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Sample records for monitor lizard rbc

  1. Earliest example of a giant monitor lizard (Varanus, Varanidae, Squamata.

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    Jack L Conrad

    Full Text Available BACKGROUND: Varanidae is a clade of tiny (600 mm PCL lizards first appearing in the Cretaceous. True monitor lizards (Varanus are known from diagnostic remains beginning in the early Miocene (Varanus rusingensis, although extremely fragmentary remains have been suggested as indicating earlier Varanus. The paleobiogeographic history of Varanus and timing for origin of its gigantism remain uncertain. METHODOLOGY/PRINCIPAL FINDINGS: A new Varanus from the Mytilini Formation (Turolian, Miocene of Samos, Greece is described. The holotype consists of a partial skull roof, right side of a braincase, partial posterior mandible, fragment of clavicle, and parts of six vertebrae. A cladistic analysis including 83 taxa coded for 5733 molecular and 489 morphological characters (71 previously unincluded demonstrates that the new fossil is a nested member of an otherwise exclusively East Asian Varanus clade. The new species is the earliest-known giant (>600 mm PCL terrestrial lizard. Importantly, this species co-existed with a diverse continental mammalian fauna. CONCLUSIONS/SIGNIFICANCE: The new monitor is larger (longer than 99% of known fossil and living lizards. Varanus includes, by far, the largest limbed squamates today. The only extant non-snake squamates that approach monitors in maximum size are the glass-snake Pseudopus and the worm-lizard Amphisbaena. Mosasauroids were larger, but exclusively marine, and occurred only during the Late Cretaceous. Large, extant, non-Varanus, lizards are limbless and/or largely isolated from mammalian competitors. By contrast, our new Varanus achieved gigantism in a continental environment populated by diverse eutherian mammal competitors.

  2. Evolution of extreme body size disparity in monitor lizards (Varanus).

    Science.gov (United States)

    Collar, David C; Schulte, James A; Losos, Jonathan B

    2011-09-01

    Many features of species' biology, including life history, physiology, morphology, and ecology are tightly linked to body size. Investigation into the causes of size divergence is therefore critical to understanding the factors shaping phenotypic diversity within clades. In this study, we examined size evolution in monitor lizards (Varanus), a clade that includes the largest extant lizard species, the Komodo dragon (V. komodoensis), as well as diminutive species that are nearly four orders of magnitude smaller in adult body mass. We demonstrate that the remarkable body size disparity of this clade is a consequence of different selective demands imposed by three major habitat use patterns-arboreality, terrestriality, and rock-dwelling. We reconstructed phylogenetic relationships and ancestral habitat use and applied model selection to determine that the best-fitting evolutionary models for species' adult size are those that infer oppositely directed adaptive evolution associated with terrestriality and rock-dwelling, with terrestrial lineages evolving extremely large size and rock-dwellers becoming very small. We also show that habitat use affects the evolution of several ecologically important morphological traits independently of body size divergence. These results suggest that habitat use exerts a strong, multidimensional influence on the evolution of morphological size and shape disparity in monitor lizards.

  3. RBC indices

    Science.gov (United States)

    ... due to low iron levels, lead poisoning, or thalassemia ). MCV normal. Normocytic anemia (may be due to ... valve surgery Hemoglobin Hemolytic anemia RBC count Sepsis Thalassemia Vitamin B12 Review Date 3/13/2016 Updated ...

  4. RBC-Y和RET-Y在肾性贫血患者铁缺乏监测中的应用%Application of RBC-Y and RET-Y in monitoring renal anemia patients with iron deficiency

    Institute of Scientific and Technical Information of China (English)

    黄福达; 杨山虹

    2014-01-01

    目的:探讨RBC-Y和RET-Y在肾性贫血患者铁缺乏监测中的应用价值。方法收集慢性肾衰竭(CRF)引起的肾性贫血组和健康对照组血液标本,分别检测 RBC-Y、RET-Y、铁蛋白(SF)、可溶性转铁蛋白受体(sTfR)等指标,以sTfR>2.25 mg/L作为铁缺乏的“金标准”,利用 ROC曲线分析RBC-Y、RET-Y和SF等参数在诊断肾性贫血患者铁缺乏的性能。结果肾性贫血组与健康对照组间RBC-Y和RET-Y两参数结果差异有统计学意义(P<0.001),经ROC曲线分析RBC-Y、RET-Y和SF在诊断肾性贫血患者铁缺乏时曲线下面积分别为0.811、0.780、0.530,当临界值为151.6时,RBC-Y诊断铁缺乏的灵敏度为81.0%,特异性为75.0%;当临界值为1580.5时,RET-Y诊断铁缺乏的灵敏度为74.6%,特异性为75.0%;当临界值为96μg/L时,SF诊断铁缺乏的灵敏度为61.9%,特异性为58.3%。结论 RBC-Y和RET-Y可作为CRF引起的肾性贫血患者铁缺乏的诊断指标。%Objective To explore the clinical value of RBC-Y and RET-Y in monitoring the iron deficiency of the patients who suffer with renal anemia .Methods Blood samples were collected from patients with renal anemia of CRF and normal control individuals ,then RBC-Y ,RET-Y ,SF and sTfR were detected respectively and sTfR >2 .25 mg/L was regarded as "gold standard"of the iron deficiency ,using ROC curve to analyze RBC-Y ,RET-Y and SF for the diagnosis of the iron deficiency of the patients who suffer with renal anemia was studied .Results There are sig-nificant differences in RBC-Y and RET-Y between renal anemia group and control group .The RBC-Y ,RET-Y and SF area under the ROC curve are 0 .811 ,0 .780 ,0 .530 ,the sensitivity of RBC-Y in diagnosing iron deficiency is 81 .0%and specificity is 75 .0% when the critical value is 151 .6 ;sensitivity of RET-Y is 74 .6% and specificity is 75 .0%when the critical value is 1 580 .5;sensitivity of

  5. Yolk coelomitis in a white-throated monitor lizard (Varanus albigularis : short communication

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    B.R. Gardner

    2010-05-01

    Full Text Available Yolk coelomitis as a result of pre-ovulatory follicular stasis is a common disorder in captive reptiles, especially in captive lizards of various genera. The clinical signs are generally fairly non-specific and diagnosis is based on clinical signs together with most of the common diagnostic modalities. The condition is most likely a husbandry and environment-related reproductive disorder. It has not been reported in wild free-living specimens. This report describes the clinical presentation and post mortem lesions in a white-throated monitor lizard that died during treatment for non-specific clinical signs related to a severe yolk coelomitis.

  6. Head shape evolution in monitor lizards (Varanus): interactions between extreme size disparity, phylogeny and ecology.

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    Openshaw, G H; Keogh, J S

    2014-02-01

    Characterizing patterns of observed current variation, and testing hypotheses concerning the potential drivers of this variation, is fundamental to understanding how morphology evolves. Phylogenetic history, size and ecology are all central components driving the evolution of morphological variation, but only recently have methods become available to tease these aspects apart for particular body structures. Extant monitor lizards (Varanus) have radiated into an incredible range of habitats and display the largest body size range of any terrestrial vertebrate genus. Although their body morphology remains remarkably conservative, they have obvious head shape variation. We use two-dimensional geometric morphometric techniques to characterize the patterns of dorsal head shape variation in 36 species (375 specimens) of varanid, and test how this variation relates to size, phylogenetic history and ecology as represented by habitat. Interspecific head shape disparity is strongly allometric. Once size effects are removed, principal component analysis shows that most shape variation relates to changes in the snout and head width. Size-corrected head shape variation has strong phylogenetic signal at a broad level, but habitat use is predictive of shape disparity within phylogenetic lineages. Size often explains shape disparity among organisms; however, the ability to separate size and shape variation using geometric morphometrics has enabled the identification of phylogenetic history and habitat as additional key factors contributing to the evolution of head shape disparity among varanid lizards.

  7. RBC nuclear scan

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    ... page: //medlineplus.gov/ency/article/003835.htm RBC nuclear scan To use the sharing features on this page, please enable JavaScript. An RBC nuclear scan uses small amounts of radioactive material to ...

  8. Tracing the diet of the monitor lizard Varanus mabitang by stable isotope analyses (δ15N, δ13C)

    Science.gov (United States)

    Struck, Ulrich; Altenbach, Alexander; Gaulke, Maren; Glaw, Frank

    2002-09-01

    In this study, we used analyses of stable isotopes of nitrogen (δ15N) and carbon (δ13C) to determine the trophic ecology of the monitor lizard Varanus mabitang. Stable isotopes from claws, gut contents, and soft tissues were measured from the type specimen. Samples from Varanus olivaceus, Varanus prasinus, Varanus salvator, the herbivorous agamid lizard Hydrosaurus pustulatus, and some plant matter were included for comparison. Our data show a rapid decrease in δ13C (about10‰) from food plants towards gut contents and soft tissues of herbivorous species. For the varanids, we found a significant linear correlation of decreasing δ13C and increasing δ15N from herbivorous towards carnivorous species. In terms of trophic isotope ecology, the type specimen of V. mabitang is a strict herbivore. Thus it differs significantly in its isotopic composition from the morphologically next closest related species V. olivaceus. The most highly carnivorous species is V. salvator, while δ15N values for V. prasinus and V. olivaceus are intermediate. Claws provide very valuable samples for such measurements, because they can be sampled from living animals without harm. Additionally, their range of variability is relatively small in comparison with measurements from soft tissues.

  9. RBC Antibody Screen

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    ... test also may be used to help diagnose autoimmune-related hemolytic anemia in conjunction with a DAT. This condition may be caused when a person produces antibodies against his or her own RBC antigens. This can happen with some autoimmune disorders , such as lupus , with diseases such as ...

  10. Scale Morphology and Micro-Structure of Monitor Lizards (Squamata: Varanidae: Varanus spp.) and their Allies: Implications for Systematics, Ecology, and Conservation.

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    Bucklitsch, Yannick; Böhme, Wolfgang; Koch, André

    2016-08-17

    We analysed scale morphology and micro-structure from five different body regions using scanning electron microscopy (SEM) across all nine recognized subgenera of the monitor lizard genus Varanus including 41 different species investigated. As far as we are aware, this qualitative visual technique was applied by us for the first time to most monitor lizard species and probably also to the primary outgroup and sister species Lanthanotus borneensis. A comprehensive list of 20 scalation characters each with up to seven corresponding character states was established and defined for the five body regions sampled. For the phylogenetic approach, parsimony analyses of the resulting morphological data matrix as well as Bremer and bootstrap support calculations were performed with the software TNT. Our results demonstrate that a variety of micro-ornamentations (i.e., ultra- or micro-dermatoglyphics) as seen in various squamate groups is hardly present in monitor lizards. In several species from six out of nine subgenera, however, we found a honeycomb-shaped micro-structure of foveate polygons. Two further samples of Euprepiosaurus Fitzinger, 1843 exhibit each another unique microscopic structure on the scale surface. Notably, the majority of species showing the honeycombed ultra-structure inhabit arid habitats in Australia, Africa and the Middle East. Therefore, it can be inferred that this microscopic scalation feature, which has also been identified in other desert dwelling lizard species, is taxonomically and ecologically correlated with a xeric habitat type in varanids, too. In addition, the systematic affiliation of V. spinulosus, an endemic monitor lizard species from the Solomon Islands with an extraordinary scale shape, is discussed in the light of current hypotheses about its phylogenetic position within the Varanidae. Due to its unique scalation characteristics, in combination with other morphological evidence, a new monotypic subgenus, Solomonsaurus subgen. nov

  11. Optimal body size with respect to maximal speed for the yellow-spotted monitor lizard (Varanus panoptes; Varanidae).

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    Clemente, Christofer J; Withers, Philip C; Thompson, Graham

    2012-01-01

    Studies of locomotor performance often link variation in morphology with ecology. While maximum sprint speed is a commonly used performance variable, the absolute limits for this performance trait are not completely understood. Absolute maximal speed has often been shown to increase linearly with body size, but several comparative studies covering a large range of body sizes suggest that maximal speed does not increase indefinitely with body mass but rather reaches an optimum after which speed declines. Because of the comparative nature of these studies, it is difficult to determine whether this decrease is due to biomechanical constraints on maximal speed or is a consequence of phylogenetic inertia or perhaps relaxed selection for lower maximal speed at large body size. To explore this issue, we have examined intraspecific variations in morphology, maximal sprint speed, and kinematics for the yellow-spotted monitor lizard Varanus panoptes, which varied in body mass from 0.09 to 5.75 kg. We show a curvilinear relationship between body size and absolute maximal sprint speed with an optimal body mass with respect to speed of 1.245 kg. This excludes the phylogenetic inertia hypothesis, because this effect should be absent intraspecifically, while supporting the biomechanical constraints hypothesis. The relaxed selection hypothesis cannot be excluded if there is a size-based behavioral shift intraspecifically, but the biomechanical constraints hypothesis is better supported from kinematic analyses. Kinematic measurements of hind limb movement suggest that the distance moved by the body during the stance phase may limit maximum speed. This limit is thought to be imposed by a decreased ability of the bones and muscles to support body mass for larger lizards.

  12. Trapper readies trap for lizard

    Science.gov (United States)

    2000-01-01

    State-licensed animal trapper James Dean sets the open door of an animal trap on KSC. He hopes to catch a large monitor lizard spotted recently near S.R. 3, a route into the Center, by several area residents. The lizard is not a native of the area, and possibly a released pet. Dean is working with the cooperation of KSC and the Merritt Island National Wildlife Refuge.

  13. A spectacular new Philippine monitor lizard reveals a hidden biogeographic boundary and a novel flagship species for conservation

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    Welton, Luke J.; Siler, Cameron D.; Bennett, Daniel; Diesmos, Arvin; Duya, M. Roy; Dugay, Roldan; Rico, Edmund Leo B.; Van Weerd, Merlijn; Brown, Rafe M.

    2010-01-01

    As humans continue to explore the last uncharted regions of the planet, discoveries of previously unknown species of large vertebrates have become infrequent. Here, we report on the discovery of a spectacular new species of giant, secretive, frugivorous, forest monitor lizard (Genus: Varanus) from the forests of the northern Philippines. Using data from morphology and mitochondrial and nuclear DNA sequences, we demonstrate the taxonomic distinctiveness of this new 2 m long species and provide insight into its historical biogeography and systematic affinities. Our molecular phylogenetic analyses indicate that the new species is closely related to Varanus olivaceus (from southern Luzon and nearby islands), but it differs from this and other varanids with respect to characteristics of scalation, colour pattern, body size, anatomy of the reproductive organs and genetic divergence. The new species appears to be restricted to forests of the central and northern Sierra Madre mountain range; it is separated from the range of V. olivaceus by a more than 150 km stretch that includes at least three low-elevation river valley barriers to dispersal. This discovery identifies a seldom-perceived biogeographic boundary and emphasizes the need for continued biodiversity research in the megadiverse conservation hotspot of the Philippines. It is anticipated that the new species will serve as an important flagship species for conservation efforts aimed at preserving the remaining forests of northern Luzon. PMID:20375042

  14. A spectacular new Philippine monitor lizard reveals a hidden biogeographic boundary and a novel flagship species for conservation.

    Science.gov (United States)

    Welton, Luke J; Siler, Cameron D; Bennett, Daniel; Diesmos, Arvin; Duya, M Roy; Dugay, Roldan; Rico, Edmund Leo B; Van Weerd, Merlijn; Brown, Rafe M

    2010-10-23

    As humans continue to explore the last uncharted regions of the planet, discoveries of previously unknown species of large vertebrates have become infrequent. Here, we report on the discovery of a spectacular new species of giant, secretive, frugivorous, forest monitor lizard (Genus: Varanus) from the forests of the northern Philippines. Using data from morphology and mitochondrial and nuclear DNA sequences, we demonstrate the taxonomic distinctiveness of this new 2 m long species and provide insight into its historical biogeography and systematic affinities. Our molecular phylogenetic analyses indicate that the new species is closely related to Varanus olivaceus (from southern Luzon and nearby islands), but it differs from this and other varanids with respect to characteristics of scalation, colour pattern, body size, anatomy of the reproductive organs and genetic divergence. The new species appears to be restricted to forests of the central and northern Sierra Madre mountain range; it is separated from the range of V. olivaceus by a more than 150 km stretch that includes at least three low-elevation river valley barriers to dispersal. This discovery identifies a seldom-perceived biogeographic boundary and emphasizes the need for continued biodiversity research in the megadiverse conservation hotspot of the Philippines. It is anticipated that the new species will serve as an important flagship species for conservation efforts aimed at preserving the remaining forests of northern Luzon.

  15. The rediscovery of the Common Water Monitor Lizard Varanus salvator (Squamata: Varanidae in northern Myanmar

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    Sai Sein Lin Oo

    2016-05-01

    Full Text Available On 09 June 2015, a Common Water Monitor Varanus salvator (Laurenti, 1768 was observed and photographed (Image 1 on the campus of Banmaw University, Banmaw (Bhamo, Kachin State, Myanmar (24018’15”N & 97015’52”E.  Subsequently, a second individual was observed 140km to the west at Banmauk, Sagaing Division (24024’N & 95051’E. These two observations are the first records of Varanus salvator from Upper Myanmar since Anderson (1878. It would be interesting to conduct follow-up studies to determine whether this is indeed a relict northern population. 

  16. Trappers set up trap for lizard

    Science.gov (United States)

    2000-01-01

    In hope of catching a large monitor lizard seen in the area, state-licensed animal trappers Dewey Kessler and James Dean (at left), with Gary Povitch (kneeling) of the U.S. Wildlife and Dan Turner (standing) set up a trap on KSC. The lizard has been spotted recently near S.R. 3, a route into the Center, by several area residents. Turner is a monitor expert. The lizard is not a native of the area, and possibly a released pet. Dean is working with the cooperation of KSC and the Merritt Island National Wildlife Refuge.

  17. Highly species-specific centromeric repetitive DNA sequences in lizards: molecular cytogenetic characterization of a novel family of satellite DNA sequences isolated from the water monitor lizard (Varanus salvator macromaculatus, Platynota).

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    Chaiprasertsri, Nampech; Uno, Yoshinobu; Peyachoknagul, Surin; Prakhongcheep, Ornjira; Baicharoen, Sudarath; Charernsuk, Saranon; Nishida, Chizuko; Matsuda, Yoichi; Koga, Akihiko; Srikulnath, Kornsorn

    2013-01-01

    Two novel repetitive DNA sequences, VSAREP1 and VSAREP2, were isolated from the water monitor lizard (Varanus salvator macromaculatus, Platynota) and characterized using molecular cytogenetics. The respective lengths and guanine-cytosine (GC) contents of the sequences were 190 bp and 57.5% for VSAREP1 and 185 bp and 59.7% for VSAREP2, and both elements were tandemly arrayed as satellite DNA in the genome. VSAREP1 and VSAREP2 were each located at the C-positive heterochromatin in the pericentromeric region of chromosome 2q, the centromeric region of chromosome 5, and 3 pairs of microchromosomes. This suggests that genomic compartmentalization between macro- and microchromosomes might not have occurred in the centromeric repetitive sequences of V. salvator macromaculatus. These 2 sequences did only hybridize to genomic DNA of V. salvator macromaculatus, but no signal was observed even for other squamate reptiles, including Varanus exanthematicus, which is a closely related species of V. salvator macromaculatus. These results suggest that these sequences were differentiated rapidly or were specifically amplified in the V. salvator macromaculatus genome.

  18. Multiple-capillary measurement of RBC speed, flux, and density with optical coherence tomography.

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    Lee, Jonghwan; Wu, Weicheng; Lesage, Frederic; Boas, David A

    2013-11-01

    As capillaries exhibit heterogeneous and fluctuating dynamics even during baseline, a technique measuring red blood cell (RBC) speed and flux over many capillaries at the same time is needed. Here, we report that optical coherence tomography can capture individual RBC passage simultaneously over many capillaries located at different depths. Further, we demonstrate the ability to quantify RBC speed, flux, and linear density. This technique will provide a means to monitor microvascular flow dynamics over many capillaries at different depths at the same time.

  19. RBC-NOS-dependent S-nitrosylation of cytoskeletal proteins improves RBC deformability.

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    Marijke Grau

    Full Text Available BACKGROUND: Red blood cells (RBC possess a nitric oxide synthase (RBC-NOS whose activation depends on the PI3-kinase/Akt kinase pathway. RBC-NOS-produced NO exhibits important biological functions like maintaining RBC deformability. Until now, the cellular target structure for NO, to exert its influence on RBC deformability, remains unknown. In the present study we analyzed the modification of RBC-NOS activity by pharmacological treatments, the resulting influence on RBC deformability and provide first evidence for possible target proteins of RBC-NOS-produced NO in the RBC cytoskeletal scaffold. METHODS/FINDINGS: Blood from fifteen male subjects was incubated with the NOS substrate L-arginine to directly stimulate enzyme activity. Direct inhibition of enzyme activity was induced by L-N5-(1-Iminoethyl-ornithin (L-NIO. Indirect stimulation and inhibition of RBC-NOS were achieved by applying insulin and wortmannin, respectively, substances known to affect PI3-kinase/Akt kinase pathway. The NO donor sodium nitroprusside (SNP and the NO scavenger 2-(4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO were additionally applied as NO positive and negative controls, respectively. Immunohistochemical staining was used to determine phosphorylation and thus activation of RBC-NOS. As a marker for NO synthesis nitrite was measured in plasma and RBCs using chemiluminescence detection. S-nitrosylation of erythrocyte proteins was determined by biotin switch assay and modified proteins were identified using LC-MS. RBC deformability was determined by ektacytometry. The data reveal that activated RBC-NOS leads to increased NO production, S-nitrosylation of RBC proteins and RBC deformability, whereas RBC-NOS inhibition resulted in contrary effects. CONCLUSION/SIGNIFICANCE: This study first-time provides strong evidence that RBC-NOS-produced NO modifies RBC deformability through direct S-nitrosylation of cytoskeleton proteins, most likely α- and

  20. Communication Signals in Lizards.

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    Carpenter, Charles C.

    1983-01-01

    Discusses mechanisms and functional intent of visual communication signals in iguanid/agamid lizards. Demonstrated that lizards communicate with each other by using pushups and head nods and that each species does this in its own way, conveying different types of information. (JN)

  1. Sand swimming lizard: sandfish

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    Maladen, Ryan D; Kamor, Adam; Goldman, Daniel I

    2009-01-01

    We use high-speed x-ray imaging to reveal how a small (~10cm) desert dwelling lizard, the sandfish (Scincus scincus), swims within a granular medium [1]. On the surface, the lizard uses a standard diagonal gait, but once below the surface, the organism no longer uses limbs for propulsion. Instead it propagates a large amplitude single period sinusoidal traveling wave down its body and tail to propel itself at speeds up to ~1.5 body-length/sec. Motivated by these experiments we study a numerical model of the sandfish as it swims within a validated soft sphere Molecular Dynamics granular media simulation. We use this model as a tool to understand dynamics like flow fields and forces generated as the animal swims within the granular media. [1] Maladen, R.D. and Ding, Y. and Li, C. and Goldman, D.I., Undulatory Swimming in Sand: Subsurface Locomotion of the Sandfish Lizard, Science, 325, 314, 2009

  2. A Braitenberg Lizard:

    DEFF Research Database (Denmark)

    Shaikh, Danish; Hallam, John; Christensen-Dalsgaard, Jakob;

    2009-01-01

    The peripheral auditory system of a lizard is structured as a pressure difference receiver with strong broadband directional sensitivity. Previous work has demonstrated that this system can be implemented as a set of digital filters generated by considering the lumped-parameter model of the audit......The peripheral auditory system of a lizard is structured as a pressure difference receiver with strong broadband directional sensitivity. Previous work has demonstrated that this system can be implemented as a set of digital filters generated by considering the lumped-parameter model...

  3. Advantages in exploring a new environment with the left eye in lizards.

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    Bonati, Beatrice; Csermely, Davide; Sovrano, Valeria Anna

    2013-07-01

    Lizards (Podarcis muralis) preferentially use the left eye during spatial exploration in a binocular condition. Here we allowed 44 adult wild lizards to explore an unknown maze for 20 min under a temporary monocular condition whilst recording their movements, particularly the direction of turns made whilst walking within the maze. Lizards with a patch on their right eye, i.e. using their left eye to monitor the environment, moved faster than lizards with a patch on their left eye when turning both leftward and rightward in a T-cross. Hence, right eye-patched lizards were faster than left eye-patched lizards also in turning right, although their right eye was covered. Thus, lizards that could use the left eye/right hemisphere to attend spatial cues appeared to have more control and to be more prompt in exploring the maze. In addition, female lizards with their left eye covered stopped very frequently when they reached crosses, showing a high level of indecision. Results confirm that P. muralis lizards using their left eye only in exploring a new environment react faster and more efficiently than those using the right eye only in exploration. Hence lateralisation of spatial stimuli mediated by the left eye/right hemisphere could provide an advantage to this species.

  4. Status of the Island Night Lizard and Two Non-Native Lizards on Outlying Landing Field San Nicolas Island, California

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    Fellers, Gary M.; Drost, Charles A.; Murphey, Thomas G.

    2008-01-01

    More than 900 individually marked island night lizards (Xantusia riversiana) were captured on San Nicolas Island, California, between 1984 and 2007 as part of an ongoing study to monitor the status of this threatened species. Our data suggest that at least a few lizards are probably more than 20 years old, and one lizard would be 31.5 years old if it grew at an average rate for the population. Ages of 20 and 30 years seem reasonable given the remarkably slow growth during capture intervals of more than a decade for five of the lizards which we estimated to be 20 or more years old. Like other lizards, island night lizard growth rates vary by size, with larger lizards growing more slowly. In general, growth rates were somewhat greater on San Nicolas Island (compared with Santa Barbara Island), and this increase was sustained through all of the intermediate size classes. The higher growth rate may account for the somewhat larger lizards present on San Nicolas Island, although we cannot discount the possibility that night lizards on San Nicolas are merely living longer. The high percentage of small lizards in the Eucalyptus habitat might seem to reflect a healthy population in that habitat, but the high proportion of small lizards appears to be caused by good reproduction in the 1900s and substantially poorer reproduction in subsequent years. The Eucalyptus habitat has dried quite a bit in recent years. Night lizards in the Haplopappus/Grassland habitat have shown an increase in the proportion of larger lizards since 2000. There has also been an increase in the proportion of large lizards in the Rock Cobble habitat at Redeye Beach. However, there are has been some change in habitat with more elephant seals occupying the same area just above the high tide as do the night lizards. Southern alligator lizards and side-blotched lizards are both non-native on San Nicolas Island. Neither lizard causes obvious harm to island night lizards, and management time and effort should

  5. Sewage treatment in a rotating biological contactor (RBC) system

    NARCIS (Netherlands)

    Tawfik, A.; Temmink, B.G.; Zeeman, G.; Klapwijk, A.

    2006-01-01

    The treatment of domestic wastewater at a temperature of 12¿24°C was investigated in an RBC system. The RBC consists of a two stage system connected in series. The system was operated at different organic loading rates (OLR's) and hydraulic retntion times (HRT's) in order to optimize the RBC perform

  6. Looking at a predator with the left or right eye: asymmetry of response in lizards.

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    Bonati, Beatrice; Csermely, Davide; Sovrano, Valeria Anna

    2013-01-01

    Studies carried out with the common wall lizard (Podarcis muralis) revealed preferential use of the left eye during responses to predatory threat in laboratory settings and in the wild. Here we tested lizards under monocular conditions of vision, using temporary eye-patching. Lizards were facing a (simulated) predatory threat laterally, from the side of the non-patched eye. Results showed that lizards with the left eye uncovered during predatory threat used the left eye to monitor the predator, whereas lizards with the right eye uncovered nonetheless tried to use the covered left eye. Moreover, lizards frequently tried to change the eye exposition, making a body C-bend behaviour. Right-eyed lizards showed more frequent and faster C-bending responses than left-eyed lizards, trying to monitor the predator with the left eye even though it was patched. Results fit with asymmetries in spontaneous eye use observed in laboratory conditions and in the wild in this species, confirming that structures located on the right side of the brain (mainly served by the left eye) predominantly attend to predatory threat.

  7. Regulatory T Cells Are Dispensable for Tolerance to RBC Antigens.

    Science.gov (United States)

    Richards, Amanda L; Kapp, Linda M; Wang, Xiaohong; Howie, Heather L; Hudson, Krystalyn E

    2016-01-01

    Autoimmune hemolytic anemia (AIHA) occurs when pathogenic autoantibodies against red blood cell (RBC) antigens are generated. While the basic disease pathology of AIHA is well studied, the underlying mechanism(s) behind the failure in tolerance to RBC autoantigens are poorly understood. Thus, to investigate the tolerance mechanisms required for the establishment and maintenance of tolerance to RBC antigens, we developed a novel murine model. With this model, we evaluated the role of regulatory T cells (Tregs) in tolerance to RBC-specific antigens. Herein, we show that neither sustained depletion of Tregs nor immunization with RBC-specific proteins in conjunction with Treg depletion led to RBC-specific autoantibody generation. Thus, these studies demonstrate that Tregs are not required to prevent autoantibodies to RBCs and suggest that other tolerance mechanisms are likely involved.

  8. Regulatory T cells are Dispensable for Tolerance to RBC Antigens

    Directory of Open Access Journals (Sweden)

    Amanda L Richards

    2016-09-01

    Full Text Available Autoimmune hemolytic anemia (AIHA occurs when pathogenic autoantibodies against red blood cell (RBC antigens are generated. Whilst the basic disease pathology of AIHA is well studied, the underlying mechanism(s behind the failure in tolerance to RBC autoantigens are poorly understood. Thus, to investigate the tolerance mechanisms required for the establishment and maintenance of tolerance to RBC antigens, we developed a novel murine model. With this model, we evaluated the role of regulatory T cells (Tregs in tolerance to RBC-specific antigens. Herein, we show that neither sustained depletion of Tregs nor immunization with RBC-specific proteins in conjunction with Treg depletion led to RBC-specific autoantibody generation. Thus, these studies demonstrate that Tregs are not required to prevent autoantibodies to RBCs and suggest that other tolerance mechanisms are likely involved.

  9. RBC Models and the Hours-Wages Puzzle: Puzzle Solved!

    OpenAIRE

    Vasilev, Aleksandar

    2015-01-01

    This paper shows that a modified real business cycle (RBC) model, one that includes home production and fiscal spending shocks, can solve one of the RBC puzzles and generates zero correlation between wages and hours. In addition, the micro-founded model presented here provides a sound theoretical model to analyze fiscal policy in a neoclassical framework and is able to capture many aspects of the data that the benchmark RBC model was missing.

  10. Red blood cell (RBC) membrane proteomics--Part II: Comparative proteomics and RBC patho-physiology.

    Science.gov (United States)

    Pasini, Erica M; Lutz, Hans U; Mann, Matthias; Thomas, Alan W

    2010-01-03

    Membrane proteomics offers unprecedented possibilities to compare protein expression in health and disease leading potentially to the identification of markers, of targets for therapeutics and to a better understanding of disease mechanisms. From transfusion medicine to infectious diseases, from cardiovascular affections to diabetes, comparative proteomics has made a contribution to the identification of proteins unique to RBCs of patients with specific illnesses shedding light on possible RBC markers for systemic diseases. In this review we will provide a short overview of some of the main achievements obtained by comparative proteomics in the field of RBC-related local and systemic diseases and suggest some additional areas of RBCs research to which comparative proteomics approaches could be fruitfully applied or extended in combination with biochemical techniques.

  11. Comparison of the effectiveness of phalanges vs. humeri and femurs to estimate lizard age with skeletochronology

    Energy Technology Data Exchange (ETDEWEB)

    Comas, M.; Reguera, S.; Zamora-Camacho, F.J.; Salvado, H.; Moreno-Rueda, G.

    2016-07-01

    Skeletochronology allows estimation of lizard age with a single capture (from a bone), making long–term monitoring unnecessary. Nevertheless, this method often involves the death of the animal to obtain the bone. We tested the reliability of skeletochronology of phalanges (which may be obtained without killing) by comparing the estimated age from femurs and humeri with the age estimated from phalanges. Our results show skeletochronology of phalanges is a reliable method to estimate age in lizards as cross–section readings from all bones studied presented a high correlation and repeatability regardless of the bone chosen. This approach provides an alternative to the killing of lizards for skeletochronology studies. (Author)

  12. Spontaneous magnetic alignment behaviour in free-living lizards

    Science.gov (United States)

    Diego-Rasilla, Francisco J.; Pérez-Mellado, Valentín; Pérez-Cembranos, Ana

    2017-04-01

    Several species of vertebrates exhibit spontaneous longitudinal body axis alignment relative to the Earth's magnetic field (i.e., magnetic alignment) while they are performing different behavioural tasks. Since magnetoreception is still not fully understood, studying magnetic alignment provides evidence for magnetoreception and broadens current knowledge of magnetic sense in animals. Furthermore, magnetic alignment widens the roles of magnetic sensitivity in animals and may contribute to shed new light on magnetoreception. In this context, spontaneous alignment in two species of lacertid lizards ( Podarcis muralis and Podarcis lilfordi) during basking periods was monitored. Alignments in 255 P. muralis and 456 P. lilfordi were measured over a 5-year period. The possible influence of the sun's position (i.e., altitude and azimuth) and geomagnetic field values corresponding to the moment in which a particular lizard was observed on lizards' body axis orientation was evaluated. Both species exhibited a highly significant bimodal orientation along the north-northeast and south-southwest magnetic axis. The evidence from this study suggests that free-living lacertid lizards exhibit magnetic alignment behaviour, since their body alignments cannot be explained by an effect of the sun's position. On the contrary, lizard orientations were significantly correlated with geomagnetic field values at the time of each observation. We suggest that this behaviour might provide lizards with a constant directional reference while they are sun basking. This directional reference might improve their mental map of space to accomplish efficient escape behaviour. This study is the first to provide spontaneous magnetic alignment behaviour in free-living reptiles.

  13. Rotating Biological Contractors (RBC's). Instructor's Guide. Biological Treatment Process Control.

    Science.gov (United States)

    Zickefoose, Charles S.

    This two-lesson unit on rotating biological contactors (RBC's) is designed to be used with students who have had some experience in wastewater treatment and a basic understanding of biological treatment. The first lesson provides information on the concepts and components of RBC treatment systems. The second lesson focuses on design operation and…

  14. Rotating Biological Contactors (RBC's). Student Manual. Biological Treatment Process Control.

    Science.gov (United States)

    Zickefoose, Charles S.

    This student manual provides the textual material for a unit on rotating biological contactors (RBC's). Topic areas considered include: (1) flow patterns of water through RBC installations; (2) basic concepts (shaft and stage); (3) characteristics of biomass; (4) mechanical features (bearings, mechanical drive systems, and air drive systems); (5)…

  15. STUDY OF RBC HISTOGRAM IN VARIOUS ANEMIAS

    Directory of Open Access Journals (Sweden)

    Sandhya

    2014-12-01

    Full Text Available Over the past few years complete blood count (CBC by the automated hematology analyzers and microscopic examination of peripheral smear have complemented each other to provide a comprehensive report on patients’ blood sample. Numerous classifications for anemia have been established and the important parameters involved in the classifications are Hb, HCT, MCV, RDW, MCH, MCHC, reticulocytes and IRF. Many of these values are obtained only by automated heamatology analyzers. One histogram graph is worth 1000 numbers. A large collection of data, displayed as a visual image, can convey information with far more impact than the numbers alone. In hematology, these data take on several forms, one of which is the RBC histogram. Therefore a study of variation in RBC histograms in various anemias. Many times it is seen that histogram patterns show varying features when a simultaneous peripheral smear is reported. It is also seen that there are many limitations when manual peripheral smears reporting is done for example: peripheral smear reports are subjective, labor intensive and statistically unreliable. However microscopic peripheral smear examination also has their advantages. This study intends to create a guide to laboratory personnel and clinicians with sufficient accuracy to presumptively diagnose morphological classes of anemia directly from the automated hematology cell counter forms and correlate with morphological features of peripheral smear examination. OBJECTIVE: 1. The objective of the study is to know the utility and advantage of red cell histograms. 2. To study the automated histogram patterns along with morphological features noticed on peripheral smear examination. SOURCE OF DATA: All anemic patients from Central Diagnostic Laboratory of A.J.IMS. METHOD OF COLLECTION OF DATA: A total of about 100 patients were included in the study. Complete blood count including HB, TC, DC, Platelet count hematocrit value, RBC indices was obtained

  16. RBC aggregation based system for long-term photoplethysmography (PPG): new prospects for PPG applications

    Science.gov (United States)

    Shvartsman, Leonid D.; Tverskoy, Boris

    2015-03-01

    We present system for long-term continuous PPG monitoring, and physical model for PPG analysis. The system is based on ideology of light scattering modulated by the process of RBC aggregation. OXIRATE's system works in reflection geometry. The sensor is tiny, completely mobile phone compatible, it can be placed nearly everywhere on the body surface. These technical features allow all-night comfortable PPG monitoring that was performed and analyzed. We can define various sleep stages on the basis of different reproducible time-behavior of PPG signal. Our system of PPG monitoring was used also for reflection pulse oximetry and for extreme PPG studies, such as diving.

  17. Acoustical coupling of lizard eardrums

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, Jakob; Manley, Geoffrey A

    2008-01-01

    Lizard ears are clear examples of two-input pressure-difference receivers, with up to 40-dB differences in eardrum vibration amplitude in response to ipsi- and contralateral stimulus directions. The directionality is created by acoustical coupling of the eardrums and interaction of the direct and...

  18. Adaptive evolution of rbcL in Conocephalum (Hepaticae, bryophytes).

    Science.gov (United States)

    Miwa, Hidetsugu; Odrzykoski, Ireneusz J; Matsui, Atsushi; Hasegawa, Masami; Akiyama, Hiroyuki; Jia, Yu; Sabirov, Renat; Takahashi, Hideki; Boufford, David E; Murakami, Noriaki

    2009-07-15

    An excess of nonsynonymous substitutions over synonymous ones has been regarded as an important indicator of adaptive evolution or positive selection at the molecular level. We now report such a case for rbcL sequences among cryptic species in Conocephalum (Hepaticae, Bryophytes). This finding can be regarded as evidence of adaptive evolution in several cryptic species (especially in F and JN types) within the genus. Bryophytes are small land plants with simple morphology. We can therefore expect the existence of several biologically distinct units or cryptic species within each morphological species. In our previous study, we found three rbcL types in Asian Conocephalum japonicum (Thunb.) Grolle and also found evidence strongly suggesting that the three types are reproductively isolated cryptic species. Additionally, we examined rbcL sequence variation in six cryptic species of C. conicum (L.) Dumort. previously recognized by allozyme analyses. As a result, we were able to discriminate the six cryptic species based only on their rbcL sequences. We were able to show that rbcL sequence variation is also useful in finding cryptic species of C. conicum.

  19. Chronic electrical stimulation drives mitochondrial biogenesis in skeletal muscle of a lizard, Varanus exanthematicus.

    Science.gov (United States)

    Schaeffer, Paul J; Nichols, Scott D; Lindstedt, Stan L

    2007-10-01

    We investigated the capacity for phenotypic plasticity of skeletal muscle from Varanus exanthematicus, the savannah monitor lizard. Iliofibularis muscle from one leg of each lizard was electrically stimulated for 8 weeks. Both stimulated and contralateral control muscles were collected and processed for electron microscopy. We used stereological analysis of muscle cross-sections to quantify the volume densities of contractile elements, sarcoplasmic reticulum, mitochondria and intracellular lipids. We found that mitochondrial volume density was approximately fourfold higher in the stimulated muscle compared to controls, which were similar to previously reported values. Sarcoplasmic reticulum volume density was reduced by an amount similar to the increase in mitochondrial volume density while the volume density of contractile elements remained unchanged. Intracellular lipid accumulation was visibly apparent in many stimulated muscle sections but the volume density of lipids did not reach a significant difference. Although monitor lizards lack the highly developed aerobic metabolism of mammals, they appear to possess the capacity for muscle plasticity.

  20. Biodegradation and detoxification potential of rotating biological contactor (RBC) with Irpex lacteus for remediation of dye-containing wastewater.

    Science.gov (United States)

    Malachova, Katerina; Rybkova, Zuzana; Sezimova, Hana; Cerven, Jiri; Novotny, Cenek

    2013-12-01

    Use of fungal organisms in rotating biological contactors (RBC) for bioremediation of liquid industrial wastes has so far been limited in spite of their significant biodegradation potential. The purpose was to investigate the power of RBC using Irpex lacteus for decolorization and detoxification of industrial dyes and dyeing textile liquors. Recalcitrant dye Methylene Blue (150 mg L(-1)) was decolorized within 70 days, its mutagenicity removed, and the biological toxicity decreased more than 10-fold. I. lacteus biofilm in the RBC completely decolorized within 26 and 47 days dyeing liquors containing disperse or reactive dyes adjusted to pH4.5 and 5-fold diluted with the growth medium, respectively. Their respective biological toxicity values were reduced 10- to 10(4)-fold in dependence of the test used. A battery of toxicity tests comprising Vibrio fisheri, Lemna minor and Sinapis alba was efficient to monitor the toxicity of textile dyes and wastewaters. Strong decolorization and detoxification power of RBC using I. lacteus biofilms was demonstrated.

  1. An introduced competitor elevates corticosterone responses of a Native Lizard (Varanus varius).

    Science.gov (United States)

    Jessop, Tim S; Anson, Jennifer R; Narayan, Edward; Lockwood, Tim

    2015-01-01

    Glucocorticoid hormone profiles are increasingly used as physiological markers to infer the strength of species interactions that can influence fitness and ensuing population dynamics of animals. Here we investigated two aims. First, we measured the effect of a 90-min capture stress protocol on the plasma corticosterone responses of a large native Australian lizard, the lace monitor (Varanus varius). Second, we compared the basal and postcapture stress corticosterone responses of lace monitors in habitats where they were exposed to high or low densities of the European red fox (Vulpes vulpes), an introduced competitor. Lace monitors responded to the capture stress protocol by significantly increasing plasma levels of corticosterone above basal at 45- and 90-min-postcapture blood-sampling intervals. In habitats with high fox densities, lace monitors produced a significantly greater basal and capture-stress-induced corticosterone response compared to individuals in low-fox density habitat. A significant interaction among fox density, time postcapture, and body condition was also found to influence plasma corticosterone values. These results suggest competition with red fox, perhaps via nutritional stress and increased hypersensitivity of the adrenocortical axis in lizards. At present, without further research, we do not understand whether such responses mediate lizard fitness or whether they have adaptive or maladaptive consequences for lizard populations in response to red fox competition. Nevertheless, our results help broaden understanding of the physiological implications arising from species interactions and specifically how introduced competitors could mediate diverse impacts on native biodiversity.

  2. Understanding lizard's microhabitat use based on a mechanistic model of behavioral thermoregulation

    Science.gov (United States)

    Fei, Teng; Venus, Valentijn; Toxopeus, Bert; Skidmore, Andrew K.; Schlerf, Martin; Liu, Yaolin; van Overdijk, Sjef; Bian, Meng

    2008-12-01

    Lizards are an "excellent group of organisms" to examine the habitat and microhabitat use mainly because their ecology and physiology is well studied. Due to their behavioral body temperature regulation, the thermal environment is especially linked with their habitat use. In this study, for mapping and understanding lizard's distribution at microhabitat scale, an individual of Timon Lepidus was kept and monitored in a terrarium (245×120×115cm) in which sand, rocks, burrows, hatching chambers, UV-lamps, fog generators and heating devices were placed to simulate its natural habitat. Optical cameras, thermal cameras and other data loggers were fixed and recording the lizard's body temperature, ground surface temperature, air temperature, radiation and other important environmental parameters. By analysis the data collected, we propose a Cellular Automata (CA) model by which the movement of lizards is simulated and translated into their distribution. This paper explores the capabilities of applying GIS techniques to thermoregulatory activity studies in a microhabitat-scale. We conclude that microhabitat use of lizards can be explained in some degree by the rule based CA model.

