饥饿对眼斑双锯鱼(Amphiprion ocellaris)幼鱼形态性状与体质量相关性的影响

本研究运用多变量路径分析技术,分析饥饿7d （饥饿组）和非饥饿状态下（对照组）眼斑双锯鱼（Amphiprion ocellaris）幼鱼的体质量和形态特征之间的相互依赖关系。实验对两种状态下的幼鱼进行体质量（g）和全长（L₁）、体长（L₂）、体高（L₃）、头长（L₄）、头高（L₅）、吻长（L₆）、尾柄长（L₇）、尾柄高（L₈）、背鳍前距（L₉）、胸鳍前距（L₁₀）、腹鳍前距（L₁₁）、臀鳍前距（L₁₂）、眼径（L₁₃）等13个形态性状（mm）的准确测定。采用相关系数、决定系数、通径系数和回归方程等统计方法分析两种状态下眼斑双锯鱼幼鱼的形态性状对体质量的影响。结果显示,两个实验组14个性状间均存在极显著相关关系（P<0.01）;剔除共线性影响后,通径分析筛选出了对照组对体质量影响显著的4个形态性状,直接作用由大到小排序：L₃ > L₂ > L₆ > L₅,间接作用由大到小排序：L₅ > L₆ > L₂ > L₃,单独决定系数由大到小排序：L₃ > L₂ > L₅ > L₆;饥饿组筛选出5个形态性状,直接作用由大到小是L₃ > L₂ > L₁₂ > L₆ > L₇,间接作用由大到小是L₇ > L₁₂ > L₂ > L₆ > L₃,单独决定系数由大到小为L₃ > L₂ > L₁₂ > L₇ > L₆;对照组和饥饿组体质量与形态性状的多元回归方程分别为：W=-0.819+0.106L₃+0.027L₂+0.006L₆-0.050L₅,R²=0.94;W=-0.778+0.078L₃+0.016L₁₂+0.015L₂-0.055L₇+0.018L₆,R²=0.930。结果表明,饥饿影响了形态性状与体质量的相关性,但饥饿和非饥饿状态下体高、体长和吻长都是影响体质量的关键因子,其中体高是最主要的因子,该结果可在眼斑双锯鱼的选育工作中对选育指标的确定提供理论支持。     

三维几何形态测量方法在石制品分析中的应用

几何形态测量方法是生物学研究中用于形态特征分析和形态比较研究的一种常用方法。其核心思想是利用空间坐标点获取研究对象的形态数据,再通过坐标数据的多元统计分析,定量探讨研究对象的形态特征及影响其形态变异的因素。近年来,随着三维扫描技术的广泛应用以及对于石制品形态特征量化分析要求的提高,基于三维模型的几何形态测量方法开始出现在相关的旧石器考古研究中。本文首先对三维几何形态测量分析方法及其在石制品研究中的应用情况进行介绍,随后具体阐述了该方法的分析流程。为便于国内学者更好地了解这一方法,本文进一步以广西百色盆地南坡山遗址发现的手斧为例,利用三维几何形态测量方法对这些手斧的几何形态特征进行了初步探讨。三维几何形态测量方法为石制品形态研究提供了新思路和新视角,有望成为今后中国旧石器考古研究中一个重要的发展方向。     

Are zebrafish Danio rerio males better swimmers than females?

Swimming performance of zebrafish Danio rerio males and females initially reared in four different temperatures was assessed by measuring their relative critical swimming speed after acclimation to a common temperature. Males reared at 31° C achieved higher swimming speeds than females reared at the same temperature. Morphometric measurements indicate differences in body shape between sexes that could account for the difference in swimming speed.     

Rings without a lord? Enigmatic fossils from the lower Palaeozoic of Bohemia and the Carnic Alps

Fossilized ring‐like structures with enigmatic function and taxonomic affiliation were recovered for the first time from the Upper Ordovician of the Carnic Alps and the Silurian of Bohemia. These rings, already mentioned as minor constituents in previous conodont studies (e.g. Webers 1966, p. 1; Bischoff 1973, p. 147), were reported from the Palaeozoic of several regions in Europe and North America. Originally considered as inwardly accreted adhering discs of a benthic hyolithelminth worm with a phosphatic tubular projection, they were later reinterpreted in relation to a putative crinoid epibiont or even as possible scyphozoans. Despite a long debate, neither the function of the enigmatic Palaeozoic rings nor their taxonomic affiliation has been fully clarified. The studied material, extracted by a standard technique in use for conodonts, consists of 235 elements from 16 stratigraphic levels in the Plöcken Formation (Carnic Alps, Cellon Section; Amorphognathus ordovicicus Biozone, Hirnantian, Ordovician) and in the Kopanina Formation (Bohemia, Mu?lovka Quarry; Polygnathoides siluricus Biozone, Ludfordian, Silurian). To explore whether ring size and shape changed over time, we employed a novel combination of geometric morphometric approaches for outlines with no ‘homologous’ landmarks and showed that only size appreciably varied with an increase of ca. 20%. The emerging data from this study are consistent with the interpretation of the rings as an adhering structure of a benthic organism living on a relatively uniform hard substrate.     

On the trail of Neolithic mice and men towards Transcaucasia: zooarchaeological clues from Nakhchivan (Azerbaijan)

Transcaucasia comprises a key region for understanding the history of both the hybrid zone between house mouse lineages and the dispersal of the Neolithic way of life outside its Near Eastern cradle. The opportunity to document the colonization history of both men and mice in Transcaucasia was made possible by the discovery of mouse remains accumulated in pits from a 6000‐year‐old farming village in the Nakhchivan (Autonomous Republic of Nakhchivan, Azerbaijan). The present study investigated their taxonomy and most likely dispersal path through the identification of the Mus lineage to which they might belong using a geometric morphometric approach of dental traits distances between archaeological and modern populations of the different Mus lineages of South‐West Asia. We demonstrate that the mouse remains trapped in the deep storage pits of the dwelling belong to the Mus musculus domesticus from the Near East, with dental shapes similar to current populations in Northern Syria. These results strongly suggest that the domesticus lineage was dispersed into Transcaucasia from the upper Euphrates valley by Neolithic migration, some time between the 7th and 5th millennium BC, providing substantial evidence to back up the scenario featuring near‐eastern stimuli in the emergence of agriculture in the South Caucasus. The domesticus mitochondrial DNA signature of the current house mouse in the same location 5000 years later, as well as their turnover towards a subspecies musculus/castaneus phenotype, suggests that early domesticus colonizers hybridized with a later musculus (and maybe castaneus) dispersal originating from south of the Caspian Sea and/or Northern Caucasia. © 2013 The Linnean Society of London     

Description of Two New Neotropical Helicopsyche (Trichoptera: Helicopsychidae)

Helicopsyche flinti sp.n. and Helicopsyche cochleara sp.n. are described from Brazil and Ecuador. H. cochleara sp.n. has certain affinities with H. planorboides Machado from eastern Brazil. H. flinti sp.n. is related with other Neotropical Helicopsyche.     

中华姬鼠与大林姬鼠头骨的几何形态学研究

中华姬鼠Apodemus draco和大林姬鼠A.peninsulae形态与习性相似,北京地区的这两种鼠都存在还是只有大林姬鼠存在一直存在争议.通过新兴的几何形态测量技术对北京地区捕获的137只姬鼠头骨与黑龙汀的9只大林姬鼠头骨进行背面和侧面的形态对比分析.系统聚类分析结果、主成分分析结果和判别函数分析结果显示,北京地...