基于耳石几何形态测量学的长江安徽江段刀鲚群体识别研究

为了解长江安徽江段刀鲚耳石的形态特征和尝试识别不同群体,研究选用基于地标点的几何形态测量学手段,对不同年份采于长江安徽安庆、铜陵江段长颌鲚和短颌鲚2种生态表型的5个群体刀鲚矢耳石形态差异性进行了比较研究。基于12个地标点,将其坐标进行相对扭曲主成分分析及判别分析,经薄板样条分析和网格变形,使其耳石形态变异矢量可视化。结果显示,在相对扭曲主成分分析中,提取的地标点中多为Ⅱ类地标点,其贡献率为69.48%,说明Ⅱ类地标点是耳石形态差异的主要来源。5个群体刀鲚判别分析的综合判别准确率为95.6%,表明这些刀鲚群体耳石形态的差异总体显著。这种差异显著性尤其存在于长颌鲚与短颌鲚生态表型间及长颌鲚和短颌鲚不同群体间,显示出刀鲚不同生态表型分化及其群体间差异性已可体现在耳石的形态特征上。上述发现可为长江十年禁渔前后安徽江段刀鲚群体组成和群体差异性的客观评价提供理论支撑。     

中国鲚属鱼类的矢耳石形态特征

分析了205尾分布于中国的4种2龄鲚属鱼类的矢耳石形态特征。结果显示,这4种鱼类的矢耳石都具有翼叶和基叶,但无后基叶和副基叶,中央突也不明显。背侧有脊突,叶形晶状突呈小三角形,仅限于腹侧。主凹槽明显,直管状,后端封闭。4种鱼矢耳石长轴长为体长的1.68%~2.82%,矢耳石重为体重的0.26‰~1.71‰;不论绝对重量或面积,均以七丝鲚和凤鲚的最大,刀鲚的次之,短颌鲚的最小,显现出与在海水中生活的时间呈正相关性。刀鲚和短颌鲚的矢耳石较轻薄,单位面积均重1.22~1.40mg/mm2;七丝鲚和凤鲚的较厚重,单位面积均重约1.86mg/mm2。矢耳石的长轴、短轴和单位重量等的变异系数,均要小于其体长特别是体重的变异系数,矢耳石形态的稳定性显著优于其身体形态的稳定性。     

基于耳石形态的鱚属鱼类鉴别

利用9个耳石形状指标对我国鱚属鱼类少鳞鱚、多鳞鱚及斑鱚共78个个体的矢耳石形态进行了多元统计分析,同时对3个群体的74个少鳞鱚矢耳石形态进行了判别分析。单因子方差分析结果显示,少鳞鱚与多鳞鱚矢耳石的9个形状指标均存在显著差异(P<0.05);反映耳石长、短轴差异程度的第1主成分与反映耳石三维特征的第2主成分解释了85.943%的形态差异;9个指标在种间判别分析中的综合判别正确率为93.6%,种内判别分析中的综合判别正确率为93.2%。研究表明形状指标法可以作为中国鱚属鱼类鉴别的有效手段。     

基于椭圆傅里叶分析的次南极电灯鱼矢耳石形态多样性

次南极电灯鱼矢耳石形态特征具有多样性.为了深入研究其形态特征,利用南设得兰群岛外侧水域采集的456尾次南极电灯鱼(体长范围6.0～8.8 cm)样本,对其矢耳石形态进行分析和判别.根据形态特征将次南极电灯鱼耳石分为4种类型,并采用椭圆傅里叶分析法选取表征耳石类型的77个傅里叶特征系数进行了分析.结果表明: 对4种耳石类型两两比较后发现,具有显著性差异的傅里叶特征系数最多及最少分别占总体的61%和28.6%;对77个傅里叶系数进行主成分分析,前22个主成分解释了总变异的76.6%;选取了17个傅里叶特征系数进行判别分析,建立判别函数,总体判别率为87.2%;根据椭圆傅里叶分析重建的耳石轮廓反映了4种耳石类型间的差异.4种耳石类型在不同体长及体质量的次南极电灯鱼中皆有出现,表明耳石类型具有随机性,且左右耳石类型不一致,表明其左右耳石外形具有差异性.4种耳石类型中,Ⅰ型和Ⅱ型占总体的72.6%,为次南极电灯鱼耳石的主要形态;Ⅲ型和Ⅳ型占总体的27.4%,为次要形态.     