  3. Short-term dispersal response of an endangered Australian lizard varies with time of year.

    Science.gov (United States)

    Ebrahimi, Mehregan; Bull, C Michael

    2014-01-01

    Dispersal is an important component in the demography of animal populations. Many animals show seasonal changes in their tendency to disperse, reflecting changes in resource availability, mating opportunities, or in population age structure at the time when new offspring enter the population. Understanding when and why dispersal occurs can be important for the management of endangered species. The pygmy bluetongue lizard is an endangered Australian species that occupies and defends single burrow refuges for extended periods of time, rarely moving far from the burrow entrance. However, previous pitfall trapping data have suggested movement of adult males in spring and of juveniles in autumn of each year. In the current study we compared behaviours of adult lizards each month, over the spring-summer activity period over two consecutive field seasons, to provide deeper understanding of the seasonal dispersal pattern. We released adult pygmy bluetongue lizards into a central area, provided with artificial burrows, within large enclosures, and monitored the behaviour and movements of the released lizards over a four day period. There was a consistent decline in time spent basking, amount of movement around burrow entrances, and rates of dispersal from the central release area from early spring to late summer. Results could be relevant to understanding and managing natural populations and for any translocation attempts of this endangered lizard species.

  4. Temperature, activity, and lizard life histories.

    Science.gov (United States)

    Adolph, S C; Porter, W P

    1993-08-01

    Lizard life-history characteristics vary widely among species and populations. Most authors seek adaptive or phylogenetic explanations for life-history patterns, which are usually presumed to reflect genetic differences. However, lizard life histories are often phenotypically plastic, varying in response to temperature, food availability, and other environmental factors. Despite the importance of temperature to lizard ecology and physiology, its effects on life histories have received relatively little attention. We present a theoretical model predicting the proximate consequences of the thermal environment for lizard life histories. Temperature, by affecting activity times, can cause variation in annual survival rate and fecundity, leading to a negative correlation between survival rate and fecundity among populations in different thermal environments. Thus, physiological and evolutionary models predict the same qualitative pattern of life-history variation in lizards. We tested our model with published life-history data from field studies of the lizard Sceloporus undulatus, using climate and geographical data to reconstruct estimated annual activity seasons. Among populations, annual activity times were negatively correlated with annual survival rate and positively correlated with annual fecundity. Proximate effects of temperature may confound comparative analyses of lizard life-history variation and should be included in future evolutionary models.

  5. Lizard locomotion in heterogeneous granular media

    Science.gov (United States)

    Schiebel, Perrin; Goldman, Daniel

    2014-03-01

    Locomotion strategies in heterogeneous granular environments (common substrates in deserts), are relatively unexplored. The zebra-tailed lizard (C. draconoides) is a useful model organism for such studies owing to its exceptional ability to navigate a variety of desert habitats at impressive speed (up to 50 body-lengths per second) using both quadrapedal and bidepal gaits. In laboratory experiments, we challenge the lizards to run across a field of boulders (2.54 cm diameter glass spheres or 3.8 cm 3D printed spheres) placed in a lattice pattern and embedded in a loosely packed granular medium of 0.3 mm diameter glass particles. Locomotion kinematics of the lizard are recorded using high speed cameras, with and without the scatterers. The data reveals that unlike the lizard's typical quadrupedal locomotion using a diagonal gait, when scatterers are present the lizard is most successful when using a bipedal gait, with a raised center of mass (CoM). We propose that the kinematics of bipedal running in conjunction with the lizard's long toes and compliant hind foot are the keys to this lizard's successful locomotion in the presence of such obstacles. NSF PoLS

  6. [French validation of the anger reactions and goals scale (RBC)].

    Science.gov (United States)

    Recchia, S; Steffgen, G; Weber, H; Kubiak, T

    2010-06-01

    The study presents the French validation of a German scale (AERZ) [Diagnostica 49 (2003) 97-109, revised Eur J Pers (2009)] measuring anger regulation. The French validation (RBC scale) comprises two subscales measuring seven anger reactions and seven anger goals. Disentangling dimensions related to anger reactions and anger goals, respectively, is the main advantage of this scale. In addition to seven cognitive-behavioral anger reactions (i.e., venting, rumination, submission, feedback, distraction, humor and downplaying the incident's negative impact), the RBC scale also addresses the cognitive representations underlying anger reactions by exploring anger goals (i.e., enforcing personal standards, enforcing social standards, downregulating affect, avoiding conflicts, protecting one's reputation, weighing costs and gaining revenge). The original scale was translated following the scientific guidelines and recommendations for cultural adaptation of instruments. The adapted French version was tested with a sample of students (n=184, 70.7% were females) from the University of Luxembourg (M=21.31, S.D.=1.93). Students filled in a questionnaire composed of the RBC scale, the SF-36 quality of life scale and the STAXI-II anger instrument. The RBC scale comprises 56 items; reactions are assessed on a 4 point Likert scale from "almost never" (1) to "always" (4), whereas goals are assessed on a 4 point Likert scale from "not at all" (1) to "completely" (4). Factor analysis revealed a seven-factor solution for the anger reactions subscale (that explained 63.13% of the common variance) and a six-factor solution for the anger goals subscale (that explained 57.45% of the common variance). The original factorial structure was examined in confirmatory factor analysis. For the anger reactions subscale, a good model fit was found, with chi(2)(329)=546.38, pscale's internal consistencies were found satisfactory with Cronbach's alphas ranging from 0.60 to 0.83 for the various

  7. Unique Structural Features Facilitate Lizard Tail Autotomy

    DEFF Research Database (Denmark)

    Sanggaard, Kristian Wejse; Danielsen, C. C.; Wogensen, L.

    2012-01-01

    Autotomy refers to the voluntary shedding of a body part; a renowned example is tail loss among lizards as a response to attempted predation. Although many aspects of lizard tail autotomy have been studied, the detailed morphology and mechanism remains unclear. In the present study, we showed...... that tail shedding by the Tokay gecko (Gekko gecko) and the associated extracellular matrix (ECM) rupture were independent of proteolysis. Instead, lizard caudal autotomy relied on biological adhesion facilitated by surface microstructures. Results based on bio-imaging techniques demonstrated that the tail...

  8. Fullerene molecule strain in RbC 60

    Science.gov (United States)

    Aksenov, V. L.; Ossipyan, Yu. À.; Forro, L.; Khasanov, S.; Chernyshev, V. V.; Shakhmatov, V. S.

    2000-04-01

    Strain displacements of carbon atoms in a Ñ 60 molecule in the Pnnm phase of the RbC 60 fulleride are first determined by X-ray diffraction. The measurements show that the polymeric bond length between carbon atoms of two nearest molecules C 60 is equal to 1.69(1) Å, the rotation angle of the molecule about the polymeric direction is 47.0(3)°.

  9. Fullerene Molecule Strain in $RbC_{60}$

    CERN Document Server

    Aksenov, V L; Forró, L; Khasanov, S S; Chernyshev, V V; Shakhmatov, V S

    2000-01-01

    Strain displacements of carbon atoms in a C$_60$ molecule in the $Pnnm$ phase of the RbC$_60$ fulleride are first determined by X-ray diffraction. The measurements show that the polymeric bond length between carbon atoms of two nearest molecules C$_60$ is equal to 1.69(1) $\\AA$, the rotation angle of the molecule about the polymeric direction is 47.0(3)$^0$.

  10. Platelet production in hypoxic and RBC-transfused mice

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, T.P.

    1978-01-01

    Platelet production rates were studied in hypoxic, red blood cell (RBC) transfused, and normal mice. In addition, platelet depletion was induced in some of the mice by injection of rabbit anti-mouse platelet serum (RAMPS) to stimulate platelet production. Hypoxia alone caused an increase in haematocrit and platelet count at 1 to 3 d, followed by a decrease in platelet counts to below normal values at 6 to 7 d. On the other hand, RBC transfusion caused increased haematocrit and decreased platelet count of mice at 1 to 4 d, with a return of platelet counts to normal by 5 to 6 d. Normal mice and mice transfused with RBC responded to platelet depletion with rebound-thrombocytosis with maximum platelet production 3 to 5 d later and elevated platelet counts on day 5 to 6. However, platelet production in platelet-depleted mice exposed to hypoxia was less marked, and platelet counts did not reach normal levels. The data are consistent with the hypothesis that hypoxia causes thrombocytopenia by stem cell competition between erythroid and megakaryocytic cell lines and/or inhibition of thrombopoietin production.

  11. Extinction, reintroduction, and restoration of a lizard meta-population equilibrium in the Missouri Ozarks.

    Science.gov (United States)

    Sites, Jack W

    2013-07-01

    In this issue of Molecular Ecology, Neuwald & Templeton (2013) report on a 22-year study of natural populations of Collared Lizards (Crotaphytus collaris) that evolved on isolated on rock outcrops (‘glades’) in the Ozark Mountains in eastern Missouri. This ecosystem was originally maintained by frequent fires that kept the forest understory open, but fire-suppression was adopted as official policy in about 1945, which led to a loss of native biodiversity, including local extinctions of some lizard populations. Policies aimed at restoring biodiversity included controlled burns and re-introductions of lizards to some glades, which began in 1984. Populations were monitored from 1984–2006, and demographic and genetic data collected from 1 679 lizards were used to documents shifts in meta-population dynamics over four distinct phases of lizard recovery: 1–an initial translocation of lizards drawn from the same source populations onto three glades that were likely part of one metapopulation; 2–a period of isolation and genetic drift associated with the absence of fires; 3–a period of rapid colonization and population increase following restoration of fire; and 4–stabilization of the meta-population under regular prescribed burning. This study system thus provides a rare opportunity to characterize the dynamics of a landscape-scale management strategy on the restoration of the meta-population of a reintroduced species; long-term case studies of the extinction, founding, increase, and stabilization of a well-defined meta-population, based on both demographic and population genetic data, are rare in the conservation, ecological, and evolutionary literature.

  12. Penelitian penentuan konstanta saturasi (Ks pada rbc unit

    Directory of Open Access Journals (Sweden)

    Prayitno Prayitno

    1992-04-01

    Full Text Available Kinetic of Rotating Biological Contractor have been investigated by manu researchers. In general the model emploued either saturation kinetic (following Monod equation or first order kinetic to describe substrate removal. In this experiment, saturation kinetic model was used to find out the saturation constant of the RBC unit. The influent fed into the unit was synthetic waste water with glucose as organic carbon sources. The flow was maintained constant at 20.4 1/d and COD influent resulted the saturation constant (Ks 11.17 mg/I with 20 hours of detention time.

  13. The different mechanisms of hypoxic acclimatization and adaptation in Lizard Phrynocephalus vlangalii living on Qinghai-Tibet Plateau.

    Science.gov (United States)

    He, Jianzheng; Xiu, Minghui; Tang, Xiaolong; Yue, Feng; Wang, Ningbo; Yang, Shaobin; Chen, Qiang

    2013-03-01

    Phrynocephalus vlangalii is a species of lizard endemic in China, which lives on Qinghai-Tibet Plateau ranging from 2000 to 4600 m above sea level. In this study, P. vlangalii were collected from low altitude (2750 m) and high altitude (4564 m). The lizards from low altitude were acclimatized in simulated hypoxic chamber (equivalent to 4600 m) for 7, 15, and 30 days. The hematological parameters, heart weight, myocardial capillary density, and myocardial enzyme activities were examined. The results showed that acclimatization to hypoxia significantly increased hemoglobin concentration ([Hb]), hematocrit (Hct), heart weight (HW), heart weight to body mass (HW/BM), lactate dehydrogenase (LDH) activity, but markedly decreased mean corpuscular hemoglobin concentration (MCHC) and succinate dehydrogenase (SDH) activity. Red blood cell (RBC) count, body mass (BM), myocardial capillary density did not change markedly during hypoxic acclimatization. On the other hand, [Hb], Hct, MCHC, HW/BM, myocardium capillary density, and SDH activity of P. vlangalii from high altitude were remarkably higher than those from low-altitude; however, LDH activity of high-altitude P. vlangalii was lower than that of low-altitude lizards. There was no significant difference in HW or BM between populations of high-altitude and low-altitude. Based on the present data, we suggest that P. vlangalii has special anatomical, physiological, and biochemical accommodate mechanisms to live in hypoxic environment, and the regulative mechanisms are different between hypoxic acclimatization and adaptation.

  14. Restinga lizards (Reptilia: Squamata at the Imbassaí Preserve on the northern coast of Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Danilo Couto-Ferreira

    2011-08-01

    Full Text Available This study presents the diversity of lizard species at the Imbassaí Preserve, located in the Mata de São João municipality, on the northern coast of Bahia region, Brazil, with special attention to the threatened and endemic species. We present the main results on richness and abundance, from a long term monitoring program and especially from the period between November 2008 and June 2010. We applied the visual search method associated with pitfall traps and random encounters, on a 200m linear transect, in four different vegetation habitats. We detected 26 lizard species, distributed in 19 genera of 10 families. The study reveals a high diversity area for lizards, within the restinga ecosystem along the northern coast line, and therefore contributes to the knowledge of the herpetofauna on the northern coast of the Bahia region, as well as to future management and monitoring programs.

  15. Body Size and Reproductive Tactics in Varanid lizards

    Institute of Scientific and Technical Information of China (English)

    Yu DU; Longhui LIN; Yuntao YAO; Chixian LIN; Xiang JI

    2014-01-01

    Body size and female reproduction in the water monitor lizard(Varanus salvator) were studied. Forty-two adult females larger than 500 mm SVL and 32 adult males larger than 400 mm SVL were donated by local people in Ledong, Hainan under permit to our laboratory in Hainan in 2013 and 2014. The largest male and female measured 745 and 755 mm SVL, respectively. The mean SVL was greater in adult females than in adult males. Males had larger heads (head width) than females of the same SVL. The smallest reproductive female in our sample was 565 mm SVL. Females produced a single clutch of 17.1 (10−23) pliable-shelled eggs per breeding season stretching from mid-June and mid-September. Clutch size and clutch mass were all positively related to female SVL. However, there was no signiifcant linear relationship between egg mass and female SVL. Larger females generally produced more eggs, and thus heavier clutches than did smaller ones. There was no signiifcant linear relationship between relative clutch mass and female SVL. Phylogenetic generalized least squares (PGLS) analysis, accounting for phylogenetic relationships, showed that clutch size was positively correlated with mean maternal SVL in varanid lizards. PGLS analysis showed that phylogenetic relationships did not affect clutch (or/and egg) mass and the SVL although there were significant linear relationship between clutch (or/and egg) mass and mean maternal SVL. Therefore, we could draw some general conclusions about the body size and reproductive tactics in varanid lizards that larger females generally produced more eggs, larger eggs and thus heavier clutches than did smaller ones.

  16. Cranial kinesis in gekkonid lizards

    Science.gov (United States)

    Herrel; De Vree F; Delheusy; Gans

    1999-12-01

    Cranial kinesis was studied in two species of gekkonid lizard, Gekko gecko and Phelsuma madagascariensis, using cineradiography and electromyography. The skull of these geckoes showed the three types of kinesis described by Versluys at the beginning of this century: streptostyly, mesokinesis and metakinesis. In accordance with the later model of Frazzetta, the skull of these animals can be modelled by a quadratic crank system: when the mouth opens during feeding, the quadrate rotates forward, the palato-maxillary unit is lifted and the occipital unit swings forward. During jaw closing, the inverse movements are observed; during crushing, the system is retracted beyond its resting position. The data gathered here indicate that the coupled kinesis (streptostyly + mesokinesis) is most prominently present during the capture and crushing cycles of feeding and is largely absent during late intraoral transport, swallowing, drinking and breathing. The electromyographic data indicate a consistent pattern of muscular activation, with the jaw opener and pterygoid protractor always active during the fast opening phase, and the jaw closers active during closing and crushing. Our data generally support the model of Frazzetta. Although the data gathered here do not allow speculation on the functional significance of the kinesis, they clearly provide some key elements required for a further investigation of the functional and adaptive basis of the system.

  17. Lizard-Skin Surface Texture

    Science.gov (United States)

    2007-01-01

    [figure removed for brevity, see original site] Figure 1 The south polar region of Mars is covered seasonally with translucent carbon dioxide ice. In the spring gas subliming (evaporating) from the underside of the seasonal layer of ice bursts through weak spots, carrying dust from below with it, to form numerous dust fans aligned in the direction of the prevailing wind. The dust gets trapped in the shallow grooves on the surface, helping to define the small-scale structure of the surface. The surface texture is reminiscent of lizard skin (figure 1). Observation Geometry Image PSP_003730_0945 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on 14-May-2007. The complete image is centered at -85.2 degrees latitude, 181.5 degrees East longitude. The range to the target site was 248.5 km (155.3 miles). At this distance the image scale is 24.9 cm/pixel (with 1 x 1 binning) so objects 75 cm across are resolved. The image shown here has been map-projected to 25 cm/pixel . The image was taken at a local Mars time of 06:04 PM and the scene is illuminated from the west with a solar incidence angle of 69 degrees, thus the sun was about 21 degrees above the horizon. At a solar longitude of 237.5 degrees, the season on Mars is Northern Autumn.

  18. Less is more: removing membrane attachments stiffens the RBC cytoskeleton

    Energy Technology Data Exchange (ETDEWEB)

    Gov, Nir S [Department of Chemical Physics, The Weizmann Institute of Science, PO Box 26, Rehovot 76100 (Israel)

    2007-11-15

    The polymerized network of the cytoskeleton of the red-blood cell (RBC) contains different protein components that maintain its overall integrity and attachment to the lipid bilayer. One of these key components is the band 3-ankyrin complex that attaches the spectrin filaments to the fluid bilayer. Defects in this particular component result in the shape transformation called spherocytosis, through the shedding of membrane nano-vesicles. We show here that this transition and membrane shedding can be explained through the increased stiffness of the network when the band 3-ankyrin complexes are removed. ATP-induced transient dissociations lead to network softening, which offsets the stiffening to some extent, and causes increased fragility of these mutant cells, as is observed.

  19. Plasma lipid concentrations for some Brazilian lizards.

    Science.gov (United States)

    Gillett, M P; Lima, V L; Costa, J C; Sibrian, A M

    1979-01-01

    1. Plasma concentrations of cholesterol, cholesteryl esters, phospholipids and triglycerides were determined for ten species of Brazilian lizards, Iguana iguana, Tropidurus torquatos and T. semitaeniatus (Iguanidae), Tupinambis teguixin, Ameiva ameiva and Cnemidophorus ocellifer (Teiidae), Mabuya maculata (Scincidae), Hemidactylus mabouia (Gekkonidae), Amphisbaenia vermicularis and Leposternon polystegum (Amphisbaenidae). 2. Considerable inter- and intra-species variations in plasma lipid concentrations were observed. 3. The percentage of total cholesterol esterified and the individual phospholipid composition of plasma were relatively constant for each species. 4. Over 60% of the cholesteryl esters present in plasma from three species each of iguanid and teiid lizards were polyenoic.

  20. A stem acrodontan lizard in the Cretaceous of Brazil revises early lizard evolution in Gondwana.

    Science.gov (United States)

    Simões, Tiago R; Wilner, Everton; Caldwell, Michael W; Weinschütz, Luiz C; Kellner, Alexander W A

    2015-08-26

    Iguanians are one of the most diverse groups of extant lizards (>1,700 species) with acrodontan iguanians dominating in the Old World, and non-acrodontans in the New World. A new lizard species presented herein is the first acrodontan from South America, indicating acrodontans radiated throughout Gondwana much earlier than previously thought, and that some of the first South American lizards were more closely related to their counterparts in Africa and Asia than to the modern fauna of South America. This suggests both groups of iguanians achieved a worldwide distribution before the final breakup of Pangaea. At some point, non-acrodontans replaced acrodontans and became the only iguanians in the Americas, contrary to what happened on most of the Old World. This discovery also expands the diversity of Cretaceous lizards in South America, which with recent findings, suggests sphenodontians were not the dominant lepidosaurs in that continent as previously hypothesized.

  1. Effects of acute low temperature stress on the endocrine reactions of the Qinghai toad-headed lizard

    Institute of Scientific and Technical Information of China (English)

    Chunwang LI; Yuan GU; Songhua TANG; Hongxia FANG; Guohua JIANG; Zhigang JIANG

    2011-01-01

    Endocrinological action is generally thought to be a way for animals to respond to stress at low temperatures.To learn the role of hormones in eetotherms inhabiting alpine environments,we studied the effects of acute low temperature exposure on the endocrinological reactions of Qinghai toad-headed lizards in the Qinghai-Tibetan Plateau.We monitored plasma corticosterone and insulin concentration of the lizards under five low temperature treatments.We found no significant difference in plasma corticosterone or insulin in lizards among our five different treatments.For males and females the correlation between plasma corticosterone and insulin concentrations was not significant.In contrast to other studies on reptiles at low altitude,we suggest that due to the alpine environment (low temperature and low oxygen concentration) they inhabit,Qinghai toad-headed lizards respond to experimental cold stress slightly to mobilize energy and live their vivid life.In addition,corticosterone and insulin of Qinghai toad-headed lizards are secreted independently along with low temperature treatments [Current Zoology 57 (6):775-780,2011].

  2. Lizard thermal biology: do genders differ?

    Science.gov (United States)

    Huey, Raymond B; Pianka, Eric R

    2007-09-01

    For more than six decades, physiological ecologists have intensively studied diverse aspects of lizard thermal biology. Nevertheless, a recent review notes that prior studies have generally ignored gender differences in body temperatures, thermal sensitivity, or other aspects of thermal biology. We concur that gender differences have been ignored and should be examined: if gender differences prove common, standard protocols for studying lizard natural history, thermal physiology, and ecology will require significant modification. To help resolve this issue, we conducted a retrospective analysis of our huge data set on the thermal biology of many desert lizards (more than 11,000 individuals from 56 species in seven major clades) from Africa, Australia, and North America. Results are unambiguous: gender differences in body temperature, air temperature, and time of activity--and thus in field thermal biology--are almost always minor. In fact, mean body temperatures of males and females differ by less than 1 degrees C in 80.4% of species. For desert lizards, gender differences in thermal biology are the exception, not the rule. Nevertheless, gender differences should be examined when feasible because exceptions--though likely rare--could be biologically interesting.

  3. Integrative biology of tail autotomy in lizards.

    Science.gov (United States)

    Higham, Timothy E; Russell, Anthony P; Zani, Peter A

    2013-01-01

    Self-amputation (autotomy) of the tail is essential for the survival of many lizards. Accordingly, it has garnered the attention of scientists for more than 200 years. Several factors can influence the release of the tail, such as the size, sex, and age of the lizard; type of predator; ecology; and evolutionary history of the lineage. Once lost, the tail will writhe for seconds to minutes, and these movements likely depend on the size and physiology of the tail, habitat of the lizard, and predation pressure. Loss of the tail will, in turn, have impacts on the lizard, such as modified locomotor performance and mechanics, as well as escape behavior. However, the tail is almost always regenerated, and this involves wound healing, altered investment of resources, and tissue differentiation. The regenerated tail generally differs from the original in several ways, including size, shape, and function. Here we summarize recent findings of research pertaining to tail autotomy, and we propose a framework for future investigations.

  4. Coupled ears in lizards and crocodilians

    DEFF Research Database (Denmark)

    Carr, Catherine E; Christensen-Dalsgaard, Jakob; Bierman, Hilary

    2016-01-01

    Lizard ears are coupled across the pharynx, and are very directional. In consequence all auditory responses should be directional, without a requirement for computation of sound source location. Crocodilian ears are connected through sinuses, and thus less tightly coupled. Coupling may improve...

  5. Lizards of Brazilian Amazonia (Reptilia: Squamata)

    NARCIS (Netherlands)

    Avila-Pires, T.C.S.

    1995-01-01

    Eighty-nine species of lizards, six of which polytypic (forming a total of 97 taxa), are presently known from Brazilian Amazonia. This number includes six species and one subspecies described as new to science in this paper: Stenocercus fimbriatus, Lepidoblepharis hoogmoedi, Leposoma osvaldoi, L. sn

  6. 77 FR 50487 - Application To Export Electric Energy; RBC Energy Services LP

    Science.gov (United States)

    2012-08-21

    ... Application To Export Electric Energy; RBC Energy Services LP AGENCY: Office of Electricity Delivery and... applied to renew its authority to transmit electric energy from the United States to Canada pursuant to... Order No. EA-328 authorizing RBC Energy to transmit electric energy from the United States to Canada...

  7. ROLE OF RBC COUNT AND RBC INDICES IN DIAGNOSING AND DIFFERENTIATING ANEMIAS CAUSED DUE TO VARIOUS CLINICAL SITUATIONS IN A TERTIARY CARE HOSPITAL IN VADODARA, GUJARAT

    Directory of Open Access Journals (Sweden)

    Sandeep

    2015-11-01

    Full Text Available BACKGROUND : Latest technologies have made it easier for the pathologist and clinician to diagnose any case of anemia. Automated cell counters are widely used since last two decades that have further facilitated and made it easy for the clinicians to reach to the root cause of anemia. RBC count and entire RBC indices along with HB estimation gives a definite idea as to what could be the cause of anemia. The whole spectrum of RBC indices i.e. MCV, MCH and MCHC along with RBC count, PCV and Hemoglobin estimation plays a vital role to analyze the cause of anemia. MATERIAL AND METHODS: A cross sectional study was carried out at Parul Institute of Medical Science and Research, Limda, Vadodara, Gujarat. Investigations of RBC count and RBC indic es of patients were carried out on fully automated cell counter – by Merck diagnostics. Study included 700 patients with Hemoglobin <10gm% which included males and females of age group 15 - 50 years. RESULTS: Total 700 anemic patients with Hemoglobin < 10gm % were enrolled in the study. Among them 569 were females which included pregnant females also and 131 were males. Patients were of age group 15 - 50 years. Data revealed that 45 % of patients had iron deficiency anemia, 14 % had megaloblastic anemia, 13% ha d hemolytic anemia, 6 % had anemia due to chronic illness whereas 10 % had dimorphic type of anemia. In iron deficiency anemia, blood picture showed relatively high to normal RBC count and PCV i.e. hematocrit, typically low MCV and MCH values and low to no rmal MCHC. In megaloblastic anemia, RBC count was very low due to premature destruction of RBC’s and they had low PCV whereas high to very high MCV, MCH and MCHC values. In hemolytic anemia it is seen that RBC count is low and so is the PCV or hematocrit w hile such patients have normal to high MCV and normal MCH and MCHC. In anemia of chronic disease all parameters are relatively normal except low to normal MCV. CONCLUSION: RBC indices vary in

  8. Adaptations to pressure in the RBC metabolism of diving mammals.

    Science.gov (United States)

    Castellini, M A; Castellini, J M; Rivera, P M

    2001-07-01

    Marine mammals are known to dive up to 2000 m and, therefore, tolerate as much as 200 atm. of hydrostatic pressure. To examine possible metabolic adaptations to these elevated pressures, fresh blood samples from marine and terrestrial mammals were incubated for 2 h at 37 degrees C under 136 atm (2000 psi) of hydrostatic pressure. The consumption of plasma glucose and the production of lactate over the 2-h period were used to assess glycolytic flux in the red cells. The results indicate that glycolytic flux as measured by lactate production under pressure can be significantly depressed in most terrestrial mammals and either not altered or accelerated in marine mammals. The data also suggest that there is a significant shift in the ratio of lactate produced to glucose consumed under pressure. Interestingly, human and dolphin blood do not react to pressure. These combined data imply a metabolic adaptation to pressure in marine mammal RBC that may not be necessary in human or dolphin cells due to their unique patterns of glucose metabolism.

  9. Discriminating plants using the DNA barcode rbcLb: an appraisal based on a large data set.

    Science.gov (United States)

    Dong, Wenpan; Cheng, Tao; Li, Changhao; Xu, Chao; Long, Ping; Chen, Chumming; Zhou, Shiliang

    2014-03-01

    The ideal DNA barcode for plants remains to be discovered, and the candidate barcode rbcL has been met with considerable skepticism since its proposal. In fact, the variability within this gene has never been fully explored across all plant groups from algae to flowering plants, and its performance as a barcode has not been adequately tested. By analysing all of the rbcL sequences currently available in GenBank, we attempted to determine how well a region of rbcL performs as a barcode in species discrimination. We found that the rbcLb region was more variable than the frequently used rbcLa region. Both universal and plant group-specific primers were designed to amplify rbcLb, and the performance of rbcLa and rbcLb was tested in several ways. Using blast, both regions successfully identified all families and nearly all genera; however, the successful species identification rates varied significantly among plant groups, ranging from 24.58% to 85.50% for rbcLa and from 36.67% to 90.89% for rbcLb. Successful species discrimination ranged from 5.19% to 96.33% for rbcLa and from 22.09% to 98.43% for rbcLb in species-rich families, and from 0 to 88.73% for rbcLa and from 2.04% to 100% for rbcLb in species-rich genera. Both regions performed better for lower plants than for higher plants, although rbcLb performed significantly better than rbcLa overall, particularly for angiosperms. Considering the applicability across plants, easy and unambiguous alignment, high primer universality, high sequence quality and high species discrimination power for lower plants, we suggest rbcLb as a universal plant barcode. © 2013 John Wiley & Sons Ltd.

  10. Habitat degradation may affect niche segregation patterns in lizards

    Science.gov (United States)

    Pelegrin, N.; Chani, J. M.; Echevarria, A. L.; Bucher, E. H.

    2013-08-01

    Lizards partition resources in three main niche dimensions: time, space and food. Activity time and microhabitat use are strongly influenced by thermal environment, and may differ between species according to thermal requirements and tolerance. As thermal characteristics are influenced by habitat structure, microhabitat use and activity of lizards can change in disturbed habitats. We compared activity and microhabitat use of two abundant lizard species of the Semi-arid Chaco of Argentina between a restored and a highly degraded Chaco forest, to determine how habitat degradation affects lizard segregation in time and space, hypothesizing that as activity and microhabitat use of lizards are related to habitat structure, activity and microhabitat use of individual species can be altered in degraded habitats, thus changing segregation patterns between them. Activity changed from an overlapped pattern in a restored forest to a segregated pattern in a degraded forest. A similar trend was observed for microhabitat use, although to a less extent. No correlation was found between air temperature and lizard activity, but lizard activity varied along the day and among sites. Contrary to what was believed, activity patterns of neotropical diurnal lizards are not fixed, but affected by multiple factors related to habitat structure and possibly to interspecific interactions. Changes in activity patterns and microhabitat use in degraded forests may have important implications when analyzing the effects of climate change on lizard species, due to synergistic effects.

  11. Soft tissue preservation in a fossil marine lizard with a bilobed tail fin.

    Science.gov (United States)

    Lindgren, Johan; Kaddumi, Hani F; Polcyn, Michael J

    2013-01-01

    Mosasaurs are secondarily aquatic squamates that became the dominant marine reptiles in the Late Cretaceous about 98-66 million years ago. Although early members of the group possessed body shapes similar to extant monitor lizards, derived forms have traditionally been portrayed as long, sleek animals with broadened, yet ultimately tapering tails. Here we report an extraordinary mosasaur fossil from the Maastrichtian of Harrana in central Jordan, which preserves soft tissues, including high fidelity outlines of a caudal fluke and flippers. This specimen provides the first indisputable evidence that derived mosasaurs were propelled by hypocercal tail fins, a hypothesis that was previously based on comparative skeletal anatomy alone. Ecomorphological comparisons suggest that derived mosasaurs were similar to pelagic sharks in terms of swimming performance, a finding that significantly expands our understanding of the level of aquatic adaptation achieved by these seagoing lizards.

  12. An On-Chip RBC Deformability Checker Significantly Improves Velocity-Deformation Correlation

    Directory of Open Access Journals (Sweden)

    Chia-Hung Dylan Tsai

    2016-10-01

    Full Text Available An on-chip deformability checker is proposed to improve the velocity–deformation correlation for red blood cell (RBC evaluation. RBC deformability has been found related to human diseases, and can be evaluated based on RBC velocity through a microfluidic constriction as in conventional approaches. The correlation between transit velocity and amount of deformation provides statistical information of RBC deformability. However, such correlations are usually only moderate, or even weak, in practical evaluations due to limited range of RBC deformation. To solve this issue, we implemented three constrictions of different width in the proposed checker, so that three different deformation regions can be applied to RBCs. By considering cell responses from the three regions as a whole, we practically extend the range of cell deformation in the evaluation, and could resolve the issue about the limited range of RBC deformation. RBCs from five volunteer subjects were tested using the proposed checker. The results show that the correlation between cell deformation and transit velocity is significantly improved by the proposed deformability checker. The absolute values of the correlation coefficients are increased from an average of 0.54 to 0.92. The effects of cell size, shape and orientation to the evaluation are discussed according to the experimental results. The proposed checker is expected to be useful for RBC evaluation in medical practices.

  13. Coupled, Active Oscillators and Lizard Otoacoustic Emissions

    Science.gov (United States)

    Bergevin, Christopher; Velenovsky, David S.; Bonine, Kevin E.

    2011-11-01

    The present study empirically explores the relationship between spontaneous otoacoustic emissions (SOAEs) and stimulus-frequency emissions (SFOAEs) in lizards, an ideal group for such research given their relatively simple inner ear (e.g., lack of basilar membrane traveling waves), diverse morphology across species/families (e.g., tectorial membrane structure) and robust emissions. In a nutshell, our results indicate that SFOAEs evoked using low-level tones are intimately related to underlying SOAE activity, and appear to represent the entrained response of active oscillators closely tuned to the probe frequency. The data described here indicate several essential features that are desirable to capture in theoretical models for auditory transduction in lizards, and potentially represent generic properties at work in many different classes of "active" ears.

  14. Use of RBC-O and S-MCV parameters of SYSMEX XE-2100 in a patient with RBC cold agglutination.

    Science.gov (United States)

    Wang, Hong; Lu, Lin; Zhou, Yun; Liu, Jian; Qian, Min; Tang, Weiming; Jie, Zhang; Pan, Shiyang

    2013-01-01

    Sometimes EDTA blood of erythrocyte agglutination cannot be well resolved by incubation at 37 degrees C. In this case report, however, such a specimen was detected from a lymphoma patient at room temperature by using RBC-O and S-MCV parameters of the SYSMEX XE-2100 hematology analyzer. The specimen was diluted with 0.9% NaCL solution at 1:1 before measurement. HCT, MCV, and MCHC, corrected by RBC-O, HGB and S-MCV, were all in their normal ranges. This case indicates that RBC-O and S-MCV parameters of XE-2100 can be used in the routine blood examination of erythrocyte agglutination specimen at room temperature.

  15. Eocene lizard from Germany reveals amphisbaenian origins.

    Science.gov (United States)

    Müller, Johannes; Hipsley, Christy A; Head, Jason J; Kardjilov, Nikolay; Hilger, André; Wuttke, Michael; Reisz, Robert R

    2011-05-19

    Amphisbaenia is a speciose clade of fossorial lizards characterized by a snake-like body and a strongly reinforced skull adapted for head-first burrowing. The evolutionary origins of amphisbaenians are controversial, with molecular data uniting them with lacertids, a clade of Old World terrestrial lizards, whereas morphology supports a grouping with snakes and other limbless squamates. Reports of fossil stem amphisbaenians have been falsified, and no fossils have previously tested these competing phylogenetic hypotheses or shed light on ancestral amphisbaenian ecology. Here we report the discovery of a new lacertid-like lizard from the Eocene Messel locality of Germany that provides the first morphological evidence for lacertid-amphisbaenian monophyly on the basis of a reinforced, akinetic skull roof and braincase, supporting the view that body elongation and limblessness in amphisbaenians and snakes evolved independently. Morphometric analysis of body shape and ecology in squamates indicates that the postcranial anatomy of the new taxon is most consistent with opportunistically burrowing habits, which in combination with cranial reinforcement indicates that head-first burrowing evolved before body elongation and may have been a crucial first step in the evolution of amphisbaenian fossoriality.

  16. Physico-chemical factors affecting the E.coli removal in a rotating biological contactor (RBC) treating UASB effluent

    NARCIS (Netherlands)

    Tafwik, A.; Klapwijk, A.; Buuren, van J.C.L.; El-Gohary, F.; Lettinga, G.

    2004-01-01

    The removal mechanism of E coli from UASB effluent using a Rotating Biological Contractor (RBC) has been investigated. Preliminary batch experiments in a RBC indicate a first-order removal kinetics. Variation in the dissolved oxygen concentration and E coli counts over the depth of the RBC has been

  17. Physico-chemical factors affecting the E.coli removal in a rotating biological contactor (RBC) treating UASB effluent

    NARCIS (Netherlands)

    Tafwik, A.; Klapwijk, A.; Buuren, van J.C.L.; El-Gohary, F.; Lettinga, G.

    2004-01-01

    The removal mechanism of E coli from UASB effluent using a Rotating Biological Contractor (RBC) has been investigated. Preliminary batch experiments in a RBC indicate a first-order removal kinetics. Variation in the dissolved oxygen concentration and E coli counts over the depth of the RBC has been

  18. Tissue-carbon incorporation rates in lizards: implications for ecological studies using stable isotopes in terrestrial ectotherms.

    Science.gov (United States)

    Warne, Robin W; Gilman, Casey A; Wolf, Blair O

    2010-01-01

    Carbon stable isotope (delta(13)C) analysis can be used to infer the origin and to estimate the flow of nutrient resources through animals and across ecological compartments. These applications require knowledge of the rates at which carbon is incorporated into animal tissues and diet-to-tissue discrimination factors (Delta(13)C). Studies of carbon dynamics in terrestrial vertebrates to date have focused almost solely on endothermic animals; ectotherms such as reptiles have received little attention. Here we determined carbon incorporation rates and Delta(13)C in tissues of prairie lizards (Sceloporus undulatus consobrinus) and collared lizards (Crotaphytus collaris). The smaller lizard, S. undulatus, had carbon retention times of 25 and 61 d in plasma and red blood cells (RBC), respectively, compared with 44 and 311 d for the larger C. collaris. Liver, muscle, and skin carbon retention times for S. undulatus were 21, 81, and 94 d. Growth contributed 9%-19% of the carbon incorporated into these tissues. This contribution is similar to endotherms measured at comparable developmental stages. Mean Delta(13)C for plasma (-0.2 per thousand +/- 0.4 per thousand Vienna Pee Dee Belemnite Standard) and RBCs (-1.3 per thousand +/- 0.8 per thousand) were similar to values reported for other vertebrates. Carbon incorporation rates for these ectotherms, however, are seven times slower than in similarly sized adult endotherms. Although a limited comparison with data for warm-water fishes suggests comparable incorporation rates between aquatic and terrestrial ectotherms, this study highlights the lack of experimental data for isotope dynamics in ectotherms across a range of temperatures, body sizes, and developmental stages.

  19. Growth and activity of Sceloporus cowlesi (southwestern fence lizard)

    Science.gov (United States)

    Heather L. Bateman; Alice Chung-MacCoubrey

    2012-01-01

    Lizards from the Sceloporus undulatus complex have been the subject of many studies on lizard ecology (Hager 2001; Rosenblum 2006; Rosenblum et al. 2007), behavior (Hein and Whitaker 1997; Robertson and Rosenblum 2009), and reproduction (Vinegar 1975; Robertson and Rosenblum 2010). However, genetic data (Leache and Reeder 2002) support reallocation of the subspecies of...

  20. Serum iron metabolism and erythropoiesis in patients with myelodysplastic syndrome not receiving RBC transfusions

    OpenAIRE

    Cui, Rui; Gale, Robert Peter; Zhu, Guoqing; Xu, Zefeng; Qin, Tiejun; Zhang, Yue; Huang, Gang; Li, Bing; Fang, Liwei; Zhang, Hongli; Pan, Lijuan; Hu, Naibo; Qu, Shiqiang; Xiao, Zhijian

    2014-01-01

    Dysregulation of hepcidin, a key iron regulating hormone, is important in the pathogenesis of iron overload in patients with myelodysplatic syndrome (MDS). However, most studies of hepcidin levels are complicated by concomitant RBC transfusions. To evaluate the relationship between iron metabolism and erythropoiesis, we measured serum levels of hepcidin, growth-differentiation factor-15 (GDF15) and other markers of erythropoiesis in 107 subjects with MDS not receiving RBC transfusions. Patien...

  1. Impact of temporal resolution on estimating capillary RBC-flux with optical coherence tomography

    Science.gov (United States)

    Li, Baoqiang; Wang, Hui; Fu, Buyin; Wang, Ruopeng; Sakadžić, Sava; Boas, David A.

    2017-01-01

    Optical coherence tomography (OCT) has been used to measure capillary red blood cell (RBC) flux. However, one important technical issue is that the accuracy of this method is subject to the temporal resolution (Δt) of the repeated RBC-passage B-scans. A ceiling effect arises due to an insufficient Δt limiting the maximum RBC-flux that can be measured. In this letter, we first present simulations demonstrating that Δt=1.5 ms permits measuring RBC-flux up to 150 RBCs/s with an underestimation of 9%. The simulations further show that measurements with Δt=3 and 4.5 ms provide relatively less accurate estimates for typical physiological fluxes. We provide experimental data confirming the simulation results showing that reduced temporal resolution (i.e., a longer Δt) results in an underestimation of mean flux and compresses the distribution of measured fluxes, which potentially confounds physiological interpretation of the results. The results also apply to RBC-passage measurements made with confocal and two-photon microscopy for estimating capillary RBC-flux.

  2. Omnivory of an Insular Lizard: Sources of Variation in the Diet of Podarcis lilfordi (Squamata, Lacertidae.

    Directory of Open Access Journals (Sweden)

    Ana Pérez-Cembranos

    Full Text Available Through 17 years and from a sample of 7,790 faecal pellets and 26,346 prey items, we studied the diet of the Balearic lizard Podarcis lilfordi in Aire Island (Menorca, Balearic Islands, Spain. We analysed the diet in terms of prey frequencies, as well as by their volume and biomass contributions. The diet of the Balearic lizard was extremely variable through the years, months and areas under study. The dominance of small clumped prey, particularly ants, was confirmed. However, the main contribution by volume corresponded to beetles, with a relevant role for Diplopoda and terrestrial Isopoda during some months and at particular areas of the island. Several prey items were probably captured at the base of shrubs, under stones or inside rock crevices. Therefore, our estimations of electivity would only be reliable for epigeal and flying prey. The capacity of the Balearic lizard to include marine subsidies in its diet, such as coastal crustaceans, is noteworthy. Also, its consumption of carrion from carcasses of gulls and rabbits and leftovers from human visitors is remarkable. Juvenile conspecifics can also be a sporadic food resource, especially during the second half of summer, whereas the consumption of vegetal matter is constant for each whole year. The shifts of vegetal exploitation among areas of the island and months take place according to availability of different plant species at each area or during a given period. Thus, lizards are able to conduct a thorough monitoring of plant phenology, exploiting a large variety of plant species. Omnivory does not imply the indiscriminate inclusion of any edible food in its diet. Rather, the inclusion of several food items means the adoption of a wide range of foraging behaviours adapted to the exploitation of each food resource.

