Partial tail loss has no severe effects on energy stores and locomotor performance in a lacertid lizard, <Emphasis Type="Italic">Takydromus septentrionalis</Emphasis>

Many species of lizards use caudal autotomy as a defense strategy to avoid predation, but tail loss entails costs. These topics were studied experimentally in the northern grass lizard, Takydromus septentrionalis. We measured lipids in the three-tail segments removed from each of the 20 experimental lizards (adult females) initially having intact tails to evaluate the effect of tail loss on energy stores; we obtained data on locomotor performance (sprint speed, the maximal length traveled without stopping and the number of stops in the racetrack) for these lizards before and after the tail-removing treatments to evaluate the effect of tail loss on locomotor performance. An independent sample of 20 adult females that retained intact tails was measured for locomotor performance to serve as controls for successive measurements taken for the experimental lizards. The lipids stored in the removed tail was positively correlated with tailbase width when holding the tail length constant, indicating that thicker tails contained more lipids than did thinner tails of the same overall length. Most of the lipids stored in the tail were concentrated in the proximal portion of the tail. Locomotor performance was almost unaffected by tail loss until at least more than 71% of the tail (in length) was lost. Our data show that partial tail loss due to predatory encounters or other factors may not severely affect energy stores and locomotor performance in T. septentrionalis.     

单性木兰花粉壁超微结构的研究

本文首次报道单性木兰花粉的形态特征和外壁超微结构。花粉外部形态与木兰科各属特征一致,表明单性木兰花粉的原始性。但花粉外壁超微结构显示其外壁表面具皱波状纹饰;覆盖层波浪状,具稀疏的小穿孔;柱状层很薄,小柱典型,直立,短而细。外壁超微结构表明单性木兰属在木兰亚族中是一个较进化的属。扫描电镜和透射电镜资料揭示出单性木兰在植物分类系统中的特殊地位和重要学术价值。     

白条草蜥多态性微卫星位点的分离与鉴定

白条草蜥(Takydromus wolteri)是一种年产多窝卵的蜥蜴。为了对其婚配制度、同一雌性个体所产卵的窝内和窝间的父权状况、种群的遗传结构和物种的进化历史等研究内容进行探讨,本研究筛选出白条草蜥的9个具有高度多态性的微卫星位点。微卫星位点筛选自包含(AC)n和(ATAG)n重复片度的微卫星富集文库。在白条草蜥安徽滁州种群的16～32个个体中对上述位点进行检测后发现,上述座位的等位基因数目范围为12～20个,期望杂合度范围为0.894～0.955,观测杂合度范围0.565～0.938,表明这些微卫星标记具有良好的遗传多样性,它们将在白条草蜥的种群遗传结构、基因流水平、种群分化和婚配制度的研究中发挥重要作用。     

广东肇庆北岭山南草蜥生态习性初步观察

2004～2005年观察研究了肇庆北岭山地区南草蜥（Takydromus sexlineatus meridionalis Gunther）的生态习性。成体全长（TL）245．104mm,尾长为体长的3．9倍,尾再生能力强。12月到翌年2月冬眠,14℃以下完全入眠,20℃以上陆续出蛰,3～5月为活动盛期。性成熟雌体年产多窝柔性壳卵,每窝2-4枚,卵重0．1773g,长径为8.855mm,短径为6．157mm,孵化期为40天左右,5月出现当年幼体。     

Collections from the mesophytic zone off Bermuda reveal three species of Kallymeniaceae (Gigartinales,Rhodophyta) in genera with transoceanic distributions

A molecular survey of red algae collected by technical divers and submersibles from 90 m in the mesophotic zone off the coast of Bermuda revealed three species assignable to the Kallymeniaceae. Two of the species are representative of recently described genera centered in the western Pacific in Australia and New Zealand, Austrokallymenia and Psaromenia and the third from the Mediterranean Sea and the eastern Atlantic, Nothokallymenia. A phylogenetic analysis of concatenated mitochondrial (COI‐5P) and chloroplast (rbcL) genes, as well as morphological characteristics, revealed that two are shown to be new species with distant closest relatives (N. erosa and Psaromenia septentrionalis), while the third represents a deep water western Atlantic species now moved to an Australasian genus (A. westii).     

北草蜥种群间生活史变异的成因分析:热环境、食物可利用性和体温的岛屿间差异

比较浙江温州北麂岛与洞头岛的热环境、食物可利用性以及动物体温,以辨析北草蜥岛屿种群间生活史特征差异中环境因子的作用。通过测定岛屿上北草蜥栖息地植被和环境温度,比较岛屿热环境的差异。野外测定活动蜥蜴的体温、环境温度和活动规律,实验室温梯板中测定动物喜好体温。用陷阱法测定无脊椎动物多样性和丰度,以比较岛屿蜥蜴种群的食物可利用性。岛屿植被存在差异导致热环境的差异。洞头岛植被高于北麂岛,地表层光线透入率则低于北麂岛。因而,洞头岛郁闭地表的平均温度和最高温度显著低于北麂岛,但两岛裸露地面的温度无显著差异。热环境的岛屿间差异进而影响北草蜥的野外体温。在春季,洞头岛的野外有效温度和基底温度显著大于北麂岛,而两岛北草蜥的体温无显著差异;在夏季,洞头岛的北草蜥体温、有效温度和基质温度均显著高于北麂岛;到秋季,北麂岛蜥蜴体温和环境温度高于洞头岛。地面无脊椎动物多样性和丰度的岛屿间差异表明北麂岛食物可利用性大于洞头岛。岛屿间北草蜥日活动规律和喜好体温无显著差异。本研究表明:(1)温度和食物可利用性存在岛屿间差异,岛屿种群间生活史特征差异可能与之有关;(2)两岛屿北草蜥主要采取行为调节对策来适应自然界的热环境变化,尚未发现热生理学特征的进化性漂移[动物学报51(5):797-805,2005]。     