基于耳石微化学的长江安徽和县江段刀鲚生境履历重建

为了解长江刀鲚(Coilia nasus)的“生境履历”, 利用电子探针微区分析技术研究了2015年5月17日在长江安徽和县江段捕获的刀鲚短颌鲚与长颌鲚类型耳石Sr和Ca微化学特征。短颌鲚的耳石Sr/Ca值变化动态为2类, 一类比值稳定在2.00左右(1.65±0.87—2.03±0.96), 反映了其纯淡水的生境履历; 另一类比值波动显著, 不仅具有对应淡水生境的低值(2.39±1.18—2.63±0.85), 还具有对应半咸水生境的高值(3.22±1.17—3.29±1.14), 显现了其江海生活的生境履历。长颌鲚耳石的Sr/Ca值均波动显著, 同时具有对应淡水生境的低值(1.35±1.07—2.37±1.04)和半咸水、海水生境的高值(3.47±1.09—8.35±1.25), 表现了其均为溯河洄游的生境履历。Sr面分析结果也与上述Sr/Ca值的结果相印证。长江安徽和县江段刀鲚资源组成复杂, 群体可由纯淡水型和江海生活型的个体共同组成。     

细鳞斜颌鲴三个群体形态差异

将传统形态学数据与现代框架数据相结合,分析了细鳞斜颌鲴3个群体(龙窝湖群体、梁子湖群体和淮河群体)的形态差异,探讨了它们的形态亲缘关系。方差分析表明,3个群体间8个可数性状参数差异不显著(P0.05)。聚类分析显示,龙窝湖群体与梁子湖群体首先聚为一类,然后再与淮河群体相距。在28个测量参数中挑选7个对判别贡献较大的参数建立判别函数,判别效果极显著(P0.01),判别准确率93.55%～100%,综合判别率96.81%,通过判别函数可将这3个群体很好地区分开。主成分分析概括出方差贡献率较大的3个主成分,累计方差贡献率为82.99%。主成分1主要反映鱼体躯干部的形态变化,方差贡献率52.83%;主成分2主要反映鱼体头部的形态变化,方差贡献率22.22%;主成分3主要反映鱼体尾柄部的形态变化,方差贡献率7.94%。主成分1和2二维平面图显示,虽然龙窝湖群体和梁子湖群体有少量重叠区域,但3个群体还是可以清晰分开的。3个群体间形态性状的差异系数均小于1.28,群体间尚未达到亚种差异水平。     

基于线粒体COⅠ基因DNA条形码的中国鲚属物种有效性分析

分析了150尾刀鲚Coilia nasus、湖鲚C.nasus taihuensis、短颌鲚C.brachygnathus、七丝鲚C.grayii及凤鲚C.mystus个体的COⅠ基因DNA条形码序列变异。结果显示,150条COⅠ基因条形码序列包含63种单倍型,单突变位点主要集中在100bp和600bp附近。刀鲚、短颌鲚和湖鲚群体间的遗传距离在0.253%～0.557%之间,显著低于COⅠ基因DNA条形码鉴别不同物种2%的遗传距离阈值,表明这3个群体应为同一物种。但是凤鲚两群体间的遗传距离为5.08%,大于2%的鉴别阈值,显示凤鲚两群体可能达到了种或亚种级差异水平。以日本鳀Engraulisjaponicus为外群,用邻接法、最大简约法和最大似然法构建了分子系统树显示,刀鲚、湖鲚和短颌鲚群体聚在一起,未能各自形成单系;凤鲚根据地理分布聚为两支;七丝鲚则聚成单系。研究表明COⅠ基因条形码技术可用于我国鲚属物种的鉴定。     

西沙群岛鹦嘴鱼科耳石形态学物种鉴定的可行性研究

研究于2018—2021年在西沙群岛海域采集鹦嘴鱼样本,通过传统形态测量法选取的19个耳石形态指标和椭圆傅里叶分析法选取的77个椭圆傅里叶系数对其进行鉴别分析,探究耳石形态在鹦嘴鱼科物种鉴别中的可行性。结果表明,仅使用耳石形态指标鉴别鹦嘴鱼时综合判别率为56.8%,低于仅使用椭圆傅里叶系数的63.1%和两种参数结合的75.7%;而结合两种参数对其4个属的综合判别率为88.6%,其中绚鹦嘴鱼属的判别率达到100%; 15种鹦嘴鱼的耳石形态聚类结果与已有研究的进化树结果基本一致,特别是属层面的聚类,呈现高度一致,证实了耳石形态具有遗传的属性,也说明了耳石形态学用于鱼类物种鉴定的可行性。研究结果将为西沙群岛鹦嘴鱼的基础研究提供科学资料,为鹦嘴鱼资源的保护与开发提供理论依据。     