  3. Omnivory of an Insular Lizard: Sources of Variation in the Diet of Podarcis lilfordi (Squamata, Lacertidae).

    Science.gov (United States)

    Pérez-Cembranos, Ana; León, Alicia; Pérez-Mellado, Valentín

    2016-01-01

    Through 17 years and from a sample of 7,790 faecal pellets and 26,346 prey items, we studied the diet of the Balearic lizard Podarcis lilfordi in Aire Island (Menorca, Balearic Islands, Spain). We analysed the diet in terms of prey frequencies, as well as by their volume and biomass contributions. The diet of the Balearic lizard was extremely variable through the years, months and areas under study. The dominance of small clumped prey, particularly ants, was confirmed. However, the main contribution by volume corresponded to beetles, with a relevant role for Diplopoda and terrestrial Isopoda during some months and at particular areas of the island. Several prey items were probably captured at the base of shrubs, under stones or inside rock crevices. Therefore, our estimations of electivity would only be reliable for epigeal and flying prey. The capacity of the Balearic lizard to include marine subsidies in its diet, such as coastal crustaceans, is noteworthy. Also, its consumption of carrion from carcasses of gulls and rabbits and leftovers from human visitors is remarkable. Juvenile conspecifics can also be a sporadic food resource, especially during the second half of summer, whereas the consumption of vegetal matter is constant for each whole year. The shifts of vegetal exploitation among areas of the island and months take place according to availability of different plant species at each area or during a given period. Thus, lizards are able to conduct a thorough monitoring of plant phenology, exploiting a large variety of plant species. Omnivory does not imply the indiscriminate inclusion of any edible food in its diet. Rather, the inclusion of several food items means the adoption of a wide range of foraging behaviours adapted to the exploitation of each food resource.

  4. R and G color component competition of RGB image decomposition as a criterion to register RBC agglutinates for blood group typing.

    Science.gov (United States)

    Doubrovski, Valeri A; Ganilova, Yuliya A; Zabenkov, Igor V

    2014-03-01

    A new approach of the criterion assignment for registration of erythrocyte agglutinates to instrumentally determine blood group type is suggested. The criterion is based on comparison of R and G components of RGB decomposition of microscopy digital image taken for the blood-serum mixture sample. For the chosen experimental conditions, the minimal size (area) of RBC agglutinate to be registered by the criterion suggested is estimated theoretically. The proposed method was tested experimentally on the example of monitoring agglutinates in flow. The encouraging experimental results were obtained for improvement of the resolving power of the method; the optimal experimental conditions were revealed for maximum resolution. Though the suggested method was realized for dynamic (flow) blood group determination, it could also be applied for diagnostics in a stationary environment. This approach increases the reliability of RBC agglutinates registration and, hence, blood group typing. The results may be used to develop the apparatus for automated determination of human blood group.

  5. Effects of oil pollution at Kuwait's Greater Al-Burgan oil field on the timing of morning emergence, basking and foraging behaviors by the sand lizard Acanthodactylus scutellatus.

    Science.gov (United States)

    Al-Hashem, M Abdulla; Brain, P F; Omar, S Ahmad

    2008-02-15

    An attempt was made to study the effects of oil pollution in a desert location (the Greater Al-Burgan oil fields, an area damaged in the second Gulf War) in Kuwait on the behaviour of the Sand lizard A. scutellatus. Polluted sites with apparently different degrees of contamination (namely tar mat, soot and clear sites) were compared with control areas outside this region. Between 2002 and 2003, ten lizards (5 of each sex) on each polluted and each control site were observed in the field at a time of the year when they were highly active. Air, substrate and burrow temperatures were recorded and lizards were monitored for their morning emergence times, as well as their basking and foraging activities. The present study confirmed that the morning emergence times and the basking behavior varied in sand lizards among the different pollution site categories. Physical changes in the tar mat sites caused the substrate temperatures in these locations to rise more quickly in the morning in response to solar gain than was the case in the other sites. This gives lizards in these locations the opportunity to emerge earlier and to start eating more quickly, giving them an energetic advantage (perhaps, in turn, influencing their rates of growth and fecundity). The clear sites had the next earliest emergence and were the next hottest but it is difficult to account for this in terms of the physical characteristics of this site. The basking times were clearly shorter on the dark soot and tar mat sites that appeared to have higher solar gain than control or clear sites. There did not appear to be any obvious differences in foraging activity of lizards in the different locations. It appears that some aspects of simple behaviour in these lizards provides a reliable, noninvasive indices for assessing oil pollution in desert locations. The precise impact of these changes in these reptiles on their long-term viability needs to be evaluated.

  6. Perch-height specific predation on tropical lizard clay models: implications for habitat selection in mainland neotropical lizards.

    Science.gov (United States)

    Steffen, John E

    2009-09-01

    Predation has been hypothesized to be a strong selective force structuring communities of tropical lizards. Comparisons of perch height and size-based predation frequencies can provide a unique window into understanding how predation might shape habitat selection and morphological patterns in lizards, especially anoles. Here I use plasticine clay models, placed on the trunks of trees and suspended in the canopy to show that predation frequency on clay models differs primarily according to habitat (canopy vs. trunk-ground), but not according to size. These data are discussed in light of observed lizard abundances in the lowland forests of Costa Rica, and are presented as partial explanation for why fewer lizards are found in tree canopies, and more lizards are found on ground-trunk habitats.

  7. Interhabitat differences in energy acquisition and expenditure in a lizard

    Energy Technology Data Exchange (ETDEWEB)

    Karasov, W.H.; Anderson, R.A.

    1984-02-01

    Cnemidophorus hyperythrus, a small (approx. =4-g) teiid lizard, occurs along an elevational thorn scrub-thorn woodland-thorn forest habitat gradient in the cape region of Baja California. The authors compared body size, daily energy expenditure (DEE, measured with double labeled water), relative feeding rate (as reflected by H/sub 2/O influx rate), behavior, and abundance of this species at two sites along the gradient. At the inland thorn woodland site C. hyperythrus were more abundant (approx. =50 lizards/ha.). Mean body mass of woodland site lizards was 13% greater than that of scrub lizards. The DEE of the thorn woodland lizards, 330 site J x g/sup -1/ x d/sup -1/, and their H/sub 2/O influx, 99 mm/sup 3/ x g/sup -1/ x d/sup -1/, were also higher than the thorn scrub lizards', 219 J x g/sup -1/ x d/sup -1/ and 52 mm/sup 3/ x g/sup -1/ x d/sup -1/. Diets at the two sites were similar. There were no differences between sexes in diet, DEE, or H/sub 2/ influx. Daily maintenance energy costs were calculated based upon laboratory measures of O/sub 2/ consumption of resting lizards at a series of temperatures that represented the daily range of body temperatures experienced by lizards in the field. Activity costs (=DEE minus maintenance) were three times higher in the woodland lizards. Behavioral observations showed that woodland lizards were active most of the day (approx. =9 h/d) whereas scrub lizards were active primarily in the morning (approx. =3.5 h/d). Thus, the higher activity cost, DEE, and feeding rate of woodland lizards can be explained by their longer daily activity period. We suggest causal factors for the difference in daily activity period, and discuss implications of length of daily forging period for adult body size, population density, and various life history parameters of lizards.

  8. Analysis of diversity of chromophytic phytoplankton in a mangrove ecosystem using rbcL gene sequencing.

    Science.gov (United States)

    Samanta, Brajogopal; Bhadury, Punyasloke

    2014-04-01

    Phytoplankton forms the basis of primary production in mangrove environments. The phylogeny and diversity based on the amplification and sequencing of rbcL, the large subunit encoding the key enzyme ribulose-1, 5-bisphosphate carboxylase/oxygenase was investigated for improved understanding of the community structure and temporal trends of chromophytic eukaryotic phytoplankton assemblages in Sundarbans, the world's largest continuous mangrove. Diatoms (Bacillariophyceae) were by far the most frequently detected group in clone libraries (485 out of 525 clones), consistent with their importance as a major bloom-forming group. Other major chromophytic algal groups including Cryptophyceae, Haptophyceae, Pelagophyceae, Eustigmatophyceae, and Raphidophyceae which are important component of the assemblages were detected for the first time from Sundarbans based on rbcL approach. Many of the sequences from Sundarbans rbcL clone libraries showed identity with key bloom forming diatom genera namely Thalassiosira, Skeletonema and Nitzschia. Similarly, several rbcL sequences which were diatom-like were also detected highlighting the need to explore diatom communities from the study area. Some of the rbcL sequences detected from Sundarbans were ubiquitous in distribution showing 100% identities with uncultured rbcL sequences targeted previously from the Gulf of Mexico and California upwelling system that are geographically separated from study area. Novel rbcL lineages were also detected highlighting the need to culture and sequence phytoplankton from the ecoregion. Principal component analysis revealed that nitrate is an important variable that is associated with observed variation in phytoplankton assemblages (operational taxonomic units). This study applied molecular tools to highlight the ecological significance of diatoms, in addition to other chromophytic algal groups in Sundarbans.

  9. GABAergic cell types in the lizard hippocampus.

    Science.gov (United States)

    Guirado, S; Dávila, J C

    1999-04-01

    The neurochemical classification of GABAergic cells in the lizard hippocampus resulted in a further division into four major, non-overlapping subtypes. Each GABAergic cell subtype displays specific targets on the principal hippocampal neurons. The synaptic targets of the GABA/neuropeptide subtype are the distal apical dendrites of principal neurons. Calretinin- and parvalbumin-containing GABAergic cells synapse on the cell body and proximal dendrites of principal cells. Calbindin is expressed in a distinct group of interneurons, the synapses of which are directed to the dendrites of principal neurons. Finally, another subtype displays NADPH-diaphorase activity, but its synaptic target has not been established.

  10. The Lizard Wireless Station of Guglielmo Marconi

    Science.gov (United States)

    Montstein, Christian

    2014-08-01

    During the vacation with my wife in Cornwall, we by chance were walking by the Lizard wireless station, originally installed by Guglielmo Marconi and recently refurbished by The National Trust/UK. Fortunately the shed was open for public visitors and a student was present telling stories about the station and its history. The historic equipment was demonstrated by sending some Morse codes. The high voltage sparks and its sound were quite impressive while in the background the Morse code receiver punched dots and dashes onto the strip chart.

  11. Prevalence of neutralising antibodies against adenoviruses in lizards and snakes.

    Science.gov (United States)

    Ball, Inna; Ofner, Sabine; Funk, Richard S; Griffin, Chris; Riedel, Ulf; Möhring, Jens; Marschang, Rachel E

    2014-10-01

    Adenoviruses (AdVs) are relatively common in lizards and snakes, and several genetically distinct AdVs have been isolated in cell culture. The aims of this study were to examine serological relationships among lizard and snake AdVs and to determine the frequency of AdV infections in these species. Isolates from a boa constrictor (Boa constrictor), a corn snake (Pantherophis gutattus) and a central bearded dragon (Pogona vitticeps), and two isolates from helodermatid lizards (Heloderma horridum and H. suspectum) were used in neutralisation tests for the detection of antibodies in plasma from 263 lizards from seven families (including 12 species) and from 141 snakes from four families (including 28 species) from the USA and Europe. Most lizard and snake samples had antibodies against a range of AdV isolates, indicating that AdV infection is common among these squamates. Neutralisation tests with polyclonal antibodies raised in rabbits demonstrated serological cross-reactivity between both helodermatid lizard isolates. However, squamate plasma showed different reactions to each of these lizard isolates in neutralisation tests.

  12. Distribution pattern and number of ticks on lizards.

    Science.gov (United States)

    Dudek, Krzysztof; Skórka, Piotr; Sajkowska, Zofia Anna; Ekner-Grzyb, Anna; Dudek, Monika; Tryjanowski, Piotr

    2016-02-01

    The success of ectoparasites depends primarily on the site of attachment and body condition of their hosts. Ticks usually tend to aggregate on vertebrate hosts in specific areas, but the distribution pattern may depend on host body size and condition, sex, life stage or skin morphology. Here, we studied the distribution of ticks on lizards and tested the following hypothesis: occurrence or high abundance of ticks is confined with body parts with smaller scales and larger interscalar length because such sites should provide ticks with superior attachment conditions. This study was performed in field conditions in central Poland in 2008-2011. In total, 500 lizards (Lacerta agilis) were caught and 839 ticks (Ixodes ricinus, larvae and nymphs) were collected from them. Using generalised linear mixed models, we found that the ticks were most abundant on forelimbs and their axillae, with 90% of ticks attached there. This part of the lizard body and the region behind the hindlimb were covered by the smallest scales with relatively wide gaps between them. This does not fully support our hypothesis that ticks prefer locations with easy access to skin between scales, because it does not explain why so few ticks were in the hindlimb area. We found that the abundance of ticks was positively correlated with lizard body size index (snout-vent length). Tick abundance was also higher in male and mature lizards than in female and young individuals. Autotomy had no effect on tick abundance. We found no correlation between tick size and lizard morphology, sex, autotomy and body size index. The probability of occurrence of dead ticks was positively linked with the total number of ticks on the lizard but there was no relationship between dead tick presence and lizard size, sex or age. Thus lizard body size and sex are the major factors affecting the abundance of ticks, and these parasites are distributed nearly exclusively on the host's forelimbs and their axillae.

  13. Nephtyidae (Annelida: Phyllodocida) of Lizard Island, Great Barrier Reef, Australia.

    Science.gov (United States)

    Murray, Anna; Wong, Eunice; Hutchings, Pat

    2015-09-18

    Seven species of the family Nephtyidae are recorded from Lizard Island, none previously reported from the Great Barrier Reef. Two species of Aglaophamus, four species of Micronephthys, one new and one previously unreported from Australia, and one species of Nephtys, were identified from samples collected during the Lizard Island Polychaete Workshop 2013, as well as from ecological studies undertaken during the 1970s and deposited in the Australian Museum marine invertebrate Collections. A dichotomous key to aid identification of these species newly reported from Lizard Island is provided.

  14. Experimental prestorage filtration removes antibodies and decreases lipids in RBC supernatants mitigating TRALI in vivo.

    Science.gov (United States)

    Silliman, Christopher C; Kelher, Marguerite R; Khan, Samina Y; LaSarre, Monica; West, F Bernadette; Land, Kevin J; Mish, Barbara; Ceriano, Linda; Sowemimo-Coker, Samuel

    2014-05-29

    Transfusion-related acute lung injury (TRALI) remains a significant cause of transfusion-related mortality with red cell transfusion. We hypothesize that prestorage filtration may reduce proinflammatory activity in the red blood cell (RBC) supernatant and prevent TRALI. Filters were manufactured for both small volumes and RBC units. Plasma containing antibodies to human lymphocyte antigen (HLA)-A2 or human neutrophil antigen (HNA)-3a was filtered, and immunoglobulins and specific HNA-3a and HLA-2a neutrophil (PMN) priming activity were measured. Antibodies to OX27 were added to plasma, and filtration was evaluated in a 2-event animal model of TRALI. RBC units from 31 donors known to have antibodies against HLA antigens and from 16 antibody-negative controls were filtered. Furthermore, 4 RBC units were drawn and underwent standard leukoreduction. Immunoglobulins, HLA antibodies, PMN priming activity, and the ability to induce TRALI in an animal model were measured. Small-volume filtration of plasma removed >96% of IgG, antibodies to HLA-A2 and HNA-3a, and their respective priming activity, as well as mitigating antibody-mediated in vivo TRALI. In RBC units, experimental filtration removed antibodies to HLA antigens and inhibited the accumulation of lipid priming activity and lipid-mediated TRALI. We conclude that filtration removes proinflammatory activity and the ability to induce TRALI from RBCs and may represent a TRALI mitigation step.

  15. Evaluation of serum homocysteine, high-sensitivity CRP, and RBC folate in patients with alopecia areata

    Directory of Open Access Journals (Sweden)

    Maryam Yousefi

    2014-01-01

    Full Text Available Introduction: Alopecia areata (AA is a common type of hair loss with an autoimmune basis. As the role of homocysteine (Hcys, folate, and CRP has been considered in some autoimmune diseases. Objectives: To evaluate homocysteine, folate and CRP level in AA. Methods: This study was performed on 29 patients who had AA for at least 6 months affecting more than 20% of scalp, and 32 healthy controls. Levels of serum Hcys, blood high-sensitivity CRP, and RBC folate were measured in all subjects. Results: The mean level of RBC folate was significantly lower in the patient group than that in controls (P < 0.001. Also, the level of RBC folate was significantly lower in patients with extensive forms of disease (alopecia totalis/alopecia universalis in comparison with more localized form (patchy hair loss (P < 0.05. Patients with higher "Severity of Alopecia Total" (SALT score had lower RBC folate, as well. Serum Hcys and blood high-sensitivity CRP levels did not show a significant difference in two groups. Conclusion: Patients with alopecia areata have lower level of RBC folate which is in negative correlation with both severity and extension of AA.

  16. Limb development in the gekkonid lizard Gonatodes albogularis: A reconsideration of homology in the lizard carpus and tarsus.

    Science.gov (United States)

    Leal, Francisca; Tarazona, Oscar A; Ramírez-Pinilla, Martha Patricia

    2010-11-01

    Despite the attention squamate lizards have received in the study of digit and limb loss, little is known about limb morphogenesis in pentadactyl lizards. Recent developmental studies have provided a basis for understanding lizard autopodial element homology based on developmental and comparative anatomy. In addition, the composition and identity of some carpal and tarsal elements of lizard limbs, and reptiles in general, have been the theme of discussions about their homology compared to non-squamate Lepidosauromorpha and basal Amniota. The study of additional embryonic material from different lizard families may improve our understanding of squamate limb evolution. Here, we analyze limb morphogenesis in the gekkonid lizard Gonatodes albogularis describing patterns of chondrogenesis and ossification from early stages of embryonic development to hatchlings. Our results are in general agreement with previous developmental studies, but we also show that limb development in squamates probably involves more chondrogenic elements for carpal and tarsal morphogenesis, as previously recognized on the grounds of comparative anatomy. We provide evidence for the transitory presence of distal carpale 1 and intermedium in the carpus and tibiale, intermedium, distal centralia, and distal tarsale 2 in the tarsus. Hence, we demonstrate that some elements that were believed to be lost in squamate evolution are conserved as transitory elements during limb development. However, these elements do not represent just phylogenetic burden but may be important for the morphogenesis of the lizard autopodium.

  17. Quantum Probabilistic Structures in Competing Lizard Communities

    CERN Document Server

    Aerts, Diederik; Kuna, Maciej; Sinervo, Barry; Sozzo, Sandro

    2012-01-01

    Almost two decades of research on the use of the mathematical formalism of quantum theory as a modeling tool for entities and their dynamics in domains different from the micro-world has now firmly shown the systematic appearance of quantum structures in aspects of human behavior and thought, such as in cognitive processes of decision-making, and in the way concepts are combined into sentences. In this paper, we extend this insight to animal behavior showing that a quantum probabilistic structure models the mating competition of three side-blotched lizard morphs. We analyze a set of experimental data collected from 1990 to 2011 on these morphs, whose territorial behavior follows a cyclic rock-paper-scissors (RPS) dynamics. Consequently we prove that a single classical Kolmogorovian space does not exist for the lizard's dynamics, and elaborate an explicit quantum description in Hilbert space faithfully modeling the gathered data. This result is relevant for population dynamics as a whole, since many systems, e...

  18. DNA barcoding of arid wild plants using rbcL gene sequences.

    Science.gov (United States)

    Bafeel, S O; Arif, I A; Bakir, M A; Al Homaidan, A A; Al Farhan, A H; Khan, H A

    2012-07-19

    DNA barcoding is currently gaining popularity due to its simplicity and high accuracy as compared to the complexity and subjective biases associated with morphology-based identification of taxa. The standard chloroplast DNA barcode for land plants recommended by the Consortium for the Barcode of Life (CBOL) plant working group needs to be evaluated for a wide range of plant species. We therefore tested the potential of the rbcL marker for the identification of wild plants belonging to diverse families of arid regions. Maximum likelihood tree analysis was performed to evaluate the discriminatory power of the rbcL gene. Our findings showed that using rbcL gene sequences enabled identification of the majority of the samples (92%) to genus level and only 17% to species level.

  19. Cloning and sequence analysis of the partial sequence of the rbcL from Bryopsis hypnoides

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The partial sequence of the rbcL from Bryopsis hypnoides, including the sequences of the upstream, extron and partial intron, was amplified by PCR and their sequences were determined. With Spinacia oleracea as the outgroup, neighbor-joining method and maximum parsimony method were used respectively to build phylogenetic trees according to the rbcL exon sequence among 13species that were the typical species of six phyla. Two kinds of trees showed clearly that there were two groups among those species,the green lineage and the non-green lineage. And the relationships of algae in the green lineage were similar in the two trees but those in the non-green lineage were not consistent. Analysis of codon preference indicated that the codon preference of the rbcL exon of Bryopsis hypnoides distinctly differed from that of the relevant sequence of photosynthetic bacteria.

  20. Undulatory Swimming in Sand: Subsurface Locomotion of the Sandfish Lizard

    National Research Council Canada - National Science Library

    Ryan D. Maladen; Yang Ding; Chen Li; Daniel I. Goldman

    2009-01-01

    .... High-speed x-ray imaging shows that below the surface, the lizard no longer uses limbs for propulsion but generates thrust to overcome drag by propagating an undulatory traveling wave down the body...

  1. A New Eocene Casquehead Lizard (Reptilia, Corytophanidae) from North America.

    Science.gov (United States)

    Conrad, Jack L

    2015-01-01

    A new fossil showing affinities with extant Laemanctus offers the first clear evidence for a casquehead lizard (Corytophanidae) from the Eocene of North America. Along with Geiseltaliellus from roughly coeval rocks in central Europe, the new find further documents the tropical fauna present during greenhouse conditions in the northern mid-latitudes approximately 50 million years ago (Ma). Modern Corytophanidae is a neotropical clade of iguanian lizards ranging from southern Mexico to northern South America.

  2. Rapid rather than gradual weight reduction impairs hemorheological parameters of Taekwondo athletes through reduction in RBC-NOS activation.

    Directory of Open Access Journals (Sweden)

    Woo Hwi Yang

    Full Text Available Rapid weight reduction is part of the pre-competition routine and has been shown to negatively affect psychological and physiological performance of Taekwondo (TKD athletes. This is caused by a reduction of the body water and an electrolyte imbalance. So far, it is unknown whether weight reduction also affects hemorheological properties and hemorheology-influencing nitric oxide (NO signaling, important for oxygen supply to the muscles and organs.For this purpose, ten male TKD athletes reduced their body weight by 5% within four days (rapid weight reduction, RWR. After a recovery phase, athletes reduced body weight by 5% within four weeks (gradual weight reduction, GWR. Each intervention was preceded by two baseline measurements and followed by a simulated competition. Basal blood parameters (red blood cell (RBC count, hemoglobin concentration, hematocrit, mean corpuscular volume, mean cellular hemoglobin and mean cellular hemoglobin concentration, RBC-NO synthase activation, RBC nitrite as marker for NO synthesis, RBC deformability and aggregation parameters were determined on a total of eight investigation days.Basal blood parameters were not affected by the two interventions. In contrast to GWR, RWR decreased activation of RBC-NO synthase, RBC nitrite, respective NO concentration and RBC deformability. Additionally, RWR increased RBC aggregation and disaggregation threshold.The results point out that a rapid weight reduction negatively affects hemorheological parameters and NO signaling in RBC which might limit performance capacity. Thus, GWR should be preferred to achieve the desired weight prior to a competition to avoid these negative effects.

  3. Ranavirus infections associated with skin lesions in lizards.

    Science.gov (United States)

    Stöhr, Anke C; Blahak, Silvia; Heckers, Kim O; Wiechert, Jutta; Behncke, Helge; Mathes, Karina; Günther, Pascale; Zwart, Peer; Ball, Inna; Rüschoff, Birgit; Marschang, Rachel E

    2013-09-27

    Ranaviral disease in amphibians has been studied intensely during the last decade, as associated mass-mortality events are considered to be a global threat to wild animal populations. Several studies have also included other susceptible ectothermic vertebrates (fish and reptiles), but only very few cases of ranavirus infections in lizards have been previously detected. In this study, we focused on clinically suspicious lizards and tested these animals for the presence of ranaviruses. Virological screening of samples from lizards with increased mortality and skin lesions over a course of four years led to the detection of ranaviral infections in seven different groups. Affected species were: brown anoles (Anolis sagrei), Asian glass lizards (Dopasia gracilis), green anoles (Anolis carolinensis), green iguanas (Iguana iguana), and a central bearded dragon (Pogona vitticeps). Purulent to ulcerative-necrotizing dermatitis and hyperkeratosis were diagnosed in pathological examinations. All animals tested positive for the presence of ranavirus by PCR and a part of the major capsid protein (MCP) gene of each virus was sequenced. Three different ranaviruses were isolated in cell culture. The analyzed portions of the MCP gene from each of the five different viruses detected were distinct from one another and were 98.4-100% identical to the corresponding portion of the frog virus 3 (FV3) genome. This is the first description of ranavirus infections in these five lizard species. The similarity in the pathological lesions observed in these different cases indicates that ranaviral infection may be an important differential diagnosis for skin lesions in lizards.

  4. Life-History Patterns of Lizards of the World.

    Science.gov (United States)

    Mesquita, Daniel O; Costa, Gabriel C; Colli, Guarino R; Costa, Taís B; Shepard, Donald B; Vitt, Laurie J; Pianka, Eric R

    2016-06-01

    Identification of mechanisms that promote variation in life-history traits is critical to understand the evolution of divergent reproductive strategies. Here we compiled a large life-history data set (674 lizard populations, representing 297 species from 263 sites globally) to test a number of hypotheses regarding the evolution of life-history traits in lizards. We found significant phylogenetic signal in most life-history traits, although phylogenetic signal was not particularly high. Climatic variables influenced the evolution of many traits, with clutch frequency being positively related to precipitation and clutches of tropical lizards being smaller than those of temperate species. This result supports the hypothesis that in tropical and less seasonal climates, many lizards tend to reproduce repeatedly throughout the season, producing smaller clutches during each reproductive episode. Our analysis also supported the hypothesis that viviparity has evolved in lizards as a response to cooler climates. Finally, we also found that variation in trait values explained by clade membership is unevenly distributed among lizard clades, with basal clades and a few younger clades showing the most variation. Our global analyses are largely consistent with life-history theory and previous results based on smaller and scattered data sets, suggesting that these patterns are remarkably consistent across geographic and taxonomic scales.

  5. Ranavirus infections associated with skin lesions in lizards

    Science.gov (United States)

    2013-01-01

    Ranaviral disease in amphibians has been studied intensely during the last decade, as associated mass-mortality events are considered to be a global threat to wild animal populations. Several studies have also included other susceptible ectothermic vertebrates (fish and reptiles), but only very few cases of ranavirus infections in lizards have been previously detected. In this study, we focused on clinically suspicious lizards and tested these animals for the presence of ranaviruses. Virological screening of samples from lizards with increased mortality and skin lesions over a course of four years led to the detection of ranaviral infections in seven different groups. Affected species were: brown anoles (Anolis sagrei), Asian glass lizards (Dopasia gracilis), green anoles (Anolis carolinensis), green iguanas (Iguana iguana), and a central bearded dragon (Pogona vitticeps). Purulent to ulcerative-necrotizing dermatitis and hyperkeratosis were diagnosed in pathological examinations. All animals tested positive for the presence of ranavirus by PCR and a part of the major capsid protein (MCP) gene of each virus was sequenced. Three different ranaviruses were isolated in cell culture. The analyzed portions of the MCP gene from each of the five different viruses detected were distinct from one another and were 98.4-100% identical to the corresponding portion of the frog virus 3 (FV3) genome. This is the first description of ranavirus infections in these five lizard species. The similarity in the pathological lesions observed in these different cases indicates that ranaviral infection may be an important differential diagnosis for skin lesions in lizards. PMID:24073785

  6. [The comparative aspects of spatial ecology of lizards exemplified by the toad-headed lizards (Reptilia, Agamidae, Phrynocephalus)].

    Science.gov (United States)

    Semenov, D V

    2007-01-01

    The possibility of analysis of phylogenetic parameters of the spatial distribution of populations is discussed by an example of the agamid toad-headed lizards (Phrynocephalus). Summarizing both original and published data on the individual home ranges and the relocation of individuals of 30 populations from 12 species showed that differentiation of the type of spatial distribution is weak in toad-headed lizards. This observation confirms the idea that this clade of agamids is phylogenetically young and relatively recently radiated. At the interspecific level, positive correlation between home range size and body size was observed in the studied group. Such spatial parameters, shared by all toad-headed lizards, as relatively large size and weakly structured individual home ranges can be explained by the peculiarities of their reproduction features and their foraging mode. The individual type of space-usage in toad-headed does not fit the traditional scheme dividing all the lizards into the territorial Iguania and the nonterritorial Autarchoglossa.

  7. Predictors of telomere content in dragon lizards

    Science.gov (United States)

    Ballen, Cissy; Healey, Mo; Wilson, Mark; Tobler, Michael; Olsson, Mats

    2012-08-01

    Telomeres shorten as a consequence of DNA replication, in particular in cells with low production of telomerase and perhaps in response to physiological stress from exposure to reactive oxygen species, such as superoxide. This process of telomere attrition is countered by innate antioxidation, such as via the production of superoxide dismutase. We studied the inheritance of telomere length in the Australian painted dragon lizard ( Ctenophorus pictus) and the extent to which telomere length covaries with mass-corrected maternal reproductive investment, which reflects the level of circulating yolk precursor and antioxidant, vitellogenin. Our predictors of offspring telomere length explained 72 % of telomere variation (including interstitial telomeres if such are present). Maternal telomere length and reproductive investment were positively influencing offspring telomere length in our analyses, whereas flow cytometry-estimated superoxide level was negatively impacting offspring telomere length. We suggest that the effects of superoxide on hatchling telomere shortening may be partly balanced by transgenerational effects of vitellogenin antioxidation.

  8. Treatment of domestic sewage in a combined UASB/RBC system. Process optimization for irrigation purposes

    NARCIS (Netherlands)

    Tawfik Ibrahim, A.; Zeeman, G.; Klapwijk, A.; Sanders, W.T.M.; El-Gohary, F.; Lettinga, G.

    2003-01-01

    A Rotating Biological Contactor (RBC) was fed with raw domestic wastewater or anaerobic effluents. The experiments were conducted at increasing operational temperatures viz. 11, 20 and 30degreesC to assess the potential increase in removal efficiencies for the different COD fractions (CODtotal, CODs

  9. RBC volume deficiency in patients with excessive orthostatic decrease in cerebral blood flow velocity

    Directory of Open Access Journals (Sweden)

    Chun-Jen Lin

    2014-04-01

    Conclusion: The results of our study indicated that low RBC volume may play an important role in the pathophysiology of OI in this group of patients. Moreover, its role seems even more relevant in patients with POTS than in those without. Further studies for mechanistic evaluation are needed in the future.

  10. A comprehensive framework for functional diversity patterns of marine chromophytic phytoplankton using rbcL phylogeny

    Science.gov (United States)

    Samanta, Brajogopal; Bhadury, Punyasloke

    2016-02-01

    Marine chromophytes are taxonomically diverse group of algae and contribute approximately half of the total oceanic primary production. To understand the global patterns of functional diversity of chromophytic phytoplankton, robust bioinformatics and statistical analyses including deep phylogeny based on 2476 form ID rbcL gene sequences representing seven ecologically significant oceanographic ecoregions were undertaken. In addition, 12 form ID rbcL clone libraries were generated and analyzed (148 sequences) from Sundarbans Biosphere Reserve representing the world’s largest mangrove ecosystem as part of this study. Global phylogenetic analyses recovered 11 major clades of chromophytic phytoplankton in varying proportions with several novel rbcL sequences in each of the seven targeted ecoregions. Majority of OTUs was found to be exclusive to each ecoregion, whereas some were shared by two or more ecoregions based on beta-diversity analysis. Present phylogenetic and bioinformatics analyses provide a strong statistical support for the hypothesis that different oceanographic regimes harbor distinct and coherent groups of chromophytic phytoplankton. It has been also shown as part of this study that varying natural selection pressure on form ID rbcL gene under different environmental conditions could lead to functional differences and overall fitness of chromophytic phytoplankton populations.

  11. Absolute Population Densities of the Lizards of Ritidian Point, Guam National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Intensive sampling for lizards of Guam NWR at Ritidian Point using a total removal methodology quantifies the lizard fauna in unprecedented detail, providing...

  12. Artificial Water Point for Livestock Influences Spatial Ecology of a Native Lizard Species

    OpenAIRE

    Leu, Stephan T.; C Michael Bull

    2016-01-01

    Pastoralism is a major agricultural activity in drier environments, and can directly and indirectly impact native species in those areas. We investigated how the supply of an artificial watering point to support grazing livestock affected movement and activity patterns of the Australian sleepy lizard (Tiliqua rugosa) during a drought year. We observed 23 adult lizards; six had access to a dam, whereas 17 lizards did not. Lizards with access to the dam had larger home ranges, were substantiall...

  13. Simulator for training operators of electric substation: an approach via RBC-Paraconsistent; Simulador para treinamento de operadores de subestacao eletrica: um enfoque via RBC-paraconsistente

    Energy Technology Data Exchange (ETDEWEB)

    Lambert-Torres, G.; Martins, H.G.; Coutinho, M.P.; Goulart, J.D.C.; Soares, F.M.A. [Universidade Federal de Itajuba (UNIFEI), MG (Brazil). Dept. de Engenharia Eletrica], Emails: germanoltorres@gmail.com, helgagonzaga@gmail.com, maurilio.coutinho@gmail.com, janaina157@yahoo.com.br, francis.azevedo@gmail.com

    2009-07-01

    This article presents a combination of two techniques applied artificial intelligence to solve problems to Restoration of an Electric Substation: Casebased Reasoning - CBR and the Four Values Annotated Paraconsistent Logic - 4vAPL. The process occurs in the connection functions of belief, disbelief, specialty and temporality to LPA4v in the retrieval of cases to determine process diagnostic of an RBC. The field of CBR is applied in a recovery of an electric substation. The LPA4v is the support applied in problems that have inconsistent information, partials and undefined. Thus this study is closer of the real situations.

  14. Potentials of using a rotating biological contactor (RBC) for post-treatment of anaerobically pre-treated domestic wastewater

    NARCIS (Netherlands)

    Tawfik, A.; Klapwijk, A.; El-Gohary, F.; Lettinga, G.

    2005-01-01

    This study has been carried out in order to assess the impact of CODhiod in an UASB effluent applied to a single stage, a two stage RBC system and an anoxic up-flow submerged bio-filter followed by a segmental two stage aerobic RBC on the removal efficiency of different COD fractions, Escherichia co

  15. The study on RBC characteristic in paroxysmal nocturnal hemoglobinuria (PNH) patients using common path interferometric quantitative phase microscopy

    Science.gov (United States)

    Park, Byung Jun; Won, Youngjae; Kim, Byungyeon; Lee, Seungrag

    2016-03-01

    We have studied the RBC membrane properties between a normal RBC and a RBC in Paroxysrnal nocturnal hemoglobinuria (PNH) patient using common path interferometric quantitative phase microscopy (CPIQPM). CPIQPM system has provided the subnanometer optical path length sensitivity on a millisecond. We have measured the dynamic thickness fluctuations of a normal RBC membrane and a RBC membrane in PNH patient over the whole cell surface with CPIQPM. PNH is a rare and serious disease of blood featured by destruction of red blood cells (RBCs). This destruction happens since RBCs show the defect of protein which protects RBCs from the immune system. We have applied CPIQPM to study the characteristic of RBC membrane in PNH patient. We have shown the morphological shape, volume, and projected surface for both different RBC types. The results have showed both RBCs had the similar shape with donut, but membrane fluctuations in PNH patient was shown to reveal the difference of temporal properties compared with a normal RBC. In order to demonstrate the practical tool of the CPIQPM technique, we have also obtained the time series thickness fluctuation outside a cell.

  16. Spatial, ontogenetic and sexual effects on the diet of a Teiid lizard in arid South America

    NARCIS (Netherlands)

    Leeuwen, van J.P.; Catenazzi, A.; Holmgren, M.

    2011-01-01

    Most lizard species feed on small arthropods, and although some are omnivorous, only a few species are strict herbivores. We studied the diet of Dicrodon guttulatum, a teiid lizard endemic to the arid coastal deserts and dry forests of northern Peru. Herbivory by this lizard has been identified as a

  17. Artificial Water Point for Livestock Influences Spatial Ecology of a Native Lizard Species.

    Directory of Open Access Journals (Sweden)

    Stephan T Leu

    Full Text Available Pastoralism is a major agricultural activity in drier environments, and can directly and indirectly impact native species in those areas. We investigated how the supply of an artificial watering point to support grazing livestock affected movement and activity patterns of the Australian sleepy lizard (Tiliqua rugosa during a drought year. We observed 23 adult lizards; six had access to a dam, whereas 17 lizards did not. Lizards with access to the dam had larger home ranges, were substantially active on more days (days with >100 steps, and moved more steps per day compared to lizards that did not have access to the dam, both during the early and late period of our observation. Furthermore, while the two groups of lizards had similar body condition early in the season, they differed later in the season. Lizards with dam access retained, whereas lizards without access lost body condition. Local heterogeneity in access to an artificial water resource resulted in spatially dependent behavioural variation among sleepy lizard individuals. This suggests that sleepy lizards have flexible responses to changing climatic conditions, depending on the availability of water. Furthermore, while reducing activity appears a suitable short term strategy, if harsh conditions persist, then access to dams could be of substantial benefit and could support sustained lizard activity and movement and allow maintenance of body condition. Hence, artificial watering points, such as the dams constructed by pastoralists, may provide local higher quality refugia for sleepy lizards and other species during drought conditions.

  18. Artificial Water Point for Livestock Influences Spatial Ecology of a Native Lizard Species.

    Science.gov (United States)

    Leu, Stephan T; Bull, C Michael

    2016-01-01

    Pastoralism is a major agricultural activity in drier environments, and can directly and indirectly impact native species in those areas. We investigated how the supply of an artificial watering point to support grazing livestock affected movement and activity patterns of the Australian sleepy lizard (Tiliqua rugosa) during a drought year. We observed 23 adult lizards; six had access to a dam, whereas 17 lizards did not. Lizards with access to the dam had larger home ranges, were substantially active on more days (days with >100 steps), and moved more steps per day compared to lizards that did not have access to the dam, both during the early and late period of our observation. Furthermore, while the two groups of lizards had similar body condition early in the season, they differed later in the season. Lizards with dam access retained, whereas lizards without access lost body condition. Local heterogeneity in access to an artificial water resource resulted in spatially dependent behavioural variation among sleepy lizard individuals. This suggests that sleepy lizards have flexible responses to changing climatic conditions, depending on the availability of water. Furthermore, while reducing activity appears a suitable short term strategy, if harsh conditions persist, then access to dams could be of substantial benefit and could support sustained lizard activity and movement and allow maintenance of body condition. Hence, artificial watering points, such as the dams constructed by pastoralists, may provide local higher quality refugia for sleepy lizards and other species during drought conditions.

  19. Spatial, ontogenetic and sexual effects on the diet of a Teiid lizard in arid South America

    NARCIS (Netherlands)

    Leeuwen, van J.P.; Catenazzi, A.; Holmgren, M.

    2011-01-01

    Most lizard species feed on small arthropods, and although some are omnivorous, only a few species are strict herbivores. We studied the diet of Dicrodon guttulatum, a teiid lizard endemic to the arid coastal deserts and dry forests of northern Peru. Herbivory by this lizard has been identified as a

  20. The Ins & Outs of Developing a Field-Based Science Project: Learning by Lassoing Lizards

    Science.gov (United States)

    Matthews, Catherine E.; Huffling, Lacey D.; Benavides, Aerin

    2014-01-01

    We describe a field-based lizard project we did with high school students as a part of our summer Herpetological Research Experiences. We describe data collection on lizards captured, identified, and marked as a part of our mark-recapture study. We also describe other lizard projects that are ongoing in the United States and provide resources for…

  1. 76 FR 62087 - Draft Conservation Plan and Draft Environmental Assessment; Dunes Sagebrush Lizard, Texas

    Science.gov (United States)

    2011-10-06

    ... Lizard, Texas AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice of availability; announcement... application includes the draft Texas Conservation Plan for the Dunes Sagebrush Lizard (TCP). The draft TCP... Service (Service) and the Applicant for the dunes sagebrush lizard (Sceloporus arenicolus) throughout...

  2. Spontaneous otoacoustic emissions in lizards: a comparison of the skink-like lizard families Cordylidae and Gerrhosauridae.

    Science.gov (United States)

    Manley, Geoffrey A

    2009-09-01

    Lizard families can be grouped into larger units comprising those families that are closely related and whose auditory papillae are morphologically very similar. Based on the few species studied at that time [Manley, G.A., 1997. Diversity in hearing-organ structure and the characteristics of spontaneous otoacoustic emissions in lizards. In: Lewis, E.R., Long, G.R., Lyon, R.F., Narins, P.M., Steele, C.R. (Eds.), Diversity in Auditory Mechanics. World Scientific Publishing Co., Singapore, pp. 32-38], it was suggested that SOAE spectral patterns are strongly influenced by papillar anatomy. However, in two family groups, only one single species has been studied and we have no data on the regularity of pattern within related lizard families. Within the group of skink-like lizards, whose papillae all have salletal tectorial structures, the only detailed SOAE studies so far were on the skink genus Tiliqua. To ascertain the similarity of SOAE in species from families related to the skinks, we have studied one species each from two families that are closely related to skinks, the Cordylidae (Girdle-tailed lizards) and the Gerrhosauridae (plated lizards). Gerrhosaurus and Cordylus have a similar number and amplitudes of SOAE to Tiliqua (Skinkidae). The maximal frequency shifts of SOAE under the influence of external tones is also similar to that of Tiliqua. However, the maximal suppression and maximal facilitation are smaller. In general, the patterns displayed by the SOAE of lizards of these two new families are recognizably similar to the skink Tiliqua, suggesting that the anatomy of the papilla and the tectorial structures do play an important role in determining how SOAE are manifested in papillae that possess tectorial sallets.

  3. Wind constraints on the thermoregulation of high mountain lizards.

    Science.gov (United States)

    Ortega, Zaida; Mencía, Abraham; Pérez-Mellado, Valentín

    2017-03-01

    Thermal biology of lizards affects their overall physiological performance. Thus, it is crucial to study how abiotic constraints influence thermoregulation. We studied the effect of wind speed on thermoregulation in an endangered mountain lizard (Iberolacerta aurelioi). We compared two populations of lizards: one living in a sheltered rocky area and the other living in a mountain ridge, exposed to strong winds. The preferred temperature range of I. aurelioi, which reflects thermal physiology, was similar in both areas, and it was typical of a cold specialist. Although the thermal physiology of lizards and the structure of the habitat were similar, the higher wind speed in the exposed population was correlated with a significant decrease in the effectiveness thermoregulation, dropping from 0.83 to 0.74. Our results suggest that wind reduces body temperatures in two ways: via direct convective cooling of the animal and via convective cooling of the substrate, which causes conductive cooling of the animal. The detrimental effect of wind on thermoregulatory effectiveness is surprising, since lizards are expected to thermoregulate more effectively in more challenging habitats. However, wind speed would affect the costs and benefits of thermoregulation in more complex ways than just the cooling of animals and their habitats. For example, it may reduce the daily activity, increase desiccation, or complicate the hunting of prey. Finally, our results imply that wind should also be considered when developing conservation strategies for threatened ectotherms.

  4. A genome draft of the legless anguid lizard, Ophisaurus gracilis.

    Science.gov (United States)

    Song, Bo; Cheng, Shifeng; Sun, Yanbo; Zhong, Xiao; Jin, Jieqiong; Guan, Rui; Murphy, Robert W; Che, Jing; Zhang, Yaping; Liu, Xin

    2015-01-01

    Transition from a lizard-like to a snake-like body form is one of the most important transformations in reptilian evolution. The increasing number of sequenced reptilian genomes is enabling a deeper understanding of vertebrate evolution, although the genetic basis of the loss of limbs in reptiles remains enigmatic. Here we report genome sequencing, assembly, and annotation for the Asian glass lizard Ophisaurus gracilis, a limbless lizard species with an elongated snake-like body form. Addition of this species to the genome repository will provide an excellent resource for studying the genetic basis of limb loss and trunk elongation. O. gracilis genome sequencing using the Illumina HiSeq2000 platform resulted in 274.20 Gbp of raw data that was filtered and assembled to a final size of 1.78 Gbp, comprising 6,717 scaffolds with N50 = 1.27 Mbp. Based on the k-mer estimated genome size of 1.71 Gbp, the assembly appears to be nearly 100% complete. A total of 19,513 protein-coding genes were predicted, and 884.06 Mbp of repeat sequences (approximately half of the genome) were annotated. The draft genome of O. gracilis has similar characteristics to both lizard and snake genomes. We report the first genome of a lizard from the family Anguidae, O. gracilis. This supplements currently available genetic and genomic resources for amniote vertebrates, representing a major increase in comparative genome data available for squamate reptiles in particular.

