湖南平江棘胸蛙两性异形和雌性个体生育力

测定了湖南平江棘胸蛙成体的体长、体质量、头长、头宽、前肢长、后肢长等形态指标以及雌体的怀卵数量．结果表明：棘胸蛙雄体体长和体质量显著大于雌体．以体长为协变量的多元方差分析表明,雌雄两性在局部形态上不存在显著差异．各局部形态特征指标与体长呈正相关,它们随体长的增长速率在雌雄间无显著差异．棘胸蛙雌体怀卵量与体长和体质量皆成正相关关系,表明棘胸蛙通过增加个体的大小增加繁殖输出．     

金线侧褶蛙的两性异形及雌性繁殖特征的研究

测定了金线侧褶蛙成体的8个主要形态指标和雌体的怀卵量．结果表明。各形态指标均与体长呈正相关，金线侧褶蛙雌体的体长和体重均显大于雄体．以体长为协变量的协方差分析表明。只有雄体的鼓膜径显大于雌体．而头长、头宽、眼径、前肢长和后肢长不存在明显的两性差异．雌蛙怀卵量与自身体重和体长成正相关．表明该蛙通过增加个体大小增加繁殖输出．     

棘腹蛙的两性异形及雌性繁殖特征

为研究棘腹蛙的两性异形及雌性繁殖特征,测定了采自广西龙胜和贵州凯里棘腹蛙成体的体长、头宽、前肢长、后肢长、足长5项形态学指标及雌体的怀卵数量.用SPSS 20.0统计软件分析测量获得的数据.结果表明:成年雄性棘腹蛙体长、头宽、前肢长、后肢长、足长均值都较雌性棘腹蛙大,棘腹蛙存在显著的两性差异;雌雄两性前肢长、后肢长、足长与体长呈正相关,它们随体长的增长速率在雌雄间无显著差异;雄性体长对雌性体长的比值为1.08,棘腹蛙的两性异形程度为0.075,棘腹蛙怀卵数量与体长呈正相关.表明成年雄性棘腹蛙体长、头宽、前肢长、后肢长、足长均值都较雌性棘腹蛙大,且通过增加个体大小增加繁殖输出.     

草原沙晰（Phyrnocephalus frontalis）生殖策略的研究

草原沙晰（Phyrnocephalus frontalis）每年产卵一次，平均窝卵数为3，平均生殖投入（卵重／体重）为0.164，生殖投入与体长、体重、年龄不相关；窝卵数与生殖投入显著正相关，y=0.025x 0.095,r=0.462，即生殖投入随窝卵数增加而增加；体重与窝卵数显著正相关y=0.35x 0.86,r=0.65；体长与窝卵数刀显著正相关，y=0.1x-2.45,r=0.51。根据繁列期前后性比（♀/♂）的变化，推测部分雌晰繁殖后死亡，说明生殖对雌性有一定的损害作用，根据各项生态学特征的比较，草原沙晰的繁殖策略属K选择。     

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.     

比较不同pH值对萼花臂尾轮虫(Brachionus calyciflorus)繁殖的影响

萼花臂尾轮虫的生活史有三种独立的个体——非混交雌体、混交雌体和雄体。非混交雌体繁殖的唯一方法是孤雌生殖,它们的卵带有双倍数目的染色体,在不良的环境条件下,非混交雌体产的卵,会发育为混交雌体。本文仅以非混交雌体为材料,了解不同PH值对它们的繁殖影响及该种轮虫产生混交雌体的条件。萼花臂尾轮虫分布广、且个体出现的数量很多,个体全长300—350μm,宽180—190μm[1],个体平均生物量为2.5μg[4],轮虫是主要经济鱼类在鱼苗阶段的主要饵料,在水产养殖上具有重要的经济价值[2]。     

无蹼壁虎的产卵习性

无蹼壁虎是一种季节性繁殖的爬行动物，出蛰后的雌体卵巢迅速增大，产卵期一般从５月中旬至８月，对产卵场所有一定的选择性，产粘性卵．在一个繁殖季节中，雌体产卵一窝，但部分雌体可能产第二窝卵。旧碉堡内的壁虎卵孵化期为４５～６５ｄ。     

