Enclosure utilization and activity of Round Island geckos (Phelsuma guentheri)

This study evaluated space use and activity of individually housed Phelsuma guentheri to formulate recommendations for environmental enrichment. Gecko location within small (0.03 m³) and large (0.22 m³) vivaria and substrate use data were collected over five 24 h periods. Thermogradients within each enclosure type were determined by measuring temperature at various heights. From these data, geckos' space use, activity cycle, and substrate preference were calculated in relation to temperature changes and photoperiod. Geckos did not utilize their environment uniformly. Heavily utilized locations contained cage furnishings or hides. Geckos avoided the use of vertical glass walls. Thermogradients were not actively utilized; however, when given the opportunity, geckos would orient towards natural sunlight. Enclosure size did not affect activity cycle, which was nocturnal with crepuscular peaks. Recommendations for enclosure improvement include provision of more furnishings and hides at different thermal levels. An alternate focal heat source other than UV light is recommended to provide warmth without light. Larger enclosures may encourage more uniform use of available space. Transparent glass may not be an appropriate substrate for these geckos. Once recommendations have been implemented, a similar study must be conducted to assess benefit. © 1995 Wiley-Liss, Inc.     

多疣壁虎胚胎发育分期的形态学特征

脊椎动物发育生物学的研究通常依赖于数量有限的模式生物的形态变化,胚胎发育分期表的建立为物种胚胎发育的一系列过程确立了一个统一的标准,成为研究形态演化的重要工具。本研究对多疣壁虎(Gekko japonicus)28℃孵化条件下的胚胎发育过程进行显微观察,并记录了整个胚胎发育历程。基于多疣壁虎胚胎发育过程中头部、咽、四肢等形态变化及皮肤色素沉积和被鳞的情况,将多疣壁虎胚胎发育分为42个时期。刚排出体外的受精卵,其胚胎发育一般已经发生至28期,该期胚胎头部和躯干分化明显,眼泡、咽弓、心和体节可见;29期前、后肢芽均可见;30期肢芽延长并开始出现分区,31期可见明显肢身,32期四肢均出现肢柱和肢杆的分区;33期咽裂消失,指和趾开始显现;35期指和趾间带退化,指和趾完全形成;36期出现爪;37期爪完全形成;38期皮肤色素沉积明显;39期指、趾底部膨大,形成单行攀瓣;40期身体背部和四肢色素沉积且被鳞明显;41期腹部出现色素沉积且被覆鳞片。42期鼻孔开放,体背整体呈灰棕色。对多疣壁虎卵产出后胚胎28~42期发育期形态学变化进行了详细描述,旨在为蜥蜴类胚胎发育研究提供参考。     

Effects of Gekko sulfated polysaccharide on the proliferation and differentiation of hepatic cancer cell line

Gekko swinhonis Gūenther has been used as an anti-cancer drug in traditional Chinese medicine. Gekko sulfated polysaccharide (Gepsin) was investigated for its activity in hepatocellular carcinoma. Hepatocarcinoma cell line (Bel-7402) and liver cell line (L-02) were exposed to Gepsin (100 microg/ml and 10 microg/ml). Gepsin did not suppress the proliferation and viability of normal liver L-02 cells, but strongly inhibited the proliferation of hepatocarcinoma Bel-7402 cells. Gepsin did not induce the apoptosis of Bel-7402 cells, but blocked cells in G2/M phase. Treated with Gepsin, Bel-7402 cells showed ultrastructural features of differentiation. AFP secretion decreased while ALB secretion increased markedly on Gepsin-treated cells. The data show that Gepsin suppressed the proliferation and induced differentiation of hepatocarcinoma, but the toxicity to normal liver cells was negligible.     

Experimental analysis of retreat‐site selection by thick‐tailed geckos Nephrurus milii

Abstract Although animals use habitats non‐randomly in the wild, complex correlations among environmental features mean that proximate influences on habitat selection can be identified only by experimental manipulation of potential cues. Thick‐tailed geckos Nephrurus milii are large lizards that are widely distributed through southern Australia. These nocturnally active animals typically spend daylight hours under surface rocks. We presented captive geckos with alternative retreat‐sites (rock crevices) differing in attributes potentially relevant to habitat selection. The lizards showed strong preference for shelter‐sites that enhanced thermoregulation (warm rather than cool) and that reduced the animal's vulnerability to predators (narrow crevices with small openings and not containing the scent of a predatory snake). Horizontal rather than sloping crevices were also preferred. Overall crevice size and thickness of the overlying rock did not influence retreat‐site selection in the laboratory, but could be important in the field because of their influence on thermal regimes under rocks. The present study supports the idea that nocturnal reptiles base their selection of diurnal shelters on multiple aspects related to the fitness consequences of occupancy of alternative available retreat‐sites.     