  5. Experimental infections in Venezuelan lizards by Trypanosoma cruzi.

    Science.gov (United States)

    Urdaneta-Morales, S; McLure, I

    1981-06-01

    Virulent trypomastigotes of the Y strain of Trypanosoma cruzi were administered to Tropidurus hispidus, Ameiva ameiva, Cnemidophorus lemniscatus, Polychrus marmoratus, and Phyllodactylus ventralis (Sauria). Intraperitoneal and subcutaneous inoculations of lizards with mouse blood or with feces of infected Rhodnius prolixus (Reduviidae, Triatominae), as well as forced ingestion of triturated Rhodnius, produced no parasitaemias detectable either directly or by xenodiagnosis, while control mice became parasitized. Pretreatment with the immunosuppressive drug Fluocinolone acetonide led to establishing patent infections in inoculated lizards. Cryptic infections were established by inoculation of 1 X 10(6) parasites from Davis' medium, or by 95 X 10(3) parasites from lizard tissue culture. Parasites were not seen in tissues. Mice inoculated with blood or tissue homogenates from these lizards became parasitized. Parasites from Davis' medium inoculated into the peritoneal cavity of lizards were capable, to a very low degree, of penetrating the free peritoneal macrophages and changing into amastigotes. The factors possibly responsible for the natural resistance of poikilothermic vertebrates to T. cruzi are discussed.

  6. Effects of inorganic lead on Western fence lizards (Sceloporus occidentalis)

    Energy Technology Data Exchange (ETDEWEB)

    Salice, Christopher J., E-mail: chris.salice@ttu.ed [US Army Center for Health Promotion and Preventive Medicine, Aberdeen Proving Ground, MD 21010 (United States); Suski, Jamie G., E-mail: jamie.suski@ttu.ed [US Army Center for Health Promotion and Preventive Medicine, Aberdeen Proving Ground, MD 21010 (United States); Bazar, Matthew A., E-mail: matthew.bazar@us.army.mi [US Army Center for Health Promotion and Preventive Medicine, Aberdeen Proving Ground, MD 21010 (United States); Talent, Larry G., E-mail: larry.talent@okstate.ed [Oklahoma State University, Department of Natural Resource Ecology and Management, Stillwater, OK 74078 (United States)

    2009-12-15

    Although anthropogenic pollutants are thought to threaten reptilian species, there are few toxicity studies on reptiles. We evaluated the toxicity of Pb as lead acetate to the Western fence lizard (Sceloporus occidentalis). The acute lethal dose and sub-acute (14-day) toxicity studies were used to narrow exposure concentrations for a sub-chronic (60-day) study. In the sub-chronic study, adult and juvenile male lizards were dosed via gavage with 0, 1, 10 and 20 mg Pb/kg-bw/day. Mortality was limited and occurred only at the highest dose (20 mg Pb/kg-bw/d). There were statistically significant sub-lethal effects of 10 and 20 mg Pb/kg-bw/d on body weight, cricket consumption, organ weight, hematological parameters and post-dose behaviors. Of these, Pb-induced changes in body weight are most useful for ecological risk assessment because it is linked to fitness in wild lizard populations. The Western fence lizard is a useful model for reptilian toxicity studies. - The Western fence lizard, Sceloporus occidentalis, is sensitive to Pb and is a useful laboratory model for ecotoxicological testing of reptiles.

  7. Nereididae (Annelida: Phyllodocida) of Lizard Island, Great Barrier Reef, Australia.

    Science.gov (United States)

    Glasby, Christopher J

    2015-09-18

    Nereididae is one of the most ubiquitous of polychaete families, yet knowledge of their diversity in the northern Great Barrier Reef is poor; few species have been previously reported from any of the atolls or islands including Lizard Island. In this study, the diversity of the family from Lizard Island and surrounding reefs is documented based on museum collections derived from surveys conducted mostly over the last seven years. The Lizard Island nereidid fauna was found to be represented by 14 genera and 38 species/species groups, including 11 putative new species. Twelve species are newly reported from Lizard Island; four of these are also first records for Australia. For each genus and species, diagnoses and/or taxonomic remarks are provided in addition to notes on their habitat on Lizard Island, and general distribution; the existence of tissue samples tied to vouchered museum specimens is indicated. Fluorescence photography is used to help distinguish closely similar species of Nereis and Platynereis. A key is provided to facilitate identification and encourage further taxonomic, molecular and ecological studies on the group.

  8. Wind constraints on the thermoregulation of high mountain lizards

    Science.gov (United States)

    Ortega, Zaida; Mencía, Abraham; Pérez-Mellado, Valentín

    2017-03-01

    Thermal biology of lizards affects their overall physiological performance. Thus, it is crucial to study how abiotic constraints influence thermoregulation. We studied the effect of wind speed on thermoregulation in an endangered mountain lizard ( Iberolacerta aurelioi). We compared two populations of lizards: one living in a sheltered rocky area and the other living in a mountain ridge, exposed to strong winds. The preferred temperature range of I. aurelioi, which reflects thermal physiology, was similar in both areas, and it was typical of a cold specialist. Although the thermal physiology of lizards and the structure of the habitat were similar, the higher wind speed in the exposed population was correlated with a significant decrease in the effectiveness thermoregulation, dropping from 0.83 to 0.74. Our results suggest that wind reduces body temperatures in two ways: via direct convective cooling of the animal and via convective cooling of the substrate, which causes conductive cooling of the animal. The detrimental effect of wind on thermoregulatory effectiveness is surprising, since lizards are expected to thermoregulate more effectively in more challenging habitats. However, wind speed would affect the costs and benefits of thermoregulation in more complex ways than just the cooling of animals and their habitats. For example, it may reduce the daily activity, increase desiccation, or complicate the hunting of prey. Finally, our results imply that wind should also be considered when developing conservation strategies for threatened ectotherms.

  9. Wind constraints on the thermoregulation of high mountain lizards

    Science.gov (United States)

    Ortega, Zaida; Mencía, Abraham; Pérez-Mellado, Valentín

    2016-08-01

    Thermal biology of lizards affects their overall physiological performance. Thus, it is crucial to study how abiotic constraints influence thermoregulation. We studied the effect of wind speed on thermoregulation in an endangered mountain lizard (Iberolacerta aurelioi). We compared two populations of lizards: one living in a sheltered rocky area and the other living in a mountain ridge, exposed to strong winds. The preferred temperature range of I. aurelioi, which reflects thermal physiology, was similar in both areas, and it was typical of a cold specialist. Although the thermal physiology of lizards and the structure of the habitat were similar, the higher wind speed in the exposed population was correlated with a significant decrease in the effectiveness thermoregulation, dropping from 0.83 to 0.74. Our results suggest that wind reduces body temperatures in two ways: via direct convective cooling of the animal and via convective cooling of the substrate, which causes conductive cooling of the animal. The detrimental effect of wind on thermoregulatory effectiveness is surprising, since lizards are expected to thermoregulate more effectively in more challenging habitats. However, wind speed would affect the costs and benefits of thermoregulation in more complex ways than just the cooling of animals and their habitats. For example, it may reduce the daily activity, increase desiccation, or complicate the hunting of prey. Finally, our results imply that wind should also be considered when developing conservation strategies for threatened ectotherms.

  10. The alteration of proportion of different lizard species compared to each other at The Great Pasture of Hajdubagos

    OpenAIRE

    Antal, Zsuzsanna

    2006-01-01

    Three different lizard species can be found at the great pasture of Hajúbagos. These are the balkan or crimean wall lizard (Podarcis taurica), the sand lizard (Lacerta agilis) and the green lizard (Lacerta viridis). All of them are protected by law in Hungary but while sand lizard and green lizard is common all over the country, the amount of the balkan wall lizard is decreasing. The main cause of this regrettable possession is the habitat degradation and thus habitat loss. Namely balkan wall...

  11. Prey transport kinematics in Tupinambis teguixin and Varanus exanthematicus: conservation of feeding behavior in 'chemosensory-tongued' lizards.

    Science.gov (United States)

    Elias, J A; McBrayer, L D; Reilly, S M

    2000-02-01

    Although lizards have been predicted to show extensive intraoral prey-processing behaviors, quantitative analyses of the types of prey-processing behavior they demonstrate and of their kinematics have been limited. The more basal lizard lineages (Iguanians) have undergone some study, but the prey-processing repertoires of crown taxa have not been thoroughly examined and quantitative comparisons of behaviors within or among species have not been made. In this study, the prey transport behavior of the savannah monitor (Varanus exanthematicus) and gold tegu (Tupinambis teguixin) are described. Although these two lineages have independently evolved tongues that are highly specialized for chemoreception, we found that they share the same three distinct types of transport behavior. These behavior patterns are (i) a purely inertial transport, (ii) an inertial transport with use of the tongue, and (iii) a non-inertial lingual transport. The tongue is used extensively in both the inertial and the purely lingual transport behaviors. More than 75 % of all transport behaviors involved tongue movements. These species appear to exhibit a conservation of feeding kinematics compared with patterns known for basal lizards. A hypothesis for the evolution of inertial feeding is proposed.

  12. RBC count

    Science.gov (United States)

    ... Failure of the right side of the heart ( cor pulmonale ) Dehydration (for example, from severe diarrhea) Kidney tumor ( ... Read More Alport syndrome Anemia CBC blood test Cor pulmonale Dehydration Erythropoietin test Folic acid in diet Glucose- ...

  13. High sensitivity to short wavelengths in a lizard and implications for understanding the evolution of visual systems in lizards.

    Science.gov (United States)

    Fleishman, Leo J; Loew, Ellis R; Whiting, Martin J

    2011-10-07

    Progress in developing animal communication theory is frequently constrained by a poor understanding of sensory systems. For example, while lizards have been the focus of numerous studies in visual signalling, we only have data on the spectral sensitivities of a few species clustered in two major clades (Iguania and Gekkota). Using electroretinography and microspectrophotometry, we studied the visual system of the cordylid lizard Platysaurus broadleyi because it represents an unstudied clade (Scinciformata) with respect to visual systems and because UV signals feature prominently in its social behaviour. The retina possessed four classes of single and one class of double cones. Sensitivity in the ultraviolet region (UV) was approximately three times higher than previously reported for other lizards. We found more colourless oil droplets (associated with UV-sensitive (UVS) and short wavelength-sensitive (SWS) photoreceptors), suggesting that the increased sensitivity was owing to the presence of more UVS photoreceptors. Using the Vorobyev-Osorio colour discrimination model, we demonstrated that an increase in the number of UVS photoreceptors significantly enhances a lizard's ability to discriminate conspecific male throat colours. Visual systems in diurnal lizards appear to be broadly conserved, but data from additional clades are needed to confirm this.

  14. Tail regeneration affects the digestive performance of a Mediterranean lizard

    Science.gov (United States)

    Sagonas, Kostas; Karambotsi, Niki; Bletsa, Aristoula; Reppa, Aikaterini; Pafilis, Panayiotis; Valakos, Efstratios D.

    2017-04-01

    In caudal autotomy, lizards shed their tail to escape from an attacking predator. Since the tail serves multiple functions, caudal regeneration is of pivotal importance. However, it is a demanding procedure that requires substantial energy and nutrients. Therefore, lizards have to increase energy income to fuel the extraordinary requirements of the regenerating tail. We presumed that autotomized lizards would adjust their digestion to acquire this additional energy. To clarify the effects of tail regeneration on digestion, we compared the digestive performance before autotomy, during regeneration, and after its completion. Tail regeneration indeed increased gut passage time but did not affect digestive performance in a uniform pattern: though protein income was maximized, lipid and sugar acquisition remained stable. This divergence in proteins may be attributed to their particular role in tail reconstruction, as they are the main building blocks for tissue formation.

  15. Serpulidae (Annelida) of Lizard Island, Great Barrier Reef, Australia.

    Science.gov (United States)

    Kupriyanova, Elena K; Sun, Yanan; Hove, Harry A Ten; Wong, Eunice; Rouse, Greg W

    2015-09-18

    Serpulidae are obligatory sedentary polychaetes inhabiting calcareous tubes that are most common in subtropical and tropical areas of the world. This paper describes serpulid polychaetes collected from Lizard Island, Great Barrier Reef, Australia in 1983-2013 and deposited in Australian museums and overseas. In total, 17 serpulid genera were recorded, but although the study deals with 44 nominal taxa, the exact number of species remains unclear because a number of genera (i.e., Salmacina, Protula, Serpula, Spirobranchus, and Vermiliopsis) need world-wide revisions. Some species described herein are commonly found in the waters around Lizard Island, but had not previously been formally reported. A new species of Hydroides (H. lirs) and two new species of Semivermilia (S. annehoggettae and S. lylevaili) are described. A taxonomic key to all taxa found at Lizard Island is provided.

  16. Compositional Studies on Tropical Species of Agama agama Lizards

    Directory of Open Access Journals (Sweden)

    V.O. Onibon

    2007-01-01

    Full Text Available The aim of this study was to assess nutrient values of lizards (Agama agama. The samples earmarked for this study were obtained at Federal College of Agriculture, Akure, Nigeria. In male and female Agama agama lizards, anatomical weights, proximate and mineral contents, tannin, oxalate and phytate compositions were determined using standard methods. The samples contained: 54.05-57.69% protein; 2.56-3.01% fat, 1.11-3.18% fibre, 12.91-13.40% ash, 21.38-21.94% NFE, 3.85-4.18% moisture and 328.80-347.5 kcal energy. All the major elements determined were found to be high. The tannin, oxalate, phytate contents were low, meaning that the bioavailability of protein and minerals are high. The values recorded for proximate and minerals compared with other animal sources. It is recommended that nutritional qualities of lizards should be harnessed.

  17. Oxidative stress decreases with elevation in the lizard Psammodromus algirus.

    Science.gov (United States)

    Reguera, Senda; Zamora-Camacho, Francisco J; Trenzado, Cristina E; Sanz, Ana; Moreno-Rueda, Gregorio

    2014-06-01

    Oxidative stress is considered one of the main ecological and evolutionary forces. Several environmental stressors vary geographically and thus organisms inhabiting different sites face different oxidant environments. Nevertheless, there is scarce information about how oxidative damage and antioxidant defences vary geographically in animals. Here we study how oxidative stress varies from lowlands (300-700 m asl) to highlands (2200-2500 m asl) in the lizard Psammodromus algirus. To accomplish this, antioxidant enzymatic activity (catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase, glutathione transferase, DT-diaphorase) and lipid peroxidation were assayed in tissue samples from the lizards' tail. Lipid peroxidation was higher in individuals from lowlands than from highlands, indicating higher oxidative stress in lowland lizards. These results suggest that environmental conditions are less oxidant at high elevations with respect to low ones. Therefore, our study shows that oxidative stress varies geographically, which should have important consequences for our understanding of geographic variation in physiology and life-history of organisms.

  18. Changes in heart rate are important for thermoregulation in the varanid lizard Varanus varius.

    Science.gov (United States)

    Seebacher, F; Grigg, G C

    2001-06-01

    Laboratory studies and a single field study have shown that heart rate in some reptiles is faster during heating than during cooling at any given body temperature. This phenomenon, which has been shown to reflect changes in peripheral blood flow, is shown here to occur in the lizard Varanus varius (lace monitor) in the wild. On a typical clear day, lizards emerged from their shelters in the morning to warm in the sun. Following this, animals were active, moving until they again entered a shelter in the evening. During their period of activity, body temperature was 34-36 degrees C in all six study animals (4.0-5.6 kg), but the animals rarely shuttled between sun and shade exposure. Heart rate during the morning heating period was significantly faster than during the evening cooling period. However, the ratio of heating to cooling heart rate decreased with increasing body temperature, being close to 2 at body temperatures of 22-24 degrees C and decreasing to 1.2-1.3 at body temperatures of 34-36 degrees C. There was a significant decrease in thermal time constants with increasing heart rate during heating and cooling confirming that changes in heart rate are linked to rates of heat exchange.

  19. Seasonal reproductive endothermy in tegu lizards.

    Science.gov (United States)

    Tattersall, Glenn J; Leite, Cleo A C; Sanders, Colin E; Cadena, Viviana; Andrade, Denis V; Abe, Augusto S; Milsom, William K

    2016-01-01

    With some notable exceptions, small ectothermic vertebrates are incapable of endogenously sustaining a body temperature substantially above ambient temperature. This view was challenged by our observations of nighttime body temperatures sustained well above ambient (up to 10°C) during the reproductive season in tegu lizards (~2 kg). This led us to hypothesize that tegus have an enhanced capacity to augment heat production and heat conservation. Increased metabolic rates and decreased thermal conductance are the same mechanisms involved in body temperature regulation in those vertebrates traditionally acknowledged as "true endotherms": the birds and mammals. The appreciation that a modern ectotherm the size of the earliest mammals can sustain an elevated body temperature through metabolic rates approaching that of endotherms enlightens the debate over endothermy origins, providing support for the parental care model of endothermy, but not for the assimilation capacity model of endothermy. It also indicates that, contrary to prevailing notions, ectotherms can engage in facultative endothermy, providing a physiological analog in the evolutionary transition to true endothermy.

  20. Does thermal ecology influence dynamics of side-blotched lizards and their micro-parasites?

    Science.gov (United States)

    Paranjpe, Dhanashree A; Medina, Dianna; Nielsen, Erica; Cooper, Robert D; Paranjpe, Sharayu A; Sinervo, Barry

    2014-07-01

    Hosts and parasites form interacting populations that influence each other in multiple ways. Their dynamics can also be influenced by environmental and ecological factors. We studied host-parasite dynamics in a previously unexplored study system: side-blotched lizards and their micro-parasites. Compared with uninfected lizards, the infected lizards elected to bask at lower temperatures that were outside their range of preferred temperatures. Infected lizards also were not as precise as uninfected lizards in maintaining their body temperatures within a narrow range. At the ecological scale, areas with higher infection rates coincided with more thermally heterogeneous microhabitats as well as with the areas where lizards tended to live longer. Thermal heterogeneity of lizards' microhabitats may provide important clues to the spatial and temporal distribution of infections.

  1. Tail-assisted pitch control in lizards, robots and dinosaurs.

    Science.gov (United States)

    Libby, Thomas; Moore, Talia Y; Chang-Siu, Evan; Li, Deborah; Cohen, Daniel J; Jusufi, Ardian; Full, Robert J

    2012-01-04

    In 1969, a palaeontologist proposed that theropod dinosaurs used their tails as dynamic stabilizers during rapid or irregular movements, contributing to their depiction as active and agile predators. Since then the inertia of swinging appendages has been implicated in stabilizing human walking, aiding acrobatic manoeuvres by primates and rodents, and enabling cats to balance on branches. Recent studies on geckos suggest that active tail stabilization occurs during climbing, righting and gliding. By contrast, studies on the effect of lizard tail loss show evidence of a decrease, an increase or no change in performance. Application of a control-theoretic framework could advance our general understanding of inertial appendage use in locomotion. Here we report that lizards control the swing of their tails in a measured manner to redirect angular momentum from their bodies to their tails, stabilizing body attitude in the sagittal plane. We video-recorded Red-Headed Agama lizards (Agama agama) leaping towards a vertical surface by first vaulting onto an obstacle with variable traction to induce a range of perturbations in body angular momentum. To examine a known controlled tail response, we built a lizard-sized robot with an active tail that used sensory feedback to stabilize pitch as it drove off a ramp. Our dynamics model revealed that a body swinging its tail experienced less rotation than a body with a rigid tail, a passively compliant tail or no tail. To compare a range of tails, we calculated tail effectiveness as the amount of tailless body rotation a tail could stabilize. A model Velociraptor mongoliensis supported the initial tail stabilization hypothesis, showing as it did a greater tail effectiveness than the Agama lizards. Leaping lizards show that inertial control of body attitude can advance our understanding of appendage evolution and provide biological inspiration for the next generation of manoeuvrable search-and-rescue robots.

  2. Spatial patterns in the abundance of the coastal horned lizard

    Science.gov (United States)

    Fisher, Robert N.; Suarez, Andrew V.; Case, Ted J.

    2002-01-01

    Coastal horned lizards (   Phrynosoma coronatum) have undergone severe declines in southern California and are a candidate species for state and federal listing under the Endangered Species Act. Quantitative data on their habitat use, abundance, and distribution are lacking, however. We investigated the determinants of abundance for coastal horned lizards at multiple spatial scales throughout southern California. Specifically, we estimated lizard distribution and abundance by establishing 256 pitfall trap arrays clustered within 21 sites across four counties. These arrays were sampled bimonthly for 2–3 years. At each array we measured 26 “local” site descriptors and averaged these values with other “regional” measures to determine site characteristics. Our analyses were successful at identifying factors within and among sites correlated with the presence and abundance of coastal horned lizards. These factors included the absence of the invasive Argentine ant (  Linepithema humile) (and presence of native ant species eaten by the lizards), the presence of chaparral community plants, and the presence of sandy substrates. At a regional scale the relative abundance of Argentine ants was correlated with the relative amount of developed edge around a site. There was no evidence for spatial autocorrelation, even at the scale of the arrays within sites, suggesting that the determinants of the presence or absence and abundance of horned lizard can vary over relatively small spatial scales ( hundreds of meters). Our results suggest that a gap-type approach may miss some of the fine-scale determinants of species abundance in fragmented habitats.

  3. Measurement of RBC agglutination with microscopic cell image analysis in a microchannel chip.

    Science.gov (United States)

    Cho, Chi Hyun; Kim, Ju Yeon; Nyeck, Agnes E; Lim, Chae Seung; Hur, Dae Sung; Chung, Chanil; Chang, Jun Keun; An, Seong Soo A; Shin, Sehyun

    2014-01-01

    Since Landsteiner's discovery of ABO blood groups, RBC agglutination has been one of the most important immunohematologic techniques for ABO and RhD blood groupings. The conventional RBC agglutination grading system for RhD blood typings relies on macroscopic reading, followed by the assignment of a grade ranging from (-) to (4+) to the degree of red blood cells clumping. However, with the new scoring method introduced in this report, microscopically captured cell images of agglutinated RBCs, placed in a microchannel chip, are used for analysis. Indeed, the cell images' pixel number first allows the differentiation of agglutinated and non-agglutinated red blood cells. Finally, the ratio of agglutinated RBCs per total RBC counts (CRAT) from 90 captured images is then calculated. During the trial, it was observed that the agglutinated group's CRAT was significantly higher (3.77-0.003) than that of the normal control (0). Based on these facts, it was established that the microchannel method was more suitable for the discrimination between agglutinated RBCs and non-agglutinated RhD negative, and thus more reliable for the grading of RBCs agglutination than the conventional method.

  4. Modifying Directionality through Auditory System Scaling in a Robotic Lizard

    DEFF Research Database (Denmark)

    Shaikh, Danish; Hallam, John; Christensen-Dalsgaard, Jakob

    2010-01-01

    The peripheral auditory system of a lizard is strongly directional. This directionality is created by acoustical coupling of the two eardrums and is strongly dependent on characteristics of the middle ear, such as interaural distance, resonance frequency of the middle ear cavity and of the tympanum....... Therefore, directionality should be strongly influenced by their scaling. In the present study, we have exploited an FPGA–based mobile robot based on a model of the lizard ear to investigate the influence of scaling on the directional response, in terms of the robot’s performance in a phonotaxis task...

  5. Haemostatic function and biomarkers of endothelial damage before and after RBC transfusion in patients with haematologic disease

    DEFF Research Database (Denmark)

    Larsen, A M; Leinøe, E B; Johansson, P I;

    2015-01-01

    BACKGROUND AND OBJECTIVES: Transfusion of red blood cells (RBC) is beneficial for the patient but can also be harmful, as randomized trials have demonstrated increased infection rates, bleeding and mortality. The study aim was to investigate the response of the vascular system (the haemostatic...... function and the endothelium) to RBC transfusion. MATERIALS AND METHODS: Blood was sampled from patients with various transfusion-dependent haematologic diseases before 1 and 24 h after RBC transfusion. Primary and secondary haemostasis was evaluated by whole-blood impedance aggregometry (Multiplate...

  6. Auditory hair cell innervational patterns in lizards.

    Science.gov (United States)

    Miller, M R; Beck, J

    1988-05-22

    The pattern of afferent and efferent innervation of two to four unidirectional (UHC) and two to nine bidirectional (BHC) hair cells of five different types of lizard auditory papillae was determined by reconstruction of serial TEM sections. The species studies were Crotaphytus wislizeni (iguanid), Podarcis (Lacerta) sicula and P. muralis (lacertids), Ameiva ameiva (teiid), Coleonyx variegatus (gekkonid), and Mabuya multifasciata (scincid). The main object was to determine in which species and in which hair cell types the nerve fibers were innervating only one (exclusive innervation), or two or more hair cells (nonexclusive innervation); how many nerve fibers were supplying each hair cell; how many synapses were made by the innervating fibers; and the total number of synapses on each hair cell. In the species studies, efferent innervation was limited to the UHC, and except for the iguanid, C. wislizeni, it was nonexclusive, each fiber supplying two or more hair cells. Afferent innervation varied both with the species and the hair cell types. In Crotaphytus, both the UHC and the BHC were exclusively innervated. In Podarcis and Ameiva, the UHC were innervated exclusively by some fibers but nonexclusively by others (mixed pattern). In Coleonyx, the UHC were exclusively innervated but the BHC were nonexclusively innervated. In Mabuya, both the UHC and BHC were nonexclusively innervated. The number of afferent nerve fibers and the number of afferent synapses were always larger in the UHC than in the BHC. In Ameiva, Podarcis, and Mabuya, groups of bidirectionally oriented hair cells occur in regions of cytologically distinct UHC, and in Ameiva, unidirectionally oriented hair cells occur in cytologically distinct BHC regions.

  7. Evolution of Anolis lizard dewlap diversity.

    Directory of Open Access Journals (Sweden)

    Kirsten E Nicholson

    Full Text Available BACKGROUND: The dewlaps of Anolis lizards provide a classic example of a complex signaling system whose function and evolution is poorly understood. Dewlaps are flaps of skin beneath the chin that are extended and combined with head and body movements for visual signals and displays. They exhibit extensive morphological variation and are one of two cladistic features uniting anoles, yet little is known regarding their function and evolution. We quantified the diversity of anole dewlaps, investigated whether dewlap morphology was informative regarding phylogenetic relationships, and tested two separate hypotheses: (A similar Anolis habitat specialists possess similar dewlap configurations (Ecomorph Convergence hypothesis, and (B sympatric species differ in their dewlap morphologies to a greater extent than expected by chance (Species Recognition hypothesis. METHODOLOGY/PRINCIPAL FINDINGS: We found that dewlap configurations (sizes, patterns and colors exhibit substantial diversity, but that most are easily categorized into six patterns that incorporate one to three of 13 recognizable colors. Dewlap morphology is not phylogenetically informative and, like other features of anoles, exhibits convergence in configurations. We found no support for the Ecomorph Convergence hypothesis; species using the same structural habitat were no more similar in dewlap configuration than expected by chance. With one exception, all sympatric species in four communities differ in dewlap configuration. However, this provides only weak support for the Species Recognition hypothesis because, due to the great diversity in dewlap configurations observed across each island, few cases of sympatric species with identical dewlaps would be expected to co-occur by chance alone. CONCLUSIONS/SIGNIFICANCE: Despite previous thought, most dewlaps exhibit easily characterizable patterns and colorations. Nevertheless, dewlap variation is extensive and explanations for the origin and

  8. Sialoglycosylation of RBC in visceral leishmaniasis leads to enhanced oxidative stress, calpain-induced fragmentation of spectrin and hemolysis.

    Directory of Open Access Journals (Sweden)

    Sajal Samanta

    Full Text Available Visceral leishmaniasis (VL caused by the intracellular parasite Leishmania donovani accounts for an estimated 12 million cases of human infection. It is almost always associated with anemia, which severely complicates the disease course. However, the pathological processes leading to anemia in VL have thus far not been adequately characterized to date. In studying the glycosylation patterns of peripheral blood cells we found that the red blood cells (RBC of VL patients (RBC(VL express eight 9-O-acetylated sialoglycoproteins (9-O-AcSGPs that are not detected in the RBC of healthy individuals (RBC(N. At the same time, the patients had high titers of anti-9-O-AcSGP IgG antibodies in their sera. These two conditions appear to be linked and related to the anemic state of the patients, as exposure of RBC(VL but not RBC(N to anti-9-O-AcSGPs antibodies purified from patient sera triggered a series of responses. These included calcium influx via the P/Q-type but not L-type channels, activation of calpain I, proteolysis of spectrin, enhanced oxidative stress, lipid peroxidation, externalization of phosphatidyl serine with enhanced erythrophagocytosis, enhanced membrane fragility and, finally, hemolysis. Taken together, this study suggests that the enhanced hemolysis is linked to an impairment of membrane integrity in RBC(VL which is mediated by ligand-specific interaction of surface 9-O-AcSGPs. This affords a potential explanation for the structural and functional features of RBC(VL which are involved in the hemolysis related to the anemia which develops in VL patients.

  9. Importance of Heparin Provocation and SPECT/CT in Detecting Obscure Gastrointestinal Bleeding on 99mTc-RBC Scintigraphy

    OpenAIRE

    2015-01-01

    Abstract We presented a pediatric case with a history of intermittent melena for 3 years because of angiodyplasia of small intestine. The results of frequent upper gastrointestinal endoscopies and colonoscopies as well as both 99mTc-red blood cell (RBC) and Meckel's scintigraphies for several times were negative in detection of bleeding site. However, 99mTc-RBC scintigraphy with single-photon emission computed tomography (SPECT)/computed tomography (CT) after heparin augmentation detected a s...

  10. Learning to Localize Sound with a Lizard Ear Model

    DEFF Research Database (Denmark)

    Shaikh, Danish; Hallam, John; Christensen-Dalsgaard, Jakob

    The peripheral auditory system of a lizard is strongly directional in the azimuth plane due to the acoustical coupling of the animal's two eardrums. This feature by itself is insufficient to accurately localize sound as the extracted directional information cannot be directly mapped to the sound...

  11. Structure and function of the hearts of lizards and snakes.

    Science.gov (United States)

    Jensen, Bjarke; Moorman, Antoon F M; Wang, Tobias

    2014-05-01

    With approximately 7000 species, snakes and lizards, collectively known as squamates, are by far the most species-rich group of reptiles. It was from reptile-like ancestors that mammals and birds evolved and squamates can be viewed as phylogenetically positioned between them and fishes. Hence, their hearts have been studied for more than a century yielding insights into the group itself and into the independent evolution of the fully divided four-chambered hearts of mammals and birds. Structurally the heart is complex and debates persist on rudimentary issues such as identifying structures critical to understanding ventricle function. In seeking to resolve these controversies we have generated three-dimensional (3D) models in portable digital format (pdf) of the anaconda and anole lizard hearts ('typical' squamate hearts) and the uniquely specialized python heart with comprehensive annotations of structures and cavities. We review the anatomy and physiology of squamate hearts in general and emphasize the unique features of pythonid and varanid lizard hearts that endow them with mammal-like blood pressures. Excluding pythons and varanid lizards it is concluded that the squamate heart has a highly consistent design including a disproportionately large right side (systemic venous) probably due to prevailing pulmonary bypass (intraventricular shunting). Unfortunately, investigations on rudimentary features are sparse. We therefore point out gaps in our knowledge, such as the size and functional importance of the coronary vasculature and of the first cardiac chamber, the sinus venosus, and highlight areas with implications for vertebrate cardiac evolution.

  12. The auditory brainstem response in two lizard species

    DEFF Research Database (Denmark)

    Brittan-Powell, Elizabeth F; Christensen-Dalsgaard, Jakob; Tang, Yezhong

    2010-01-01

    Although lizards have highly sensitive ears, it is difficult to condition them to sound, making standard psychophysical assays of hearing sensitivity impractical. This paper describes non-invasive measurements of the auditory brainstem response (ABR) in both Tokay geckos (Gekko gecko; nocturnal...... in most bird species....

  13. Technique for Measuring Speed and Visual Motion Sensitivity in Lizards

    Science.gov (United States)

    Woo, Kevin L.; Burke, Darren

    2008-01-01

    Testing sensory characteristics on herpetological species has been difficult due to a range of properties related to physiology, responsiveness, performance ability, and the type of reinforcer used. Using the Jacky lizard as a model, we outline a successfully established procedure in which to test the visual sensitivity to motion characteristics.…

  14. Ecology and behavior of the Jamaican Lizard Cuckoo

    NARCIS (Netherlands)

    Cruz, Alexander

    1975-01-01

    On Jamaica many of the endemic land birds are poorly known from an ecological and behavioral standpoint. Therefore, the following information on the food, foraging behavior, and habitats of the Jamaican Lizard Cuckoo Saurothera vetula), obtained while engaged in other studies, should be helpful in t

  15. Comparative morphology of Liolaemus lizards precloacal glands

    Directory of Open Access Journals (Sweden)

    Soledad Valdecantos

    2014-12-01

    Full Text Available Liolaemid lizards and amphisbaenids have precloacal pores in the anterior border of the cloaca, where epidermal glands drain and expel pheromonal secretions. Precloacal glands occur usually only in males, but in those few species where both sexes have precloacal glands, these are larger in males. Only the morphology and/or histology of precloacal glands of amphisbaenids have been described, and it is unknown whether in lizards these glands differ across ages, sexes and/or species, and if the lack of pores is associated with a lack of glands. We investigated for the first time the morphology and histology of lizard precloacal glands, by studying three Liolaemus species that differ in the presence of pores in their cloaca: L. irregularis, in which adults and juveniles of both sexes have pores; L. poecilochromus, in which only adult males have pores, and L. neuquensis, in which the adults of both sexes lack pores. Results show that the number of pores varies among species and sexes, but not between ages of a species. Adults, but not juveniles, of L. irregularis have sexual dimorphism in pore sizes; these are larger in males than in females. In addition, pores are larger in adult males of L. irregularis than in L. poecilochromus. Glands are tubuloalveolar with holocrine secretion, having similar structure across individuals, although adult males have larger glands than females and juveniles. Finally, the structure of Liolaemus precloacal glands is very similar to those of the amphisbaenid precloacal glands and the femoral glands of other lizard species.

  16. Microhabitat choice in island lizards enhances camouflage against avian predators.

    Science.gov (United States)

    Marshall, Kate L A; Philpot, Kate E; Stevens, Martin

    2016-01-25

    Camouflage can often be enhanced by genetic adaptation to different local environments. However, it is less clear how individual behaviour improves camouflage effectiveness. We investigated whether individual Aegean wall lizards (Podarcis erhardii) inhabiting different islands rest on backgrounds that improve camouflage against avian predators. In free-ranging lizards, we found that dorsal regions were better matched against chosen backgrounds than against other backgrounds on the same island. This suggests that P. erhardii make background choices that heighten individual-specific concealment. In achromatic camouflage, this effect was more evident in females and was less distinct in an island population with lower predation risk. This suggests that behavioural enhancement of camouflage may be more important in females than in sexually competing males and related to predation risk. However, in an arena experiment, lizards did not choose the background that improved camouflage, most likely due to the artificial conditions. Overall, our results provide evidence that behavioural preferences for substrates can enhance individual camouflage of lizards in natural microhabitats, and that such adaptations may be sexually dimorphic and dependent on local environments. This research emphasizes the importance of considering links between ecology, behaviour, and appearance in studies of intraspecific colour variation and local adaptation.

  17. Ecology and behavior of the Jamaican Lizard Cuckoo

    NARCIS (Netherlands)

    Cruz, Alexander

    1975-01-01

    On Jamaica many of the endemic land birds are poorly known from an ecological and behavioral standpoint. Therefore, the following information on the food, foraging behavior, and habitats of the Jamaican Lizard Cuckoo Saurothera vetula), obtained while engaged in other studies, should be helpful in

  18. A review of diagnostic imaging of snakes and lizards.

    Science.gov (United States)

    Banzato, T; Hellebuyck, T; Van Caelenberg, A; Saunders, J H; Zotti, A

    2013-07-13

    Snakes and lizards are considered 'stoic' animals and often show only non-specific signs of illness. Consequently, diagnostic imaging--along with clinical examination and laboratory tests--is gaining importance in making a final diagnosis and establishing a correct therapy. The large number of captive snake and lizard species commonly kept as pets, together with the high inter- and intraspecific morphological variability that is innate in these animals, make the analysis of diagnostic images challenging for the veterinary practitioner. Moreover, a thorough knowledge of the anatomy, physiology and pathology of the species that are the object of clinical investigation is mandatory for the correct interpretation of diagnostic images. Despite the large amount of clinical and scientific work carried out in the past two decades, the radiographic features of snakes and lizards have not undergone systematic description, and therefore veterinarians often have to rely mostly on anatomical studies rather than radiological literature. The aim of this paper is to review the most commonly used diagnostic imaging modalities, as well as to provide an overview of the available international original studies and scientific reviews describing the normal and pathological imaging features in snakes and lizards.

  19. Ecology and behavior of the Jamaican Lizard Cuckoo

    NARCIS (Netherlands)

    Cruz, Alexander

    1975-01-01

    On Jamaica many of the endemic land birds are poorly known from an ecological and behavioral standpoint. Therefore, the following information on the food, foraging behavior, and habitats of the Jamaican Lizard Cuckoo Saurothera vetula), obtained while engaged in other studies, should be helpful in t

  20. Lizard\\'s fauna of the Sabzevar with particular emphasis on the syntopic lizard and presentation of a framework for reptile distribution of Iran

    Directory of Open Access Journals (Sweden)

    Masoud Yousefi

    2013-11-01

    Full Text Available Sabzevar is one of the most biologically diverse regions in northeast Iran, with the area of 19500 km2 and an elevational of 950-2977 m. During a long term study of lizards in this area which lasted 3 years, 21 species and subspecies of lizards belonging to 13 genera and 5 families were collected, recognized and reported. The families Anguidae, Eublepharidae and Uromastycidae were not represented in the area. The genus Eremias with 6 species was the most diverse genus in Sabzevar district. More emphasis was given to the syntopic reptiles. This showed that Trapelus agailis with having 18 syntopic species and Cyrtopodion caspium with no syntopic species were in the extreme sides. Due to our little knowledge on the distribution of reptiles in Iran, we designed a framework for providing a reptile's distribution map in Iran.

  1. Quantitative and qualitative morphologic, cytochemical, and ultrastructural characteristics of blood cells in captive Asian water monitors.

    Science.gov (United States)

    Salakij, Chaleow; Salakij, Jarernsak; Prihirunkit, Kreangsak; Narkkong, Naul-Anong; Sanyathitiseree, Pornchai; Kranjanapitukkul, Kwanjai

    2014-12-01

    The Asian water monitor (Varanus salvator) is the most common monitor lizard in Thailand. Reported data regarding hematology and morphology of blood cells for this species are scarce. The objective of this study was to assess routine hematologic variables and characterize the morphology, cytochemical staining, and ultrastructural features of blood cells in the Asian water monitor. Blood samples from 55 monitors (22 males and 33 females) were obtained for a CBC. Cytochemical staining (Sudan black B [SBB], peroxidase [PO], α-naphthyl acetate esterase [ANAE], and beta-glucuronidase [BG]), and scanning and transmission electron microscopy were performed using standard methods. Determined mean (range) hematologic results of all monitors included PCV 0.32 L/L (0.20-0.44 L/L), HGB 106 g/L (62-157 g/L), WBC 15.9 × 10(9) /L (4.0-34.0 × 10(9) /L), heterophil 6.3 × 10(9) /L (1.5-17.1 × 10(9) /L, azurophil 2.6 × 10(9) /L (0.7-9.5 × 10(9) /L), basophil 0.1 (0.1-0.5 × 10(9) /L), lymphocyte 6.8 × 10(9) /L (0.5-13.1 × 10(9) /L), and monocyte 0.2 × 10(9) /L (0.04-1 × 10(9) /L) counts. Heterophils and basophils stained strongly positive with SBB, ANAE, and BG. Heterophils contained 2 types of granules, round SBB-positive and PO-negative granules, and electron-dense, large rod-shaped granules. Gamonts of Hepatozoon sp. were found in <1% RBC of 43 monitors. There was no significant difference between hematologic variables in Hepatozoon-positive and -negative monitors. Heterophils in Asian water monitors may also function as eosinophils based on cytochemical and ultrastructural features. The quantitative results may be used as base for further studies in healthy and diseased Asian water monitors. © 2014 American Society for Veterinary Clinical Pathology.

  2. The decoupling of abundance and species richness in lizard communities.

    Science.gov (United States)

    Nimmo, Dale G; James, Simon G; Kelly, Luke T; Watson, Simon J; Bennett, Andrew F

    2011-05-01

    1. Patterns of species richness often correlate strongly with measures of energy. The more individuals hypothesis (MIH) proposes that this relationship is facilitated by greater resources supporting larger populations, which are less likely to become extinct. Hence, the MIH predicts that community abundance and species richness will be positively related. 2. Recently, Buckley & Jetz (2010, Journal of Animal Ecology, 79, 358-365) documented a decoupling of community abundance and species richness in lizard communities in south-west United States, such that richer communities did not contain more individuals. They predicted, as a consequence of the mechanisms driving the decoupling, a more even distribution of species abundances in species-rich communities, evidenced by a positive relationship between species evenness and species richness. 3. We found a similar decoupling of the relationship between abundance and species richness for lizard communities in semi-arid south-eastern Australia. However, we note that a positive relationship between evenness and richness is expected because of the nature of the indices used. We illustrate this mathematically and empirically using data from both sets of lizard communities. When we used a measure of evenness, which is robust to species richness, there was no relationship between evenness and richness in either data set. 4. For lizard communities in both Australia and the United States, species dominance decreased as species richness increased. Further, with the iterative removal of the first, second and third most dominant species from each community, the relationship between abundance and species richness became increasingly more positive. 5. Our data support the contention that species richness in lizard communities is not directly related to the number of individuals an environment can support. We propose an alternative hypothesis regarding how the decoupling of abundance and richness is accommodated; namely, an inverse

  3. Functional and structural diversification of the Anguimorpha lizard venom system.

    Science.gov (United States)

    Fry, Bryan G; Winter, Kelly; Norman, Janette A; Roelants, Kim; Nabuurs, Rob J A; van Osch, Matthias J P; Teeuwisse, Wouter M; van der Weerd, Louise; McNaughtan, Judith E; Kwok, Hang Fai; Scheib, Holger; Greisman, Laura; Kochva, Elazar; Miller, Laurence J; Gao, Fan; Karas, John; Scanlon, Denis; Lin, Feng; Kuruppu, Sanjaya; Shaw, Chris; Wong, Lily; Hodgson, Wayne C

    2010-11-01

    Venom has only been recently discovered to be a basal trait of the Anguimorpha lizards. Consequently, very little is known about the timings of toxin recruitment events, venom protein molecular evolution, or even the relative physical diversifications of the venom system itself. A multidisciplinary approach was used to examine the evolution across the full taxonomical range of this ∼130 million-year-old clade. Analysis of cDNA libraries revealed complex venom transcriptomes. Most notably, three new cardioactive peptide toxin types were discovered (celestoxin, cholecystokinin, and YY peptides). The latter two represent additional examples of convergent use of genes in toxic arsenals, both having previously been documented as components of frog skin defensive chemical secretions. Two other novel venom gland-overexpressed modified versions of other protein frameworks were also recovered from the libraries (epididymal secretory protein and ribonuclease). Lectin, hyaluronidase, and veficolin toxin types were sequenced for the first time from lizard venoms and shown to be homologous to the snake venom forms. In contrast, phylogenetic analyses demonstrated that the lizard natriuretic peptide toxins were recruited independently of the form in snake venoms. The de novo evolution of helokinestatin peptide toxin encoding domains within the lizard venom natriuretic gene was revealed to be exclusive to the helodermatid/anguid subclade. New isoforms were sequenced for cysteine-rich secretory protein, kallikrein, and phospholipase A(2) toxins. Venom gland morphological analysis revealed extensive evolutionary tinkering. Anguid glands are characterized by thin capsules and mixed glands, serous at the bottom of the lobule and mucous toward the apex. Twice, independently this arrangement was segregated into specialized serous protein-secreting glands with thick capsules with the mucous lobules now distinct (Heloderma and the Lanthanotus/Varanus clade). The results obtained

  4. Functional and Structural Diversification of the Anguimorpha Lizard Venom System*

    Science.gov (United States)

    Fry, Bryan G.; Winter, Kelly; Norman, Janette A.; Roelants, Kim; Nabuurs, Rob J. A.; van Osch, Matthias J. P.; Teeuwisse, Wouter M.; van der Weerd, Louise; Mcnaughtan, Judith E.; Kwok, Hang Fai; Scheib, Holger; Greisman, Laura; Kochva, Elazar; Miller, Laurence J.; Gao, Fan; Karas, John; Scanlon, Denis; Lin, Feng; Kuruppu, Sanjaya; Shaw, Chris; Wong, Lily; Hodgson, Wayne C.

