大山雀身体大小的性二态及其季节变化

动物中普遍存在雌雄个体身体大小的性二态现象。了解近缘种之间身体大小性二态现象的差异，可为深入探讨身体大小性二态现象的潜在驱动机制提供证据。国外对欧亚大山雀（Parus major）的研究发现，其喙长、跗跖长、翅长等 6 项身体大小指标存在着明显的性二态，且喙长的性二态存在季节间差异。大山雀（P. cinereus）曾被作为欧亚大山雀的一个亚种，其形态和行为与欧亚大山雀存在着诸多相似之处。为探讨大山雀是否也存在身体大小性二态及季节性差异，本研究分析了 2018 至 2020 年间在河南董寨国家级自然保护区捕捉的 226 只（雌性 96 只和雄性 130 只）大山雀的喙长、头喙长、跗跖长、翅长、尾长和体长这 6 项体征指标的两性差异及其季节变化。结果显示，大山雀上述 6 项身体大小指标均存在不同程度的性二态现象，且雄性个体仅喙长与雌性的差异不显著，其余 5 项指标均显著大于雌性。此外，身体大小指标的两性差异不随季节显著变化，但两性的跗跖长在秋季均显著短于冬季和繁殖季，尾长在繁殖季均显著长于秋季和冬季。上述结果表明，大山雀身体大小的性二态及其季节性差异与欧亚大山雀并不完全相似。无论其身体大小存在性二态和季节变化的原因，还是其与欧亚大山雀在身体大小性二态模式上的差别，都有待今后进一步的研究。     

大蹼铃蟾的两性异形

2018年6—8月,测量采自云南省昆明市金殿水库后山的71只(47♂,24♀)大蹼铃蟾Bombina maxima成体的体长、头长、头宽等15项形态特征指标并检验该物种的两性异形。结果表明:雄性平均体长为53.54 mm±1.14 mm,雌性平均体长为52.74 mm±1.45 mm,雄性与雌性平均体长比为1.015,两性异性指数为0.01;大蹼铃蟾的体长、体质量与性别之间的差异无统计学意义;除了雌性的眼间距外,其余13项形态特征与体长均有极显著相关性;以体长为协变量的协方差分析结果显示,大蹼铃蟾的头长、吻长、前臂宽、腿或后肢全长、胫长、胫宽和跗足长在两性间的差异有高度统计学意义;雄性的这7项形态特征随体长的生长速率大于雌性。性选择假说能解释大蹼铃蟾的两性异形现象。     

海陆蛙的两性异形和雌性繁殖特征

用采自海南东寨港红树林保护区的58只(35 ♀♀,23 ♂♂)成体海陆蛙(Fejervarya cancrivora),通过测量头体长、体重、头长、头宽、吻长等11个形态特征指标和雌体卵巢质量(窝卵重),研究该种形态特征的两性异形和雌性繁殖特征,并检验雌性成体大小(头体长和体重)与其繁殖的相关性.雌雄两性个体的最小头体长分别为44.9 mm和45.2 mm.除吻长和眼间距外,其余局部形态特征与头体长皆呈正相关性.头体长在雌雄两性之间差异显著,雌性显著大于雄性;而体重、头长、头宽等局部形态均无两性差异.海陆蛙雌体的窝卵重与头体长和体重之间皆成正相关关系,表明雌性可能是通过增大体型从而增加繁殖输出,而向较大体型发展.     

