南奥克尼群岛海域南极磷虾形态学特征及脂质含量

鉴别了所选南奥克尼群岛海域南极磷虾(Euphausia superba)样本的性别,测量了磷虾的体长、头胸甲长、尾长等形态学参数及其体重,并从形态学及生理的角度进行了相关分析。用索氏抽提法对磷虾虾肉干样的总脂质含量进行了测量。结果表明:南奥克尼群岛海域南极磷虾的雌雄性别比为1.90∶1,体长小于50.00 mm的个体雌雄比为1.23∶1,体长大于或等于50.00 mm的个体雌雄比为2.65∶1;雌性和雄性个体的体长均不符合正态分布;该批磷虾的体重与体长之间存在较显著的幂函数关系,头胸甲长和体长之间没有明显的函数关系,雌性个体尾长与体长之间存在较弱的线性关系,体长与头胸甲长和尾长之和存在较显著的对数函数关系;总脂质含量,雌性个体高于雄性,体长较大个体高于较小个体。     

粤北地区中国石龙子活动节律和食性的初步研究

粤北地区分布的中国石龙子（Eumeces chinensis)雌性头体长90mm开始性成熟，雄性头体长100mm开始性成熟，体全长200－300mm的个体占73％，体全长175mm以下的个体明显减少，数量呈下降趋势，主要食物为环节、软体和节肢动物。     

中华蟾蜍两性异形研究

用采自牡丹江地区的86只(59♀♀,27♂♂)成体中华蟾蜍(Bufo gargarizans)进行两性异形研究.分别测量头体长、头长、头宽等6个形态特征指标并进行检验.结果表明:中华蟾蜍雌性平均头体长为(70.89±1.69)mm(n=59),雄性的平均头体长为(64.34±1.66)mm(n=27),雄性体长明显小于雌性,雌性头体长与雄性头体长的比值为1.102,且两性头体长存在显著差异.雌雄两性的头长、头宽、前臂及手长、后肢长与胫长等形态学特征均与头体长具有显著相关性.两性的胫长存在显著差异,头长、头宽、前臂及手长、后肢长、胫长随体长的生长速率具有明显差异.     

五种蝰科蛇尾长的两性异形和种间差异

测定五种分布于浙江的蝰科蛇类的体长和尾长,检测尾长的两性异形和种间差异。五种蝰科蛇的两性个体尾长均与体长呈显著的正相关,五种蝰科蛇间体长差异显著。协方差分析显示雄性的尾长显著大于雌性。除烙铁头、竹叶青之间其余相对尾长的差异显著。     

长白山中国林蛙肥满度及体尺指标分析

对长白山中国林蛙的肥满度及体尺指标状况进行了调查分析,结果表明:长白山中国林蛙肥满度的变化范围为6.68～11.83,不同大小、性别的个体肥满度有一定差别,其总体变化规律为幼蛙>雄性成蛙>雌性成蛙.体质量与体长比随体长的增长而增大,最小(体长1.8 cm)0.28 g/cm,最大(体长8.0 cm)5.06 g/cm;雌蛙的体质量水平总体上小于雄蛙,但仅在较小成蛙样本间表现为差异显著.体质量与体长的增长呈幂函数相关,幼蛙、雌性成蛙和雄性成蛙分别具有不同b值(幂指数),其中幼蛙和雄性b<3,雌性成蛙b>3.     

青海沙蜥(蜥蜴亚目:鬣蜥科)种群的年龄结构与性别比

根据2001和2002两年间6个月的标志重捕资料，在对分布于四川西北部若尔盖草原的青海沙蜥（Phrynacephalus vlangalii)的体长、体重和尾长3组数据进行相关分析的基础上，分别对这3组数据进行聚类分析。最后选取体长的聚类分析结果把青海省沙蜥的所有个体分成3个年龄组，3个年龄组的体长范围分别是：26－36mm;37-50mm;51-65mm。各年龄组体长、体重和尾长平均值差异的F检验结果，说明用体长划分年龄较为合理。青海沙蜥种群的年龄结构基本上呈金字塔形，但第Ⅱ年龄组个体数比例较小。青海沙蜥各年龄组的性别比在3个年龄组间是不稳定的，第Ⅰ，Ⅱ，Ⅲ3个年龄组雌雄个体数量的比分别为7.7:1,32:1和1:2.1，而在整个种群中雌雄个体的比为1.76:1。青海沙蜥的体形大小的性二态在其性成熟前后是相反的。     

粤北南岭无斑肥螈的雌雄异形及雌性繁殖的研究

报道了粤北南岭无斑肥螈(Pachytriton labiatus)的两性异形和雌性繁殖.性成熟两性个体全长、头体长和体重之间差异显著,成年雌体全长、头体长、体重显著大于雄性.成体头长、头宽、尾长没有显著差异.当雌体平均全长大于127.84mm,雄体平均全长大于121.24mm时,卵巢和精巢才开始明显发育.性腺表现出明显的季节性变化,5～8月为卵巢的快速生长期,8、9、10月份卵巢重量平均值最大,12月至翌年1月降为最低值,卵巢可以划分成4个发育时期,产卵盛期在9～10月份.     