    2010-01-01

    Venom has only been recently discovered to be a basal trait of the Anguimorpha lizards. Consequently, very little is known about the timings of toxin recruitment events, venom protein molecular evolution, or even the relative physical diversifications of the venom system itself. A multidisciplinary approach was used to examine the evolution across the full taxonomical range of this ∼130 million-year-old clade. Analysis of cDNA libraries revealed complex venom transcriptomes. Most notably, three new cardioactive peptide toxin types were discovered (celestoxin, cholecystokinin, and YY peptides). The latter two represent additional examples of convergent use of genes in toxic arsenals, both having previously been documented as components of frog skin defensive chemical secretions. Two other novel venom gland-overexpressed modified versions of other protein frameworks were also recovered from the libraries (epididymal secretory protein and ribonuclease). Lectin, hyaluronidase, and veficolin toxin types were sequenced for the first time from lizard venoms and shown to be homologous to the snake venom forms. In contrast, phylogenetic analyses demonstrated that the lizard natriuretic peptide toxins were recruited independently of the form in snake venoms. The de novo evolution of helokinestatin peptide toxin encoding domains within the lizard venom natriuretic gene was revealed to be exclusive to the helodermatid/anguid subclade. New isoforms were sequenced for cysteine-rich secretory protein, kallikrein, and phospholipase A2 toxins. Venom gland morphological analysis revealed extensive evolutionary tinkering. Anguid glands are characterized by thin capsules and mixed glands, serous at the bottom of the lobule and mucous toward the apex. Twice, independently this arrangement was segregated into specialized serous protein-secreting glands with thick capsules with the mucous lobules now distinct (Heloderma and the Lanthanotus/Varanus clade). The results obtained highlight

  5. Condition-dependent chemosignals in reproductive behavior of lizards.

    Science.gov (United States)

    Martín, José; López, Pilar

    2015-02-01

    This article is part of a Special Issue "Chemosignals and Reproduction". Many lizards have diverse glands that produce chemosignals used in intraspecific communication and that can have reproductive consequences. For example, information in chemosignals of male lizards can be used in intrasexual competition to identify and assess the fighting potential or dominance status of rival males either indirectly through territorial scent-marks or during agonistic encounters. Moreover, females of several lizard species "prefer" to establish or spend more time on areas scent-marked by males with compounds signaling a better health or body condition or a higher genetic compatibility, which can have consequences for their mating success and inter-sexual selection processes. We review here recent studies that suggest that the information content of chemosignals of lizards may be reliable because several physiological and endocrine processes would regulate the proportions of chemical compounds available for gland secretions. Because chemosignals are produced by the organism or come from the diet, they should reflect physiological changes, such as different hormonal levels (e.g. testosterone or corticosterone) or different health states (e.g. parasitic infections, immune response), and reflect the quality of the diet of an individual. More importantly, some compounds that may function as chemosignals also have other important functions in the organism (e.g. as antioxidants or regulating the immune system), so there could be trade-offs between allocating these compounds to attending physiological needs or to produce costly sexual "chemical ornaments". All these factors may contribute to maintain chemosignals as condition-dependent sexual signals, which can inform conspecifics on the characteristics and state of the sender and allow making behavioral decisions with reproductive consequences. To understand the evolution of chemical secretions of lizards as sexual signals and their

  6. Detection and characterization of red blood cell (RBC) aggregation with photoacoustics

    Science.gov (United States)

    Hysi, Eno; Saha, Ratan K.; Rui, Min; Kolios, Michael C.

    2012-02-01

    Red blood cells (RBCs) aggregate in the presence of increased plasma fibrinogen and low shear forces during blood flow. RBC aggregation has been observed in deep vein thrombosis, sepsis and diabetes. We propose using photoacoustics (PA) as a non-invasive imaging modality to detect RBC aggregation. The theoretical and experimental feasibility of PA for detecting and characterizing aggregation was assessed. A simulation study was performed to generate PA signals from non-aggregated and aggregated RBCs using a frequency domain approach and to study the PA signals' dependence on hematocrit and aggregate size. The effect of the finite bandwidth nature of transducers on the PA power spectra was also investigated. Experimental confirmation of theoretical results was conducted using porcine RBC samples exposed to 1064 nm optical wavelength using the Imagio Small Animal PA imaging system (Seno Medical Instruments, Inc., San Antonio, TX). Aggregation was induced with Dextran-70 (Sigma-Aldrich, St. Louis, MO) and the effect of hematocrit and aggregation level was investigated. The theoretical and experimental PA signal amplitude increased linearly with increasing hematocrit. The theoretical dominant frequency content of PA signals shifted towards lower frequencies (<30 MHz) and 9 dB enhancements in spectral power were observed as the size of aggregates increased compared to non-aggregating RBCs. Calibration of the PA spectra with the transducer response obtained from a 200 nm gold film was performed to remove system dependencies. Analysis of the spectral parameters from the calibrated spectra suggested that PA can assess the degree of aggregation at multiple hematocrit and aggregation levels.

  7. Molecular evolution of rbcL in three gymnosperm families: identifying adaptive and coevolutionary patterns

    LENUS (Irish Health Repository)

    Sen, Lin

    2011-06-03

    Abstract Background The chloroplast-localized ribulose-1, 5-biphosphate carboxylase\\/oxygenase (Rubisco), the primary enzyme responsible for autotrophy, is instrumental in the continual adaptation of plants to variations in the concentrations of CO2. The large subunit (LSU) of Rubisco is encoded by the chloroplast rbcL gene. Although adaptive processes have been previously identified at this gene, characterizing the relationships between the mutational dynamics at the protein level may yield clues on the biological meaning of such adaptive processes. The role of such coevolutionary dynamics in the continual fine-tuning of RbcL remains obscure. Results We used the timescale and phylogenetic analyses to investigate and search for processes of adaptive evolution in rbcL gene in three gymnosperm families, namely Podocarpaceae, Taxaceae and Cephalotaxaceae. To understand the relationships between regions identified as having evolved under adaptive evolution, we performed coevolutionary analyses using the software CAPS. Importantly, adaptive processes were identified at amino acid sites located on the contact regions among the Rubisco subunits and on the interface between Rubisco and its activase. Adaptive amino acid replacements at these regions may have optimized the holoenzyme activity. This hypothesis was pinpointed by evidence originated from our analysis of coevolution that supported the correlated evolution between Rubisco and its activase. Interestingly, the correlated adaptive processes between both these proteins have paralleled the geological variation history of the concentration of atmospheric CO2. Conclusions The gene rbcL has experienced bursts of adaptations in response to the changing concentration of CO2 in the atmosphere. These adaptations have emerged as a result of a continuous dynamic of mutations, many of which may have involved innovation of functional Rubisco features. Analysis of the protein structure and the functional implications of such

  8. Thrombelastographic evaluation of the influence of 2-RBC apheresis on donor's coagulation system.

    Science.gov (United States)

    Akay, Olga Meltem; Karagulle, Mustafa; Kus, Gokhan; Mutlu, Fezan Sahın; Gunduz, Eren

    2013-06-01

    Rotation thrombelastogram (ROTEM®/TEG®) assays allow rapid global assessment of hemostatic function using whole blood. Since published data about the effects of automated red cell collection on coagulation system are scarce, we aimed to investigate the effects of 2-RBC apheresis on donor's coagulation system using ROTEM® assays. In INTEM assay, CFT was significantly shortened 24h after apheresis compared with baseline value (papheresis and 24h after apheresis compared with baseline value (papheresis and 24h after apheresis compared with baseline value (p=0.001 and papheresis compared with baseline value (papheresis.

  9. Ocular anatomy and retinal photoreceptors in a skink, the sleepy lizard (Tiliqua rugosa).

    Science.gov (United States)

    New, Shaun T D; Hemmi, Jan M; Kerr, Gregory D; Bull, C Michael

    2012-10-01

    The Australian sleepy lizard (Tiliqua rugosa) is a large day-active skink which occupies stable overlapping home ranges and maintains long-term monogamous relationships. Its behavioral ecology has been extensively studied, making the sleepy lizard an ideal model for investigation of the lizard visual system and its specializations, for which relatively little is known. We examine the morphology, density, and distribution of retinal photoreceptors and describe the anatomy of the sleepy lizard eye. The sleepy lizard retina is composed solely of photoreceptors containing oil droplets, a characteristic of cones. Two groups could be distinguished; single cones and double cones, consistent with morphological descriptions of photoreceptors in other diurnal lizards. Although all photoreceptors were cone-like in morphology, a subset of photoreceptors displayed immunoreactivity to rhodopsin-the visual pigment of rods. This finding suggests that while the morphological properties of rod photoreceptors have been lost, photopigment protein composition has been conserved during evolutionary history.

  10. Genetic Analysis of Multiple Paternity in an Endangered Ovoviviparous Lizard Shinisaurus crocodilurus

    Institute of Scientific and Technical Information of China (English)

    Huayuan HUANG; Dan LUO; Cong Guo; Zhuo TANG; Zhengjun WU; Jinping CHEN

    2015-01-01

    The crocodile lizard (Shinisaurus crocodilurus) is an ovoviviparous lizard belonging to a monotypic family that originated during the end of the quaternary ice age. A rare species in the wild, the crocodile lizard was listed in CITES Appendix Ⅱ . Knowledge of the reproductive biology and mating system of this species is important for designing conservation strategies and improving genetic variation. To investigate the paternity of the crocodile lizards and to interpret their reproductive behaviour, we collected saliva from females, potential fathers and offspring in a semi-natural enclosure experiment and analyzed the paternity of the crocodile lizard using 12 microsatellite genetic loci. The overall observed incidence of multiple paternity was 42.9% (6 of 14 clutches) and Fis was 0.089 ± 0.056. These results indicate that the primary mating mode of the crocodile lizard is that males are polygynous while with females are polyandrous, and there is multiple paternity among offspring of the same mother.

  11. Rock-dwelling lizards exhibit less sensitivity of sprint speed to increases in substrate rugosity.

    Science.gov (United States)

    Collins, Clint E; Self, Jessica D; Anderson, Roger A; McBrayer, Lance D

    2013-06-01

    Effectively moving across variable substrates is important to all terrestrial animals. The effects of substrates on lizard performance have ecological ramifications including the partitioning of habitat according to sprinting ability on different surfaces. This phenomenon is known as sprint sensitivity, or the decrease in sprint speed due to change in substrate. However, sprint sensitivity has been characterized only in arboreal Anolis lizards. Our study measured sensitivity to substrate rugosity among six lizard species that occupy rocky, sandy, and/or arboreal habitats. Lizards that use rocky habitats are less sensitive to changes in substrate rugosity, followed by arboreal lizards, and then by lizards that use sandy habitats. We infer from comparative phylogenetic analysis that forelimb, chest, and tail dimensions are important external morphological features related to sensitivity to changes in substrate rugosity.

  12. Medical cautery units as a permanent and non-invasive method of marking lizards

    Directory of Open Access Journals (Sweden)

    Anna Ekner

    2011-12-01

    Full Text Available The identification of previously captured individuals is essential for a wide variety of ecological and behavioural studies. A lot of different methods are used for marking lizards, however they have many drawbacks. In presented study we used heat-branding method, using pen-like medical cautery units, previously employed to successfully mark other lizard species and snakes. The technique is permanent, readable and harmless for lizards, as well quick and easy. In 2009 we marked 111 individuals of sand lizard, Lacerta agilis. Next year we caught 88 lizards, 17 of them were re-captured. Among these re-captured lizards, five were caught after 26.8 (± 16.3 days (means in the same year and 12 after 308.8 (± 64.3 days (means in the next year. Recaptured individuals were still unambiguously recognisable.

  13. Increased metal concentrations in giant sungazer lizards (Smaug giganteus) from mining areas in South Africa.

    Science.gov (United States)

    McIntyre, Trevor; Whiting, Martin J

    2012-11-01

    Environmental contaminants from anthropogenic activity such as mining can have profound health effects on the animals living in adjacent areas. We investigated whether inorganic contaminants associated with gold-mining waste discharges were accumulated by a threatened species of lizard, Smaug giganteus, in South Africa. Lizards were sampled from two mining sites and two control sites. Blood samples from the most contaminated mining site had significantly greater concentrations of lithium, sodium, aluminum, sulfur, silicon, chromium, manganese, iron, nickel, copper, tungsten, and bismuth than the remaining sites. Contaminant concentrations were not significantly related to lizard body condition, although these relationships were consistently negative. The adult sex ratio of the population inhabiting the most contaminated site also deviated from an expected 1:1 ratio in favour of female lizards. We demonstrate that lizards at these mining sites contained high concentrations of heavy metals that may be imposing as yet poorly understood costs to these lizards.

  14. A quality monitoring program for red blood cell components: in vitro quality indicators before and after implementation of semiautomated processing.

    Science.gov (United States)

    Acker, Jason P; Hansen, Adele L; Kurach, Jayme D R; Turner, Tracey R; Croteau, Ioana; Jenkins, Craig

    2014-10-01

    Canadian Blood Services has been conducting quality monitoring of red blood cell (RBC) components since 2005, a period spanning the implementation of semiautomated component production. The aim was to compare the quality of RBC components produced before and after this production method change. Data from 572 RBC units were analyzed, categorized by production method: Method 1, RBC units produced by manual production methods; Method 2, RBC units produced by semiautomated production and the buffy coat method; and Method 3, RBC units produced by semiautomated production and the whole blood filtration method. RBC units were assessed using an extensive panel of in vitro tests, encompassing regulated quality control criteria such as hematocrit (Hct), hemolysis, and hemoglobin (Hb) levels, as well as adenosine triphosphate, 2,3-diphosphoglycerate, extracellular K(+) and Na(+) levels, methemoglobin, p50, RBC indices, and morphology. Throughout the study, all RBC units met mandated Canadian Standards Association guidelines for Hb and Hct, and most (>99%) met hemolysis requirements. However, there were significant differences among RBC units produced using different methods. Hb content was significantly lower in RBC units produced by Method 2 (51.5 ± 5.6 g/unit; p < 0.001). At expiry, hemolysis was lowest in Method 2-produced RBC units (p < 0.05) and extracellular K(+) levels were lowest in units produced by Method 1 (p < 0.001). While overall quality was similar before and after the production method change, the observed differences, although small, indicate a lack of equivalency across RBC products manufactured by different methods. © 2014 AABB.

  15. Segregating variation for temperature-dependent sex determination in a lizard

    OpenAIRE

    Rhen, T; Schroeder, A.; Sakata, J T; Huang, V.; Crews, D.

    2010-01-01

    Temperature-dependent sex determination (TSD) was first reported in 1966 in an African lizard. It has since been shown that TSD occurs in some fish, several lizards, tuataras, numerous turtles and all crocodilians. Extreme temperatures can also cause sex reversal in several amphibians and lizards with genotypic sex determination. Research in TSD species indicates that estrogen signaling is important for ovary development and that orthologs of mammalian genes have a function in gonad different...

  16. Are mountain habitats becoming more suitable for generalist than cold-adapted lizards thermoregulation?

    OpenAIRE

    Zaida Ortega; Abraham Mencía; Valentín Pérez-Mellado

    2016-01-01

    Mountain lizards are highly vulnerable to climate change, and the continuous warming of their habitats could be seriously threatening their survival. We aim to compare the thermal ecology and microhabitat selection of a mountain lizard, Iberolacerta galani, and a widely distributed lizard, Podarcis bocagei, in a montane area. Both species are currently in close syntopy in the study area, at 1,400 m above the sea level. We determined the precision, accuracy and effectiveness of thermoregulatio...

  17. New genus and species names for the Eocene lizard Cadurcogekko rugosus Augé, 2005.

    Science.gov (United States)

    Bolet, Arnau; Daza, Juan D; Augé, Marc; Bauer, Aaron M

    2015-07-10

    Cadurcogekko rugosus Augé, 2005 was described as a gekkotan lizard from the Eocene of France. A revision of the material has revealed that the holotype, a nearly complete dentary, actually belongs to a scincid lizard, for which we erect the new genus Gekkomimus. The rest of material originally referred to C. rugosus is of undoubted gekkotan nature and is included in the new species Cadurcogekko verus, with the exception of a partial left dentary belonging to the iguanid lizard Cadurciguana hoffstetteri.

  18. Quantitative autoradiographic assessment of sup 55 Fe-RBC distribution in rat brain

    Energy Technology Data Exchange (ETDEWEB)

    Lin, S.Z.; Nakata, H.; Tajima, A.; Gruber, K.; Acuff, V.; Patlak, C.; Fenstermacher, J. (State Univ. of New York, Stony Brook (USA))

    1990-11-01

    A simple in vivo technique of labeling erythrocytes (RBCs) with {sup 55}Fe was developed for quantitative autoradiography (QAR). This procedure involved injecting 5-6 ml of ({sup 55}Fe)ferrous citrate solution (1 mCi/ml) intraperitoneally into donor rats. The number of labeled RBCs reached a maximum at around 7 days and declined very slowly thereafter. Labeled RBCs were harvested from donor rats and used for RBC volume measurement in awake rats. Brain radioactivity was assayed by QAR, which yielded spatial resolution of greater than 50 microns. Tight nearly irreversible binding of {sup 55}Fe to RBCs was found in vivo and in vitro. More than 99.5% of the {sup 55}Fe in the blood of donor rats was bound to RBCs. Because of this, labeled blood can be taken from donors and injected into recipients without further preparation. The tissue absorption of {sup 55}Fe emissions was the same in gray and white matter. Microvascular RBC volumes measured with {sup 55}Fe-labeled RBCs agreed with those assayed with {sup 51}Cr-labeled RBCs for many, but not all, brain areas. In conclusion, {sup 55}Fe-RBCs can be readily prepared by this technique and accurately quantitated in brain tissue by QAR.

  19. Asian origin for Polystichum (Dryopteridaceae)based on rbcL sequences

    Institute of Scientific and Technical Information of China (English)

    LI Chunxiang; LU Shugang; YANG Qun

    2004-01-01

    Chloroplast rbcL sequences of 60 species of Polystichum sensu lato (s.l.), including 23 new sequences from southwest China, were used to assess the phylogenetic relationships within the genus. On the basis of estimated evolution rate of rbcL gene and the genetic distance data that passed relative-rate tests, we further estimated the divergence times between some clades of the genus. The phylogenetic relationships were inferred using the neighbor-joining and maximum-parsimony methods, both methods producing trees with completely congruent topology. These trees reveal that all species of Polystichum s.l. in this study (including Cyrtomium and Cyrtomidictyum) form a monophyletic group.The basal split in Polystichum s.l. separates a clade with all Asian members from a clade containing other species from all over the world. The phylogenetic and divergence time estimation results lead us to suggest that Polystichum s.l.originated in Asia in the late Late Cretacous (≈76 Ma) and migrated into other places in the world in early Eocene (≈46 Ma).

  20. Evolutionary switch and genetic convergence on rbcL following the evolution of C4 photosynthesis.

    Science.gov (United States)

    Christin, Pascal-Antoine; Salamin, Nicolas; Muasya, A Muthama; Roalson, Eric H; Russier, Flavien; Besnard, Guillaume

    2008-11-01

    Rubisco is responsible for the fixation of CO2 into organic compounds through photosynthesis and thus has a great agronomic importance. It is well established that this enzyme suffers from a slow catalysis, and its low specificity results into photorespiration, which is considered as an energy waste for the plant. However, natural variations exist, and some Rubisco lineages, such as in C4 plants, exhibit higher catalytic efficiencies coupled to lower specificities. These C4 kinetics could have evolved as an adaptation to the higher CO2 concentration present in C4 photosynthetic cells. In this study, using phylogenetic analyses on a large data set of C3 and C4 monocots, we showed that the rbcL gene, which encodes the large subunit of Rubisco, evolved under positive selection in independent C4 lineages. This confirms that selective pressures on Rubisco have been switched in C4 plants by the high CO2 environment prevailing in their photosynthetic cells. Eight rbcL codons evolving under positive selection in C4 clades were involved in parallel changes among the 23 independent monocot C4 lineages included in this study. These amino acids are potentially responsible for the C4 kinetics, and their identification opens new roads for human-directed Rubisco engineering. The introgression of C4-like high-efficiency Rubisco would strongly enhance C3 crop yields in the future CO2-enriched atmosphere.

  1. Predation Risk Perception, Food Density and Conspecific Cues Shape Foraging Decisions in a Tropical Lizard

    National Research Council Canada - National Science Library

    Drakeley, Maximilian; Lapiedra, Oriol; Kolbe, Jason J

    2015-01-01

    .... We presented male lizards with foraging opportunities to test how the presence of conspecifics, predation-risk perception, the abundance of food, and interactions among these factors determines...

  2. Helminths of the Lizard Salvator merianae (Squamata, Teiidae) in the Caatinga, Northeastern Brazil.

    Science.gov (United States)

    Teixeira, A A M; Brito, S V; Teles, D A; Ribeiro, S C; Araujo-Filho, J A; Lima, V F; Pereira, A M A; Almeida, W O

    2017-01-01

    The lizard Salvator merianae is a widely distributed species in South America, occurring from southern Amazonia to the eastern Andes and northern Patagonia. Studies on the parasitic fauna of this lizard have revealed that it is a host for helminths in various Brazilian biomes. The present work provides new parasitological data on the gastrointestinal nematodes associated with the lizard S. merianae. Sixteen specimens were analyzed from nine different locations in a semi-arid region in northeastern Brazil. Five species of nematodes were identified. Oswaldofilaria petersi was first recorded as a parasite of the S. merianae, thus increasing the knowledge of the fauna of parasites that infect large Neotropical lizards.

  3. Epaxial muscle function during locomotion in a lizard (Varanus salvator) and the proposal of a key innovation in the vertebrate axial musculoskeletal system

    Science.gov (United States)

    Ritter

    1995-01-01

    The pattern of electromyographic activity in the epaxial muscles of walking and running lizards (water monitors, Varanus salvator) was quantified with high-speed video and synchronized electromyography. Muscle denervation experiments were performed and ground reaction forces were recorded to evaluate hypotheses of muscle function. Water monitors exhibit unilateral, uniphasic activation of the epaxial muscles ipsilateral to rear limb support. The iliocostalis and longissimus dorsi muscles are active throughout the support phase of the rear limb, while the transversospinalis is active only during the second half of the support phase. The timing of muscle activity does not support the presumed locomotor function of the epaxial muscles of lizards (lateral bending of the trunk). Bilateral denervation of the two most lateral epaxial muscles (iliocostalis and longissimus dorsi) caused no significant change in the amplitude of lateral trunk bending. These two epaxial muscles do not appear to be necessary for lateral bending of the trunk, nor do they appear to be involved in resisting lateral bending of the trunk. On the basis of the data reported in this study, as well as a re-evaluation of previously existing data, it is proposed that the locomotor function of the epaxial muscles of lizards is to stabilize the trunk against the vertical component of the ground reaction forces; i.e. the epaxial muscles function in a postural role during locomotion in lizards, as they do in other amniotes. This proposed postural role of the epaxial muscles may represent a key innovation of amniotes, made possible by the loss of an aquatic larval stage in their common ancestor.

  4. Technique for measuring speed and visual motion sensitivity in lizards

    Directory of Open Access Journals (Sweden)

    Darren Burke

    2008-01-01

    Full Text Available Testing sensory characteristics on herpetological species has been difficult due to a range of properties related to physiology, responsiveness, performance ability, and the type of reinforcer used. Using the Jacky lizard as a model, we outline a successfully established procedure in which to test the visual sensitivity to motion characteristics. We incorporated modifications to traditional operant paradigms by using three video playback systems to deliver random-dot kinematogram motion stimuli coupled with salient computer-animated secondary reinforcers representative of biologically important appetitive stimuli. This procedure has the capacity to test other visual aspects in lizards as well as other nonhuman species using video playback and computer-animation techniques as experimental tools.

  5. Colorful displays signal male quality in a tropical anole lizard

    Science.gov (United States)

    Cook, Ellee G.; Murphy, Troy G.; Johnson, Michele A.

    2013-10-01

    Parasites influence colorful ornaments and their behavioral display in many animal hosts. Because coloration and display behavior are often critical components of communication, variation in these traits may have important implications for individual fitness, yet it remains unclear whether such traits are signals of quality in many taxa. We investigated the association between ectoparasitic mite load and the color and behavioral use of the throat fan (dewlap) by male Anolis brevirostris lizards. We found that heavily parasitized lizards exhibited lower body condition, duller dewlaps, and less frequent dewlap displays than less parasitized individuals. Our results thus suggest that highly parasitized individuals invest less in both ornamental color and behavioral display of that color. Because the two components of the signal simultaneously provide information on male quality, this study provides novel support for the long-standing hypothesis that colorful traits may function as social or sexual signals in reptiles.

  6. Physiological ecology of frillneck lizards in a seasonal tropical environment.

    Science.gov (United States)

    Christian, Keith A; Griffiths, Anthony D; Bedford, Gavin S

    1996-04-01

    The frillneck lizard, Chlamydosaurus kingii, is a conspicuous component of the fauna of the wetdry tropics of northern Australia during the wet season, but it is rarely seen in the dry season. Previous studies have demonstrated that during the dry season the field metabolic rate (FMR) is only about one-quarter of the wet-season rate, and one factor involved in this seasonal drop is a change in the behavioural thermoregulation of the species such that lower body temperatures (T bs) are selected during dry-season days. Here we examine other factors that could be responsible for the seasonal change in FMR: standard metabolic rates (SMR) and activity. Samples from stomach flushing revealed that the lizards in the dry season continued to feed, but the volume of food was half as much as in the wet season. SMR in the laboratory was 30% less in the dry season. During the dry season, the energy expended by the lizards is 60.4 kJ kg(-1) day(-1) less than during the wet season. Combining laboratory and field data, we determined the relative contribution of the factors involved in this energy savings: 10% can be attributed to lower nighttime T b, 12% is attributable to lower daytime T b, 12% is attributable to decreased metabolism, and the remaining 66% is attributable to other activities (including e.g. locomotion, reproductive costs, digestion). Calculations indicate that if FMR did not drop in the dry season the lizards would not survive on the observed food intake during this season. Seasonal analysis of blood plasma and urine indicated an accumulation of some electrolytes during the dry season suggesting modest levels of water stress.

  7. 青杄 PwRbcS 基因克隆及对逆境响应分析%Cloning and Stress Response Analysis of PwRbcS in Picea wilsonii

    Institute of Scientific and Technical Information of China (English)

    鞠丹; 胡安妮; 张杰; 张凌云

    2016-01-01

    RbcS 基因编码了植物光合作用中核酮糖1,5二磷酸羧化酶/加氧酶的亚基,这种酶能催化二氧化碳的固定和碳氧化两者之间竞争反应。本实验中通过 RACE-PCR 方法成功获得了青杄 RbcS 的 cDNA 全长,对 PwRbcS 的 cDNA 序列进行了生物信息学分析预测,同时利用实时定量 PCR 技术测定青杄各个组织及非生物胁迫下 PwRbcS 的表达水平。结果表明:PwRbcS 基因cDNA 全长936 bp,编码区共552 bp,共编码186个氨基酸。蛋白质分子量为20.7126 kD,等电点为9.07。组织特异性表达结果发现 PwRbcS 该基因主要在叶片中表达,且成熟叶表达量最高。非生物胁迫实验结果表明,ABA 和 NaCl 以及低温处理处理下响应十分明显。在 NaCl 处理下,表达量先上升后下降,处理6 h 时达到对照的14倍,施加 ABA 时,在处理8 h 时上升至对照的24倍,低温胁迫下,表达量先上升后下降,6 h 达到对照的12倍,而高温胁迫及 PEG(polyethylene glycol)下表达量变化不明显。因此PwRbcS 作为一个在木本植物青杄中发现的新的 RbcS 基因,可能在青杄逆境响应中行使一定的功能。%RbcS gene encodes a subunit of nuclear plant photosynthesis 1,5 two ribulose bisphosphate carboxylase / oxygenase. In this study,PwRbcS cDNA was obtained using RACE -PCR method. Bioinformatics analysis and real-time PCR technique were used to determine the relative expression of PwRbcS. The results showed that the full-length of PwRbcS cDNA was 936 bp,including the ORF of 552 bp encoding 186 amino acids. The theoretical molecular weight of PwRbcS is 20.712 6 kD and the pI value was 9.07. RT-qPCR showed that PwRbcS is mainly expressed in the needles,especially in mature needles. The expression of PwRbcS changed obviously under the treatment of NaCl,ABA and low temperature,respectively. After NaCl treatment,the expression level of PwRbcS changed significantly,reaching to 14 times

  8. Study on Ericaceae Plants and Analysis of Rubisco large subunit (RbcL)%杜鹃花科植物及其 Rubisco 大亚基(RbcL)初探

    Institute of Scientific and Technical Information of China (English)

    周晓馥; 陈思霖; 武慧; 徐洪伟

    2016-01-01

    Ericaceae is a kind of woody plants widely distributed around the world .It is not only the landscape plants worldwide,but also has significant economic and medicinal value .Ribulose-1,5-bisphosphate carboxylase/oxygenase ( Rubisco ) is involved in the assimilation of CO2 and also closely related to photosynthesis and photorespiration in plants.The catalytic sites of Rubisco mainly located in the Rubisco large subunit (RbcL),so it has a great significance to study the structure and character of RbcL .The existing Ericaceae plants in China and the RbcL obtained from NCBI were classified in the present study .This study not only lay a solid foundation for further research into the structure and character of RbcL as well as the photosynthesis mechanism of Ericaceae ,but also has great significance in the conservation ,development and utilization of plant resources .%杜鹃花科( Ericaceae )植物为木本植物,在世界范围内分布十分广泛,其不仅是世界主要的观赏花卉,而且还具有重要的经济价值和药用价值。核酮糖-1,5-二磷酸羧化酶/加氧酶( Ribulose-1,5-bisphosphate carbox-ylase/oxygenase,Rubisco)参与CO2的同化,与植物的光合作用和光呼吸密切相关,而Rubisco具有催化活性的位点主要位于Rubisco大亚基(RbcL),因此对于RbcL的研究显得尤为重要。该研究对截至2016年5月1日,我国现存的杜鹃花科植物进行了分类,同时对从NCBI中获得的杜鹃花科RbcL条目进行了统计及分类。这不仅为更好地剖析杜鹃花科植物光合作用机理及RbcL结构和功能的研究奠定基础,同时对于珍惜植物资源的保护、开发和利用具有重要意义。

  9. Climatic control of trophic interaction strength: the effect of lizards on spiders.

    Science.gov (United States)

    Spiller, David A; Schoener, Thomas W

    2008-01-01

    We investigated how temporal variation in rainfall influences the impact of lizards on spiders inhabiting small islands in Abaco, Bahamas. Annual censuses of web spiders were conducted on nine lizard islands and on eight no-lizard islands 1994-2003. Repeated-measures ANOVA showed that annual variation in spider density (time) and in the lizard effect on spider density (lizard x time) were both significant. Correlation coefficients between the lizard effect (ln ratio of no-lizard to lizard spider densities) and number of rainfall days were generally negative, and strengthened with length of the time period during which rainfall was measured prior to annual spider censuses. Spider density was also negatively correlated with rainfall days and strengthened with length of the prior time period. Longer time intervals included the hurricane season, suggesting that the strong negative correlations were linked to high rainfall years during which tropical storms impacted the region and reduced spider and lizard densities. Split-plot ANOVA showed that rainfall during the hurricane season had a significant effect on the lizard effect and on spider density. Results in this study are opposite to those found in our previous 10-year study (1981-1990) conducted in the Exuma Cays, a moderately xeric region of the Bahamas, where the relation between rainfall and the lizard effect on spider density was positive. Combined data from the Exuma and Abaco studies produce a unimodal relation between trophic interaction strength and rainfall; we suggest that the negative effect of storms associated with rainfall was paramount in the present study, whereas the positive bottom-up effect of rainfall prevailed in our previous study. We conclude that climatic variability has a major impact on the trophic interaction and suggest that a substantial change in precipitation in either direction may weaken the interaction significantly.

  10. Species composition, richness and nestedness of lizard assemblages from Restinga habitats along the brazilian coast.

    Science.gov (United States)

    Rocha, C F D; Vrcibradic, D; Kiefer, M C; Menezes, V A; Fontes, A F; Hatano, F H; Galdino, C A B; Bergallo, H G; Van Sluys, M

    2014-05-01

    Habitat fragmentation is well known to adversely affect species living in the remaining, relatively isolated, habitat patches, especially for those having small range size and low density. This negative effect has been critical in coastal resting habitats. We analysed the lizard composition and richness of restinga habitats in 16 restinga habitats encompassing three Brazilian states (Rio de Janeiro, Espírito Santo and Bahia) and more than 1500km of the Brazilian coast in order to evaluate if the loss of lizard species following habitat reduction occur in a nested pattern or at random, using the "Nestedness Temperature Calculator" to analyse the distribution pattern of lizard species among the restingas studied. We also estimated the potential capacity that each restinga has to maintain lizard species. Eleven lizard species were recorded in the restingas, although not all species occurred in all areas. The restinga with the richest lizard fauna was Guriri (eight species) whereas the restinga with the lowest richness was Praia do Sul (located at Ilha Grande, a large coastal island). Among the restingas analysed, Jurubatiba, Guriri, Maricá and Praia das Neves, were the most hospitable for lizards. The matrix community temperature of the lizard assemblages was 20.49° (= P lizard assemblages in the coastal restingas exhibited a considerable nested structure. The degree in which an area is hospitable for different assemblages could be used to suggest those with greater value of conservation. We concluded that lizard assemblages in coastal restingas occur at a considerable level of ordination in restinga habitats and that some restinga areas such as Jurubatiba, Guriri, Maricá and Praia das Neves are quite important to preserve lizard diversity of restinga environments.

  11. Species composition, richness and nestedness of lizard assemblages from Restinga habitats along the brazilian coast

    Directory of Open Access Journals (Sweden)

    CFD. Rocha

    Full Text Available Habitat fragmentation is well known to adversely affect species living in the remaining, relatively isolated, habitat patches, especially for those having small range size and low density. This negative effect has been critical in coastal resting habitats. We analysed the lizard composition and richness of restinga habitats in 16 restinga habitats encompassing three Brazilian states (Rio de Janeiro, Espírito Santo and Bahia and more than 1500km of the Brazilian coast in order to evaluate if the loss of lizard species following habitat reduction occur in a nested pattern or at random, using the “Nestedness Temperature Calculator” to analyse the distribution pattern of lizard species among the restingas studied. We also estimated the potential capacity that each restinga has to maintain lizard species. Eleven lizard species were recorded in the restingas, although not all species occurred in all areas. The restinga with the richest lizard fauna was Guriri (eight species whereas the restinga with the lowest richness was Praia do Sul (located at Ilha Grande, a large coastal island. Among the restingas analysed, Jurubatiba, Guriri, Maricá and Praia das Neves, were the most hospitable for lizards. The matrix community temperature of the lizard assemblages was 20.49° (= P <0.00001; 5000 randomisations; randomisation temperature = 51.45° ± 7.18° SD, indicating that lizard assemblages in the coastal restingas exhibited a considerable nested structure. The degree in which an area is hospitable for different assemblages could be used to suggest those with greater value of conservation. We concluded that lizard assemblages in coastal restingas occur at a considerable level of ordination in restinga habitats and that some restinga areas such as Jurubatiba, Guriri, Maricá and Praia das Neves are quite important to preserve lizard diversity of restinga environments.

  12. Eating lizards: a millenary habit evidenced by Paleoparasitology

    Directory of Open Access Journals (Sweden)

    Sianto Luciana

    2012-10-01

    Full Text Available Abstract Background Analyses of coprolites have contributed to the knowledge of diet as well as infectious diseases in ancient populations. Results of paleoparasitological studies showed that prehistoric groups were exposed to spurious and zoonotic parasites, especially food-related. Here we report the findings of a paleoparasitological study carried out in remote regions of Brazil’s Northeast. Findings Eggs of Pharyngodonidae (Nematoda, Oxyuroidea, a family of parasites of lizards and amphibians, were found in four human coprolites collected from three archaeological sites. In one of these, lizard scales were also found. Conclusions Through the finding of eggs of Pharyngodonidae in human coprolites and reptile scales in one of these, we have provided evidence that humans have consumed reptiles at least 10,000 years ago. This food habit persists to modern times in remote regions of Brazil’s Northeast. Although Pharyngodonidae species are not known to infect humans, the consumption of raw or undercooked meat from lizards and other reptiles may have led to transmission of a wide range of zoonotic agents to humans in the past.

  13. The first iguanian lizard from the Mesozoic of Africa

    Science.gov (United States)

    Daza, Juan D.; Simões, Tiago R.; Rage, Jean Claude

    2016-01-01

    The fossil record shows that iguanian lizards were widely distributed during the Late Cretaceous. However, the biogeographic history and early evolution of one of its most diverse and peculiar clades (acrodontans) remain poorly known. Here, we present the first Mesozoic acrodontan from Africa, which also represents the oldest iguanian lizard from that continent. The new taxon comes from the Kem Kem Beds in Morocco (Cenomanian, Late Cretaceous) and is based on a partial lower jaw. The new taxon presents a number of features that are found only among acrodontan lizards and shares greatest similarities with uromastycines, specifically. In a combined evidence phylogenetic dataset comprehensive of all major acrodontan lineages using multiple tree inference methods (traditional and implied weighting maximum-parsimony, and Bayesian inference), we found support for the placement of the new species within uromastycines, along with Gueragama sulamericana (Late Cretaceous of Brazil). The new fossil supports the previously hypothesized widespread geographical distribution of acrodontans in Gondwana during the Mesozoic. Additionally, it provides the first fossil evidence of uromastycines in the Cretaceous, and the ancestry of acrodontan iguanians in Africa. PMID:27703708

  14. Fear no colors? Observer clothing color influences lizard escape behavior.

    Science.gov (United States)

    Putman, Breanna J; Drury, Jonathan P; Blumstein, Daniel T; Pauly, Gregory B

    2017-01-01

    Animals often view humans as predators, leading to alterations in their behavior. Even nuanced aspects of human activity like clothing color affect animal behavior, but we lack an understanding of when and where such effects will occur. The species confidence hypothesis posits that birds are attracted to colors found on their bodies and repelled by non-body colors. Here, we extend this hypothesis taxonomically and conceptually to test whether this pattern is applicable in a non-avian reptile and to suggest that species should respond less fearfully to their sexually-selected signaling color. Responses to clothing color could also be impacted by habituation to humans, so we examine whether behavior varied between areas with low and high human activity. We quantified the effects of four T-shirt colors on flight initiation distances (FID) and on the ease of capture in western fence lizards (Sceloporus occidentalis), and we accounted for detectability against the background environment. We found no differences in lizard behavior between sites. However, lizards tolerated the closest approaches and were most likely to be captured when approached with the T-shirt that resembled their sexually-selected signaling color. Because changes in individual behavior affect fitness, choice of clothing color by people, including tourists, hikers, and researchers, could impact wildlife populations and research outcomes.

  15. Morphology of the feeding system in agamid lizards: ecological correlates.

    Science.gov (United States)

    Herrel, A; Aerts, P; Fret, J; de Vree, F

    1999-04-01

    The interaction of organismal design with ecology, and its evolutionary development are the subject of many functional and ecomorphological studies. Many studies have shown that the morphology and mechanics of the masticatory apparatus in mammals are adapted to diet. To investigate the relations between diet and the morphological and physiological properties of the lizard jaw system, a detailed analysis of the structure of the jaw apparatus was undertaken in the insectivorous lizard Plocederma stellio and in closely related herbivorous lizards of the genus Uromastix. The morphological and physiological properties of the jaw system in P. stellio and U. aegyptius were studied by means of dissections, light microscopy, histochemical characterisations, and in vivo stimulation experiments. The skull of Uromastix seems to be built for forceful biting (high, short snout). Additionally, the pterygoid muscle is modified in P. stellio, resulting in an additional force component during static biting. Stimulation experiments indicate that jaw muscles in both species are fast, which is supported by histochemical stainings. However, the oxidative capacity of the jaw muscles is larger in Uromastix. Contraction characteristics and performance of the feeding system (force output) are clearly thermally dependent. We conclude that several characteristics of the jaw system (presence of extra portion of the pterygoid muscle, large oxidative capacity of jaw muscles) in Uromastix may be attributed to its herbivorous diet. Jaw muscles, however, are still faster than expected. This is presumably the result of trade-offs between the thermal characteristics of the jaw adductors and the herbivorous lifestyle of these animals.

  16. Behavioural flexibility and problem-solving in a tropical lizard.

    Science.gov (United States)

    Leal, Manuel; Powell, Brian J

    2012-02-23

    The role of behavioural flexibility in responding to new or changing environmental challenges is a central theme in cognitive ecology. Studies of behavioural flexibility have focused mostly on mammals and birds because theory predicts that behavioural flexibility is favoured in species or clades that exploit a diversity of habitats or food sources and/or have complex social structure, attributes not associated with ectothermic vertebrates. Here, we present the results of a series of experiments designed to test cognitive abilities across multiple cognitive modules in a tropical arboreal lizard: Anolis evermanni. This lizard shows behavioural flexibility across multiple cognitive tasks, including solving a novel motor task using multiple strategies and reversal learning, as well as rapid associative learning. This flexibility was unexpected because lizards are commonly believed to have limited cognitive abilities and highly stereotyped behaviour. Our findings indicate that the cognitive abilities of A. evermanni are comparable with those of some endothermic species that are recognized to be highly flexible, and strongly suggest a re-thinking of our understanding of the cognitive abilities of ectothermic tetrapods and of the factors favouring the evolution of behavioural flexibility.

