The role of learning in fish orientation

Past research on fish orientation and migration has tended to focus on genetically fixed patterns of behaviour. However, in most aquatic environments, the physical landscape as well as biologically important locations will be subject to varying degrees of change, favouring an ability to learn. Here, we review the evidence from field and laboratory‐based experiments that fish can and do use learning and memory to orientate within their natural environments, relying on information from a diverse array of different sources. Comparisons of different species and populations suggest that fish may be predisposed to learn specific associations at specific times or places, appropriate for the particular navigational problems that they are likely to encounter.     

不同产地中华绒螯蟹形态差异的地标点法分析

为了解长江水系的太湖、洪泽湖、高宝湖、长荡湖、阳澄湖以及巴城、兴化"泓膏"养殖水域和长江口崇明自然水域等知名产区产中华绒螯蟹形态上的差异,首次运用地标点法研究其形态的产地差异性。背甲以及腹甲的形态使用地标点法进行分析,经图像处理后提取地标点坐标,进行相对扭曲主成分分析以及判别分析,利用薄板样条分析和网格变形将其形态变异矢量可视化。结果显示,在相对扭曲主成分分析中,提取了许多Ⅱ型地标点,其贡献率为82.637%~97.698%,作用较大,解释了主要形态变异。特别是相对扭曲主成分的判别分析对雄性以及雌性蟹背甲的判别准确率均为100%。研究表明,不同产地养殖环境可以导致中华绒螯蟹的形态出现差异;而以背甲为对象的形态地标点法分析应该可以作为判别不同产地中华绒螯蟹的有效方法。     

嘉陵江不同江段蛇的形态差异比较

为探讨嘉陵江不同江段蛇鮈群体的形态表型特征及其差异性,本研究对采至嘉陵江上游、中游和下游共120尾样本进行了传统形态测量和地标点几何形态学测量分析。形态分析结果表明：嘉陵江不同江段蛇鮈群体间形态表型存在的显著差异。差异主要集中于头部、鳍和尾柄;其中上游群体的蛇鮈最为纤长（叉长、胸腹距、躯干距最大）,眼间距、背鳍基长、头高和口角须长也最长;中游群体的胸鳍、腹鳍、尾鳍最长,尾柄也最为粗壮（尾柄宽,尾柄高最大）,头长、体宽、胸鳍前距最大;下游群体的肛臀距和头宽最大。但主成分分析结果显示：无法有效将不同江段蛇鮈群体区分。性状差异性分析结果表明,不同江段蛇鮈群体形态表型差异均属于种内差异。这些表型差异可能是蛇鮈对嘉陵江不同江段环境（如流速、水温、饵料类型）多样性的适应性表现。     

Qualitative analysis of cartilaginous jaw element malformation in cultured yellowtail kingfish (Seriola lalandi) larvae

A central problem facing worldwide culture of yellowtail kingfish (Seriola lalandi) is the presence of skeletal malformations, including jaw deformities. This study presents a morphological characterization of normal and abnormal cartilage jaw structures during early larval development. Samples of 70–150 larvae were collected from three cohorts from 2 to 9 days post hatching, anaesthetized and fixed for cartilage staining. Cartilaginous components were defined clearly at four days post hatch (dph) (4.65 ± 0.05 mm total length), and abnormal jaw structures were detectable at this time. Jaw deformities observed included extension of Meckel's cartilage with or without ventral bending of the anterior tip, displacement of ceratohyal and hypohyal cartilage ventrally and below Meckel's cartilage, and shortening and dorsal flexion of the lower jaw. At 4 dph, between 44% and 47% of all larvae examined had jaw abnormalities. The contribution of each deformity to the total number of deformities was variable among the three cohorts examined. To compare shape difference accurately we performed an exploratory, landmark‐based geometric morphometric analysis using seven homologous landmarks. Larvae were classified into three jaw morphology groups. The geometric morphometric approach provides a useful tool to standardize classification of cartilage jaw abnormalities at early developmental larval stages. Early recognition of developing abnormalities is of importance for fish farmers in both improving fish selection efficiency and for evaluating effects of rearing parameters.     