华南湍蛙的两性异形

2014年7月,在浙江开化古田山国家级自然保护区,用数显游标卡尺测量了161只华南湍蛙(Amolops ricketti)个体的头体长等12项形态指标,分析了华南湍蛙的个体大小和两性异形.结果表明,除眼间距外,其余的11个形态特征均与物种的头体长呈显著的相关关系.进一步的分析显示:华南湍蛙雌性成体的头体长、头长、头宽、吻长、眼间距和前臂及手长等形态特征均显著大于雄性成体;雌性成体头宽的生长速率明显快于雄性个体;雄性成体的眼间距与亚成体存在显著差异;而雌性成体则在眼间距和胫长2个形态特征上显著大于亚成体.     

六种游蛇属蛇尾长的两性异形和种间差异

测定六种分布于浙江的游蛇属蛇类的体长和尾长,检测尾长的两性异形和种间差异.六种游蛇属蛇的两性个体尾长均与体长呈显著的正相关,六种游蛇属蛇间体长差异显著.协方差分析显示渔游蛇、草游蛇、虎斑游蛇的雄性的尾长显著大于雌性,水赤链游蛇、锈链游蛇、乌游蛇的尾长无显著的两性差异.种间相对尾长的差异显著.     

中华假磷虾发光器大小与结构的研究

中华假磷虾有１０个发光器：眼柄１对，胸部２对，腹部４个。发光器的大小随体长而异，体长越长，发光器越大；不同性别发光器的大小也有差异；雌性个体较雄性大；同一个体不同部位发光器大小也不同，以眼柄处最大，腹部次之，胸部最小。发光器的结构一般由发光体、晶体、内细胞团、反射器和外胚层细胞构成。位于胸部和腹部的发光器具有上述典型结构，而位于眼柄的发光器仅由发光体、内细胞团和反射器组成。     

Unusually dynamic sex roles in a fish

Sex roles are typically thought of as being fixed for a given species. In most animals males compete for females, whereas the females are more reluctant to mate. Therefore sexual selection usually acts most strongly on males. This is explained by males having a higher potential reproductive rate than females, leading to more males being sexually active (a male-biased operational sex ratio). However, what determines sex roles and the strength of sexual selection is a controversial and much debated question. In this large-scale field study, we show a striking temporal plasticity in the mating competition of a fish (two-spotted goby, Gobiusculus flavescens). Over the short breeding season fierce male-male competition and intensive courtship behaviour in males were replaced by female-female competition and actively courting females. Hence, sex role reversal occurred rapidly. This is the first time that a shift in sex roles has been shown in a vertebrate. The shift might be explained by a large decline in male abundance, strongly skewing the sex ratio towards females. Notably, the sex role reversal did not occur at an equal operational sex ratio, contrary to established sex role theory.     

Intrasexual competition and sexual selection in cooperative mammals

In most animals, the sex that invests least in its offspring competes more intensely for access to the opposite sex and shows greater development of secondary sexual characters than the sex that invests most. However, in some mammals where females are the primary care-givers, females compete more frequently or intensely with each other than males. A possible explanation is that, in these species, the resources necessary for successful female reproduction are heavily concentrated and intrasexual competition for breeding opportunities is more intense among females than among males. Intrasexual competition between females is likely to be particularly intense in cooperative breeders where a single female monopolizes reproduction in each group. Here, we use data from a twelve-year study of wild meerkats (Suricata suricatta), where females show high levels of reproductive skew, to show that females gain greater benefits from acquiring dominant status than males and traits that increase competitive ability exert a stronger influence on their breeding success. Females that acquire dominant status also develop a suite of morphological, physiological and behavioural characteristics that help them to control other group members. Our results show that sex differences in parental investment are not the only mechanism capable of generating sex differences in reproductive competition and emphasize the extent to which competition for breeding opportunities between females can affect the evolution of sex differences and the operation of sexual selection.     

155mm掠入射平场谱仪的理论研究

介绍了一种用于测量软X线的掠入射平场谱仪,依据变栅距刻线光栅的光路函数,计算了曲率半径为5 649 mm的光栅各点的间距,并推导和计算了入射光源为点光源时在聚焦平面上形成的聚焦点的分布,验证了先前文献中给出的结论.进一步计算了当改变入射距离为155 mm时所形成的像散,理论上验证了缩短入射距离后谱仪的可用性.     

太行山猕猴掌面花纹嵴数的性差

用太行山猕猴掌面花纹嵴数变量建立性别判别函数。测量25例(雌17例,雄8例)太行山猕猴掌面指间Ⅱ-Ⅳ区花纹的嵴数。用SPSS13.0统计软件进行多变量分析.选择掌面纹线脊数变量建立性别判别函数。结果表明:10项变量中有5项在雌雄之间达到显著性差异(P0.05),太行山猕猴的掌面花纹嵴数具有明显的性差,性别的正确的判别率为88.0～100.0%.     