  17. Polyandry in dragon lizards: inbred paternal genotypes sire fewer offspring.

    Science.gov (United States)

    Frère, Celine H; Chandrasoma, Dani; Whiting, Martin J

    2015-04-01

    Multiple mating in female animals is something of a paradox because it can either be risky (e.g., higher probability of disease transmission, social costs) or provide substantial fitness benefits (e.g., genetic bet hedging whereby the likelihood of reproductive failure is lowered). The genetic relatedness of parental units, particularly in lizards, has rarely been studied in the wild. Here, we examined levels of multiple paternity in Australia's largest agamid lizard, the eastern water dragon (Intellagama lesueurii), and determined whether male reproductive success is best explained by its heterozygosity coefficient or the extent to which it is related to the mother. Female polyandry was the norm: 2/22 clutches (9.2%) were sired by three or more fathers, 17/22 (77.2%) were sired by two fathers, and only 3/22 (13.6%) clutches were sired by one father. Moreover, we reconstructed the paternal genotypes for 18 known mother-offspring clutches and found no evidence that females were favoring less related males or that less related males had higher fitness. However, males with greater heterozygosity sired more offspring. While the postcopulatory mechanisms underlying this pattern are not understood, female water dragons likely represent another example of reproduction through cryptic means (sperm selection/sperm competition) in a lizard, and through which they may ameliorate the effects of male-driven precopulatory sexual selection.

  18. The first iguanian lizard from the Mesozoic of Africa.

    Science.gov (United States)

    Apesteguía, Sebastián; Daza, Juan D; Simões, Tiago R; Rage, Jean Claude

    2016-09-01

    The fossil record shows that iguanian lizards were widely distributed during the Late Cretaceous. However, the biogeographic history and early evolution of one of its most diverse and peculiar clades (acrodontans) remain poorly known. Here, we present the first Mesozoic acrodontan from Africa, which also represents the oldest iguanian lizard from that continent. The new taxon comes from the Kem Kem Beds in Morocco (Cenomanian, Late Cretaceous) and is based on a partial lower jaw. The new taxon presents a number of features that are found only among acrodontan lizards and shares greatest similarities with uromastycines, specifically. In a combined evidence phylogenetic dataset comprehensive of all major acrodontan lineages using multiple tree inference methods (traditional and implied weighting maximum-parsimony, and Bayesian inference), we found support for the placement of the new species within uromastycines, along with Gueragama sulamericana (Late Cretaceous of Brazil). The new fossil supports the previously hypothesized widespread geographical distribution of acrodontans in Gondwana during the Mesozoic. Additionally, it provides the first fossil evidence of uromastycines in the Cretaceous, and the ancestry of acrodontan iguanians in Africa.

  19. Remote sensing as a tool to analyse lizards behaviour

    Science.gov (United States)

    Dos Santos, Remi; Teodoro, Ana C.; Carretero, Miguel; Sillero, Neftalí

    2016-10-01

    Although the spatial context is expected to be a major influence in the interactions among organisms and their environment, it is commonly ignored in ecological studies. This study is part of an investigation on home ranges and their influence in the escape behaviour of Iberian lizards. Fieldwork was conducted inside a 400 m2 mesocosm, using three acclimatized adult male individuals. In order to perform analyses at this local scale, tools with high spatial accuracy are needed. A total of 3016 GPS points were recorded and processed into a Digital Elevation Model (DEM), with a pixel resolution of 2 cm. Then, 1156 aerial photos were taken and processed to create an orthophoto. A refuge map, containing possible locations for retreats was generated with supervised image classification algorithms, obtaining four classes (refuges, vegetation, bare soil and organic soil). Furthermore, 50 data-loggers were randomly placed, recording evenly through the area temperature and humidity every 15'. After a month of recording, all environmental variables were interpolated using Kriging. The study area presented an irregular elevation. The humidity varied according to the topography and the temperature presented a West-East pattern. Both variables are of paramount importance for lizard activity and performance. In a predation risk scenario, a lizard located in a temperature close to its thermal optimum will be able to escape more efficiently. Integration of such ecologically relevant elements in a spatial context exemplifies how remote sensing tools can contribute to improve inference in behavioural ecology.

  20. The first iguanian lizard from the Mesozoic of Africa

    Science.gov (United States)

    Apesteguía, Sebastián; Daza, Juan D.; Simões, Tiago R.; Rage, Jean Claude

    2016-09-01

    The fossil record shows that iguanian lizards were widely distributed during the Late Cretaceous. However, the biogeographic history and early evolution of one of its most diverse and peculiar clades (acrodontans) remain poorly known. Here, we present the first Mesozoic acrodontan from Africa, which also represents the oldest iguanian lizard from that continent. The new taxon comes from the Kem Kem Beds in Morocco (Cenomanian, Late Cretaceous) and is based on a partial lower jaw. The new taxon presents a number of features that are found only among acrodontan lizards and shares greatest similarities with uromastycines, specifically. In a combined evidence phylogenetic dataset comprehensive of all major acrodontan lineages using multiple tree inference methods (traditional and implied weighting maximum-parsimony, and Bayesian inference), we found support for the placement of the new species within uromastycines, along with Gueragama sulamericana (Late Cretaceous of Brazil). The new fossil supports the previously hypothesized widespread geographical distribution of acrodontans in Gondwana during the Mesozoic. Additionally, it provides the first fossil evidence of uromastycines in the Cretaceous, and the ancestry of acrodontan iguanians in Africa.

  1. Age-dependent social learning in a lizard.

    Science.gov (United States)

    Noble, Daniel W A; Byrne, Richard W; Whiting, Martin J

    2014-07-01

    Evidence of social learning, whereby the actions of an animal facilitate the acquisition of new information by another, is taxonomically biased towards mammals, especially primates, and birds. However, social learning need not be limited to group-living animals because species with less interaction can still benefit from learning about potential predators, food sources, rivals and mates. We trained male skinks (Eulamprus quoyii), a mostly solitary lizard from eastern Australia, in a two-step foraging task. Lizards belonging to 'young' and 'old' age classes were presented with a novel instrumental task (displacing a lid) and an association task (reward under blue lid). We did not find evidence for age-dependent learning of the instrumental task; however, young males in the presence of a demonstrator learnt the association task faster than young males without a demonstrator, whereas old males in both treatments had similar success rates. We present the first evidence of age-dependent social learning in a lizard and suggest that the use of social information for learning may be more widespread than previously believed.

  2. The usefulness of mesocosms for ecotoxicity testing with lacertid lizards

    Directory of Open Access Journals (Sweden)

    Maria José Amaral

    2012-12-01

    Full Text Available Mesocosms (i.e., outdoor, man-made representations of natural ecosystems have seldom been used to study the impact of contaminants on terrestrial ecosystems. However, mesocosms can be a useful tool to provide a link between field and laboratory studies. We exposed juvenile lacertid lizards for a period of over one year to pesticides (herbicides and insecticides in mesocosm enclosures with the intention of validating field observations obtained in a previous study that examined the effects of corn pesticides in Podarcis bocagei. Our treatments replicated field conditions and consisted of a control, an herbicides only treatment (alachlor, terbuthylazine, mesotrione and glyphosate and an herbicides and insecticide treatment (including chlorpyrifos. We used a multi-biomarker approach that examined parameters at an individual and sub-individual level, including growth, locomotor performance, standard metabolic rate, biomarkers of oxidative stress, esterases and liver histopathologies. Although mortality over the course of the exposures was high (over 60%, surviving individuals prospered relatively well in the mesocosms and displayed a broad range of natural behaviours. The low numbers of replicate animals compromised many of the statistical comparisons, but in general, surviving lizards exposed to pesticides in mesocosm enclosures for over one year, thrived, and displayed few effects of pesticide exposure. Despite the difficulties, this work acts as an important stepping-stone for future ecotoxicology studies using lizards.

  3. 75 FR 9377 - Endangered and Threatened Wildlife and Plants; Listing the Flat-Tailed Horned Lizard as Threatened

    Science.gov (United States)

    2010-03-02

    ... Flat- Tailed Horned Lizard as Threatened AGENCY: Fish and Wildlife Service, Interior. ACTION..., proposed rule to list the flat-tailed horned lizard (Phrynosoma mcallii) as threatened under the Endangered..., 1993 (58 FR 62624), to list the flat-tailed horned lizard as a threatened species, and reopens...

  4. Tests of the contribution of acclimation to geographic variation in water loss rates of the West Indian lizard Anolis cristatellus.

    Science.gov (United States)

    Gunderson, Alex R; Siegel, Jeremy; Leal, Manuel

    2011-10-01

    Phenotypic plasticity can contribute to the process of adaptive radiation by facilitating population persistence in novel environments. West Indian Anolis lizards provide a classic example of an adaptive radiation, in which divergence has occurred along two primary ecological axes: structural microhabitat and climate. Adaptive plasticity in limb morphology is hypothesized to have facilitated divergence along the structural niche axis in Anolis, but very little work has explored plasticity in physiological traits. Here, we experimentally ask whether Puerto Rican Anolis cristatellus from mesic and xeric habitats differ in desiccation rates, and whether these lizards exhibit an acclimation response to changes in relative humidity. We first present microclimatic data collected at lizard perch sites that demonstrate that abiotic conditions experienced by lizards differ between mesic and xeric habitat types. In Experiment 1, we measured desiccation rates of lizards from both habitats maintained under identical laboratory conditions. This experiment demonstrated that desiccation rates differ between populations; xeric lizards lose water more slowly than mesic lizards. In Experiment 2, lizards from each habitat were either maintained under the conditions of Experiment 1, or under extremely low relative humidity. Desiccation rates did not differ between lizards from the same habitat maintained under different treatments and xeric lizards maintained lower desiccation rates than mesic lizards within each treatment. Our results demonstrate that A. cristatellus does not exhibit an acclimation response to abrupt changes of hydric conditions, and suggest that tropical Anolis lizards might be unable to exhibit physiological plasticity in desiccation rates in response to varying climatic conditions.

  5. A comparative analysis on ranking insurance firms using RBC and CAMELS

    Directory of Open Access Journals (Sweden)

    Zahra Houshmand Neghabi

    2012-10-01

    Full Text Available Ranking insurance firms plays an important role on choosing the most appropriate company for receiving appropriate services especially long term insurances such as life insurances. The proposed model of this paper uses two well-known methods of CAMELS and RBC to rank 18 active private and governmental insurance firms in Iran over the period of 2009-2011. The results of Spearman test imply that there is no meaningful difference between these two methods for year 2010 and year 2011 and according to Freedman test, there is not meaningful difference between these two methods in any three years of 2009, 2010 and 2011. In summary, we can conclude that the results of both methods could be used in practice.

  6. Diagnostic de défauts par l'approche RBC ratio

    OpenAIRE

    Mnassri, Baligh; Ouladsine, Mustapha; El Adel, El Mostafa

    2012-01-01

    International audience; Dans le cadre de l'ACP, les concepts de détectabilité et d'isolabilité de défauts ont été développés plus particulièrement pour quelques indices de détection. Dans ce papier, nous avons étendu ces concepts afin d'être unifiés et valables pour tout indice ayant une forme quadratique. L'approche RBC a été utilisée pour le diagnostic de défauts unidimensionnels de grandes amplitudes. En revanche, les défauts peuvent être dans plusieurs directions. Pour cala, nous avons pr...

  7. Phylogenetic studies of the core Alismatales inferred from morphology and rbcL sequences

    Institute of Scientific and Technical Information of China (English)

    Xiaoxian Li; Zhekun Zhou

    2009-01-01

    The phylogeny of Alismatales remains an area of deep uncertainty, with different arrangements being found in studies that examined various subsets of genes and taxa. Herein we conducted separate and combined analyses of 103 morphological characters and 52 rbcL sequences to explore the controversial phylogenies of the families. Congruence between the two data sets was explored by computing several indices. Morphological data sets contain poor phylogenetic signals. The homology of morphological characters was tested based on the total evidence of phylogeny. The ineongruence between DNA and morphological results; the hypothesis of the 'Cymodoceaceae complex'; the relationships between Najadaceae and Hydrocharitaceae; the intergeneric relationships of Hydrocharitaceae; and the evo-lutionary convergence of morphological characters were analyzed and discussed.

  8. Developmental and organ-specific changes in promoter DNA-protein interactions in the tomato rbcS gene family.

    Science.gov (United States)

    Manzara, T; Carrasco, P; Gruissem, W

    1991-12-01

    The five genes encoding ribulose-1,5-bisphosphate carboxylase (rbcS) from tomato are differentially expressed. Transcription of the genes is organ specific and developmentally regulated in fruit and light regulated in cotyledons and leaves. DNase I footprinting assays were used to map multiple sites of DNA-protein interaction in the promoter regions of all five genes and to determine whether the differential transcriptional activity of each gene correlated with developmental or organ-specific changes in DNA-protein interactions. We show organ-specific differences in DNase I protection patterns, suggesting that differential transcription of rbcS genes is controlled at least in part at the level of DNA-protein interactions. In contrast, no changes were detected in the DNase I footprint pattern generated with nuclear extracts from dark-grown cotyledons versus cotyledons exposed to light, implying that light-dependent regulation of rbcS transcription is controlled by protein-protein interactions or modification of DNA binding proteins. During development of tomato fruit, most DNA-protein interactions in the rbcS promoter regions disappear, coincident with the transcriptional inactivation of the rbcS genes. In nuclear extracts from nonphotosynthetic roots and red fruit, the only detectable DNase I protection corresponds to a G-box binding activity. Detection of other DNA binding proteins in extracts from these organs and expression of nonphotosynthetic genes exclude the possibility that roots and red fruit are transcriptionally inactive. The absence of complex promoter protection patterns in these organs suggests either that cooperative interactions between different DNA binding proteins are necessary to form functional transcription complexes or that there is developmental and organ-specific regulation of several rbcS-specific transcription factors in these organs. The DNase I-protected DNA sequences defined in this study are discussed in the context of conserved DNA

  9. Choroideremia Is a Systemic Disease With Lymphocyte Crystals and Plasma Lipid and RBC Membrane Abnormalities

    Science.gov (United States)

    Zhang, Alice Yang; Mysore, Naveen; Vali, Hojatollah; Koenekoop, Jamie; Cao, Sang Ni; Li, Shen; Ren, Huanan; Keser, Vafa; Lopez-Solache, Irma; Siddiqui, Sorath Noorani; Khan, Ayesha; Mui, Jeannie; Sears, Kelly; Dixon, Jim; Schwartzentruber, Jeremy; Majewski, Jacek; Braverman, Nancy; Koenekoop, Robert K.

    2015-01-01

    Purpose Photoreceptor neuronal degenerations are common, incurable causes of human blindness affecting 1 in 2000 patients worldwide. Only half of all patients are associated with known mutations in over 250 disease genes, prompting our research program to identify the remaining new genes. Most retinal degenerations are restricted to the retina, but photoreceptor degenerations can also be found in a wide variety of systemic diseases. We identified an X-linked family from Sri Lanka with a severe choroidal degeneration and postulated a new disease entity. Because of phenotypic overlaps with Bietti's crystalline dystrophy, which was recently found to have systemic features, we hypothesized that a systemic disease may be present in this new disease as well. Methods For phenotyping, we performed detailed eye exams with in vivo retinal imaging by optical coherence tomography. For genotyping, we performed whole exome sequencing, followed by Sanger sequencing confirmations and cosegregation. Systemic investigations included electron microscopy studies of peripheral blood cells in patients and in normal controls and detailed fatty acid profiles (both plasma and red blood cell [RBC] membranes). Fatty acid levels were compared to normal controls, and only values two standard deviations above or below normal controls were further evaluated. Results The family segregated a REP1 mutation, suggesting choroideremia (CHM). We then found crystals in peripheral blood lymphocytes and discovered significant plasma fatty acid abnormalities and RBC membrane abnormalities (i.e., elevated plasmalogens). To replicate our discoveries, we expanded the cohort to nine CHM patients, genotyped them for REP1 mutations, and found the same abnormalities (crystals and fatty acid abnormalities) in all patients. Conclusions Previously, CHM was thought to be restricted to the retina. We show, to our knowledge for the first time, that CHM is a systemic condition with prominent crystals in lymphocytes and

  10. 76 FR 19304 - Endangered and Threatened Wildlife and Plants; Endangered Status for Dunes Sagebrush Lizard

    Science.gov (United States)

    2011-04-07

    ... Fish and Wildlife Service 50 CFR Part 17 RIN 1018-AV97 Endangered and Threatened Wildlife and Plants; Endangered Status for Dunes Sagebrush Lizard AGENCY: Fish and Wildlife Service, Interior. ACTION: Proposed... rule to list the dunes sagebrush lizard (Sceloporus arenicolus) under the Endangered Species Act...

  11. Predicting micro thermal habitat of lizards in a dynamic thermal environment

    NARCIS (Netherlands)

    Fei, T.; Skidmore, A.K.; Venus, V.; Wang, T.; Toxopeus, A.G.; Bian, B.M.; Liu, Y.

    2012-01-01

    Understanding behavioural thermoregulation and its consequences is a central topic in ecology. In this study, a spatial explicit model was developed to simulate the movement and thermal habitat use of lizards in a controlled environment. The model incorporates a lizard's transient body temperatures

  12. A new scincid lizard of the genus Tribolonotus from Manus Island, New Guinea

    NARCIS (Netherlands)

    Cogger, H.G.

    1972-01-01

    INTRODUCTION The scincid lizards of the genus Tribolonotus are generally dull-coloured, armoured, thigmothermic, cryptozoic lizards with several unique features in their morphology and biology. These features include the possession of abdominal glands and volar pores, a vestigial left oviduct, the p

  13. Impact of the experimental removal of lizards on Lyme disease risk.

    Science.gov (United States)

    Swei, Andrea; Ostfeld, Richard S; Lane, Robert S; Briggs, Cheryl J

    2011-10-07

    The distribution of vector meals in the host community is an important element of understanding and predicting vector-borne disease risk. Lizards (such as the western fence lizard; Sceloporus occidentalis) play a unique role in Lyme disease ecology in the far-western United States. Lizards rather than mammals serve as the blood meal hosts for a large fraction of larval and nymphal western black-legged ticks (Ixodes pacificus--the vector for Lyme disease in that region) but are not competent reservoirs for the pathogen, Borrelia burgdorferi. Prior studies have suggested that the net effect of lizards is to reduce risk of human exposure to Lyme disease, a hypothesis that we tested experimentally. Following experimental removal of lizards, we documented incomplete host switching by larval ticks (5.19%) from lizards to other hosts. Larval tick burdens increased on woodrats, a competent reservoir, but not on deer mice, a less competent pathogen reservoir. However, most larvae failed to find an alternate host. This resulted in significantly lower densities of nymphal ticks the following year. Unexpectedly, the removal of reservoir-incompetent lizards did not cause an increase in nymphal tick infection prevalence. The net result of lizard removal was a decrease in the density of infected nymphal ticks, and therefore a decreased risk to humans of Lyme disease. Our results indicate that an incompetent reservoir for a pathogen may, in fact, increase disease risk through the maintenance of higher vector density and therefore, higher density of infected vectors.

  14. Statistical properties of spontaneous otoacoustic emissions in one bird and three lizard species

    NARCIS (Netherlands)

    vanDijk, P; Manley, GA; Gallo, L; Pavusa, A; Taschenberger, G

    1996-01-01

    Spontaneous otoacoustic emissions were recorded in the barn owl Tyto alba guttata (five ears), and in three lizard species (Callopistes maculatus, one ear; Varanus exanthematicus, seven ears; Gerrhonotus leiocephalus, one ear). The barn owl ears emitted one or two emission frequencies; the lizard

  15. A new scincid lizard of the genus Tribolonotus from Manus Island, New Guinea

    NARCIS (Netherlands)

    Cogger, H.G.

    1972-01-01

    INTRODUCTION The scincid lizards of the genus Tribolonotus are generally dull-coloured, armoured, thigmothermic, cryptozoic lizards with several unique features in their morphology and biology. These features include the possession of abdominal glands and volar pores, a vestigial left oviduct, the

  16. Statistical properties of spontaneous otoacoustic emissions in one bird and three lizard species

    NARCIS (Netherlands)

    vanDijk, P; Manley, GA; Gallo, L; Pavusa, A; Taschenberger, G

    1996-01-01

    Spontaneous otoacoustic emissions were recorded in the barn owl Tyto alba guttata (five ears), and in three lizard species (Callopistes maculatus, one ear; Varanus exanthematicus, seven ears; Gerrhonotus leiocephalus, one ear). The barn owl ears emitted one or two emission frequencies; the lizard ea

  17. Stable isotope analysis of diet confirms niche separation of two sympatric species of Namib Desert lizard.

    Science.gov (United States)

    Murray, Ian W; Lease, Hilary M; Hetem, Robyn S; Mitchell, Duncan; Fuller, Andrea; Woodborne, Stephan

    2016-01-01

    We used stable isotopes of carbon and nitrogen to study the trophic niche of two species of insectivorous lizards, the Husab sand lizard Pedioplanis husabensis and Bradfield's Namib day gecko living sympatrically in the Namib Desert. We measured the δ(13) C and δ(15) N ratios in lizard blood tissues with different turnover times (whole blood, red blood cells and plasma) to investigate lizard diet in different seasons. We also measured the δ(13) C and δ(15) N ratios in available arthropod prey and plant tissues on the site, to identify the avenues of nutrient movement between lizards and their prey. Through the use of stable isotope mixing models, we found that the two lizard species relied on a largely non-overlapping but seasonally variable array of arthropods: P. husabensis primarily fed on termites, beetles and wasps, while R. bradfieldi fed mainly on ants, wasps and hemipterans. Nutrients originating from C3 plants were proportionally higher for R. bradfieldi than for P. husabensis during autumn and late autumn/early winter, although not summer. Contrary to the few available data estimating the trophic transfer of nutrients in ectotherms in mixed C3 and C4 /crassulacean acid metabolism (CAM) plant landscapes, we found that our lizard species primarily acquired nutrients that originated from C4 /CAM plants. This work adds an important dimension to the general lack of studies using stable isotope analyses to estimate lizard niche partitioning and resource use.

  18. Geographic genetic differentiation of a malaria parasite, Plasmodium mexicanum, and its lizard host, Sceloporus occidentalis.

    Science.gov (United States)

    Fricke, Jennifer M; Vardo-Zalik, Anne M; Schall, Jos J

    2010-04-01

    Gene flow, and resulting degree of genetic differentiation among populations, will shape geographic genetic patterns and possibly local adaptation of parasites and their hosts. Some studies of Plasmodium falciparum in humans show substantial differentiation of the parasite in locations separated by only a few kilometers, a paradoxical finding for a parasite in a large, mobile host. We examined genetic differentiation of the malaria parasite Plasmodium mexicanum, and its lizard host, Sceloporus occidentalis, at 8 sites in northern California, with the use of variable microsatellite markers for both species. These lizards are small and highly territorial, so we expected local genetic differentiation of both parasite and lizard. Populations of P. mexicanum were found to be differentiated by analysis of 5 markers (F(st) values >0.05-0.10) over distances as short as 230-400 m, and greatly differentiated (F(st) values >0.25) for sites separated by approximately 10 km. In contrast, the lizard host had no, or very low, levels of differentiation for 3 markers, even for sites >40 km distant. Thus, gene flow for the lizard was great, but despite the mobility of the vertebrate host, the parasite was locally genetically distinct. This discrepancy could result if infected lizards move little, but their noninfected relatives were more mobile. Previous studies on the virulence of P. mexicanum for fence lizards support this hypothesis. However, changing prevalence of the parasite, without changes in density of the lizard, could also result in this pattern.

  19. Direct and socially-mediated effects of food availability late in life on life-history variation in a short-lived lizard.

    Science.gov (United States)

    Mugabo, Marianne; Marquis, Olivier; Perret, Samuel; Le Galliard, Jean-François

    2011-08-01

    Food availability is a major environmental factor that can influence life history within and across generations through direct effects on individual quality and indirect effects on the intensity of intra- and intercohort competition. Here, we investigated in yearling and adult common lizards (Zootoca vivipara) the immediate and delayed life-history effects of a prolonged food deprivation in the laboratory. We generated groups of fully fed or food-deprived yearlings and adults at the end of one breeding season. These lizards were released in 16 outdoor enclosures together with yearlings and adults from the same food treatment and with food-deprived or fully fed juveniles, creating four types of experimental populations. Experimental populations were then monitored during 2 years, which revealed complex effects of food on life-history trajectories. Food availability had immediate direct effects on morphology and delayed direct effects on immunocompetence and female body condition at winter emergence. Also, male annual survival rate and female growth rate and body size were affected by an interaction between direct effects of food availability and indirect effects on asymmetric competition with juveniles. Reproductive outputs were insensitive to past food availability, suggesting that female common lizards do not solely rely on stored energy to fuel reproduction. Finally, food conditions had socially-mediated intergenerational effects on early growth and survival of offspring through their effects on the intensity of competition. This study highlights the importance of social interactions among cohorts for life-history trajectories and population dynamics in stage-structured populations.

  20. Change your diet or die: predator-induced shifts in insectivorous lizard feeding ecology.

    Science.gov (United States)

    Hawlena, Dror; Pérez-Mellado, Valentín

    2009-08-01

    Animal feeding ecology and diet are influenced by the fear of predation. While the mechanistic bases for such changes are well understood, technical difficulties often prevent testing how these mechanisms interact to affect a mesopredator's diet in natural environments. Here, we compared the insectivorous lizard Acanthodactylus beershebensis' feeding ecology and diet between high- and low-risk environments, using focal observations, intensive trapping effort and fecal pellet analysis. To create spatial variation in predation risk, we planted "artificial trees" in a scrubland habitat that lacks natural perches, allowing avian predators to hunt for lizards in patches that were previously unavailable to them. Lizards in elevated-risk environments became less mobile but did not change their microhabitat use or temporal activity. These lizards changed their diet, consuming smaller prey and less plant material. We suggest that diet shifts were mainly because lizards from risky environments consumed prey items that required shorter handling time.

  1. Effect of temperature on feeding period of larval blacklegged ticks (Acari: Ixodidae) on eastern fence lizards

    Science.gov (United States)

    Rulison, Eric L.; LeBrun, Roger A.; Ginsberg, Howard S.

    2014-01-01

    Ambient temperature can influence tick development time, and can potentially affect tick interactions with pathogens and with vertebrate hosts. We studied the effect of ambient temperature on duration of attachment of larval blacklegged ticks, Ixodes scapularis Say, to eastern fence lizards, Sceloporus undulatus (Bose & Daudin). Feeding periods of larvae that attached to lizards under preferred temperature conditions for the lizards (WARM treatment: temperatures averaged 36.6°C at the top of the cage and 25.8°C at the bottom, allowing behavioral thermoregulation) were shorter than for larvae on lizards held under cool conditions (COOL treatment temperatures averaged 28.4°C at top of cage and 24.9°C at the bottom). The lizards were infested with larvae four times at roughly monthly intervals. Larval numbers successfully engorging and dropping declined and feeding period was longer after the first infestation.

  2. Perch-height specific predation on tropical lizard clay models: implications for habitat selection in mainland neotropical lizards

    Directory of Open Access Journals (Sweden)

    John E Steffen

    2009-09-01

    Full Text Available Predation has been hypothesized to be a strong selective force structuring communities of tropical lizards. Comparisons of perch height and size-based predation frequencies can provide a unique window into understanding how predation might shape habitat selection and morphological patterns in lizards, especially anoles. Here i use plasticine clay models, placed on the trunks of trees and suspended in the canopy to show that predation frequency on clay models differs primarily according to habitat (canopy vs. trunk-ground, but not according to size. These data are discussed in light of observed lizard abundances in the lowland forests of Costa Rica, and are presented as partial explanation for why fewer lizards are found in tree canopies, and more lizards are found on ground-trunk habitats. Rev. Biol. Trop. 57 (3: 859-864. Epub 2009 September 30.Existe la hipótesis de que la depredación es una fuerte fuerza selectiva que estructura las comunidades de lagartijas tropicales. Las comparaciones de las frecuencias de altura de la percha y de depredación con base en el tamaño pueden proveer una ventana única en el entendimiento de cómo la depredación podría moldear la selección del hábitat y los patrones morfológicos en las lagartijas, especialmente anoles. En este estudio uso modelos de plasticina, ubicados en troncos de árboles y suspendidos en el dosel para mostrar que la frecuencia de depredación en los modelos de plasticina difiere primariamente según el hábitat (dosel vs. tronco-suelo pero no según el tamaño. Estos datos se discuten a la luz de las abundancias de lagartijas observadas en los bosques de bajura de Costa Rica, y se presentan como una explicación parcial a porqué menos lagartijas se encuentran en los doseles, y más lagartijas se encuentran en los hábitats suelo-tronco.

  3. The lizard celestial compass detects linearly polarized light in the blue.

    Science.gov (United States)

    Beltrami, Giulia; Parretta, Antonio; Petrucci, Ferruccio; Buttini, Paola; Bertolucci, Cristiano; Foà, Augusto

    2012-09-15

    The present study first examined whether ruin lizards, Podarcis sicula, are able to orientate using plane-polarized light produced by an LCD screen. Ruin lizards were trained and tested indoors, inside a hexagonal Morris water maze positioned under an LCD screen producing white polarized light with a single E-vector, which provided an axial cue. White polarized light did not include wavelengths in the UV. Lizards orientated correctly either when tested with E-vector parallel to the training axis or after 90 deg rotation of the E-vector direction, thus validating the apparatus. Further experiments examined whether there is a preferential region of the light spectrum to perceive the E-vector direction of polarized light. For this purpose, lizards reaching learning criteria under white polarized light were subdivided into four experimental groups. Each group was tested for orientation under a different spectrum of plane-polarized light (red, green, cyan and blue) with equalized photon flux density. Lizards tested under blue polarized light orientated correctly, whereas lizards tested under red polarized light were completely disoriented. Green polarized light was barely discernible by lizards, and thus insufficient for a correct functioning of their compass. When exposed to cyan polarized light, lizard orientation performances were optimal, indistinguishable from lizards detecting blue polarized light. Overall, the present results demonstrate that perception of linear polarization in the blue is necessary - and sufficient - for a proper functioning of the sky polarization compass of ruin lizards. This may be adaptively important, as detection of polarized light in the blue improves functioning of the polarization compass under cloudy skies, i.e. when the alternative celestial compass based on detection of the sun disk is rendered useless because the sun is obscured by clouds.

  4. PCR Amplification System of DNA Barcoding Genes ITS, ITS2 and rbcL from Xanthium%DNA条形码基因ITS·ITS2及rbcL在苍耳属可采用相同的PCR条件

    Institute of Scientific and Technical Information of China (English)

    胡伟毅; 汪连军; 盛志超

    2013-01-01

    [目的]为植物 DNA条形码标准基因筛选研究提供参考,减少植物 DNA条形码研究中的工作量。[方法]对7种苍耳属植物 ITS、ITS2及 rbcL基因采用相同的扩增条件(95℃4 min;[35 cycles:94℃30 s;52℃45 s;72℃45 s];72℃10 min;4℃保存)。[结果]3种DNA条形码基因同时成功扩增。[结论]这说明植物 DNA条形码基因中 ITS、ITS2及 rbcL的PCR条件存在合并可能性。%[Objective] This study aimed to provide reference and reduce the workload for screening standard DNA barcoding genes of plants. [Method] Three DNA bar-coding genes ITS, ITS2 and rbcL were amplified from seven Xanthium species un-der the same PCR condition: PCR amplification was started with initial denaturation at 95 ℃ for 4 min, fol owed by 35 cycles of denaturation at 94 ℃ for 30 s, anneal-ing at 52 ℃ for 45 s, and extension at 72 ℃ for 45 s; the amplification was com-pleted by holding the reaction mixture at 72 ℃ for 10 min to al ow complete exten-sion of PCR, and the PCR products were stored at 4 ℃. [Result] Three DNA bar-coding genes ITS, ITS2 and rbcL were al amplified successful y. [Conclusion] This study indicates that PCR amplification conditions for DNA barcoding genes ITS, ITS2 and rbcL in plants may be consistent.

  5. Effects of oil pollution at Kuwait's greater Al-Burgan oil field on polycyclic aromatic hydrocarbon concentrations in the tissues of the desert lizard Acanthodactylus scutellatus and their ant prey.

    Science.gov (United States)

    Al-Hashem, Mona A; Brain, Paul F; Omar, Samira A

    2007-11-01

    Using indicator species to monitor the effects of oil pollution was thought to be useful to assess whether local desert reptiles and their insect prey could fulfill such a role in an area damaged in the second Gulf War (1990). Polluted sites with apparently different degrees of contamination (namely tar mat, soot, and clear sites) located at Kuwait's Greater Al-Burgan oil field were compared with control areas outside this region in study conducted in 2002. Five Acanthodactylus scutellatus lizards from each study and control site were humanely killed and stored in a freezer at -20 degrees C until analysis. Ants from the same sites were also collected and treated in a similar manner. Lizard and ant whole body tissues were subjected to gas chromatography-mass spectrometry (GC-MS) to determine concentrations of petroleum hydrocarbons (HCs). The study concentrated on sixteen polycyclic aromatic hydrocarbons (PAHs), EPA priority pollutants used as indicators of petrogenic HC contamination. There were significantly different concentrations of total PAHs in lizards and ants among all four study sites. Of the 16 PAHs, phenanthrene, fluoranthene, and benzo[a]anthracene were present in both lizard and ant samples from the Greater Al-Burgan oil field sites irrespective of the apparent degree of pollution but were undetectable in materials from the control sites. The range of total PAHs in lizards was 26.5-301 ng g(-1) and it was 6.7-82.1 ng g(-1) in ants. Concentrations increased progressively along an expected contamination gradient. Total PAHs were detected in biota even in an area (clear site) that did not appear, virtually, to contain petroleum soil pollution which supports the value of indicator biota species. For all three sites where PAHs were found in biota, the ratio of total PAHs in ants to lizards was consistently 3.3-3.4. These data show that, although 12 years have passed since the Kuwait oil spill catastrophe, all sites are still contaminated with PAHs. Use of

  6. Phylogenetic relationships of Biebersteinia Stephan (Geraniaceae) inferred from rbcL and atpB sequence comparisons.

    NARCIS (Netherlands)

    Bakker, F.T.; Vassiliades, D.D.; Morton C., C.; Savolainen, V.

    1998-01-01

    Phylogenetic analysis of rbcL and atpB gene sequences from Biebersteinia Stephan (represented by B. orphanidis Boiss.) and from selected taxa of the rosids I and II clades does not support traditional grouping of this genus in Geraniaceae s.s. nor in Geraniales, but indicates strong support for a po

  7. Thermal dependence of sprint performance in the lizard Psammodromus algirus along a 2200-meter elevational gradient: Cold-habitat lizards do not perform better at low temperatures.

    Science.gov (United States)

    Zamora-Camacho, Francisco Javier; Rubiño-Hispán, María Virtudes; Reguera, Senda; Moreno-Rueda, Gregorio

    2015-08-01

    Sprint speed has a capital relevance in most animals' fitness, mainly for fleeing from predators. Sprint performance is maximal within a certain range of body temperatures in ectotherms, whose thermal upkeep relies on exogenous thermal sources. Ectotherms can respond to diverse thermal environments either by shifting their thermal preferences or maintaining them through different adaptive mechanisms. Here, we tested whether maximum sprint speed of a lizard that shows conservative thermal ecology along a 2200-meter elevational gradient differs with body temperature in lizards from different elevations. Lizards ran faster at optimum than at suboptimum body temperature. Notably, high-elevation lizards were not faster than mid- and low-elevation lizards at suboptimum body temperature, despite their low-quality thermal environment. This result suggests that both preferred body temperature and thermal dependence of speed performance are co-adapted along the elevational gradient. High-elevation lizards display a number of thermoregulatory strategies that allow them to achieve high optimum body temperatures in a low thermal-quality habitat and thus maximize speed performance. As for reproductive condition, we did not find any effect of it on sprint speed, or any significant interaction with elevation or body temperature. However, strikingly, gravid females were significantly slower than males and non-gravid females at suboptimum temperature, but performed similarly well at optimal temperature.

  8. Sexual dimorphism in digit length ratios in two lizard species.

    Science.gov (United States)

    Rubolini, Diego; Pupin, Fabio; Sacchi, Roberto; Gentilli, Augusto; Zuffi, Marco A L; Galeotti, Paolo; Saino, Nicola

    2006-05-01

    Sexual dimorphism in digit length ratios has been reported for humans, a few other mammals, and two bird species. This dimorphism is thought to arise via an interaction between the prenatal exposure of the embryo to sex hormones and the Hox genes, which are highly conserved among vertebrates and control the development of both the appendices, including fingers and toes, and the urogenital system. In this study, we report on sexual dimorphism in 2D:3D, 2D:4D, and 3D:4D contralateral ratios of the forelimbs in two species of oviparous lizards, the common wall lizard (Podarcis muralis) and the tree skink (Mabuya planifrons), as measured on museum specimens. We found that male P. muralis had a larger 2D:4D ratio on both sides and larger 2D:3D ratio on the left side than females, whereas in M. planifrons, males had lower 2D:3D ratios than females on the left side. The two species show opposite patterns of sexual dimorphism in body size, males being larger than females in P. muralis, and the reverse in M. planifrons, suggesting that interspecific variation of sex differences in digit ratios could be associated with sex-specific growth trajectories. There was a limited evidence for directional asymmetry in digit ratios. Therefore, our findings provide the first evidence that digit ratios are sexually dimorphic in any reptile species and are consistent with the idea that the genetic link between limb development and the urogenital system had been established with the evolution of the earliest terrestrial tetrapods. Importantly, many lizard species with genetic sex determination, including the ones we studied, are oviparous and may represent valuable animal models for experimental tests of the association between prenatal exposure to androgens or estrogens and digit ratios.

  9. Chasing the Patagonian sun: comparative thermal biology of Liolaemus lizards.

    Science.gov (United States)

    Azócar, Débora Lina Moreno; Vanhooydonck, Bieke; Bonino, Marcelo F; Perotti, M Gabriela; Abdala, Cristian S; Schulte, James A; Cruz, Félix B

    2013-04-01

    The importance of the thermal environment for ectotherms and its relationship with thermal physiology and ecology is widely recognized. Several models have been proposed to explain the evolution of the thermal biology of ectotherms, but experimental studies have provided mixed support. Lizards from the Liolaemus goetschi group can be found along a wide latitudinal range across Argentina. The group is monophyletic and widely distributed, and therefore provides excellent opportunities to study the evolution of thermal biology. We studied thermal variables of 13 species of the L. goetschi group, in order to answer three questions. First, are aspects of the thermal biology of the L. goetschi group modelled by the environment or are they evolutionarily conservative? Second, have thermal characteristics of these animals co-evolved? And third, how do the patterns of co-evolution observed within the L. goetschi group compare to those in a taxonomically wider selection of species of Liolaemus? We collected data on 13 focal species and used species information of Liolaemus lizards available in the literature and additional data obtained by the authors. We tackled these questions using both conventional and phylogenetically based analyses. Our results show that lizards from the L. goetschi group and the genus Liolaemus in general vary in critical thermal minimum in relation to mean air temperature, and particularly the L. goetschi group shows that air temperature is associated with critical thermal range, as well as with body temperature. Although the effect of phylogeny cannot be ignored, our results indicate that these thermal biology aspects are modelled by cold environments of Patagonia, while other aspects (preferred body temperature and critical thermal maximum) are more conservative. We found evidence of co-evolutionary patterns between critical thermal minimum and preferred body temperature at both phylogenetic scales (the L. goetschi group and the extended sample of

  10. Telling tails: selective pressures acting on investment in lizard tails.

    Science.gov (United States)

    Fleming, Patricia A; Valentine, Leonie E; Bateman, Philip W

    2013-01-01

    Caudal autotomy is a common defense mechanism in lizards, where the animal may lose part or all of its tail to escape entrapment. Lizards show an immense variety in the degree of investment in a tail (i.e., length) across species, with tails of some species up to three or four times body length (snout-vent length [SVL]). Additionally, body size and form also vary dramatically, including variation in leg development and robustness and length of the body and tail. Autotomy is therefore likely to have fundamentally different effects on the overall body form and function in different species, which may be reflected directly in the incidence of lost/regenerating tails within populations or, over a longer period, in terms of relative tail length for different species. We recorded data (literature, museum specimens, field data) for relative tail length (n=350 species) and the incidence of lost/regenerating tails (n=246 species). We compared these (taking phylogeny into account) with intrinsic factors that have been proposed to influence selective pressures acting on caudal autotomy, including body form (robustness, body length, leg development, and tail specialization) and ecology (foraging behavior, physical and temporal niches), in an attempt to identify patterns that might reflect adaptive responses to these different factors. More gracile species have relatively longer tails (all 350 spp., P lizards (all 246 spp., P < 0.01; Scindidae, P < 0.05), larger skinks (P < 0.05), climbing geckos (P < 0.05), or active-foraging iguanids (P < 0.05). The selective advantage of investing in a relatively longer tail may be due to locomotor mechanics, although the patterns observed are also largely consistent with predictions based on predation pressure.

  11. Sexual differences in behavioral thermoregulation of the lizard Scelarcis perspicillata.

    Science.gov (United States)

    Ortega, Zaida; Mencía, Abraham; Pérez-Mellado, Valentín

    2016-10-01

    Temperature determines all aspects of the biology of ectotherms. Although sexual differences in thermal ecology are not the rule in lizards, some species exhibit such differences. We studied the effect of sex and reproductive condition on the thermoregulation of an introduced population of Scelarcis perspicillata during the summer in Menorca (Balearic Islands, Spain). These lizards live in the wall surfaces of a limestone quarry, where the sun is scarce because of the narrowness of the quarry walls. The population is sexually dimorphic, with larger males than females. We measured body temperature (Tb) of adult males and females in the field, and air (Ta) and substrate temperature (Ts) at the capture sites, and recorded exposure to sunlight, height of the perch, and type of substrate. We also recorded operative temperatures (Te) as a null hypothesis of thermoregulation. Finally, we studied the thermal preferences of adult males and females in a laboratory thermal gradient. Thermal preferences were similar for pregnant and non-pregnant females, and sex did not affect the thermal preferences of lizards, even after controlling for the effect of body size. However, in the field, females achieved higher Tb than males, and occupied microhabitats with higher Ta and Ts and lower perch heights than males. Furthermore, females selected perches in full sun at a higher frequency than males. As a consequence, females achieved a higher accuracy and effectiveness of thermoregulation (0.89) than males (0.84). Thus, all else being equal, females would achieve a higher performance than males. The observed results are attributable to sexual differences in behaviour, probably in relation with the reproductive season. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Effects of Cadmium on the Glial Architecture in Lizard Brain

    Science.gov (United States)

    Favorito, Rossana; Monaco, Antonio; Grimaldi, Maria C.; Ferrandino, Ida

    2017-01-01

    The glial cells are positioned to be the first cells of the brain parenchyma to face molecules crossing the blood-brain barrier with a relevant neuroprotective role from cytotoxic action of heavy metals on the nervous system. Cadmium is a highly toxic metal and its levels in the environment are increasing due to industrial activities. This element can pass the blood-brain barrier and have neurotoxic activity. For this reason we have studied the effects of cadmium on the glial architecture in the lizard Podarcis siculus, a significant bioindicator of chemical exposure due to its persistence in a variety of habitats. The study was performed on two groups of lizards. The first group of P. siculus was exposed to an acute treatment by a single i.p. injection (2 mg/kg-BW) of CdCl2 and sacrificed after 2, 7 and 16 days. The second one was used as control. The histology of the brain was studied by Hematoxylin/Eosin and Cresyl/Violet stains while the glial structures were analyzed by immunodetection of the glial fibrillary acidic protein (GFAP), the most widely accepted marker for astroglial cells. Evident morphological alterations of the brain were observed at 7 and 16 days from the injection, when we revealed also a decrease of the GFAP-immunopositive structures in particular in the rhombencephalic ventricle, telencephalon and optic tectum. These results show that in the lizards an acute exposure to cadmium provokes morphological cellular alterations in the brain but also a decrement of the expression of GFAP marker with possible consequent damage of glial cells functions.