长江安庆江段刀鲚耳石微化学及洄游生态学意义

刀鲚(Coilia nasus)属辐鳍鱼纲、鲱形目、鳀科,是我国长江下游一种传统的名贵经济鱼类。长江安徽江段为刀鲚的主要分布区之一,但近年来由于人类活动干扰、栖息地衰退及过捕等原因,资源量急剧下降。近期发布的《国家重点保护野生动物名录》水生野生动物调整方案已拟将刀鲚列入国家二级重点野生动物保护名录。为客观了解长江安庆江段刀鲚的生境"履历"及探讨其洄游史,利用X射线电子探针微区分析技术对2008年7月捕获于长江安庆江段的10尾刀鲚(均为传统意义上的长颌鲚)进行了耳石微化学研究。结果表明:这些个体均具典型的溯河洄游习性。从耳石核心到边缘定量线分析结果表明,耳石的沉积过程中元素Sr/Ca比值波动显著,不仅有对应淡水生境的低值(3)阶段,还具有对应河口半咸水、海水生境的高值(3)阶段。这种现象亦得到了16色Sr元素面分布分析结果的印证。根据耳石淡水系数、Sr/Ca比值高低波动特征及Sr元素面分布图谱的差异性可以将这些刀鲚分为3种淡-海水生境转换生活史类型。这种现象明显地反映出长江安庆江段刀鲚的群体具有个体组成和洄游模式的多样性。     

从线粒体控制区全序列变异看短颌鲚和湖鲚的物种有效性

经克隆测序获得我国七丝鲚(Coilia grayii)、凤鲚(C. mystus)、刀鲚(C. nasus)和短颌鲚(C. brachygnathus)以及太湖湖鲚(C. nasus taihuensis)等4个种和1亚种32尾个体的mtDNA D-loop区全序列, 以日本鳀(Engraulis japonicus)和秘鲁鳀(E. ringens)为外类群构建了中国鲚属的分子系统发育树, 并讨论了短颌鲚和湖鲚的物种有效性。结果显示, 七丝鲚的D-loop区全序列长1,208 bp, 凤鲚1,279–1,361 bp, 刀鲚1,252–1,290 bp, 短颌鲚1,214–1,252 bp, 湖鲚1,252–1,442 bp, 除七丝鲚外的其他种类个体间均表现出序列长度的多态性。短颌鲚、刀鲚和湖鲚三者间的平均K 2-P遗传距离仅为0.011–0.020, 明显小于它们与凤鲚、七丝鲚及外类群间的遗传距离(0.051–0.349)。以邻接法和最大简约法构建的系统发育树表明, 刀鲚、短颌鲚及湖鲚均未各自构成单系, 而是共同构成一个单系群, 三者并未发生显著分化。研究表明, 短颌鲚和湖鲚为刀鲚的淡水生态型种群, 并非有效物种。系统发育分析表明, 中国鲚属3个有效物种间以凤鲚最为原始, 刀鲚和七丝鲚为姐妹群, 处于较进化的位置。推测凤鲚可能是鲚属祖先种最早从起源中心扩散到西北太平洋的后裔, 而刀鲚和七丝鲚则是凤鲚在演化过程中分别适应寒冷和温暖气候而分化出的物种。     

Interspecific relations of African crocidurine shrews (Mammalia: Soricidae) based on multivariate analysis of mandibular data

Eighteen graded non-metric characters and 30 measurements of the mandible and lower dentition were used to investigate the grouping of African species of the genera Crocidura, Suncus and Sylvisorex. Seventy-seven taxa (species, subspecies and synonyms), including four European species, were represented by one to nine mandibles (147 mandibles in all), and the means of four Pleistocene African species were also included. The metric data were subjected to principal component and canonical variate analyses, and the non-metric data to principal component analysis. Grouping was detected by comparing the results of the three analyses. Six groups are recognized within the genus Crocidura , typified by C. fumosa, C. turba, C. russula, C. fuscomurina, C. hirta and C. flavescens. Sylvisorex is divisible into two groups, typified by S. lunaris and S. granti. The African species of Suncus (but not the introduced species, S. murinus ) form a single group, which is linked to the Sylvisorex granti group. Suncus is closely related to, or convergent with, the Crocidura fuscomurina group. The first non-metric principal component, the second metric principal component and the second canonical variate are significantly correlated. It is considered that these together represent a general trend of evolutionary advance. Phylogenetic relations are discussed in the light of this; Crocidura may be diphylefic.     

