations of Alstroemeria aurea (Alstroemeriaceae)

Plant architecture and phenotypic plasticity under natural conditions remain little known for many rhizomatous species. This study evaluates, in situ, the plastic responses of Alstroemeria aurea plants from three Patagonian populations to flower or flowering-shoot removal. The size and architecture of treated and untreated plants were assessed. Nutrient contents (N, P and K) were evaluated for rhizomes and roots developed in two successive years. Those plants that were deprived of their inflorescences developed, on average, a heavier rhizome than both control plants and plants from which flowering shoots had been removed. Neither of the two treatments applied altered the number of metamers or the branching pattern of the rhizomes. The contents of N, P and K were higher in rhizomes than in roots. In summer, nutrients were more concentrated in inflorescences and the new rhizome segment than in the rhizome segment developed in the previous year. The idea that fruiting failure in A. aurea promotes resource re-assignment from aerial shoots to rhizomes without altering the architecture of plants is supported. The development of the underground portion of aerial shoots in late summer-autumn allows A. aurea plants to take full advantage of short growth periods, but would impose a limit to plasticity.