Northern grass lizards (<Emphasis Type="Italic">Takydromus septentrionalis</Emphasis>) from different populations do not differ in thermal preference and thermal tolerance when acclimated under identical thermal conditions

We acclimated adults of Takydromus septentrionalis (northern grass lizard) from four localities (populations) under identical thermal conditions to examine whether local thermal conditions have a fixed influence on thermal preference and thermal tolerance in the species. Selected body temperature (Tsel), critical thermal minimum (CTMin), and critical thermal maximum (CTMax) did not differ between sexes and among localities in lizards kept under identical laboratory conditions for ∼5 months, and the interaction effects between sex and locality on these measures were not significant. Lizards acclimated to the three constant temperatures (20, 25, and 35°C) differed in Tsel, CTMin, and CTMax. Tsel, CTMin, and CTMax all shifted upward as acclimation temperature increased, with Tsel shifting from 32.0 to 34.1°C, CTMin from 4.9 to 8.0°C, and CTMax from 42.0 to 44.5°C at the change-over of acclimation temperature from 20 to 35°C. Lizards acclimated to the three constant temperatures also differed in the range of viable body temperatures; the range was widest in the 25°C treatment (38.1°C) and narrowest in the 35°C treatment (36.5°C), with the 20°C treatment in between (37.2°C). The results of this study show that local thermal conditions do not have a fixed influence on thermal preference and thermal tolerance in T. septentrionalis.     

白条草蜥消化道内分泌细胞的免疫组织化学

应用6种胃肠激素抗血清和免疫组织化学ABC法(avidin-biotin complex method),对白条草蜥(Takydromus wolteri)消化道内分泌细胞进行了免疫组织化学定位研究和形态学观察。结果表明,5-羟色胺细胞较其他5种内分泌细胞的分布更为广泛,整个消化道中(即从食管到直肠)均有分布,其分布密度高峰位于幽门。食管、回肠和直肠未检测到生长抑素细胞,生长抑素细胞在幽门部分布密度最高,总体来说生长抑素细胞的分布在胃部较高而在小肠部较低。胃泌素细胞和胰多肽细胞分布在小肠,均在十二指肠分布密度最高。胰高血糖素细胞在胃幽门部分布密度最高,十二指肠、空肠次之,回肠分布密度最低。P-物质细胞仅分布于幽门部。6种内分泌细胞以圆形和锥体形为主,它们广泛分布于消化道黏膜之间、腺泡上皮细胞之间及上皮细胞基部。内分泌细胞的密度分布与其食性、食物组成和生活环境有关,它们的形态与其内、外分泌功能是相适应的。     

北草蜥中脑视叶组织学结构观察

用光学显微镜对北草蜥(Takydromus septentrionalis)中脑视叶组织学结构进行了观察。视叶分为背侧的顶盖和腹侧的被盖,两者无明显界限。顶盖处灰质和白质交替排列。由表及里,可分为分子层、外灰质层、浅白质层、中灰质层、中白质层、深灰质层、深白质层和室管膜层。被盖处细胞层次不明显。在视叶的前部有横行的纤维将左右视叶联系起来。左右视叶室与中脑水管以及两视叶间的纵沟在视叶的中、后部相通。同时将北草蜥的中脑与其它低等脊椎动物进行了比较,推测北草蜥在进化上处于较低等地位。     

北草蜥精子的超微结构--兼评不同类群蜥蜴精子形态的差异

应用透射电镜对北草蜥精子的超微结构研究结果表明,北草蜥精子头部顶体囊始终呈圆形,由皮质和髓质组成;顶体囊单侧脊的皮质与髓质问具电子透亮区;穿孔器1个,无穿孔器基板;具顶体下腔;细胞核长形,核内小管缺,核前电子透亮区缺,核肩圆。尾部颈段具片层结构。中段短,多层膜结构缺;纵切面上具2层线粒体;横切面上每圈线粒体6个;2组致密体,具连续的环状结构;线粒体与环状结构的排列模式：rs1／mi1、rs2／mi2;纤维鞘伸人中段,具终环。主段前面部分具薄的细胞质颗粒区;纤维3和8至主段前端消失;轴丝呈“9＋2”型。蜥蜴科内不同种类的线粒体数目不同,但都具有2组致密体。不同类群蜥蜴的顶体囊、顶体下腔、核前电子透亮区、穿孔器基板、核肩,以及线粒体与致密体的数目和排列方式等精子超微结构特征都为研究蜥蜴的系统发生提供了辅助信息。