旱地沙蜥的两性异形

旱地沙蜥Phrynocephalus helioscopus是一种在我国仅分布于新疆北部的蜥蜴。通过测量和比较采自新疆塔城地区旱地沙蜥的体长、口宽、头宽、头高、头长、眼间距、腹部长、尾长等8个形态特征研究旱地沙蜥的两性异形。本研究共采集到旱地沙蜥51只,其中,雌性23只,雄性28只。雌雄平均体长分别为48.03 mm和47.69 mm。结果表明旱地沙蜥两性体长的差异无统计学意义,其体长与口宽、头宽、头高、头长、眼间距、腹部长和尾长7个形态特征均显著正相关。在控制体长的基础上比较得出,雌雄个体在头高、头长、腹部长和尾长上的差异有统计学意义,口宽、头宽、眼间距的差异无统计学意义。其中,雄性的头高、头长和尾长均大于雌性,雌性的腹部长则明显大于雄性。旱地沙蜥的腹部长呈现明显的异形生长,雌性的生长速率明显大于雄性。旱地沙蜥的两性异形可能是性选择压力与生育力选择压力共同作用的结果,雄性头部更大、尾部更长,在性选择中具有优势;雌性腹部更长,能够繁育更多的后代。     

康县隆肛蛙的两性异形

测量和比较了采自甘肃省康县的康县隆肛蛙Feirana kangxianensis标本共计90只(雌性48只,雄性42只)。结果表明,康县隆肛蛙成体的头体长、头长、头宽、吻长、鼻间距、眼间距、眼径、鼓膜长、前臂及手长、后肢全长、手长、足长的形态特征在两性间的差异有统计学意义。以头体长为协变量的协方差分析显示,康县隆肛蛙两性的差异均有统计学意义,异形指数达到0.08,雌性与雄性的平均头体长比值为1.091。对所有测量的形态特征与头体长进行一元线性回归分析表明,雌性康县隆肛蛙局部形态特征的生长速度明显大于雄性,其中,吻长、眼间距、眼径、鼓膜长、前臂及手长、手长的两性差异最明显。生育力选择假设能解释康县隆肛蛙的两性异形现象。     

红瘰疣螈玉龙雪山种群的两性异形

分别测量于2018年6—8月采自云南丽江玉龙雪山的32只(17♂,15♀)红瘰疣螈Tylototriton shanjing成体的全长、头体长、头长等13项形态特征指标,并检验该物种的两性异形。结果表明:雌性平均全长为160.72 mm±3.02 mm(n=15),雄性平均全长为138.58 mm±2.57 mm(n=17),雌性与雄性平均全长比为1.160,两性异形指数为0.138,属雌性大于雄性的两栖类;全长在两性间的差异有统计学意义;除了雌性的头宽、尾宽、尾高和腋至胯距外,其他形态特征与全长均有显著或极显著相关性;以全长为协变量的协方差分析结果显示,红瘰疣螈的头体长、头长、吻长、尾长和前肢长在两性间的差异有统计学意义;雌性的尾长和前肢长随全长的生长速率大于雄性,而头体长、头长和吻长随全长的生长速率小于雄性。生育力选择假说能解释红瘰疣螈玉龙雪山种群的两性异形现象。     

新疆沙虎的两性异形

通过测量和比较采自新疆且末县的新疆沙虎Teratoscincus przewalskii成体的体型和口宽等6个形态特征,研究了新疆沙虎的两性异形。研究共采集64只新疆沙虎(雌性26只,雄性38只),雌雄成体最小体长(SVL)分别为63.6 mm和59.7 mm。口宽、头宽、头高、眼间距和尾长5个局部形态特征均与体长呈显著正相关。新疆沙虎体长雌雄间无差异,其它身体形态特征仅口宽具有显著的两性差异,且口宽相对于体长呈异速生长,雌性增长速率大于雄性。新疆沙虎口宽的两性异形可能与两性间食性的差异有关,而体长和其它身体形态特征无显著两性差异则可能与性选择和自然选择的综合作用有关。     