青海沙蜥的生长及两性生长差异

为了研究自然生境中沙蜥的生长和两性生长差异情况，于2001～2002两年间对分布在四川西北部若尔盖地区的青海沙蜥（Phrynocephalus vlangalii）进行了6次标志重捕．结果表明：第一年8、9月出生的沙蜥到第二年的6月SVL、TL和BM都有显著的生长（P〈0、05），雌、雄个体的两性生长差异不显著（P〉0．05）；第二年6月至8、9月间，雌、雄个体的SV、TL和BM都有快速的生长（P〈0．01），从7月份开始出现了两性生长差异（雌性的生长速度小于雄性）（P〈0．01）；第三年的6月至8月间，雌性的SVL、TL和BM仍在快速生长（P〈0．01），而雄性的生长则不显著（P〉0．05），雌性的三个生长指标的生长量远大于雄性（P〈0．01），并且SVL和BM的生长量与第二年的同期生长量非常接近（P〉0．05）；四年以后，雌、雄个体的SVL和TL的生长及两性生长差异都不再显著（P〉0．05），但是在体形大小上还存在极显著的两性异形（P〈0．01）．在青海沙蜥的生长发育过程中，雄性的生长曲线近似“S”形，而雌性则是非“S”形．雌、雄个体的生长受季节和年龄的影响，造成雌、雄两性成长差异的主要原因是雌、雄个体对繁殖的能量投入不平衡．     

红耳龟的人工养殖

目的：通过红耳龟人工养殖技术的研究,促进红耳龟人工养殖的开展。方法：在本校爬行动物养殖场对红耳龟的生物学特性、养殖技术及病害防治进行了研究。结果：红耳龟的产卵高峰期为6月下旬和7月上旬,每只雌龟每年产1－2窝卵,窝卵量平均为12枚,卵的受精率为91．67％,卵化率为86．71％,常见的疾病有背腹甲畸形、腐皮病、疖疮病和水霉病。结论：红耳龟是适合推广养殖的优良品种。     

黑尾近红Ba个体繁殖力的研究

研究了长江上游泸州地区64尾黑尾近红Ba的个体繁列力变动及其雌亲体多项形态学指标的关系，结果表明：黑尾近红Ba的个体绝对繁殖力（F）平均为35726．81（4541－114356）粒；个体相对繁殖力（F／l）平均为1604．03（273．55－4462．61）粒／cm，F／m0平均为277．28（42．76－601．42）粒／g，个体绝对繁殖力（F）、个体相对繁殖力（F／l）与体长（l)、净体质量（m0)、年龄（t）、成熟系数（M）均呈显著线性正相关；相对繁殖力体（F／m0)除与成熟系数（M）成直线正相关外，与其它形态指标相关不显著；个体繁殖力随丰满度（K）变化不明显。     

人工巢箱下麻雀窝卵数和生长发育初探

2010年3～5月在人工巢箱条件下,对河池学院校园的麻雀繁殖生态进行了研究。收集的数据有麻雀的窝卵数、卵的特征值、雏鸟生长发育特征等。统计分析表明：麻雀4月初产卵,卵长径为18.85mm±0.98mm、短径为13.76 mm±0.54 mm、卵重为1.89 g±0.31 g、窝卵数3.33枚±1.00枚,育雏期15～18 d。雏鸟体重及外部器官的形态学参数可以用Logistic曲线方程很好地拟合,体重、翅长、跗跖、嘴峰长及18日龄前的尾长均呈＂S＂型。     

Egg recognition and counting reduce costs of avian conspecific brood parasitism

Birds parasitized by interspecific brood parasites often adopt defences based on egg recognition but such behaviours are puzzlingly rare in species parasitized by members of the same species. Here I show that conspecific egg recognition is frequent, accurate and used in three defences that reduce the high costs of conspecific brood parasitism in American coots. Hosts recognized and rejected many parasitic eggs, reducing the fitness costs of parasitism by half. Recognition without rejection also occurred and some hosts banished parasitic eggs to inferior outer incubation positions. Clutch size comparisons revealed that females combine egg recognition and counting to make clutch size decisions--by counting their own eggs, while ignoring distinctive parasitic eggs, females avoid a maladaptive clutch size reduction. This is clear evidence that female birds use visual rather than tactile cues to regulate their clutch sizes, and provides a rare example of the ecological and evolutionary context of counting in animals.     

紫蓬山区金腰燕繁殖生态研究

作者报道了1996年4－7月安徽紫蓬山区的金腰燕繁殖生态．结果表明,金腰燕4月初开始繁殖,巢营在室内檐下,窝卵数5．5枚,孵化期18天,育雏期28天,雏鸟体重增长的方程为     

变色沙蜥繁殖的研究

作者通过研究证明变色沙蜥Ｐｈｒｙｎｏｃｅｐｈａｌｕｓ ｖｅｒｓｉｃｏｌｏｒ的繁殖活动具有明显的季节性。雄晰性成熟时最小吻－肛长为４５ｍｍ，吻－肛长大的雄晰在一年中成熟精子出现早且维持时间长。雌蜥性成熟时的最小吻－肛长为４１ｍｍ，产卵期为５月末至７月末，每只雌性成蜥每年产卵一次，吻－肛长大的雌蜥产卵多而大且比吻－肛长小的雌晰产卵早。     