Dimensional ultrasonographic relationship of the right lobe of pancreas with associated anatomic landmarks in clinically normal dogs

The purpose of this prospective study was to establish the ultrasonographic characteristics of the dimension of the right pancreatic lobe with that of the associated anatomic landmarks in healthy dogs. Ultrasonographic examinations were performed on 25 dogs. The thickness of the right pancreatic lobe was compared with that of mural thickness of duodenum, diameter of duodenum, pancreatic duct, abdominal aorta, portal vein, caudal vena cava, and length and width of the right kidney and right adrenal gland. The correlation between each pancreatic parameter and the dimensions of the anatomical landmarks were assessed using linear regression analysis and Pearson’s correlation coefficient (r) test. Significant, but weak linear correlations were observed between thickness of right pancreatic lobe with that of duodenum mural thickness (r=0.605, R²=0.339, P=0.001); duodenum diameter (r=0.573, R²=0.299, P=0.003); and right adrenal gland length (r=0.508, R²=0.052, P=0.01). There was no significant dimensional relationship with other selected anatomic landmarks. The ratio between the thickness of right pancreatic lobe and the mural thickness of duodenum, diameter of duodenum and length of right adrenal gland were 2.88 ± 0.53, 1.27 ± 0.27 and 0.81 ± 0.15, respectively. Calculating the ratio of thickness of the right pancreatic lobe with the dimension of significantly correlated anatomic landmarks is a useful and simple method for evaluating the size of the right pancreatic lobe in dogs in clinical practice.     

城市标志性景观道路营建探索

通过对城市道路形态演进的分析,研究了景观道路的特点、选址、类型,以及建 立在道路线 形、雕塑、景观小品、路面铺装、植物种植基础上的景观道路的景观营建,总结出景观 道路的营建的 基本原则。     

蛾翅翅脉特征在夜蛾昆虫数学分类学中的应用

为对夜蛾翅脉特征进行分类研究,以6种夜蛾右前翅的翅脉为研究对象,利用tpsDig2软件在夜蛾翅室周围翅脉交叉点处提取标记点,利用普氏叠加分析消除标记点数据中的非形状因素信息,计算出相邻翅脉交点间的距离作为特征参数,利用方差分析和逐步判别分析论证各项特征参数对6种夜蛾进行分类的可行性、可靠性和重要性。研究结果表明:7个特征参数可作为分类变量,它们的作用大小依次为:(dis67、dis71)dis34(dis23、dis12)(dis45、dis56),原始判别和交叉判别结果的正确率分别为99.4%和99.4%。这充分证明了蛾翅翅脉的特征变量可用于蛾类昆虫的分类鉴定研究。     

几何形态学方法区分短吻鲾地方种群的研究

运用传统形态测量方法和地标点方法对广东阳江和湛江两个短吻鲾的形态特征进行了分析。传统测量方法的主成分分析的前两个主成分(76.29%)能明显地区分出两个种群。相对扭曲主成分分析前3个主成分(64.03%)也能明显地区分出两个种群,但效果差于传统方法的主成分分析。网格变形图显示,两地短吻鲾的形态差异主要表现在头部。地标点法避免了传统的多变量形态测量方法的信息冗余、包含的形状信息不够完整等问题,并能够重建图形,突出局部的形变,能够直观地比较出研究对象之间的细微差别。研究亮点:地标点法是国外最新发展出并被广泛使用的形态测量方法,该方法以地标点的坐标来表示生物的形状信息,再通过旋转与重叠,用网格图形和相对扭曲分析样本间的形状差异。本文在国内首次使用该方法有效地区分了短吻鲾的不同地方种群。     

城市地标性寺庙周围环境优化分析——以福州白塔为例

城市保留下来的地标性寺庙是城市历史风貌的重要物质体现。在城市快速建设中,大量现代物质元素严重影响了寺庙标志建筑在城市环境中的视觉感知。基于城市地标应具备标识性和导向性的属性,地标性寺庙视觉感知需满足可见、可达、视景美观三项目标。在分析寺庙景观特质及城市环境对视觉感知的影响因素的基础上,提出地标性寺庙周围环境的优化措施,包括不规则圆面视域构建、区段化视景处理、多层面观赏组织三方面,运用量化分析,完善地标物周围环境的优化处理。通过对福州白塔周围环境的优化分析,将理论与实践结合,成果可为其他历史建筑环境保护提供新的思路与参考。