饰纹姬蛙的两性异形及雌性繁殖能力

用采自云南省西双版纳傣族自治州勐腊县的53只(28♂♂,25♀♀)成体饰纹姬蛙(Microhyla fissipes),测量全部个体的体长、头长、头宽、体重等16项形态特征和雌体怀卵量数据,通过独立样本t检验和协方差检验该物种所有形态特征的两性差异,进而采用线性回归方法分析雌雄成体局部形态特征与体长的相关性,以及雌性成体怀卵量与局部形态特征的相关性。结果表明,饰纹姬蛙平均体长雌性为(25.08±0.40)mm,雄性为(24.78±0.31)mm,体长和体重在雌雄两性间差异不显著(P> 0.05),两性个体大小基本同形。该蛙的所有局部形态特征与体长均存在极显著正相关性(P <0.01);雌雄两性间只在头宽和前臂及手长这两个形态特征上存在显著差异(P <0.05),且随体长的增大其生长速率也存在显著差异。雌性成体的怀卵量与体长、体重、眼间距、前臂宽、胫宽和跗足长均存在显著正相关性(P <0.05),且与体重存在极显著正相关性(P <0.01)。分析认为,饰纹姬蛙成体两性异形主要表现在头宽和前臂及手长,与生存竞争中对食物的获取能力及雄性争夺交配权的成功率有关;而...     

泽陆蛙(Fejervarya limnocharis)两性异形的个体发育和雌体繁殖

2010年3月下旬-7月上旬于浙江富阳市农田采集680只泽陆蛙(Fejervarya limnocharis),研究了泽陆蛙成体和幼体的个体大小和局部形态特征的两性异形;通过解剖雌体获得窝卵数、测量抱对个体获得形态数据,研究了雌体大小与生育力关系以及抱对两性个体体形大小的相关性.结果表明:捕获个体中,雌性和雄性成体的最小体长分别为33mm和30 mm;雄性成体个体数显著超过雌性成体,两性幼体个体数无显著差异;两性成体头部大小、四肢长随体长呈同速增长,眼径和体重随体长呈异速增长,两性幼体所有被检形态特征均随体长呈同速增长;雌性成体平均体长显著大干雄性成体,去除体长差异的影响后发现,除眼径无显著的两性差异外,其余被检形态特征均为雌性大于雄性;幼体除雌性体重大于雄性外,其余被检形态特征均无两性差异;窝卵数与雌体大小(体长和体重)呈显著的正相关;两性抱对个体的体长无显著相关性;泽陆蛙雄性成体体形小于雌性成体的个体大小两性异形模式可能决定于驱使雄性向较大体形发展的进化驱动力相对较弱,雌性增大体形可增加繁殖输出,故向较大体形发展的进化驱动力相对较强;除体重外,其余被检形态特征的两性异形均形成于性成熟之后.     

金丝猴肩带和前肢的性二型

本文研究了两种金丝猴(Rhinopitheous bieti和R.brelichi)肩带及上肢的62项线性变量及指数的性二型,其中64.5%达到了显著性差异水平。结果表明,两性在运动行为上存在一些差异。在所分析的变量中,性别间的差异主要由于成熟时间的不同所引起(雄性比雌性具更长的生长时期),其次是生长速率的不同(雄性比雌性具有更明显的正异速生长率)。对一些指数及不同部位的性二型分析表明,在上肢利用和尺、桡骨的前旋及后旋活动方面,两性也具一些不同。     

Factors influencing offspring traits in the oviparous multi-clutched lizard,<Emphasis Type="Italic">Calotes versicolor</Emphasis> (Agamidae)

The determinants of offspring size and number in the tropical oviparous multi-clutched lizard,Calotes versicolor, were examined using both univariate and multivariate (path) analyses. InC. versicolor maternal snout-vent length (SVL) and body condition influence clutch mass and clutch size but have no significant influence on offspring size. The positive effect of maternal SVL and body condition on offspring number is counterbalanced by a negative effect of breeding time on egg mass. In fact, breeding time directly influences the offspring body mass and condition through variation in the egg mass. There is a trade-off between offspring mass and condition with offspring number, and breeding time influences both. Offspring hatched from the eggs of early (May–June) or mid (July–August) breeding periods invariably show lower mass and condition than those hatched from the eggs of late breeding season (September–October). Yet, there is no variation in offspring SVL among early, mid and late clutches. Thus, inC. versicolor offspring SVL is optimized while body mass and condition are not optimized.     