Post-mating clutch piracy in an amphibian

Female multiple mating and alternative mating systems can decrease the opportunity for sexual selection. Sperm competition is often the outcome of females mating with multiple males and has been observed in many animals, and alternative reproductive systems are widespread among species with external fertilization and parental care. Multiple paternity without associated complex behaviour related to mating or parental care is also seen in simultaneously spawning amphibians and fishes that release gametes into water. Here we report 'clutch piracy' in a montane population of the common frog Rana temporaria, a reproductive behaviour previously unknown in vertebrates with external fertilization. Males of this species clasp the females and the pair deposits one spherical clutch of eggs. No parental care is provided. 'Pirate' males search for freshly laid clutches, clasp them as they would do a female and fertilize the eggs that were left unfertilized by the 'parental' male. This behaviour does not seem to be size-dependent, and some males mate with a female and perform clutch piracy in the same season. Piracy affected 84% of the clutches and in some cases increased the proportion of eggs fertilized, providing direct fitness benefits both for the pirate males and the females. Sexual selection--probably caused by a strong male-biased sex ratio--occurs in this population, as indicated by size-assortative mating; however, clutch piracy may reduce its impact. This provides a good model to explore how alternative mating strategies can affect the intensity of sexual selection.     

Variation in egg size and nestling growth rate in relation to clutch size and laying sequence in great tits Parus major

The objectives of this study were to examine (1) optimal clutch size in great tits (Parus major) nesting in nest boxes; (2) variation in egg morphology and nestling growth rate with position in the laying sequence; and (3) hatching asynchrony and nestling survival as determined by infrared nest cameras. We collected data from 73 clutches in artificial nest boxes in the Zuojia Natural Preserve area in Jilin Province, China, in 2005 and 2006, using infrared cameras to match laying order to hatching order for four nests. Egg morphology and growth rate were significantly affected by clutch size and position in the laying order. Overall, egg size and growth rate increased with position in the laying order. In general, it was difficult to detect asynchronous hatching from observations alone, but data from our infrared cameras showed that early-laid eggs tended to hatch before later-laid eggs, leading to hatching asynchrony. However, females invested more into last-laid eggs and nestlings, reducing size asynchrony among the chicks and leading to higher survival rates of nestlings. Our results, therefore, provide support for the"brood survival"hypothesis rather than for the"brood reduction"hypothesis.     

Condition-dependent signalling of genetic variation in stalk-eyed flies

Handicap models of sexual selection predict that male sexual ornaments have strong condition-dependent expression and this allows females to evaluate male genetic quality. A number of previous experiments have demonstrated heightened condition-dependence of sexual ornaments in response to environmental stress. Here we show that genetic variation underlies the response to environmental stress (variable food quality) of a sexual ornament (male eye span) in the stalk-eyed fly Cyrtodiopsis dalmanni. Some male genotypes develop large eye span under all conditions, whereas other genotypes progressively reduce eye span as conditions deteriorate. Several non-sexual traits (female eye span, male and female wing length) also show genetic variation in condition-dependent expression, but their genetic response is entirely explained by scaling with body size. In contrast, the male sexual ornament still reveals genetic variation in the response to environmental stress after accounting for differences in body size. These results strongly support the hypothesis that female mate choice yields genetic benefits for offspring.     

中国石龙子头、体大小的性二态

本文研究中国石龙子（Ｅｕｍｅｃｅｓｃｈｉｎｅｎｓｉｓ）头、体大小的性二态。成雄体长和体重略大于成雌，但在统计上无明显差异。雌雄亚成体相对头长，相对头宽和相对头高无显著差异。成雄相对头长、相对头宽和相对头高显著大于成雌和亚成体。亚成体相对头长、相对头宽和相对头高与成雌无显著差异。雄性性成熟后头部的生长显著大子雌性。     

松墨天牛取食和产卵特性研究

【目的】松墨天牛是一种重要的松林蛀干害虫,也是亚洲地区松材线虫最主要的媒介昆虫,研究松墨天牛取食能力与环境温度、天牛性别以及体质量的关系,分析松墨天牛产卵能力与松树树皮厚度、树干直径以及天牛体质量的关系,为松墨天牛的科学防治提供参考。【方法】从养虫笼中收集天牛,选择体质量(M)在0.3 g≤M<0.6 g的松墨天牛放置在昆虫培养箱中,设置4个温度梯度(25、30、35和40℃),比较不同温度条件下天牛的取食能力;选取体质量相似的5头雌成虫和5头雄成虫于昆虫培养箱中,比较天牛雌雄成虫取食差异;选择不同体质量(M<0.3 g, 0.3 g≤M<0.6 g和M≥0.6g)天牛放置在温度相同的昆虫培养箱中,比较不同体质量天牛取食能力。在养虫桶中放入直径(D)不同(2.0 cm相似文献