Ecomorphology of a size-structured tropical freshwater fish community

Among nine species of a tropical community ecomorphological correlates were sought throughout ontogeny. Ontogenetic changes were distinguished by establishing six pre-defined size-classes. Morphometric data associated with feeding were compared by canonical correspondence analysis to dietary data. This analysis revealed seven significant relationships, showing 71% of the morphological variance explained 77% of the variance in diet. Based on funtional ecomorphological relationships established in other studies and results of the canonical correspondence analysis, three food characters were selected: the size of the food particles, the type of food (vegetable versus animal) and the vertical position in the water column. The morphometric data were reduced using principal component analysis into three axis explaining 83% of the variation. The morphological characters with the highest loadings were: mouth gape on the first principal component axis, length of the intestine tract on the second and the orientation of the mouth together with the presence of barbels on the third. These axis were significantly correlated with, respectively, the size, the type and the vertical position of the food. The importance of morphological changes during ontogeny in explaining dietary changes was shown because 75% of the variation in the first, and most important, morphological principal component was accounted for by differences between size-classes. Assuming functional relationships, the potential niches of the species/size-classes were established, distinguishing herbivorous, omnivorous/molluscivorous and carnivorous species which, in turn, were segregated by their potential to feed on larger prey. This revised version was published online in July 2006 with corrections to the Cover Date.     

Morphological variability of potato cyst nematodes (Globodera spp.) in the Canary Islands

Thirty populations of potato cyst nematode (Globodera spp.) from the Island of Tenerife and two populations from the UK were assessed for several morphometric and non-morphometric characters thought to discriminate between the species G. rostochiensis and G. pallida. Also 200 cysts from each population were analysed by isoelectric focusing of soluble proteins. Correlation analysis, analysis of variance and principal component analysis were used to investigate relationships between the morphometric characters, how the relationships varied between species and between populations, and which characters were most useful for discriminating between species. The two species differed significantly for each of the four morphometric characters: stylet length, fenestra length, anus-fenestra distance and the number of ridges. The stylet length and fenestra length also showed differences between populations of G. rostochiensis while stylet length and number of ridges showed differences between populations of C. pallida. In general, populations of G. pallida showed greater variation than populations of C. rostochiensis. Principal component analysis of the population means indicated that over 73% of the variation in the characters could be explained by the contrast of stylet and fenestra lengths against the anus-fenestra distance and number of ridges. A plot of the first two principal components separated the two species. Stepwise discriminant analysis provided a linear combination of these four variables which discriminated between the species. Stylet length was found to be the most useful characteristic for distinguishing the species whilst anus-fenestra distance was the least useful.     

A COMPARISON OF TEMPERATURE-INDUCED POLYPHENISM IN AFRICAN BICYCLUS BUTTERFLIES FROM A SEASONAL SAVANNAH-RAINFOREST ECOTONE