蝘蜓头、体大小的两性异形和雌体繁殖

报道了蜓 (Sphenomorphusindicus)头、体大小的两性异形和雌性繁殖。性成熟雌体大于雄体。雄性成体头长大于雌性成体 ,但头宽与雌性成体无显著差异。初生幼仔的头长和头宽无两性差异。雄性幼体头长和头宽大于雌性幼体。设置SVL恒定时 ,雄性幼体和雄性成体的头长和头宽无显著差异 ,雌性幼体的头长和头宽大于雌性成体。初生幼仔具有相对较大的头部。产仔雌体的最小SVL为 6 7 7mm ,大于此SVL的雌体均年产单窝仔。平均窝仔数、窝仔重和幼仔重分别为 7 2 ( 3～ 11)、 3 34( 1 30～ 5 19)和 0 48( 0 36～ 0 5 8)g。用卵黄沉积卵巢卵和输卵管计数的窝仔数比用幼仔计数的窝仔数多约 1 0个后代。幼仔体重与雌体SVL无关。相对窝仔重与雌体SVL边缘性地呈正相关。窝仔数、窝仔重与雌体SVL呈正相关 ,幼仔体重与窝仔数呈负相关。窝仔数与雌体状态无关。     

Reproductive ecology of the lacertid lizard Podarcis bocagei

This paper presents data on aspects of the reproductive ecology of a population of Podarcis bocagei in northwestern Spain, as monitored over a two-year period (1990–1991) Data were obtained principally on the basis of mark-recapture experiments, but also from laboratory hatching studies Mating took place between the end of March and July During the laying period, from May to July, 8 5% of reproductive females produced three clutches, 52 1% two clutches, and 39 4% one clutch In general, single clutches were produced by small females Only a small proportion of large females produced three clutches Mean clutch size was 4 8 eggs (range 4–7) in May, 4 3 (2–6) in June and 3 9 (2–4) in July There was sigmficant variation in the mean snout-to-vent length (SVL) of females laying in each month of the season Both clutch size and mean single-egg volume increased with mother's SVL There was a significant partial correlation between egg volume and clutch size when both mother's SVL and month of laying were held constant There was no significant between-year variation in clutch size, breeding females' SVL, egg weight or relative clutch mass A delay in the timing of reproductive events in one year (1991) is attributable to adverse weather conditions during early spring Hatching occurred between July and September Hatch success (as estimated in 1989, 1990 and 1991 from natural nests at the study site) was high, ranging from 83% in 1991 to 91% in 1989 The mean SVL of female hatchlings was greater than that of male hatchlings By contrast, adult females had lower mean SVL than adult males     

Size and scaling of sexually-selected traits in the lizard, Uta palmeri

Differences between the sexes in overall body size and in the size of other morphological traits, relative to overall body size, are common in many animals. In this study, patterns of growth and scaling of sexually dimorphic tratis are assessedin a lilzard and then used to sugest general developmental mechanisms responsible for sexual size dimorphism (SSD). Adult make Uta palmeri lizards are larger than adult females inoverall body size (snout-vent length, SVL), body mass, jaw length head width, and head depth. Two general growth processes produce this adult SSD. First, juvenile males have greater annual SVL growth rates than do juvenile females, contributing to adult SSD because males will be larger than females in any trait positively correlated with SVL. Secondly, males and females differ in age-related changes in growth of the three head size traits, relative to growth in SVL. Comparing slopes from reduced major axis regressions of each trait on SVL reveals that the sexes do not differ in the scaling of these traits as juveniles, but as adults males have greater slopes than adult females, indicating ontogenetic differences in scaling of these traits in males. Two other topics in SSD are addressed with these data. First, comparing these data on scaling to those of an earlier analysis that used ordinary least squares regression reveals that conclusions about underlying mechanisms in an analysis of scaling can be altered by the choice of a regression model. Secondly, these data indicate that postmaturational differences in scaling contribute to adult sexual size differences, contrary to an earlier study. Shine (1990) found that for many ectotherms, which continue to grow after sexual maturation, post-maturational events contribute little to sexual differences in overall body size. Results for U. palmeri suggest that these findings may only hold for measures of overall body size (e.g. SVL) and may not generalize to traits that exhibit sex difference in scaling.     