青海湖裸鲤寄生湟鱼棘头虫的种群季节动态研究

以在青海湖收集的寄生于青海湖裸鲤的湟鱼棘头虫（Ｅｃｈｉｎｏｒｈｙｎｃｈｕｓ ｇｙｍｎｏｃｙｐｒｉｉ）４个季节的样本研究湟鱼棘头虫种群的季节动态,结果表明：种群的平均丰度,感染强度和感染率都没有明显季节变化。这与湟鱼棘头虫温度依赖死亡、中间宿主的季节数量动态,宿主食性的季改变有关。湟鱼棘头虫种群在宿主种群的分布在各季度中都是聚集性的,这与宿主食性的分化及第一中间宿主（钩虾）的分布不均匀性有关。雄虫体     

猕猴骶骨性别判别分析

目的:探讨太行山猕猴骶骨指数性差.材料和方法:成年猕猴骶骨标本55例(雄17,雌38).选择骶骨5个线性变量和4个指数变量;统计处理采用ANOVA、多元判别分析和二元逻辑回归分析.结果:大部分骶骨线性变量存在性差(P0.05),雄性大于雌性;猕猴骶骨相对宽指数性差显著(P0.01),雌性大于雄性.多元判别分析性别正确判别率为78.2%~87.3%.逻辑回归分析性别正确判别率为83.6%~87.3%.结论:骶骨变量性差显著,骶骨体长和骶骨相对宽性别判别的能力较强.     

Sexual selection and the maintenance of sexual reproduction

The maintenance of sexual reproduction is a problem in evolutionary theory because, all else being equal, asexual populations have a twofold fitness advantage over their sexual counterparts and should rapidly outnumber a sexual population because every individual has the potential to reproduce. The twofold cost of sex exists because of anisogamy or gamete dimorphism-egg-producing females make a larger contribution to the zygote compared with the small contribution made by the sperm of males, but both males and females contribute 50% of the genes. Anisogamy also generates the conditions for sexual selection, a powerful evolutionary force that does not exist in asexual populations. The continued prevalence of sexual reproduction indicates that the 'all else being equal' assumption is incorrect. Here I show that sexual selection can mitigate or even eliminate the cost of sex. If sexual selection causes deleterious mutations to be more deleterious in males than females, then deleterious mutations are maintained at lower equilibrium frequency in sexual populations relative to asexual populations. The fitness of sexual females is higher than asexuals because there is no difference in the fecundity of sexual females and asexuals of the same genotype, but the equilibrium frequency of deleterious mutations is lower in sexual populations. The results are not altered by synergistic epistasis in males.     

山东汉族7项不对称行为特征的研究

在山东省寿光市调查了370例(男215例,女155例)山东汉族高中生扣手、利手、叠臂、叠腿、利足、起步、优势眼共7项不对称行为特征.研究结果显示:(1)山东汉族除扣手和起步的出现率左型高于右型外,其余5项的出现率均右型高于左型;(2)山东汉族除扣手存在性别间差异外,其他6项均无性别间差异;(3)u检验显示,山东汉族7项指标与蒙古族、布依族、达斡尔族和鄂温克族差异较大;(4)u检验显示,山东汉族与其他7个地区汉族人群比较,与天津汉族差异较大,与其他6个地区汉族差异相对较小;(5)山东汉族扣手与叠腿,利手与利足,利手与起步,叠腿与利手,起步与利足之间存在显著的相关性,且右型—右型组合的出现率远高于左型—左型组合的出现率;(6)聚类分析结果表明,山东地区汉族与内蒙古阿盟汉族、兴安盟汉族、巴盟汉族、回族、朝鲜族及藏族更为接近.     

Population density affects sex ratio variation in red deer.

Many mammal populations show significant deviations from an equal sex ratio at birth, but these effects are notoriously inconsistent. This may be because more than one mechanism affects the sex ratio and the action of these mechanisms depends on environmental conditions. Here we show that the adaptive relationship between maternal dominance and offspring sex ratio previously demonstrated in red deer (Cervus elaphus), where dominant females produced more males, disappeared at high population density. The proportion of males born each year declined with increasing population density and with winter rainfall, both of which are environmental variables associated with nutritional stress during pregnancy. These changes in the sex ratio corresponded to reductions in fecundity, suggesting that they were caused by differential fetal loss. In contrast, the earlier association with maternal dominance is presumed to have been generated pre-implantation. The effects of one source of variation superseded the other within about two generations. Comparison with other ungulate studies indicates that positive associations between maternal quality and the proportion of male offspring born have only been documented in populations below carrying capacity.     

猕猴掌骨长比、性差与活动强度关系研究

目的:研究猕猴掌骨长比、活动强度和性差之间的关系.方法:掌骨标本32例(雄8例,雌24例).选择变量为掌骨长比3M:5M和4M:5M.用SPSS19.0统计软件进行单因素方差分析.结果:猕猴不同活动强度组之间的3M∶5M和4M∶5M比值存在差异(P<0.05).整体水平雌性掌骨长比大于雄性掌骨长比.同一性别组中猕猴3M∶5M和4M∶5M与活动强度呈正相关.结论:猕猴一些掌骨长比与其活动强度关系密切.提示掌骨长比与指长比可能有不同的发育机制和发育历程,主要与胚胎期的和成年期的睾酮浓度有关.