Temperature-induced variation and norms of reaction have been analyzed for wing pattern elements of six species belonging to the African butterfly genus Bicyclus (Lepidoptera, Nymphalidae, Satyrinae). Five of these species are sympatric in Malawi and exhibit seasonal polyphenism in the savannah-rainforest ecotone. The sixth species originated from Cameroonian equatorial rainforest. The organisms were laboratory reared under four different temperature conditions ranging from 17–28°C. The variation in response to temperature is described by principal component analysis (PCA). Discrimination on the basis of plastic wing pattern characters was performed by discriminant function analysis (DFA) and unweighed pair-group method algorithm (UPGMA) clustering. A phylogenetic reconstruction based on adaptive plastic wing characters was compared with a cladogram built on “nonadaptive” characters. Results demonstrate that: (1) Phenotypic plasticity of wing pattern characters in response to temperature in laboratory-reared organisms is reminiscent of variation induced by seasonal change in the field. (2) Different wing pattern characters are under different control: “exposed” characters of butterflies at rest position are highly sensitive to temperature variation, whereas “hidden” characters, only visible during active behavior, are dominated by species differences. In general the sensitivity of the former can be attributed to their proposed function in deflecting predators. (3) The sexes differ especially in the size of those eyespots that are displayed during active behavior. (4) Species from seasonal and aseasonal environments react in a broadly similar manner to temperature variation. However, savannah species and species of aseasonal rainforest exhibit relatively shallow reaction norms, whereas reaction norms are steeper in species from the savannah-rainforest ecotone. Such a strong response was also apparent in so-called correlation networks between principal components for these species. (5) Phylogenetic distances are to some extent reflected in ordination in both PCA-space and DFA-space: closely related species of the safitza group remain close in both ordinations. The more distantly related species differ in ordination from a pattern as suggested by a phylogenetic reconstruction. It is argued that the wing pattern variation of these species reflects both adaptive processes and historical relationships.     

MORPHOLOGICAL EVOLUTION IN MUROID RODENTS II. CRANIOMETRIC FACTOR DIVERGENCE IN SEVEN NEOTROPICAL GENERA,WITH EXPERIMENTAL RESULTS FROM ZYGODONTOMYS

First principal components extracted from covariance matrices of log-transformed craniodental measurements closely approximate general size factors within field-collected samples representing 14 species in seven Neotropical muroid genera; because these samples are mixed-cross-sectional, scores are age-correlated and coefficients reflect postweaning growth allometries. Compared between congeners, sample first principal component coefficients are very similar, an observation that implies a nearly parallel orientation of ontogenetic trajectories in log-measurement space. On the assumption that a common general size factor (estimated as the first principal component of the pooled-within covariance matrix) accounts for most of the observed measurement covariance within samples, size-adjusted differences between congeneric species were estimated variable-by-variable in separate analyses of covariance; these differences reflect developmental adjustments of craniodental morphology that precede the measured interval of postweaning ontogeny. Vectors of size-adjusted difference coefficients are not similar from genus to genus, and a diversity of causal mechanisms is probably responsible. Analyses of captive-bred samples from two “species” of Zygodontomys provide prima facie evidence that size-adjusted differences estimated from field-collected samples have a genetic basis. Postweaning growth allometries in the muroid head skeleton may be conserved due to the biomechanical constraints of masticatory function; the apparent evolutionary plasticity of earlier ontogenetic adjustments may reflect the absence of such constraints in the fetus or suckling pup. The relevance of these results for current theories concerning the developmental genetics of mammalian morphometric evolution is discussed.     

Patterns of morphological and geographic variation in trophic bill morphs of the African finch Pyrenestes

Intra- and inter-population variability was studied in three species of tropical African estrildid finches comprising the genus Pyrenestes. Eleven characters were measured on P. ostrinus captured on a study area in Cameroon. Most of these same characters were also measured on museum specimens of this species and P. saguineus and P. minor. Data were analysed using univariate and multivariate statistical methods in order to characterize variation within and between populations and species.
Variation in all three species of Pyrenestes is greatest in bill size, resulting from an exceptional non-sex-linked polymorphism. Bill size differences between morphs are as high as between congeneric species, with extremely large coefficients of variation, while other body characters show comparatively little variation. Sexual dimorphisms and differences in size due to age occur, but contribute little to overall size variation. Distributions of bill characters in each age and sex class are bimodal or greatly skewed, and in some geographical regions tend to be trimodal. Distributions of other body characters tend not to be significantly different from normal. Bill morphs differ in both shape and size and may be separated using principal component analysis. Static allometries of bill morphs differ significantly: relative to body size, bill size increases more rapidly in the large morph. Bill size and shape also vary geographically. The three species differ in mean size but show much overlap. Bill size is negatively correlated with total annual rainfall. In regions characterized by ecotonal transition zones between forest and savanna, tentative evidence suggests that a third, yet larger bill mode occurs. This third mode apparently results from the presence of a distinct larger species of hard-seeded sedge found only in these regions. The taxonomic implications of the polymorphism are discussed.     