Evolution of biometric and life‐history traits in lizards (Gallotia) from the Canary Islands

The aim was to study as to how biometric and life‐history traits of endemic lacertids in the Canary Islands (genus Gallotia) may have evolved, and possible factors affecting the diversification process of this taxon on successively appearing islands have been deduced. To that end, comparative analyses of sexual dimorphism and scaling of different body, head and life‐history traits to body size in 10 species/subspecies of Gallotia have been carried out. Both Felsenstein's independent contrasts and Huey and Bennett's ‘minimum evolution’ analyses show that male and female snout‐vent length (SVL) changed proportionally (sexual size dimorphism not changing with body size) throughout the evolution of these lizards and all within‐sex biometric traits have changed proportionally to SVL. Life‐history traits (size at sexual maturity, clutch size, hatchling SVL and mass, and life span) are highly correlated with adult female body size, the first two being the only traits with a positive allometry to female SVL. These results, together with the finding that the slope of hatchling SVL to female SVL regression was lower than that of SVL at maturity to female SVL, indicates that larger females reach maturity at a larger size, have larger clutches and, at the same time, have relatively smaller hatchlings than smaller females. There was no significant correlation between any pair of life‐history traits after statistically removing the effect of body size. As most traits changed proportionally to SVL, the major evolutionary change has been that of body size (a ca. threefold change between the largest and the smallest species), that is suggested to be the effect of variable ecological conditions faced by founder lizards in each island.     

浙江丽水中国石龙子的食性、两性异形和雌性繁殖

丽水分布的中国石龙子（Ｅｕｍｅｃｅｓ ｃｈｉｎｅｎｓｉｓ）摄入的食物均为无脊椎动物,分别属于环节、软体和节肢动物,涉及３０余科,成体和幼体的食物生态位宽度分别为７．２６和６．６９,成体的幼体的食物生态们重叠度为０．５９。性成熟雄性个体大于雌体。成雄和幼体的头长和头宽随体长ＳＶＬ的增长速率大于成雌,成雄头长随ＳＶＬ的增长速度显著大于幼体,成雌和幼体的头长随ＳＶＬ的增长速率无显著差异。成雄头部大于成雌     

青海沙蜥的两性异型和雌性繁殖

作者研究了青海沙蜥(Phrynocephalus vlangalii)形态特征的两性异形和雌体繁殖特征。蜥蜴于2005年5月初捕自西宁以西约150km的倒淌河,被检形态特征包括体色、体长、腹长、尾长、头长和头宽,新排卵雌体维持在实验室梯度热环境中直至产仔。成体两性异形显著,而性未成熟个体缺乏两性异形。最大的成年雄体和雌体分别为70.2mmSVL(snout-vent length)和82.8mmSVL。雄性成体具有相对较大的头长、头宽和尾长,雌性成体SVL大于雄体且具有相对较大的腹长。对4个形态特征进行主成分分析(特征值≥0.5)区分出2个主成分,共解释83.9%的两性相关形态特征的变异。去除SVL差异的影响后,尾长、头长和头宽在第一主成分有较高的正负载系数(解释57.8%的变异),腹长在第二主成分有较高的负负载系数(解释26.1%的变异)。实验室梯度热环境下的雌体于6月下旬至7月中旬产单窝、2-6个后代。窝仔数和窝仔重与母体SVL呈正相关,幼仔重与母体SVL无关。未在青海沙蜥中检测到后代数量与大小之间的权衡。     