  13. Thermoregulatory consequences of salt loading in the lizard Pogona vitticeps.

    Science.gov (United States)

    Scarpellini, Carolina da Silveira; Bícego, Kênia C; Tattersall, Glenn J

    2015-04-15

    Previous research has demonstrated that dehydration increases the threshold temperature for panting and decreases the thermal preference of lizards. Conversely, it is unknown whether thermoregulatory responses such as shuttling and gaping are similarly influenced. Shuttling, as an active behavioural response, is considered one of the most effective thermoregulatory behaviours, whereas gaping has been proposed to be involved in preventing brain over-heating in lizards. In this study we examined the effect of salt loading, a proxy for increased plasma osmolality, on shuttling and gaping in Pogona vitticeps. Then, we determined the upper and lower escape ambient temperatures (UETa and LETa), the percentage of time spent gaping, the metabolic rate (V̇O2 ), the evaporative water loss (EWL) during gaping and non-gaping intervals and the evaporative effectiveness (EWL/V̇O2 ) of gaping. All experiments were performed under isotonic (154 mmol l(-1)) and hypertonic saline injections (625, 1250 or 2500 mmol l(-1)). Only the highest concentration of hypertonic saline altered the UETa and LETa, but this effect appeared to be the result of diminishing the animal's propensity to move, instead of any direct reduction in thermoregulatory set-points. Nevertheless, the percentage of time spent gaping was proportionally reduced according to the saline concentration; V̇O2 was also decreased after salt loading. Thermographic images revealed lower head than body surface temperatures during gaping; however this difference was inhibited after salt loading. Our data suggest that EWL/V̇O2 is raised during gaping, possibly contributing to an increase in heat transfer away from the lizard, and playing a role in head or brain cooling. © 2015. Published by The Company of Biologists Ltd.

  14. Modelling asymmetry in the peripheral auditory system of the lizard

    DEFF Research Database (Denmark)

    Zhang, Lei; Hallam, John; Christensen-Dalsgaard, Jakob

    2008-01-01

    The ears of lizards are highly directional. The directionality is generated by strong acoustical coupling of the eardrums. A simple lumped-parameter model of the ear followed by binaural comparisons has been shown to perform successful phonotaxis in robot implementations. However, such a model...... will produce localization erros in the form of  response bias if the ears are asymmetrical. We have evaluated how large errors are generated by asymmetry using simulations of the ear model in Mathematica 5.2. The study shows that the effect of asymmetry is minimal around the most directional frequency...

  15. Functional analysis of a Lemna gibba rbcS promoter regulated by abscisic acid and sugar

    Indian Academy of Sciences (India)

    Youru Wang

    2013-04-01

    Photosynthesis-associated nuclear genes (PhANGs) are able to respond to multiple environmental and developmental signals, including light, sugar and abscisic acid (ABA). PhANGs have been extensively studied at the level of transcriptional regulation, and several cis-acting elements important for light responsiveness have been identified in their promoter sequences. However, the regulatory elements involved in sugar and ABA regulation of PhANGs have not been completely characterized. A ribulose-1,5-bisphosphate carboxylase small subunit gene (rbcS) promoter (SSU5C promoter) was isolated from duckweed (Lemna gibba). A series of SSU5C promoter 5′ deletion fragments were fused to an intron–gus gene, and transgenic tobacco suspension cell lines were generated. Assay of tobacco suspension cell line harbouring the complete promoter in the fusion construct indicated that SSU5C promoter was negatively regulated by sugar and ABA under the condition of regular photoperiod. 5′ deletion analysis of SSU5C promoter in transgenic tobacco suspension cell lines confirmed that a region between positions $-310$ and $-152$ included the ABA-response region, and that sugar-response cis-acting elements might be located in the region between $-152$ and $-117$. Taken together, our results confirmed that the cis-regulatory region responsible for repression by ABA and sugar in the SSU5C promoter was located between $-310$ and $-117$.

  16. Cloning,Sequencing and Phylogenetic Study of rbcL Gene from Cyanobacteria Arthrospira and Spirulina

    Institute of Scientific and Technical Information of China (English)

    Liu Jinjie(刘金姐); Zhang Xuecheng; Sui Zhenghong; Mao Yunxiang; Sun Xue

    2004-01-01

    Large subunit gene of rubisco (rbcL) of cyanobacteria Arthrospira platensis FACHB341, A. Platensis FACHB439, A. Maxima OUQDSM and Spirulina sp. FACHB440 is cloned, sequenced and characterized. Results show that GC content of the gene in strain Spirulina sp. FACHB440 is higher than that in the others. The alignments based on deduced amino acid sequences indicate that Spirulina sp. FACHB440 is different from that in other three samples of Arthrospira, though they have the same conserved functional sites (95, 98, 121, 124, 221, 257). The nucleotide sequence similarity among the three strains of the genus of Arthrospira (96.5~99.6%) is higher than that between Arthrospira and Spirulina (78.1~78.5%). By comparison of the corresponding sequence of other cyanobacteria, a phylogenetic tree with two clusters is constructed. A. Platensis FACHB341, A. Maxima OUQDSM and A. Platensis FACHB439 form the monophyletic linage, which is fully supported by bootstrap values (1000), while Spirulina sp. FACHB440 and Anabaena sp. PCC7120 cluster in another linage with the bootstrap value of 909.

  17. Stability of detectability over 17 years at a single site and other lizard detection comparisons from Guam

    Science.gov (United States)

    Rodda, Gordon H.; Dean-Bradley, Kathryn; Campbell, Earl W.; Fritts, Thomas H.; Lardner, Bjorn; Yackel Adams, Amy A.; Reed, Robert N.

    2015-01-01

    To obtain quantitative information about population dynamics from counts of animals, the per capita detectabilities of each species must remain constant over the course of monitoring. We characterized lizard detection constancy for four species over 17 yr from a single site in northern Guam, a relatively benign situation because detection was relatively easy and we were able to hold constant the site, habitat type, species, season, and sampling method. We monitored two species of diurnal terrestrial skinks (Carlia ailanpalai [Curious Skink], Emoia caeruleocauda [Pacific Bluetailed Skink]) using glueboards placed on the ground in the shade for 3 h on rainless mornings, yielding 10,286 skink captures. We additionally monitored two species of nocturnal arboreal geckos (Hemidactylus frenatus [Common House Gecko]; Lepidodactylus lugubris [Mourning Gecko]) on the basis of 15,212 sightings. We compared these count samples to a series of complete censuses we conducted from four or more total removal plots (everything removed to mineral soil) totaling 400 m2(about 1% of study site) in each of the years 1995, 1999, and 2012, providing time-stamped quantification of detectability for each species. Unfortunately, the actual population trajectories taken by the four species were masked by unexplained variation in detectability. This observation of debilitating latent variability in lizard detectability under nearly ideal conditions undercuts our trust in population estimation techniques that fail to quantify venue-specific detectability, rely on pooled detection probability estimates, or assume that modulation in predefined environmental covariates suffices for estimating detectability.

  18. The relative influence of road characteristics and habitat on adjacent lizard populations in arid shrublands

    Science.gov (United States)

    Hubbard, Kaylan A.; Chalfoun, Anna D.; Gerow, Kenneth G.

    2016-01-01

    As road networks continue to expand globally, indirect impacts to adjacent wildlife populations remain largely unknown. Simultaneously, reptile populations are declining worldwide and anthropogenic habitat loss and fragmentation are frequently cited causes. We evaluated the relative influence of three different road characteristics (surface treatment, width, and traffic volume) and habitat features on adjacent populations of Northern Sagebrush Lizards (Sceloporus graciosus graciosus), Plateau Fence Lizards (S. tristichus), and Greater Short-Horned Lizards (Phrynosoma hernandesi) in mixed arid shrubland habitats in southwest Wyoming. Neither odds of lizard presence nor relative abundance was significantly related to any of the assessed road characteristics, although there was a trend for higher Sceloporus spp. abundance adjacent to paved roads. Sceloporus spp. relative abundance did not vary systematically with distance to the nearest road. Rather, both Sceloporus spp. and Greater Short-Horned Lizards were associated strongly with particular habitat characteristics adjacent to roads. Sceloporus spp. presence and relative abundance increased with rock cover, relative abundance was associated positively with shrub cover, and presence was associated negatively with grass cover. Greater Short-Horned Lizard presence increased with bare ground and decreased marginally with shrub cover. Our results suggest that habitat attributes are stronger correlates of lizard presence and relative abundance than individual characteristics of adjacent roads, at least in our system. Therefore, an effective conservation approach for these species may be to consider the landscape through which new roads and their associated development would occur, and the impact that placement could have on fragment size and key habitat elements.

  19. Regulation of skeletal muscle metabolism in the lizard Dipsosaurus dorsalis by fructose-2,6-bisphosphate.

    Science.gov (United States)

    Scholnick, D A; Gleeson, T T

    1996-11-01

    Changes in liver and skeletal muscle fructose-2,6-bisphosphate (Fru-2,6-P2) concentrations were compared during fasting, exercise, and recovery in the lizard Dipsosaurus dorsalis and in outbred mice (Mus musculus). We present the first correlative evidence that suggests that a decrease in the content of Fru-2,6-P2 may mediate elevated gluconeogenesis in lizard skeletal muscle. Contents of Fru-2,6-P2 in lizard gastrocnemius and red and white iliofibularis (IF) were significantly lower (as much as 55% in white IF) during recovery from exhaustive exercise than at rest. Recovery from exhaustive exercise had no significant effect on Fru-2,6-P2 concentrations in any mouse muscle examined. Fasting significantly depressed lizard and mouse liver Fru-2,6-P2 contents and decreased lizard red IF by over 84% from the fed condition. Lizard red and white muscle fiber bundles incubated in 20 mM lactate had significantly lower Fru-2,6-P2 (94 and 61% depression, respectively) than those incubated in 8.5 mM glucose. These results are consistent with the hypothesis that Fru-2,6-P2 acts as a signal for controlling gluconeogenesis in lizard skeletal muscle.

  20. Diagnostic sensitivity of ultrasound, radiography and computed tomography for gender determination in four species of lizards.

    Science.gov (United States)

    Di Ianni, Francesco; Volta, Antonella; Pelizzone, Igor; Manfredi, Sabrina; Gnudi, Giacomo; Parmigiani, Enrico

    2015-01-01

    Gender determination is frequently requested by reptile breeders, especially for species with poor or absent sexual dimorphism. The aims of the current study were to describe techniques and diagnostic sensitivities of ultrasound, radiography, and computed tomography for gender determination (identification of hemipenes) in four species of lizards. Nineteen lizards of known sex, belonging to four different species (Pogona vitticeps, Uromastyx aegyptia, Tiliqua scincoides, Gerrhosaurus major) were prospectively enrolled. With informed owner consent, ultrasound, noncontrast CT, contrast radiography, and contrast CT (with contrast medium administered into the cloaca) were performed in conscious animals. Imaging studies were reviewed by three different operators, each unaware of the gender of the animals and of the results of the other techniques. The lizard was classified as a male when hemipenes were identified. Nineteen lizards were included in the study, 10 females and nine males. The hemipenes were seen on ultrasound in only two male lizards, and appeared as oval hypoechoic structures. Radiographically, hemipenes filled with contrast medium appeared as spindle-shaped opacities. Noncontrast CT identified hemipenes in only two lizards, and these appeared as spindle-shaped kinked structures with hyperattenuating content consistent with smegma. Hemipenes were correctly identified in all nine males using contrast CT (accuracy of 100%). Accuracy of contrast radiography was excellent (94.7%). Accuracy of ultrasound and of noncontrast CT was poor (64.3% and 63.1%, respectively). Findings from the current study supported the use of contrast CT or contrast radiography for gender determination in lizards.

  1. One solution for two challenges: the lizard Microlophus atacamensis avoids overheating by foraging in intertidal shores.

    Science.gov (United States)

    Sepúlveda, Maritza; Sabat, Pablo; Porter, Warren P; Fariña, José Miguel

    2014-01-01

    In lizards, one of the most important behavioral mechanisms to cope with spatial and temporal variations in thermal resources observed is activity time. The longer a lizard can maintain activity, the more time it has to forage and reach larger adult body size. We studied the behavioral adjustments to different climatic regimens on daily and seasonal scales in three natural populations of the lizard Microlophus atacamensis along a latitudinal temperature and rainfall gradient. We also used Niche Mapper to determinate the amount of thermally suitable time for activity for this species. Abundance and daily activity patterns varied greatly over the year for the three populations. In summer and spring, the daily activity times were greater, and were reduced in fall and winter seasons. In summer, when stressful heat loads should prohibit activity over a midday gap, lizards did not show bimodal patterns of activity. Instead, they move to the cooler intertidal habitat. Abundance and thermal quality in the southernmost coolest site was lower, and the potential annual activity time decreases with latitude. Contrary to expectations, lizards from this locality showed the largest body sizes possibly due to diet and/or time to sexual maturation. Our results indicate that the intertidal habitat is a key factor that influences daily and seasonal activity of M. atacamensis lizards. While this habitat is not climatically optimal for lizards, it allows them to behaviorally extend their activity window and gain access to food in the intertidal areas.

  2. Thyroid disruption in the lizard Podarcis bocagei exposed to a mixture of herbicides: a field study.

    Science.gov (United States)

    Bicho, Rita C; Amaral, Maria José; Faustino, Augusto M R; Power, Deborah M; Rêma, Alexandra; Carretero, Miguel A; Soares, Amadeu M V M; Mann, Reinier M

    2013-01-01

    Pesticide exposure has been related with thyroid disrupting effects in different vertebrate species. However, very little is known about the effects of these compounds in reptiles. In the Mediterranean area, lacertid lizards are the most abundant vertebrate group in agroecosystems, and have been identified as potential model species for reptile ecotoxicology. The aim of this study was to understand if the herbicides applied in corn fields have thyroid disruptive effects in the lizard Podarcis bocagei. Adult male lizards were captured in north-western Portugal in corn fields treated with herbicides (exposed sites), and in organic agricultural fields (reference sites). Thyroid and male gonad morphology and functionality, and testosterone levels were investigated through histological, immunohistochemical and biochemical techniques. Lizards from exposed locations displayed thyroid follicular lumens with more reabsorption vacuoles and significantly larger follicular area than those from reference fields. Furthermore, testes of lizards from exposed locations had significantly larger seminiferous tubule diameters, significantly higher number of spermatogenic layers and displayed an up-regulation of thyroid hormone receptors when compared with lizards from reference areas. These findings strongly suggest that the complex mixture of herbicides that lizards are exposed to in agricultural areas have thyroid disrupting effects which ultimately affect the male reproductive system. Alachlor, which has demonstrated thyroid effects in mammals, may be largely responsible for the observed effects.

  3. Fatal clostridial enterotoxemia (Clostrium glycolcum) in an ornate nile monitor (Veranus ornarus)

    DEFF Research Database (Denmark)

    Bertelsen, Mads Frost; Weese, J. Scott

    2006-01-01

    Enterotoxemia caused by Clostridium glycolium was identified as the cause of circulatory collapse and death in a female, 3-year old, captive-bred ornate Nile monitor (Veranus ornatus). Anaerobic culture af fecal samples from 12 other monitor lizards from collection failed to demonstrate the prese...

  4. Virulence of lizard malaria: the evolutionary ecology of an ancient parasite-host association.

    Science.gov (United States)

    Schall, J J

    1990-01-01

    The negative consequences of parasitic infection (virulence) were examined for two lizard malaria parasite-host associations: Plasmodium agamae and P. giganteum, parasites of the rainbow lizard, Agama agama, in Sierra Leone, West Africa; and P. mexicanum in the western fence lizard, Sceloporus occidentalis, in northern California. These malaria species vary greatly in their reproductive characteristics: P. agamae produces only 8 merozoites per schizont, P. giganteum yields over 100, and P. mexicanum an intermediate number. All three parasites appear to have had an ancient association with their host. In fence lizards, infection with malaria is associated with increased numbers of immature erythrocytes, decreased haemoglobin levels, decreased maximal oxygen consumption, and decreased running stamina. Not affected were numbers of erythrocytes, resting metabolic rate, and sprint running speed which is supported by anaerobic means in lizards. Infected male fence lizards had smaller testes, stored less fat in preparation for winter dormancy, were more often socially submissive and, unexpectedly, were more extravagantly coloured on the ventral surface (a sexually dimorphic trait) than non-infected males. Females also stored less fat and produced smaller clutches of eggs, a directly observed reduction in fitness. Infected fence lizards do not develop behavioural fevers. P. mexicanum appears to have broad thermal buffering abilities and thermal tolerance; the parasite's population growth was unaffected by experimental alterations in the lizard's body temperature. The data are less complete for A. agama, but infected lizards suffered similar haematological and physiological effects. Infected animals may be socially submissive because they appear to gather less insect prey, possibly a result of being forced into inferior territories. Infection does not reduce clutch size in rainbow lizards, but may lengthen the time between clutches. These results are compared with

  5. Intestinal parasites of unisexual and bisexual lizards Darevskia spp. (Lacertidae from Northeastern Anatolia

    Directory of Open Access Journals (Sweden)

    Roca V.

    2016-09-01

    Full Text Available Four bisexual and two unisexual species of the lizard genus Darevskia from northeastern Anatolia were searched for intestinal parasites in adult specimens. One cestode, Nematotaenia tarentolae, and two nematode species, Spauligodon saxicolae and Strongyloides darevskyi, were found, the latest identified as a Darevskia specialist. No major differences between host species were recorded. The very low infection rates and diversity result in depauperate helminth communities for all these lacertid lizards being the lowest among the Palaearctic saurians. Patterns of these helminth communities are compared with those observed in other lacertid lizards from Anatolia and Europe.

  6. The conservation status of the Saldanha-Langebaan lizard fauna

    Directory of Open Access Journals (Sweden)

    I.G. Cordes

    1996-01-01

    Full Text Available The conservation status of relic melanistic lizard species occurring in the Saldanha- Langebaan area has been investigated. A contact zone between one melanistic form and a closely related non-melanistic form has been examined in detail. Apart from melanis- tic populations of the girdled lizards, Cordylus niger and C. polywnus, a melanistic morphotype of the Cape legless skink, Acontias meleagris meleagris also occurs in the area. The taxonomic status of this morphotype needs to be investigated. At Mauritz Bay, north of Saldanha, the ranges of C niger and the non-melanistic C cordylus are in contact over a distance of approximately 240 m, with maximum overlap of 70 m. The melanistic populations of C. polyz.onus and A. m. meleagris have relatively large ranges in the Saldanha-Langebaan area and are not threatened by urban development. The C niger population, however, is fragmented into several subpopulations, and those in the Saldanha area, including the contact zone, will be affected if urban development is allowed to continue in the area. As relic populations of other cool-adapted, melanistic invertebrate and lower vertebrate species may also occur in the area, the key areas demarcated by C. niger should be preserved.

  7. Extended molecular phylogenetics and revised systematics of Malagasy scincine lizards.

    Science.gov (United States)

    Erens, Jesse; Miralles, Aurélien; Glaw, Frank; Chatrou, Lars W; Vences, Miguel

    2017-02-01

    Among the endemic biota of Madagascar, skinks are a diverse radiation of lizards that exhibit a striking ecomorphological variation, and could provide an interesting system to study body-form evolution in squamate reptiles. We provide a new phylogenetic hypothesis for Malagasy skinks of the subfamily Scincinae based on an extended molecular dataset comprising 8060bp from three mitochondrial and nine nuclear loci. Our analysis also increases taxon sampling of the genus Amphiglossus by including 16 out of 25 nominal species. Additionally, we examined whether the molecular phylogenetic patterns coincide with morphological differentiation in the species currently assigned to this genus. Various methods of inference recover a mostly strongly supported phylogeny with three main clades of Amphiglossus. However, relationships among these three clades and the limb-reduced genera Grandidierina, Voeltzkowia and Pygomeles remain uncertain. Supported by a variety of morphological differences (predominantly related to the degree of body elongation), but considering the remaining phylogenetic uncertainty, we propose a redefinition of Amphiglossus into three different genera (Amphiglossus sensu stricto, Flexiseps new genus, and Brachyseps new genus) to remove the non-monophyly of Amphiglossus sensu lato and to facilitate future studies on this fascinating group of lizards.

  8. Conserved sex chromosomes across adaptively radiated Anolis lizards.

    Science.gov (United States)

    Rovatsos, Michail; Altmanová, Marie; Pokorná, Martina; Kratochvíl, Lukáš

    2014-07-01

    Vertebrates possess diverse sex-determining systems, which differ in evolutionary stability among particular groups. It has been suggested that poikilotherms possess more frequent turnovers of sex chromosomes than homoiotherms, whose effective thermoregulation can prevent the emergence of the sex reversals induced by environmental temperature. Squamate reptiles used to be regarded as a group with an extensive variability in sex determination; however, we document how the rather old radiation of lizards from the genus Anolis, known for exceptional ecomorphological variability, was connected with stability in sex chromosomes. We found that 18 tested species, representing most of the phylogenetic diversity of the genus, share the gene content of their X chromosomes. Furthermore, we discovered homologous sex chromosomes in species of two genera (Sceloporus and Petrosaurus) from the family Phrynosomatidae, serving here as an outgroup to Anolis. We can conclude that the origin of sex chromosomes within iguanas largely predates the Anolis radiation and that the sex chromosomes of iguanas remained conserved for a significant part of their evolutionary history. Next to therian mammals and birds, Anolis lizards therefore represent another adaptively radiated amniote clade with conserved sex chromosomes. We argue that the evolutionary stability of sex-determining systems may reflect an advanced stage of differentiation of sex chromosomes rather than thermoregulation strategy.

  9. Age structured dynamical model for an endangered lizard Eulamprus leuraensis

    Science.gov (United States)

    Supriatna, A. K.; Rachmadani, Q.; Ilahi, F.; Anggriani, N.; Nuraini, N.

    2014-02-01

    The Blue Mountains Water Skink, Eulamprus leuraensis, is listed as an endangered species under the IUCN Red List. This lizard species has a typical characteristic of growth with a low fecundity. It is known that the offspring quality may decline with maternal age of the parents despite they can grow rapidly from neonatal size to adult size within two to three years. It is also believed that low adult survival rates and specialization on rare and fragmented type of habitat are the main cause leading to the endangered status of the lizard. A mathematical model with age structure for Eulamprus leuraensis, taking into account the variation of survival rate in each structure and the declining of offspring quality with respect to maternal age is considered here. Stable coexistence of non-trivial equilibriumis shown. It is also shown that an endangered status is due to combination oflow reproductive output and low rates of adult survival. Further, understanding the age structure within populations can facilitate efective management of the endangered species.

  10. J-Integral Estimate for Circumferential Cracked Pipes Under Primary and Secondary Stress in R, RBC-MR A

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Hyun Suk; Oh, Chang Young; Kim, Yun Jae [Korea Univ., Seoul (Korea, Republic of)

    2013-05-15

    This paper provides a comparison of the J-integral estimation method under combined primary and secondary stress in the R, RBC-MR A code. The comparisons of each code are based on finite element analysis using Abacus with regard to the crack shape, crack depth, and magnitude of secondary load. The estimate of the R code is conservative near L{sub r} = 1, and that of the RBC-MR A code is conservative near L{sub r} = 0. As a result, this paper proposes a modified method of J-integral estimation in the R, RCC{sub M}R A code. The J-integral using the modified method corresponds to the finite element analysis result.

  11. A molecular phylogeny of the heterokont algae based on analyses of choroplast-encoded rbcL sequence data

    DEFF Research Database (Denmark)

    Daugbjerg, Niels; Andersen, Robert A.

    1997-01-01

    Nearly complete ribulose-1,5-bisphosphate carboxylase/ oxygenase (rbcL)sequences from 27 taxa of heterokont algae were determined and combined with rbcL sequences obtained from GenBank for four other heterokont algae and three red algae. The phylogeny of the morphologically diverse haterokont algae...... was inferred from an unambiguously aligned data matrix using the red algae as the root, Significantly higher levels of mutational saturation in third codon positions were found when plotting the pair-wise substitutions with and without corrections for multiple substitutions at the same site for first...... of heterokont algae. The Eustigmatophyceae were the most basal group, and the Dictyochophyceae branched off as the second most basal group. The branching pattern for the other classes was well supported in terms of bootstrap values in the weightedparsimony analysis but was weakly supported in the maximum...

  12. A molecular phylogeny of the heterokont algae based on analyses of choroplast-encoded rbcL sequence data

    DEFF Research Database (Denmark)

    Daugbjerg, Niels; Andersen, Robert A.

    1997-01-01

    Nearly complete ribulose-1,5-bisphosphate carboxylase/ oxygenase (rbcL)sequences from 27 taxa of heterokont algae were determined and combined with rbcL sequences obtained from GenBank for four other heterokont algae and three red algae. The phylogeny of the morphologically diverse haterokont algae...... was inferred from an unambiguously aligned data matrix using the red algae as the root, Significantly higher levels of mutational saturation in third codon positions were found when plotting the pair-wise substitutions with and without corrections for multiple substitutions at the same site for first...... of heterokont algae. The Eustigmatophyceae were the most basal group, and the Dictyochophyceae branched off as the second most basal group. The branching pattern for the other classes was well supported in terms of bootstrap values in the weightedparsimony analysis but was weakly supported in the maximum...

  13. Analysis of {sup 99m}Tc-RBC labeling efficiency between modified in-vitro method and AMC method

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Jae-Kwang [Department of Nuclear Medicine, Asan Medical Center (Korea, Republic of); Dong, Kyung-Rae, E-mail: krdong@hanmail.ne [Department of Radiological Technology, Gwangju Health College University (Korea, Republic of); Department of Nuclear Engineering, Chosun University (Korea, Republic of); Jung, Woo-Young; Shin, Sang-Ki; Cho, Shee-Man [Department of Nuclear Medicine, Asan Medical Center (Korea, Republic of); Kim, Hee-Joung; Lee, Chang-Lae [Department of Radiological Science and Institute of Health Science, Yonsei University (Korea, Republic of); Chung, Woon-Kwan [Department of Nuclear Engineering, Chosun University (Korea, Republic of); Kim, Chang-Bok; Ji, Youn-Sang [Department of Radiological Technology, Gwangju Health College University (Korea, Republic of); Choe, Chong-Hwan [Department of White Memorial Medical Center (United States)

    2010-04-15

    The aim of this study was to increase the labeling efficiency of {sup 99m}Tc-RBC. We compared the clinical utility of the conventional modified in-vitro method (MIM) with our new AMC method. Seventy-two patients (M:44 F:28) were examined. The MIM and AMC method were carried out at the same time. The mean labeling efficiency (%) of MIM vs. AMC were as follows: (1) 90.8 +- 11.4 vs. 95.9 +- 6.8 in total (p = 0.0001); (2) 89.7 +- 12.0 vs. 95.7 +- 6.8 in males (p = 0.0001), 92.9 +- 10.6 vs. 96.3 +- 3.9 in females (p = 0.0001); (3) 89.5 +- 12.9 vs. 95.5 +- 7.8 in the G-I bleeding scan (p = 0.0001), 94.6 +- 4.8 vs. 96.7 +- 3.5 in the liver hemangioma scan (p = 0.035), 96.2 +- 1.96 vs. 97.5 +- 1.11 in the MUGA scan (p = 0.08); and (4) 89.4 +- 12.5 vs. 95.5 +- 7.6 in the decreased RBC count group (p = 0.0001), and 95.9 +- 3.9 vs. 97.1 +- 3.1 the normal RBC count group (p = 0.062). There were significant differences in labeling efficiency between the MIM and AMC methods. In particular, the AMC labeling method was quite useful in decreased RBC count patients.

  14. Long-chain PUFA in Granulocytes, Mononuclear Cells, and RBC in Patients With Cystic Fibrosis: Relation to Liver Disease

    DEFF Research Database (Denmark)

    Jorgensen, Marianne H.; Ott, Peter; Michaelsen, Kim F.

    2012-01-01

    regulator protein (CFTR)-regulated tissues such as granulocytes, monocytes, and lymphocytes. The aim of the present study was to investigate whether patients with CF-related liver disease have lower n-3 LCPUFA level than patients with CF without liver disease.Methods: Twenty patients with known CF...... of liver disease was negatively associated with LCPUFA n-3 levels in CFTR-expressing white blood cells but unrelated to those levels in CFTR-negative RBC....

  15. Temporal distributions, habitat associations and behaviour of the green lizard (Lacerta bilineata and wall lizard (Podarcis muralis on roads in a fragmented landscape in Western France

    Directory of Open Access Journals (Sweden)

    Roger Meek

    2014-12-01

    Full Text Available Observations of the green lizard (Lacerta bilineata and wall lizard (Podarcis muralis on roads in Western France indicated that basking close to the road edge was the predominant activity in L. bilineata but P. muralis mostly foraged. Spatial locations of road mortalities in both species reflected this with the median distances from the road edge greater in P. muralis. Temporal differences in road presence, based on mortality counts and those of live lizards, indicated significantly more lizards were present on roads during late summer and autumn, especially in P. muralis. A significant correlation was found between the monthly presence of live lizards and monthly road mortalities in P. muralis (r = 0.73 but not in L. bilineata (r = 0.64.  Numbers of L. bilineata found on roads bisecting low-density urban areas and roads bordered by hedgerows were higher than expected in relation to the occurrence of these habitats at roadsides. In P. muralis higher than expected numbers were found alongside low-density urban areas and roads bisecting woodland. Generally both species were less commonly seen on roads alongside agricultural areas with no hedgerow border.

  16. An Experimental Study on RBC Count and Serum Potassium Concentration Changes During Compres-sion Transfusion of WBC-removal Whole Blood

    Institute of Scientific and Technical Information of China (English)

    Jin-Lian Cheng; Shi-Fan Han; Ya-Qin Li; Yin-Ping Chu; Yu-Mei Sun; Jin-Feng Guo

    2015-01-01

    Objective: To observe changes in RBC count, changes, RBC morphology, and serum potassium during compressed transfusion of WBC-removal whole blood. Methods: Prepared human WBC-removal whole blood and connected transfusion apparatus with different sizes of intravenous detaining needles ( 18G, 20G, 22G and 24G) . Observed RBC count and serum potassium concentration under different pressures ( 100 mmHg, 200 mmHg, and 300 mmHg) as blood flowed out of the pinhead end of the intravenous detaining needle. Samples ob-tained with the 20G needle were smeared on glass slides, and RBC morphologic changes were ob-served under an oil immersion lens. Results: RBC count and serum potassium changed slightly under different pressures with differ-ent sizes of intravenous detaining needles as blood flowed through the transfusion apparatus. In ad-dition, the observation of blood samples under a common light microscope revealed that coarse-prick, oblong, and spindle cell counts in the visual fields increased gradually as the pressure in-creased. Additionally, a portion of cells had undergone splintering. Conclusions: While applying 18G, 20G, 22G and 24G intravenous detaining needles for blood transfusion under less than 300 mmHg of pressure, no significant RBC count change was found in blood samples in the short term. However, there were significant RBC morphologic changes. The results could offer more basis to ensure the clinical safety of patients undergoing blood transfusion.

  17. Contínua evolução da RBC: um obrigado a todos os colaboradores!

    Directory of Open Access Journals (Sweden)

    Bruno Telles

    2017-07-01

    Full Text Available Desde de seu nascimento, a RBC prima pela divulgação do conhecimento pericial tecnicamente validado e pela discussão de novos métodos e de casos. É o caminho que há de ser constantemente trilhado pelos profissionais da perícia para que não eivem seus laudos periciais e pareceres técnicos de vícios insanáveis cujas consequências seriam nefastas para a justiça. Não é à toa que o Corpo Editorial da RBC, com o imprescindível auxílio dos editores de sessão e dos avaliadores, não envida esforços na contínua evolução da revista em direção à qualidade. Prova disso é a permanente busca por indexação em vários meios e pela elevação dos índices de qualidade por qualificação externa. A RBC aparece no Latindex, no CrossRef, no Google Scholar, no Research Gate, no Directory of Open Access Journals (DOAJ, no Electronic Journal Library (EZ3, no Scilit, no Diadorim, na ABEC Brasil, na Universitäts Bibliothek UBL Leipzig e na Qualis/CAPES.

  18. Correlated amplitude fluctuations of spontaneous otoacoustic emissions in six lizard species

    NARCIS (Netherlands)

    van Dijk, P; Manley, GA; Gallo, L

    Spontaneous otoacoustic emissions were recorded from 17 lizard ears (six species: Gerrhosaurus major, Iguana iguana, Basiliscus vittatus, Tupinambis teguixin, Varanus exanthematicus, and Cordylus tropidosternum), The spectrum of each recording contained multiple spectral peaks. For each peak, the

  19. Structure of capsule around acanthocephalan Corynosoma strumosum from uncommon paratenic hosts-lizards of two species.

    Science.gov (United States)

    Skorobrechova, Ekaterina M; Nikishin, Vladimir P; Lisitsyna, Olga I

    2012-01-01

    Micromorphology and ultrastructure of capsule forming around acanthocephalan Corynosoma strumosum in uncommon paratenic hosts-lizards Lacerta agilis and Lacerta viridis-have been studied. Experimental infestation of the lizards by acanthocephalans obtained from naturally infested sea fishes showed that only small amount of parasites occurred in the intestine of the host was able to migrate into body cavity and to be encapsulated. Micromorphology of capsules of different ages from different species of lizards and micromorphology and ultrastructure of capsules at the age of 1.5 and 10 days appeared to be similar. In the capsule's structure cells of inflammatory rank were prevailing: mononuclear and multinuclear macrophages, eosinophils, and basophils. Fibroblasts were not numerous and were located only in the outer part of a capsule; exocellular collagen fibers were absent. Inflammatory character of capsule confirms the idea that lizards are unsuitable paratenic hosts for corynosomes.

  20. Correlated amplitude fluctuations of spontaneous otoacoustic emissions in six lizard species

    NARCIS (Netherlands)

    van Dijk, P; Manley, GA; Gallo, L

    1998-01-01

    Spontaneous otoacoustic emissions were recorded from 17 lizard ears (six species: Gerrhosaurus major, Iguana iguana, Basiliscus vittatus, Tupinambis teguixin, Varanus exanthematicus, and Cordylus tropidosternum), The spectrum of each recording contained multiple spectral peaks. For each peak, the en

  1. Six genetically distinct clades of Palola (Eunicidae, Annelida) from Lizard Island, Great Barrier Reef, Australia.

    Science.gov (United States)

    Schulze, Anja

    2015-09-18

    A total of 36 lots of Palola spp. (Eunicidae, Annelida) were collected during the Lizard Island Polychaete Workshop on Lizard Island, Great Barrier Reef, Queensland, Australia. Of these, 21 specimens were sequenced for a portion of the mitochondrial cytochrome c oxidase I gene. These sequences were analysed in conjunction with existing sequences of Palola spp. from other geographic regions. The samples from Lizard Island form six distinct clades, although none of them can clearly be assigned to any of the nominal species. Four of the six Lizard Island clades fall into species group A and the remaining two into species group B (which also includes the type species, Palola viridis). All sequenced specimens were characterized morphologically as far as possible and a dichotomous key was assembled. Based on this key, the remaining samples were identified as belonging to one of the clades.

  2. Thermal biology of Phymaturus lizards: evolutionary constraints or lack of environmental variation?

    Science.gov (United States)

    Cruz, Felix B; Belver, Luciana; Acosta, Juan C; Villavicencio, Héctor J; Blanco, Graciela; Cánovas, Maria G

    2009-01-01

    Several aspects of the biology of Phymaturus lizards including their herbivorous diet, specialized microhabitat use, and viviparous reproductive mode are highly conserved within the group. Here, we explore two aspects of Phymaturus thermal biology and test for the co-evolution among aspects of the thermal biology in these lizards, such as thermal preferenda and critical temperatures. Secondly, we explore correlations among variation in thermal biology with elevation and latitude. To do so, we used phylogenetically based comparative analyses (PCM) together with conventional statistics. Our results show that thermal biology for Phymaturus is conservative and our data do not suggest the co-evolution of thermal variables. Moreover, we detected low levels of variation in the thermal parameters studied, and no clear relationships between climatic and thermal variables. As a significant association between climatic and thermal variables could be demonstrated for a set of syntopic Liolaemus lizards, we suggest that thermal biology in Phymaturus lizards may be evolutionarily or ecologically constrained.

  3. Nesting lizards (Bassiana duperreyi) compensate partly, but not completely, for climate change.

    Science.gov (United States)

    Telemeco, Rory S; Elphick, Melanie J; Shine, Richard

    2009-01-01

    Species in which ambient temperatures directly determine offspring sex may be at particular risk as global climates change. Whether or not climate change affects sex ratio depends upon the effectiveness of buffering mechanisms that link ambient regimes to actual nest temperatures. For example, females may simply lay nests earlier in the season, or in more shaded areas, such that incubation thermal regimes are unchanged despite massive ambient fluctuation. Based on eight years of monitoring nests over a 10-year period in the field at an alpine site in southeastern Australia, we show that, even though lizards (Bassiana duperreyi, Scincidae) have adjusted both nest depth and seasonal timing of oviposition in response to rising ambient temperatures, they have been unable to compensate entirely for climate change. That inability stems from the fact that the seasonal progression of soil temperatures, and thus, the degree to which thermal regimes at the time of laying predict subsequent conditions during incubation, also has shifted with climate change. As a result, mean incubation temperatures in natural nests now have crossed the thermal threshold at which incubation temperature directly affects offspring sex in this population.

  4. Comparative analysis of fiber-type composition in the iliofibularis muscle of phrynosomatid lizards (Squamata).

    Science.gov (United States)

    Bonine, K E; Gleeson, T T; Garland, T

    2001-12-01

    The lizard family Phrynosomatidae comprises three subclades: the closely related sand and horned lizards, and their relatives the Sceloporus group. This family exhibits great variation in ecology, behavior, and general body plan. Previous studies also show that this family exhibits great diversity in locomotor performance abilities; as measured on a high-speed treadmill, sand lizards are exceptionally fast sprinters, members of the Sceloporus group are intermediate, and horned lizards are slowest. These differences are paralleled by differences in relative hindlimb span. To determine if muscle fiber-type composition also varies among the three subclades, we examined the iliofibularis (IF), a hindlimb muscle used in lizard locomotion, in 11 species of phrynosomatid lizards. Using histochemical assays for myosin ATPase, an indicator of fast-twitch capacity, and succinic dehydrogenase, denoting oxidative capacity, we classified fiber types into three categories based on existing nomenclature: fast-twitch glycolytic (FG), fast-twitch oxidative-glycolytic (FOG), and slow-twitch oxidative (SO). Sand lizards have a high proportion of FG fibers (64-70%) and a low proportion of FOG fibers (25-33%), horned lizards are the converse (FG fibers 25-31%, FOG fibers 56-66%), and members of the Sceloporus group are intermediate for both FG (41-48%) and FOG (42-45%) content. Hence, across all 11 species %FOG and %FG are strongly negatively correlated. Analysis with phylogenetically independent contrasts indicate that this negative relationship is entirely attributable to the divergence between sand and horned lizards. The %SO also varies among the three subclades. Results from conventional nested ANCOVA (with log body mass as a covariate) indicate that the log mean cross-sectional area of individual muscle fibers differs among species and is positively correlated with body mass across species, but does not differ significantly among subclades. The log cross-sectional area of the IF

  5. Hepatozoon kisrae n. sp. infecting the lizard Agama stellio is transmitted by the tick Hyalomma cf. aegyptium

    Directory of Open Access Journals (Sweden)

    Paperna I.

    2002-03-01

    Full Text Available Hepatozoon kisrae n. sp. was found infecting a starred lizard at a site in southeastern Samaria, Palestine. These lizards were also hosts to the ixodid tick Hyolomma cf. aegyptium, which was demonstrated to be the vector of this hemogregarine. Hepatozoon and tick infections occurred in lizards within a very restricted locality; at a second site, nearby, ticks occurred without Hepatozoon infection. Micro- and macromeronts occurred mainly in the lungs, while cyst-like merogonic stages, mainly dizoic, occurred in the liver. Mature intraerythrocytic gametocytes were stout and encapsulated. Development from oocysts to sporocysts took place in the tick hemocoel, and was examined by transmission electron microscopy. Lizards were successfully infected when fed on sporocyst-infected ticks or viscera of infected lizards. Ticks become infected when fed on infected lizards; sporogony was complete when the ticks reached adult stage, over 40 days after initial attachment.

  6. Temperature has species-specific effects on corticosterone in alligator lizards.

    Science.gov (United States)

    Telemeco, Rory S; Addis, Elizabeth A

    2014-09-15

    In response to conditions that threaten homeostasis and/or life, vertebrates generally increase production of glucocorticoid hormones, such as corticosterone (CORT), which induces an emergency physiological state referred to as the stress response. Given that extreme temperatures pose a threat to performance and survival, glucocorticoid upregulation might be an important component of a vertebrate ectotherm's response to extreme thermal conditions. To address this hypothesis, we experimentally examined the effects of body temperature (10, 20, 28, and 35°C; 5-h exposure) on CORT in two congeneric species of lizard naturally exposed to different thermal environments, northern and southern alligator lizards (Elgaria coerulea and Elgaria multicarinata, respectively). In both species, CORT was similarly elevated at medium and high temperatures (28 and 35°C, respectively), but CORT was only elevated at low temperatures (10°C) in southern alligator lizards. We also examined CORT before and after adrenocorticotrophic hormone (ACTH) challenge. In both species, ACTH induced higher CORT levels than any temperature, suggesting that these animals could respond to further stressors at all experimental temperatures. Finally, we compared our laboratory results to measurements of CORT in field-active southern alligator lizards. Plasma CORT concentrations from our laboratory experiment had the same mean and less variance than the field lizards, suggesting that our laboratory lizards displayed CORT within natural levels. Our results demonstrate that body temperature directly affects CORT in alligator lizards. Moreover, the CORT response of these lizards appears to be adapted to their respective thermal environments. Species-specific differences in the thermal CORT response might be common in vertebrate ectotherms and have implications for species' biogeography and responses to climate change.

  7. Influence of stress on gonadotrophin induced testicular recrudescence in the lizard Mabuya Carinata.

    Science.gov (United States)

    Yajurvedi, H N; Menon, Sneha

    2005-07-01

    Administration (ip) of FSH (10 IU/0.1 ml distilled water (dw)/lizard/alternate days/30 days) to adult male lizards, Mabuya carinata, during the early recrudescence phase of the reproductive cycle caused activation of spermatogenic and steroidogenic activity of the testis, as shown by a significant increase in mean number of spermatogonia, primary spermatocytes and spermatids, and serum levels of testosterone, as compared to initial controls. In addition, there were abundant spermatozoa in the lumen of the seminiferous tubules. Interestingly, administration of a similar dosage of FSH to lizards exposed to stressors (handling, chasing, and noise randomly applied, five times a day for 30 days) resulted in a significant increase in mean number of spermatogonia and primary spermatocytes over initial control values, whereas the number of secondary spermatocytes and spermatids and serum levels of testosterone did not significantly differ from those of initial controls, and were significantly lower than FSH treated normal lizards. Further, spermatozoa were infrequently found in the seminiferous tubules of these lizards. Treatment controls (receiving 0.1 ml dw/lizard/alternate days for 30 days) did not show significant variation in mean number of spermatogonia, spermatocytes and spermatids, and serum levels of testosterone from initial controls. Another group of lizards was exposed to stressors and did not receive FSH. These lizards showed a significant decrease in mean number of secondary spermatocytes compared to treatment controls and all other parameters did not significantly differ from those of both control groups. The results reveal that gonadotrophin-induced spermatogonial proliferation occurs under stressful conditions, whereas progress of spermatogenesis beyond primary spermatocyte stage is impaired due to inhibition (under stress) of gonadotrophin induced steroidogenic activity in M. carinata.