Seed Micromorphology and Its Taxonomic Significance of Begonia (Begoniaceae) in China and Vietnam

The seed morphology of 47 species in Begonia in China and Vietnam were examined under Light Microscope (LM) and Scanning Electron Microscope (SEM), respectively. Seed varied from ellipsoidal to obovoid, sometimes broadly obovoid shape with large variation in size. The shape of operculum could be classified into three types: short claviform, broadly nipple shaped and obtuse. There are four types of epidermal ornamentations: straight striae, undulated striae, rounded punctum and herringbone shaped punctum. The principal component analysis and hierarchical cluster analysis revealed that the classification of Begonia based on the seed micromorphology was incompletely consistent with the traditional classification on the section level based on the placenta; the ornamentation of seeds showed stability in different populations of a species; the operculum shape shows a considerable difference among morphologically similar species. Seed morphological characters may relate to the dispersal patterns which showed an adaptation to the living environment.     

A Preliminary Research on the Numerical Classification of the Genus Panax from China

In this paper, 10 species and varieties of the genus Panax from China were studied by means of numerical taxonomic methods. At first, the geometric approaches and statistical treatments were used and some new characters induced by the fundamental characters were defined for the numerical representation of the morphological characters of plants. Consequently, forty-seven morphological, three chemical, one geographical and one cytological characters were adopted. The principal component analysis and the similarity coefficients were computed on the standardized data. Based upon the correlation matrix and the distance matrix respectively, the Q and R cluster analyses were carried out, and UPGMA was used in both Q and R cluster analyses. According to the R cluster analysis, all characters are mainly divided into 5 sets: A, B, C, D and E (Fig. 2). The tree-like diagram illustrates that chemical constituents of triterpenoids and the chromosome numbers are related to some morphological characters, such as the roots, the rhizomes, the seeds and the leaves. It is of interest to note that the thicker the fleshy roots, the larger the seeds and the wider the teeth of leaflet, the higher the content of the tetracyclic triterpenoids of dammarane type it contains. On the other hand, the Q cluster analysis showed that Panax as a whole may be divided into two groups (Fig. 3). The first group includes P. ginseng, P. quinquefolius, P. notoginseng and P. zingiberensis and the second group includes P. stipuleanatus, P. pseudo-ginseng, P. japonicus var. japonicus, P. japonicus var. angustifolius, P. japonicus var. major and P. japonicus var. bipinnatifidus. The results of the computation of principal component analysis indicate that the first principal component consistes of the characters occurring in the sets A and B. It shows that the variation in Panax has two opposite directions. One of them, corresponding to the set A, is represented by the first group, and the other, corresponding to the set B, is by the second group. Finally, some questions about the use of the genus in medicine were discussed.     

Size and mating success in males of the western harvester ant,Pogonomyrmex occidentalis (Hymenoptera: Formicidae)

Mating success in males of the lek mating ant species,Pogonomyrmex occidentalis, increases with increased body size. We estimated the magnitude of the selection coefficients on components of size by collecting males in copula and comparing their morphology to that of males that were collected at the lek but that were not mating. Four characters, body mass, head width, wing length, and leg length, were measured for a sample of 225 mating and 324 nonmating males and 225 females. Significant direct selection favors increased wing length and leg length. Multiple regression of transformed variables (principal components) indicated that the increased mating success of larger males is a function of all four characters. We found no evidence of positive assortative mating on the basis of any individual character or on the multivariate general size variable (the first principal component).     

Analysis of asymmetries in the African fruit bats Eidolon helvum and Rousettus egyptiacus (Mammalia: Megachiroptera) from the islands of the Gulf of Guinea. I. Variance and size components of bilateral variation

A set of cranial characters was examined in the fruit bats Rousettus egyptiacus and Eidolon helvum to compare trends and relative importance of major components of bilateral morphometric variation, and their relationship with character size. Using two‐way, sides‐by‐individuals ANOVA , four components of variation were estimated for each bilateral variable: individual variation (I), directional asymmetry (DA), non‐directional asymmetry (NDA) and measurement error (E). Both species exhibit similar major trends of variation in asymmetry across characters, as shown by principal component analysis, using variance components as variables. Degree of interspecific congruence among characters was confirmed by a two‐way ANOVA with species and variance components as fixed factors. Congruence of asymmetry patterns between species suggests that the concept of population asymmetry parameter (PAP) could be extended to higher hierarchies. PAPs above the species level may result from common mechanisms or similar developmental constraints acting on species’ buffering capacities and morphological integration processes.