多疣壁虎的体温调节及运动能力热依赖性

本文测定了多疣壁虎(Gekko japonicus)的野外活动体温、喜好体温以及运动能力热依赖性,探讨夜行性蜥蜴的体温调节及其对动物功能表达的作用。在自然条件下,多疣壁虎的活动体温存在明显的月份间差异,但无性别和年龄间的差异。在实验室条件下,怀卵雌体(29.8℃)和幼体(29.9℃)的喜好体温显著高于非怀卵雌体(28.5℃)和雄体(28.2℃)。体温能显著影响多疣壁虎的运动能力,在15℃-34℃范围内,其平均跑速随体温上升而加快,超过34℃后则随体温升高而减慢。多疣壁虎的平均跑速及其热敏感性无显著的年龄组间差异。在夜间活动期,雄体、非怀卵雌体和幼体的体温调节有效度低,而怀卵雌体的体温调节有效度则较高。结果显示怀卵雌体的体温调节较非怀卵雌体和雄体更精确     

大壁虎不同地理居群的遗传变异与分化

以线粒体细胞色素b(Cytb)基因作为分子标记,对中国广西12个地区,以及越南和老挝大壁虎(Gekko gecko)进行序列测定,获得Cytb基因424bp的序列片段,共有7个单倍型。以白脊壁虎和沙虎为外群,用邻接法和最大简约法构建了大壁虎不同地理种群的系统发育关系,其结果显示中国广西4个不同单倍型黑大壁虎之间的平均遗传距离为0.20%—1.20%,越南红大壁虎与老挝红大壁虎之间的平均遗传距离为0.50%,广西宁明红大壁虎与越南红大壁虎和老挝红大壁虎之间平均遗传距离分别为1.70%和2.20%。广西黑大壁虎种群与红大壁虎种群之间的平均遗传距离为8.60%—9.50%,达到了亚种或种分化的差异。     

无蹼壁虎入蛰时和出蛰时几项生理常数间的关系

本文揭示了无蹼壁虎（Gekkoswinhonis）入蛰时和出蛰时,雌性、雄性之体长、嗣体重、脂肪体重及生殖腺重与体重之间均呈显著的正相关关系。肥满度和躯体肥满度两个指标适用于无蹼壁虎这类爬行动物;肝系数、脂肪体系数及生殖腺系数也适用于无蹼壁虎这类爬行动物。冬眠期间雄性与雌性在躯体物质及脂肪体的消耗上存在显著差异。     

Histology and histochemistry of the gekkotan notochord and their bearing on the development of notochordal cartilage

The persistence of the notochord into the skeletally mature life stage is characteristic of gekkotans, but is otherwise of rare occurrence among amniotes. The taxonomic diversity of Gekkota affords the opportunity to investigate the structure and development of this phylogenetically ancestral component of the skeleton, and to determine its basic characteristics. The gekkotan notochord spans almost the entire postcranial long axis and is characterized by a moniliform morphology with regularly alternating zones of chordoid and chondroid tissue. Chordoid tissue persists in the region of intervertebral articulations and occupies the cavitations that lie between the centra of the amphicoelous vertebrae. Chondroid tissue is restricted to zones in which the diameter of the notochord is reduced, corresponding to mid‐vertebral locations. In the tail, these zones of chondroid tissue are associated with the autotomic fracture planes. Chondroid tissue first manifests during late embryogenesis, appears to differentiate from pre‐existing chordoid tissue, and has the histological and histochemical characteristics of cartilage. Our observations lend support to the hypothesis that cartilage can be derived directly from notochordal tissue, and suggest that the latter may be an evolutionary and developmental precursor to chordate cartilage. The persistence of chordoid tissue in the intervertebral regions of amphicoelous vertebrae is consistent with a suite of paedomorphic traits exhibited by gekkotans and suggests that the typical hydrostatic nature of notochordal tissue may play a role in mechanically governing patterns of displacement between adjacent amphicoelous vertebrae that lack extensive centrum‐to‐centrum contact. Morphol., 2012. © 2012 Wiley Periodicals, Inc.     

The Modulation and Control of the Gecko''''s Foot Movement

1IntroductionAttachment is still a difficult problem in wall-climbing robotics.There are two main types ofattachment mechanisms for wall climbing robots.One issuction,which has major drawbacks.The mechanismrequires the contacting surface being smooth,otherwise itwill be ineffective.This limits adhesion of the suctioncup to relatively smooth,non-porous,non-crackedsurfaces.Another issue associated with suction adhesionis that this method requires time to develop enoughvacuum to generate suffici…