蓝尾石龙子的头部两性异形和食性

通过测量头、体大小和胃检研究浙江泰顺产蓝尾石龙子 (Eumeceselegans)个体发育过程中两性异形和食性的变化。蓝尾石龙子成体个体大小和头部大小的两性差异显著 ,雄性大于雌性。不同发育阶段雌性头长与SVL的线性回归斜率无显著差异 ,头宽与SVL线性回归斜率的差异显著 ,成体和SVL <5 0mm幼体头宽随SVL的增长速率显著小于SVL为 5 0 - 6 9mm的幼体。雄性头部相对于SVL呈加速式异速生长。两性比较发现 :雌雄幼体头长和头宽随SVL的增长速率无显著差异 ,SVL <5 0mm幼体特定SVL的头长和头宽无显著的两性差异 ,但SVL为 5 0 - 6 9mm的雄性幼体头长和头宽大于SVL相同的雌性幼体 ;雄性成体头长和头宽随SVL的增长速率显著大于雌性。SVL <5 0mm的雌性幼体头部相对小于SVL为 5 0 - 6 9mm的同性幼体 ,性成熟雌体头部相对小于SVL为 5 0 - 6 9mm的同性幼体。雌性幼体、雄性幼体、雌性成体和雄性成体食物生态位宽度分别为 12 3、 12 5、 4 8和 14 4。雌雄幼体食物生态位重叠度最高 ,雌雄成体食物生态位重叠度次之 ,成体与幼体食物生态位重叠度较小。成体摄入食饵的大小 (用胃内完整食物长度的平均值表示 )和变化范围大于幼体。两性成、幼体摄入的食饵大小差异显著。两性个体摄入的食饵大小均与其SVL呈正相关 ,表明较大     

蜡皮蜥的两性异形和繁殖输出

为研究蜡皮蜥(Leiolepis reevesii)两性异形和繁殖输出,于2002、2003年4月下旬从海南乐东一种群捕获423头蜡皮蜥。经检测得到繁殖雌体的最小体长为89．0mm,据此判定≥89．0mm的个体为性成熟。研究结果表明：①蜡皮蜥具有两性异形,雄性大于雌性且具有较大的头部。成体雄性头长和头宽随体长的增长速率大于雌性,幼体头长和头宽随体长的增长速率无显著的两性差异。以性别和年龄(成、幼体)为因子的双因子ANOVA比较两性头长和头宽与体长的回归剩余值发现,雄性头部大于雌性,幼体头部相对大于成体。②饲养于实验室的母体中有42头于2002、2003年5月22日～7月16日产出正常卵,这些繁殖雌体具有年产多窝卵的潜力。窝卵数和卵重的变异系数分别为0．18和0．13,前者变异度大于后者。窝卵数、窝卵重和卵重均与母体体长无关。卵重与相对生育力之间无显著的负相关性,表明蜡皮蜥缺乏卵数量与卵大小之间的权衡。相对窝卵重与母体体长呈显著的负相关,表明较小的母体具有相对较大的繁殖输出。因雌体繁殖会滞缓其生长,小母体具有相对较大的繁殖输出,至少部分地解释了雌性蜡皮蜥的成体为什么个体较小。     

宁波滑蜥两性异形和雌性繁殖

蜥蜴的雌性繁殖特征对理解两性异形的进化原因起着重要作用。于2011年4月在安徽滁州采集宁波滑蜥(Scincella modesta),定量研究该种形态特征的两性异形和雌性繁殖特征,检验成体形态特征两性异形与雌性繁殖的相关性。研究共采集43条(17♀♀,26♂♂)宁波滑蜥,雄性和雌性个体的最大体长分别为47.4 mm和46.6 mm。雌雄两性在体长和头宽上没有差异,而在腹长和头长上差异显著,雄性有较大的头长,雌性有较大的腹长。宁波滑蜥年产单窝卵。窝卵数和窝卵重与雌体体长及腹长呈正相关,卵重与雌体体长无相关性。窝卵数及卵重的变异系数分别为0.20和0.12。卵长径与窝卵数呈负相关,而卵短径与窝卵数无关。雌体主要通过增加窝卵数来增加繁殖输出。这些结果表明,宁波滑蜥是雌雄个体大小同形的两性异形模式,性选择使得雄性有着较大的头长,以具有较高的交配成功率,生育力选择使得雌性有着较大的腹长,以具有较大的生育力和繁殖输出。