  8. Checklist of the lizards of Togo (West Africa), with comments on systematics, distribution, ecology, and conservation

    OpenAIRE

    Hoinsoude Segniagbeto, G.; Trape, Jean-François; Afiademanyo, K. M.; Rodel, M. O.; Ohler, A.; Dubois, A.; David, P.; Meirte, D.; Glitho, I. A.; Petrozzi, F.; L. Luiselli

    2015-01-01

    The lizard fauna of Togo, a country situated within a natural gap in the rainforest zone of West Africa, is reviewed and updated. In this article, we summarize all available data on the distribution, ecology, and conservation status of the 43 lizard species of Togo. Species richness is uneven between vegetation zones. The submontane forest (ecological zone IV), despite being the smallest, houses the greatest number of species (n = 27), followed by dry forest (ecological zone II, n = 21). Curr...

  9. Are lizards feeling the heat?: a tale of ecology and evolution under two temperatures

    OpenAIRE

    Meiri, Shai; Bauer, Aaron M.; Chirio, Laurent; Colli, Guarino R; Das, Indraneil; Doan, Tiffany M.; Feldman, Anat; Herrera, Fernando-Castro; Novosolov, Maria; Pafilis, Panayiotis; Pincheira-Donoso, Daniel; Powney, Gary; Torres-Carvajal, Omar; Uetz, Peter; Van Damme, Raoul

    2013-01-01

    Aim: Temperature influences most components of animal ecology and life history – but what kind of temperature? Physiologists usually examine the influence of body temperatures, while biogeographers and macroecologists tend to focus on environmental temperatures. We aim to examine the relationship between these two measures, to determine the factors that affect lizard body temperatures and to test the effect of both temperature measures on lizard life history. Location: World-wide. Methods: We...

  10. Preliminary observations on the reproductive cycle of female Tegu lizards (Tupinambis teguizin)

    OpenAIRE

    Yanosky, Ángel Alberto; Mercolli, Claudia

    1991-01-01

    The black tegu lizard, Tupinambis teguixin (Linnaeus 1758) is a common element in the wild all throughout Southamerica except for Chile. This teiid lizard was outstood by earlier travellers such as Sir Charles Waterton who reported for the first time about the delicate food, resembling chicken flesh and frequently consumed by local natives. Despite its relative abundance and both the intense economical and social importance of tegus, as well as its situation in the food web, the reproductive ...

  11. The peak of thermoregulation effectiveness: Thermal biology of the Pyrenean rock lizard, Iberolacerta bonnali (Squamata, Lacertidae).

    Science.gov (United States)

    Ortega, Zaida; Mencía, Abraham; Pérez-Mellado, Valentín

    2016-02-01

    We studied, at 2200m altitude, the thermal biology of the Pyrenean rock lizard, Iberolacerta bonnali, in the glacial cirque of Cotatuero (National Park of Ordesa, Huesca, Spain). The preferred thermal range (PTR) of I. bonnali indicates that it is a cold-adapted ectotherm with a narrow PTR (29.20-32.77°C). However, its PTR (3.57°C) is twice as wide as other Iberolacerta lizards, which may be explained by its broader historical distribution. The studied area is formed by a mosaic of microhabitats which offer different operative temperatures, so that lizards have, throughout their entire daily period of activity, the opportunity to choose the most thermally suitable substrates. I. bonnali achieves an effectiveness of thermoregulation of 0.95, which makes it the highest value found to date among the Lacertidae, and one of the highest among lizards. Their relatively wide distribution, their wider PTR, and their excellent ability of thermoregulation, would make I. bonnali lizards less vulnerable to climate change than other species of Iberolacerta. Thanks to its difficult access, the studied area is not visited by a large number of tourists, as are other areas of the National Park. Thus, it is a key area for the conservation of the Pyrenean rock lizard. By shuttling between suitable microhabitats, lizards achieve suitable body temperatures during all day. However, such thermally suitable microhabitats should vary in other traits than thermal quality, such as prey availability or predation risk. Hence, it seems that these not-thermal traits are not constraining habitat selection and thermoregulation in this population. Therefore, future research in this population may study the causes that would lead lizards to prioritize thermoregulation to such extent in this population. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Cytogenetic and molecular characterization of lacertid lizard species from the Iberian Peninsula

    OpenAIRE

    Rojo Oróns, Verónica

    2016-01-01

    [Abstract] Reptiles, with their great diversity of sex-determining systems, have long been regarded as a model group for studying the evolution of sex determination and sex chromosomes. They also hold a key phylogenetic position to elucidate the organization and evolution of amniote genomes. This PhD thesis aims to contribute to this understanding by investigating sex chromosomes and karyotype evolution in lacertid lizards, with a focus on rock lizard species (genus Iberolac...

  13. On the water lapping of felines and the water running of lizards: A unifying physical perspective

    OpenAIRE

    Aristoff, Jeffrey M.; Stocker, Roman; Reis, Pedro M.; Jung, Sunghwan

    2011-01-01

    We consider two biological phenomena taking place at the air-water interface: the water lapping of felines and the water running of lizards. Although seemingly disparate motions, we show that they are intimately linked by their underlying hydrodynamics and belong to a broader class of processes called Froude mechanisms. We describe how both felines and lizards exploit inertia to defeat gravity, and discuss water lapping and water running in the broader context of water exit and water entry, r...

  14. On the water lapping of felines and the water running of lizards: A unifying physical perspective

    OpenAIRE

    Aristoff, Jeffrey M.; Stocker, Roman; Reis, Pedro M.; Jung, Sunghwan

    2011-01-01

    We consider two biological phenomena taking place at the air-water interface: the water lapping of felines and the water running of lizards. Although seemingly disparate motions, we show that they are intimately linked by their underlying hydrodynamics and belong to a broader class of processes called Froude mechanisms. We describe how both felines and lizards exploit inertia to defeat gravity, and discuss water lapping and water running in the broader context of water exit and water entry, r...

  15. Recurrent evolution of herbivory in small, cold-climate lizards: Breaking the ecophysiological rules of reptilian herbivory

    OpenAIRE

    Espinoza, Robert E.; Wiens, John J.; Tracy, C. Richard

    2004-01-01

    Herbivory has evolved in many groups of vertebrates, but it is rare among both extinct and extant nonavian reptiles. Among squamate reptiles, (lizards, snakes, and their relatives), 7,800 species are considered to be herbivorous, and herbivory is restricted to lizards. Here, we show that within a group of South American lizards (Liolaemidae, ≈170 species), herbivory has evolved more frequently than in all other squamates combined and at a rate estimated to be >65 times faster. Furthermore, in...

  16. Fossilized Venom: The Unusually Conserved Venom Profiles of Heloderma Species (Beaded Lizards and Gila Monsters

    Directory of Open Access Journals (Sweden)

    Ivan Koludarov

    2014-12-01

    Full Text Available Research into snake venoms has revealed extensive variation at all taxonomic levels. Lizard venoms, however, have received scant research attention in general, and no studies of intraclade variation in lizard venom composition have been attempted to date. Despite their iconic status and proven usefulness in drug design and discovery, highly venomous helodermatid lizards (gila monsters and beaded lizards have remained neglected by toxinological research. Proteomic comparisons of venoms of three helodermatid lizards in this study has unravelled an unusual similarity in venom-composition, despite the long evolutionary time (~30 million years separating H. suspectum from the other two species included in this study (H. exasperatum and H. horridum. Moreover, several genes encoding the major helodermatid toxins appeared to be extremely well-conserved under the influence of negative selection (but with these results regarded as preliminary due to the scarcity of available sequences. While the feeding ecologies of all species of helodermatid lizard are broadly similar, there are significant morphological differences between species, which impact upon relative niche occupation.

  17. Detection of Campylobacter jejuni in Lizard Faeces from Central Australia Using Quantitative PCR

    Directory of Open Access Journals (Sweden)

    Harriet Whiley

    2016-12-01

    Full Text Available Worldwide, Campylobacter is a significant cause of gastrointestinal illness. It is predominately considered a foodborne pathogen, with human exposure via non-food transmission routes generally overlooked. Current literature has been exploring environmental reservoirs of campylobacteriosis including potential wildlife reservoirs. Given the close proximity between lizards and human habitats in Central Australia, this study examined the presence of Campylobacter jejuni from lizard faeces collected from this region. Of the 51 samples collected, 17 (33% (this included 14/46 (30% wild and 3/5 (60% captive lizard samples were positive for C. jejuni using quantitative PCR (qPCR. This was the first study to investigate the presence of C. jejuni in Australian lizards. This has public health implications regarding the risk of campylobacteriosis from handling of pet reptiles and through cross-contamination or contact with wild lizard faeces. Additionally this has implication for horizontal transmission via lizards of C. jejuni to food production farms. Further research is needed on this environmental reservoir and potential transmission routes to reduce the risk to public health.

  18. Incidence, causes and consequences of pregnancy failure in viviparous lizards: implications for research and conservation settings.

    Science.gov (United States)

    Hare, Kelly M; Cree, Alison

    2010-01-01

    Research on the causes of pregnancy failure in vertebrates has historically been mammal-focussed. However, live-birth (viviparity) has evolved multiple times, and is present in all other vertebrate taxa except Aves and Agnatha. Viviparous lizards (O. Squamata, excluding snakes and amphisbaenians) provide a valuable experimental group when studying major evolutionary events and some are also species of high conservation value. Consequently, both researchers and herpetoculturists often require high reproductive output from captive-held lizards. We reviewed the literature to determine potential or known causes of pregnancy failure for captive lizards. Pregnancy success across species averages approximately 86%, but varies extensively and does not appear to be related to embryonic stage when brought into captivity or level of placentation. Causes of pregnancy failure also vary among species, but correct thermal environments are vital to success, and providing adequate nutrition before vitellogenesis increases the number of viable offspring. A coordinated sequence of hormonal changes involving both pro-pregnancy and pro-labour factors is important for successful pregnancies, although uncertainty remains around the maternal concentrations of corticosterone that allow successful development. Several research areas commonly studied in mammals have yet to be explored or fully addressed in pregnant lizards, including impacts of toxins, parasites, UV light and nutritional quality. As viviparity has evolved over 100 times in lizards, and many different levels of placentation exist, pregnant lizards provide valuable models for studies in ecology and evolution and offer a useful comparison for studies on other viviparous vertebrates.

  19. Fossilized venom: the unusually conserved venom profiles of Heloderma species (beaded lizards and gila monsters).

    Science.gov (United States)

    Koludarov, Ivan; Jackson, Timothy N W; Sunagar, Kartik; Nouwens, Amanda; Hendrikx, Iwan; Fry, Bryan G

    2014-12-22

    Research into snake venoms has revealed extensive variation at all taxonomic levels. Lizard venoms, however, have received scant research attention in general, and no studies of intraclade variation in lizard venom composition have been attempted to date. Despite their iconic status and proven usefulness in drug design and discovery, highly venomous helodermatid lizards (gila monsters and beaded lizards) have remained neglected by toxinological research. Proteomic comparisons of venoms of three helodermatid lizards in this study has unravelled an unusual similarity in venom-composition, despite the long evolutionary time (~30 million years) separating H. suspectum from the other two species included in this study (H. exasperatum and H. horridum). Moreover, several genes encoding the major helodermatid toxins appeared to be extremely well-conserved under the influence of negative selection (but with these results regarded as preliminary due to the scarcity of available sequences). While the feeding ecologies of all species of helodermatid lizard are broadly similar, there are significant morphological differences between species, which impact upon relative niche occupation.

  20. Coloration affects heating and cooling in three color morphs of the Australian bluetongue lizard, Tiliqua scincoides.

    Science.gov (United States)

    Geen, Michael R S; Johnston, Gregory R

    2014-07-01

    The color-mediated thermoregulation hypothesis predicts that dark body color (low reflectance) allows organisms to gain heat more efficiently than does pale coloration (high reflectance). This prediction is intuitive and widely assumed to be true, but has poor empirical support. We used rare, captive-bred, mutant melanistic, albino and wild-type Australian bluetongue lizards, Tiliqua scincoides to measure the effects of skin reflectance on the heating and cooling rates. We measured heating under an artificial radiant heat source and cooling rates in an ice-cooled box using live lizards in a room with still air. The effect of skin reflectance on heat transfer was clear, despite the substantial influence of body size. Melanistic T. scincoides showed low reflectance and gained heat faster than highly reflective albinos. Melanistic lizards also lost heat faster than albinos. Wild-type lizards were intermediate in reflectance, gained heat at rates indistinguishable from melanistic lizards, and lost heat at rates indistinguishable from albino lizards. This study system allowed us to control for variables that were confounded in other studies and may explain the inconsistent support for the color-mediated thermoregulation hypothesis. Our results provide clear evidence that skin reflectance influences the rate of heating and cooling in ectotherms.

  1. The use of a lacertid lizard as a model for reptile ecotoxicology studies: part 2--biomarkers of exposure and toxicity among pesticide exposed lizards.

    Science.gov (United States)

    Amaral, Maria José; Bicho, Rita C; Carretero, Miguel A; Sanchez-Hernandez, Juan C; Faustino, Augusto M R; Soares, Amadeu M V M; Mann, Reinier M

    2012-05-01

    As part of a wider study examining the impacts of corn pesticides on lacertid lizards in north-western Portugal, we examined various physiological, biochemical, and histological biomarkers of exposure and effect among field populations of Podarcis bocagei. Biomarkers included body condition index, standard metabolic rate, locomotor performance, parasitization, glutathione oxidative pathways and related enzyme activity, lipid peroxidation and liver and testis histology. Few of the various biomarkers investigated provided statistically significant evidence of toxic effect. However, using a weight of evidence approach, we conclude that pesticides are affecting lizards living in the vicinity of pesticide exposed corn agriculture sites. Lizards from these locations present a profile of animals under metabolic stress with reduced condition indices, increased standard metabolic rate, lower incidence of hepatocyte vacuolation, altered iron metabolism, increased activation of GSH oxidation pathways, and even increased prevalence of hemoparasites.

  2. Predation Risk Perception, Food Density and Conspecific Cues Shape Foraging Decisions in a Tropical Lizard: e0138016

    National Research Council Canada - National Science Library

    Maximilian Drakeley; Oriol Lapiedra; Jason J Kolbe

    2015-01-01

    .... We presented male lizards with foraging opportunities to test how the presence of conspecifics, predation-risk perception, the abundance of food, and interactions among these factors determines...

  3. Choosing between a rock and a hard place: Camouflage in the round-tailed horned lizard Phrynosoma modestum

    Institute of Scientific and Technical Information of China (English)

    William E.COOPER; Wade C.SHERBROOKE

    2012-01-01

    The round-tailed horned lizard Phrynosoma modestum is cryptically colored and resembles a small stone when it draws legs close to its body and elevates its back.We investigated effectiveness of camouflage in P.modestum and its dependence on stones by placing a lizard in one of two microhabitats (uniform sand or sand with surface rocks approximately the same size as lizards).An observer who knew which microhabitat contained the lizard was asked to locate the lizard visually.Latency to detection was longer and probability of no detection within 60 s was higher for lizards on rock background than on bare sand.In arenas where lizards could choose to occupy rock or bare sand,much higher proportions selected rocky backgrounds throughout the day;at night all lizards slept among stones.A unique posture gives P.modestum a rounded appearance similar to many natural stones.Lizards occasionally adopted the posture,but none did so in response to a nearby experimenter.Stimuli that elicit the posture are unknown.That P.modestum is better camouflaged among rocks than on bare sand and prefers to occupy rocky areas suggests that special resemblance to rocks (masquerade) enhances camouflage attributable to coloration and immobility.

  4. A telencephalospinal projection in the Tegu lizard (Tupinambis teguixin).

    Science.gov (United States)

    Follett, K A

    1989-09-04

    Tegu lizards (Tupinambis teguixin) were studied to determine the presence of a homologue of the mammalian corticospinal tract. The sources of telencephalic efferent projections to the spinal cord were determined by evaluating the localization of retrogradely transported horseradish peroxidase applied in the cervical spinal cord. Labeled cells were present in subtelencephalic sites reported previously by other authors and, in addition, were found in the principal sensory and motor nuclei of the trigeminal nerve and in the nucleus of the posterior commissure. A telencephalospinal projection was identified, originating in the ventral caudal telencephalon. Histochemical staining revealed a high concentration of acetylcholinesterase in cells and neuropil in the same area. This tract is suggested to be homologous to the mammalian amygdalospinal tract. No reptilian homologue of the corticospinal tract was identified.

  5. Syllidae (Annelida: Phyllodocida) from Lizard Island, Great Barrier Reef, Australia.

    Science.gov (United States)

    Aguado, M Teresa; Murray, Anna; Hutchings, Pat

    2015-09-18

    Thirty species of the family Syllidae (Annelida, Phyllodocida) from Lizard Island have been identified. Three subfamilies (Eusyllinae, Exogoninae and Syllinae) are represented, as well as the currently unassigned genera Amblyosyllis and Westheidesyllis. The genus Trypanobia (Imajima & Hartman 1964), formerly considered a subgenus of Trypanosyllis, is elevated to genus rank. Seventeen species are new reports for Queensland and two are new species. Odontosyllis robustus n. sp. is characterized by a robust body and distinct colour pattern in live specimens consisting of lateral reddish-brown pigmentation on several segments, and bidentate, short and distally broad falcigers. Trypanobia cryptica n. sp. is found in association with sponges and characterized by a distinctive bright red colouration in live specimens, and one kind of simple chaeta with a short basal spur.

  6. A new filaria of a lizard transmitted by sandflies

    Directory of Open Access Journals (Sweden)

    Odile Bain

    1992-01-01

    Full Text Available A description is given of Madathamugadia wanjii n. sp., a Splendidofilariinae parasite of the gecko Ptyodactylus hasselquistii, on the west bank of the River Jordan and of its life cycle in Phlebotomus duboscqi. The new species is close to M. ivaschkini (Annaev, 1976 n. comb., of Turkmenistan, wich is also transmitted by sandflies (Reznik, 1982. The genus Madathamugadia is now comprised of four species, two from Madagascar and two from the Mediterranean sub-region; it differs from the genus Thamugadia by the presence of a double row of papillae anterior to the cloaca of the male. The larval characters of Splendidofilarinae of lizards confirm the affinity of these parasites to the Splendidofilarinae of birds (Chandlerella and Splendidofilaria; the first group could have arisen from the second by "captures" wich could have occurred in several places.

  7. Undulatory swimming in sand: subsurface locomotion of the sandfish lizard.

    Science.gov (United States)

    Maladen, Ryan D; Ding, Yang; Li, Chen; Goldman, Daniel I

    2009-07-17

    The desert-dwelling sandfish (Scincus scincus) moves within dry sand, a material that displays solid and fluidlike behavior. High-speed x-ray imaging shows that below the surface, the lizard no longer uses limbs for propulsion but generates thrust to overcome drag by propagating an undulatory traveling wave down the body. Although viscous hydrodynamics can predict swimming speed in fluids such as water, an equivalent theory for granular drag is not available. To predict sandfish swimming speed, we developed an empirical model by measuring granular drag force on a small cylinder oriented at different angles relative to the displacement direction and summing these forces over the animal movement profile. The agreement between model and experiment implies that the noninertial swimming occurs in a frictional fluid.

  8. Mitochondrial DNA recombination in a free-ranging Australian lizard.

    Science.gov (United States)

    Ujvari, Beata; Dowton, Mark; Madsen, Thomas

    2007-04-22

    Mitochondrial DNA (mtDNA) is the traditional workhorse for reconstructing evolutionary events. The frequent use of mtDNA in such analyses derives from the apparent simplicity of its inheritance: maternal and lacking bi-parental recombination. However, in hybrid zones, the reproductive barriers are often not completely developed, resulting in the breakdown of male mitochondrial elimination mechanisms, leading to leakage of paternal mitochondria and transient heteroplasmy, resulting in an increased possibility of recombination. Despite the widespread occurrence of heteroplasmy and the presence of the molecular machinery necessary for recombination, we know of no documented example of recombination of mtDNA in any terrestrial wild vertebrate population. By sequencing the entire mitochondrial genome (16761bp), we present evidence for mitochondrial recombination in the hybrid zone of two mitochondrial haplotypes in the Australian frillneck lizard (Chlamydosaurus kingii).

  9. Oogenesis in the viviparous matrotrophic lizard Mabuya brachypoda.

    Science.gov (United States)

    Hernández-Franyutti, Arlette; Uribe Aranzábal, Mari Carmen; Guillette, Louis J

    2005-08-01

    Oogenesis in the lizard Mabuya brachypoda is seasonal, with oogenesis initiated during May-June and ovulation occurring during July-August. This species ovulates an egg that is microlecithal, having very small yolk stores. The preovulatory oocyte attains a maximum diameter of 0.9-1.3 mm. Two elongated germinal beds, formed by germinal epithelia containing oogonia, early oocytes, and somatic cells, are found on the dorsal surface of each ovary. Although microlecithal eggs are ovulated in this species, oogenesis is characterized by both previtellogenic and vitellogenic stages. During early previtellogenesis, the nucleus of the oocyte contains lampbrush chromosomes, whereas the ooplasm stains lightly with a perinuclear yolk nucleus. During late previtellogenesis the ooplasm displays basophilic staining with fine granular material composed of irregularly distributed bundles of thin fibers. A well-defined zona pellucida is also observed. The granulosa, initially composed of a single layer of squamous cells during early previtellogenesis, becomes multilayered and polymorphic. As with other squamate reptiles, the granulosa at this stage is formed by three cell types: small, intermediate, and large or pyriform cells. As vitellogenesis progresses the oocyte displays abundant vacuoles and small, but scarce, yolk platelets at the periphery of the oocyte. The zona pellucida attains its maximum thickness during late oogenesis, a period when the granulosa is again reduced to a single layer of squamous cells. The vitellogenic process observed in M. brachypoda corresponds with the earliest vitellogenic stages seen in other viviparous lizard species with larger oocytes. The various species of the genus Mabuya provided us with important models to understand a major transition in the evolution of viviparity, the development of a microlecithal egg.

  10. The Crossmatch/Issue Ratio:  Use of a Novel Quality Indicator and Results of an International Survey on RBC Crossmatching and Issuing Practices

    DEFF Research Database (Denmark)

    Yazer, Mark H; Alcantara, Ramir; Beizai, Pouneh

    2016-01-01

    OBJECTIVES: To understand the worldwide scope of RBC crossmatching and issuing practices and measure efficiency using a novel quality indicator, the crossmatch/issue (C/I) ratio. METHODS: An electronic survey was disseminated to hospital transfusion services collecting details about RBC....... 1.35 ± 0.36, respectively; P = .19). CONCLUSIONS: Electronic crossmatching is common, and the C/I ratio can be an indicator of efficiency....

  11. The effect of RBC transfusions on cytokine gene expression after cardiac surgery in patients developing post-operative multiple organ failure.

    Science.gov (United States)

    Sitniakowsky, L S; Later, A F L; van de Watering, L M G; Bogaerts, M; Brand, A; Klautz, R J M; Smit, N P M; van Hilten, J A

    2011-08-01

    To determine the effect of red blood cell (RBC) transfusions during cardiac surgery on cytokine gene expression (GE) in relation to multiple organ failure (MOF) development after systemic inflammatory response syndrome (SIRS). RBC transfusion in cardiac surgery patients is dose-dependently associated with post-operative MOF, possibly acting as a second hit after cardiopulmonary bypass. For this observational study, 29 patients divided into four groups of cardiac surgery patients were selected from a randomised controlled trial (RCT). Group 1: no-RBC, no-MOF (N = 8); group 2: MOF, no-RBC (N = 7); group 3: RBC, no-MOF (N = 6); group 4: RBC and MOF (N = 8). Selection was based on age, gender, number of (leukocyte-depleted) RBC transfusions, type and duration of surgery. A 114 cytokine GE array was applied to blood samples withdrawn before and 24 h after surgery. Expression of selected genes was confirmed with reverse transcriptase real time-polymerase chain reaction (RT-PCR). Nineteen of the 39 detectable genes showed a significant change in GE after surgery. Confirmed by RT-PCR, transfused MOF patients exhibit significantly less downregulation of CD40 ligand than control patients. Patients who would develop MOF show significantly larger increases in GE of transforming growth factor-α (TGF-α), tumour necrosis factor (TNF)-superfamily members 10 and 13B (TNFsf10/13B). When tested at 24 h after surgery, cytokine GE in peripheral blood leucocytes showed no significant differences between those transfused and those not transfused. Some alterations were seen in those developing MOF compared to those who did not, but the findings offer no role of leukocyte depleted (LD) RBC transfusion in the development of MOF. © 2011 The Authors. Transfusion Medicine © 2011 British Blood Transfusion Society.

  12. Involvement of heterotrimeric G protein in signal transduc-tion of extracellular calmodu-lin in regulating rbcS expres-sion

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The role of heterotrimeric G protein in signal transduction pathway of extracellular calmodulin in regulating rbcS expression was examined in suspension-cultured cells of transgenic tobacco. Pharmalogical experiments indicated that G protein agonist cholera toxin enhanced rbcS expression and heterotrimeric G protein antagonist pertussis toxin inhibited rbcS expression in transgenic tobacco cells. Pertussis toxin also inhibited the enhancement effect caused by exogenous purified calmodulin on rbcS expression, whereas cholera toxin completely reversed the inhibitory effects caused by anti-calmodulin serum on rbcS expression. The right side-out vesicles from tobacco cell membrane were purified, which contained all of substrates for fluometric assay of GTPase activity. Exogenous purified calmodulin, when adding directly to the medium of plasma membrane vesicles, significantly activated GTPase activity in the right side-out plasma membrane vesicles, and this increase in GTPase activity was completely inhibited both by hetero-trimeric G proteins antagonist pertussis toxin and nonhy-drolyzable GTP analogs GMP-PCP. These results provided the evidence that heterotrimeric G proteins may be involved in signal transduction pathways of extracellular calmodulin to regulate rbcS gene expression.

  13. Seasonal patterns of body temperature and microhabitat selection in a lacertid lizard

    Science.gov (United States)

    Ortega, Zaida; Pérez-Mellado, Valentín

    2016-11-01

    In temperate areas, seasonal changes entail a source of environmental variation potentially important for organisms. Temperate ectotherms may be adapted to the seasonal fluctuations in environmental traits. For lizards, behavioural adaptations regarding microhabitat selection could arise to improve thermoregulation during the different seasons. However, little is still known about which traits influence microhabitat selection of lizards and their adaptation to seasonality. Here we used Podarcis guadarramae to study the role of potential intrinsic (body size, sex, age) and environmental traits (air and substrate temperatures, wind speed, and sunlight) in the seasonal changes of body temperatures and microhabitat selection of lizards. We measured body temperatures of lizards in the same habitat during the four seasons and compared the climatic variables of the microhabitats selected by lizards with the mean climatic conditions available in their habitat. Body temperatures were similar for adult males, adult females, and juveniles within each season, being significantly higher in summer than in the other seasons, and in spring than in winter. The same pattern was found regarding substrate and air temperatures of the selected microhabitats. Wind speed and air temperature did not affect body temperatures, while body length was marginally significant and substrate temperatures and season did affect the body temperatures of lizards. Our results during the whole year support the idea that the seasonality could be the most important factor affecting body temperatures of these temperate species. Regarding microhabitat selection, environmental constraints, as environmental temperatures and wind speed, affected the seasonal changes on behavioural thermoregulation of lizards. This effect was similar between sexes and age classes, and was independent of body size. In addition, importance of sunlight exposure of the selected microhabitats (full sun, filtered sun, or shade) also

  14. Ultraviolet radiation does not increase oxidative stress in the lizard Psammodromus algirus along an elevational gradient.

    Science.gov (United States)

    Reguera, Senda; Zamora-Camacho, Francisco J; Melero, Elena; García-Mesa, Sergio; Trenzado, Cristina E; Cabrerizo, Marco J; Sanz, Ana; Moreno-Rueda, Gregorio

    2015-05-01

    Lizards, as ectotherms, spend much time basking for thermoregulating exposed to solar radiation. Consequently, they are subjected to ultraviolet radiation (UVR), which is the most harmful component of solar radiation spectrum. UVR can provoke damages, from the molecular to tissue level, even cause death. Photooxidation triggered by UVR produces reactive oxidative species (ROS). When antioxidant machinery cannot combat the ROS concentration, oxidative stress occurs in the organisms. Given that UVR increases with elevation, we hypothesised that lizards from high elevations should be better adapted against UVR than lizards from lower elevations. In this work, we test this hypothesis in Psammodromus algirus along an elevation gradient (three elevational belts, from 300 to 2500 m above sea level). We ran an experiment in which lizards from each elevation belt were exposed to 5-hour doses of UVR (UV-light bulb, experimental group) or photosynthetically active radiation (white-light bulb, control group) and, 24 h after the exposure, we took tissue samples from the tail. We measured oxidative damage (lipid and protein peroxidation) and antioxidant capacity as oxidative-stress biomarkers. We found no differences in oxidative stress between treatments. However, consistent with a previous work, less oxidative damage appeared in lizards from the highlands. We conclude that UVR is not a stressor agent for P. algirus; however, our findings suggest that the lowland environment is more oxidative for lizards. Therefore, P. algirus is well adapted to inhabit a large elevation range, and this would favour the lizard in case it ascends in response to global climate change.

  15. rbcL and matK earn two thumbs up as the core DNA barcode for ferns.

    Directory of Open Access Journals (Sweden)

    Fay-Wei Li

    Full Text Available BACKGROUND: DNA barcoding will revolutionize our understanding of fern ecology, most especially because the accurate identification of the independent but cryptic gametophyte phase of the fern's life history--an endeavor previously impossible--will finally be feasible. In this study, we assess the discriminatory power of the core plant DNA barcode (rbcL and matK, as well as alternatively proposed fern barcodes (trnH-psbA and trnL-F, across all major fern lineages. We also present plastid barcode data for two genera in the hyperdiverse polypod clade--Deparia (Woodsiaceae and the Cheilanthes marginata group (currently being segregated as a new genus of Pteridaceae--to further evaluate the resolving power of these loci. PRINCIPAL FINDINGS: Our results clearly demonstrate the value of matK data, previously unavailable in ferns because of difficulties in amplification due to a major rearrangement of the plastid genome. With its high sequence variation, matK complements rbcL to provide a two-locus barcode with strong resolving power. With sequence variation comparable to matK, trnL-F appears to be a suitable alternative barcode region in ferns, and perhaps should be added to the core barcode region if universal primer development for matK fails. In contrast, trnH-psbA shows dramatically reduced sequence variation for the majority of ferns. This is likely due to the translocation of this segment of the plastid genome into the inverted repeat regions, which are known to have a highly constrained substitution rate. CONCLUSIONS: Our study provides the first endorsement of the two-locus barcode (rbcL+matK in ferns, and favors trnL-F over trnH-psbA as a potential back-up locus. Future work should focus on gathering more fern matK sequence data to facilitate universal primer development.

  16. 基于蜥蜴干扰的大针茅草原补偿生长研究%STUDIES OF LIZARD INTERFERENCE ON COMPENSATORY GROWTH OF STIPA GRANDIS STEPPE

    Institute of Scientific and Technical Information of China (English)

    杨涵越; 聂梅; 张景慧; 黄永梅

    2014-01-01

    Ecological monitoring experience in Maodeng Pasture Field Ecology Observation Area near Xilinhot city was applied to analyze differences in three plots (control,fenced,lizard)to study effects of lizard activity on biodiversity,community structure,community biomass and biomass of dominant species of steppe in Inner Mongolia,China.Data showed that lizard activity increased total above-ground biomass and diversity significantly (Plizard plot>control plot;For Stipa grandis it was control plot>lizard plot>fenced plot.Line transect method was used to reveal a linear relationship between number of lizard caves and lizard habitat patch perimeter.%基于内蒙古锡林郭勒盟大针茅草原毛登牧场的生态监测,进行实地采样,通过对围封样地、大针茅样地、蜥蜴样地进行对比,研究蜥蜴活动对大针茅草原地上生物量、物种多样性、植物个体形态的干扰作用,进而探讨蜥蜴干扰对不同植物类群补偿效应的影响.结果表明,蜥蜴活动对大针茅草原地上总生物量增加的影响极显著(P<0.01),对大针茅草原生物多样性增加的影响显著(P<0.05).大针茅和羊草个体生物量在样地间存在差异,羊草生物量由大到小排序为围封样地、蜥蜴样地、大针茅样地;大针茅生物量由大到小排序为大针茅样地、蜥蜴样地、围封样地.通过样线法对蜥蜴活动的生境状况进行调查,表明蜥蜴活动所在生境的斑块的周长与聚集的洞穴的个数成线性关系.

  17. Direct and indirect effects of petroleum production activities on the western fence lizard (Sceloporus occidentalis) as a surrogate for the dunes sagebrush lizard (Sceloporus arenicolus).

    Science.gov (United States)

    Weir, Scott M; Knox, Ami; Talent, Larry G; Anderson, Todd A; Salice, Christopher J

    2016-05-01

    The dunes sagebrush lizard (Sceloporus arenicolus) is a habitat specialist of conservation concern limited to shin oak sand dune systems of New Mexico and Texas (USA). Because much of the dunes sagebrush lizard's habitat occurs in areas of high oil and gas production, there may be direct and indirect effects of these activities. The congeneric Western fence lizard (Sceloporus occidentalis) was used as a surrogate species to determine direct effects of 2 contaminants associated with oil and gas drilling activities in the Permian Basin (NM and TX, USA): herbicide formulations (Krovar and Quest) and hydrogen sulfide gas (H2S). Lizards were exposed to 2 concentrations of H2 S (30 ppm or 90 ppm) and herbicide formulations (1× or 2× label application rate) representing high-end exposure scenarios. Sublethal behavioral endpoints were evaluated, including sprint speed and time to prey detection and capture. Neither H2S nor herbicide formulations caused significant behavioral effects compared to controls. To understand potential indirect effects of oil and gas drilling on the prey base, terrestrial invertebrate biomass and order diversity were quantified at impacted sites to compare with nonimpacted sites. A significant decrease in biomass was found at impacted sites, but no significant effects on diversity. The results suggest little risk from direct toxic effects, but the potential for indirect effects should be further explored.

  18. Variation in skull size and shape of the Common wall lizard (Podarcis muralis): allometric and non-allometric shape changes

    NARCIS (Netherlands)

    Urošević, A.; Ljubisavljević, K.; Ivanović, A.

    2014-01-01

    We analysed patterns of skull size and shape variation among populations of the Common wall lizard (Podarcis muralis) in the Central Balkans, particularly the effecs of insularity and the presence of the ecologically similar lacertid lizard species P. melisellensis. Two components of shape variation

  19. What are carotenoids signaling? Immunostimulatory effects of dietary vitamin E, but not of carotenoids, in Iberian green lizards

    Science.gov (United States)

    Kopena, Renata; López, Pilar; Martín, José

    2014-12-01

    In spite that carotenoid-based sexual ornaments are one of the most popular research topics in sexual selection of animals, the antioxidant and immunostimulatory role of carotenoids, presumably signaled by these colorful ornaments, is still controversial. It has been suggested that the function of carotenoids might not be as an antioxidant per se, but that colorful carotenoids may indirectly reflect the levels of nonpigmentary antioxidants, such as melatonin or vitamin E. We experimentally fed male Iberian green lizards ( Lacerta schreiberi) additional carotenoids or vitamin E alone, or a combination of carotenoids and vitamin E dissolved in soybean oil, whereas a control group only received soybean oil. We examined the effects of the dietary supplementations on phytohaemagglutinin (PHA)-induced skin-swelling immune response and body condition. Lizards that were supplemented with vitamin E alone or a combination of vitamin E and carotenoids had greater immune responses than control lizards, but animals supplemented with carotenoids alone had lower immune responses than lizards supplemented with vitamin E and did not differ from control lizards. These results support the hypothesis that carotenoids in green lizards are not effective as immunostimulants, but that they may be visually signaling the immunostimulatory effects of non-pigmentary vitamin E. In contrast, lizards supplemented with carotenoids alone have higher body condition gains than lizards in the other experimental groups, suggesting that carotenoids may be still important to improve condition.

  20. Variation in skull size and shape of the Common wall lizard (Podarcis muralis): allometric and non-allometric shape changes

    NARCIS (Netherlands)

    Urošević, A.; Ljubisavljević, K.; Ivanović, A.

    2014-01-01

    We analysed patterns of skull size and shape variation among populations of the Common wall lizard (Podarcis muralis) in the Central Balkans, particularly the effecs of insularity and the presence of the ecologically similar lacertid lizard species P. melisellensis. Two components of shape variation

  1. spatial distribution pattern of the steppe toad-headed lizard (phrynocephalus frontalis) and its influencing factors

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    spatial distribution patterns are associated with life history and behavioral adaptations of animals.for studying the spatial distribution pattern of the steppe toad-headed lizard (phrynocephalusfrontalis) and its influencing factors,we conducted experiments in hunshandake sandy land in inner mongolia,china in july 2009.by calculating the clustered indices,we found that the lizard was aggregately distributed when the sampling quadrat was smaller than 10 m × 10 m,and uniformly distributed when it was greater than 10 m × 10 m.the nearest neighbor rule showed a clustering distribution pattern for p frontalis and the distribution pattern was quadrat-sampling dependent.furthermore,the cluster was determined by environmental factors when the sampling quadrat was smaller than 20 m × 20 m,but it was determined by both environmental factors and characteristics of the lizard when it was larger than 20 m × 20 m.our results suggested that the steppe toad-headed lizards tended to aggregate into suitable habitat patches in desert areas.additionally,we discussed that the lizard aggregation could be potentially used as an indictor of movement of sand dunes.

  2. Are mountain habitats becoming more suitable for generalist than cold-adapted lizards thermoregulation?

    Science.gov (United States)

    Ortega, Zaida; Mencía, Abraham; Pérez-Mellado, Valentín

    2016-01-01

    Mountain lizards are highly vulnerable to climate change, and the continuous warming of their habitats could be seriously threatening their survival. We aim to compare the thermal ecology and microhabitat selection of a mountain lizard, Iberolacerta galani, and a widely distributed lizard, Podarcis bocagei, in a montane area. Both species are currently in close syntopy in the study area, at 1,400 m above the sea level. We determined the precision, accuracy and effectiveness of thermoregulation, and the thermal quality of habitat for both species. We also compared the selection of thermal microhabitats between both species. Results show that I. galani is a cold-adapted thermal specialist with a preferred temperature range of 27.9-29.7 °C, while P. bocagei would be a thermal generalist, with a broader and higher preferred temperature range (30.1-34.5 °C). In addition, I. galani selects rocky substrates while P. bocagei selects warmer soil and leaf litter substrates. The thermal quality of the habitat is higher for P. bocagei than for I. galani. Finally, P. bocagei achieves a significantly higher effectiveness of thermoregulation (0.87) than I. galani (0.80). Therefore, these mountain habitat conditions seem currently more suitable for performance of thermophilic generalist lizards than for cold-specialist lizards.

  3. Are mountain habitats becoming more suitable for generalist than cold-adapted lizards thermoregulation?

    Directory of Open Access Journals (Sweden)

    Zaida Ortega

    2016-05-01

    Full Text Available Mountain lizards are highly vulnerable to climate change, and the continuous warming of their habitats could be seriously threatening their survival. We aim to compare the thermal ecology and microhabitat selection of a mountain lizard, Iberolacerta galani, and a widely distributed lizard, Podarcis bocagei, in a montane area. Both species are currently in close syntopy in the study area, at 1,400 m above the sea level. We determined the precision, accuracy and effectiveness of thermoregulation, and the thermal quality of habitat for both species. We also compared the selection of thermal microhabitats between both species. Results show that I. galani is a cold-adapted thermal specialist with a preferred temperature range of 27.9–29.7 °C, while P. bocagei would be a thermal generalist, with a broader and higher preferred temperature range (30.1–34.5 °C. In addition, I. galani selects rocky substrates while P. bocagei selects warmer soil and leaf litter substrates. The thermal quality of the habitat is higher for P. bocagei than for I. galani. Finally, P. bocagei achieves a significantly higher effectiveness of thermoregulation (0.87 than I. galani (0.80. Therefore, these mountain habitat conditions seem currently more suitable for performance of thermophilic generalist lizards than for cold-specialist lizards.

  4. Photographic capture-recapture sampling for assessing populations of the Indian gliding lizard Draco dussumieri.

    Science.gov (United States)

    Sreekar, Rachakonda; Purushotham, Chetana B; Saini, Katya; Rao, Shyam N; Pelletier, Simon; Chaplod, Saniya

    2013-01-01

    The usage of invasive tagging methods to assess lizard populations has often been criticised, due to the potential negative effects of marking, which possibly cause increased mortality or altered behaviour. The development of safe, less invasive techniques is essential for improved ecological study and conservation of lizard populations. In this study, we describe a photographic capture-recapture (CR) technique for estimating Draco dussumieri (Agamidae) populations. We used photographs of the ventral surface of the patagium to identify individuals. To establish that the naturally occurring blotches remained constant through time, we compared capture and recapture photographs of 45 pen-marked individuals after a 30 day interval. No changes in blotches were observed and individual lizards could be identified with 100% accuracy. The population density of D. dussumieri in a two hectare areca-nut plantation was estimated using the CR technique with ten sampling occasions over a ten day period. The resulting recapture histories for 24 individuals were analysed using population models in the program CAPTURE. All models indicated that nearly all individuals were captured. The estimated probability for capturing D. dussumieri on at least one occasion was 0.92 and the estimated population density was 13±1.65 lizards/ha. Our results demonstrate the potential for applying CR to population studies in gliding lizards (Draco spp.) and other species with distinctive markings.

  5. Patterns of cranial ontogeny in lacertid lizards: morphological and allometric disparity.

    Science.gov (United States)

    Urošević, A; Ljubisavljević, K; Ivanović, A

    2013-02-01

    We explored the ontogenetic dynamics of the morphological and allometric disparity in the cranium shapes of twelve lacertid lizard species. The analysed species (Darevskia praticola, Dinarolacerta mosorensis, Iberolacerta horvathi, Lacerta agilis, L. trilineata, L. viridis, Podarcis erhardii, P. melisellensis, P. muralis, P. sicula, P. taurica and Zootoca vivipara) can be classified into different ecomorphs: terrestrial lizards that inhabit vegetated habitats (habitats with lush or sparse vegetation), saxicolous and shrub-climbing lizards. We observed that there was an overall increase in the morphological disparity (MD) during the ontogeny of the lacertid lizards. The ventral cranium, which is involved in the mechanics of jaw movement and feeding, showed higher levels of MD, an ontogenetic shift in the morphospace planes and more variable allometric patterns than more conserved dorsal crania. With respect to ecology, the allometric trajectories of the shrub-climbing species tended to cluster together, whereas the allometric trajectories of the saxicolous species were highly dispersed. Our results indicate that the ontogenetic patterns of morphological and allometric disparity in the lacertid lizards are modified by ecology and functional constraints and that the identical mechanisms that lead to intraspecific morphological variation also produce morphological divergence at higher taxonomic levels.

  6. Learning outdoors: male lizards show flexible spatial learning under semi-natural conditions.

    Science.gov (United States)

    Noble, Daniel W A; Carazo, Pau; Whiting, Martin J

    2012-12-23

    Spatial cognition is predicted to be a fundamental component of fitness in many lizard species, and yet some studies suggest that it is relatively slow and inflexible. However, such claims are based on work conducted using experimental designs or in artificial contexts that may underestimate their cognitive abilities. We used a biologically realistic experimental procedure (using simulated predatory attacks) to study spatial learning and its flexibility in the lizard Eulamprus quoyii in semi-natural outdoor enclosures under similar conditions to those experienced by lizards in the wild. To evaluate the flexibility of spatial learning, we conducted a reversal spatial-learning task in which positive and negative reinforcements of learnt spatial stimuli were switched. Nineteen (32%) male lizards learnt both tasks within 10 days (spatial task mean: 8.16 ± 0.69 (s.e.) and reversal spatial task mean: 10.74 ± 0.98 (s.e.) trials). We demonstrate that E. quoyii are capable of flexible spatial learning and suggest that future studies focus on a range of lizard species which differ in phylogeny and/or ecology, using biologically relevant cognitive tasks, in an effort to bridge the cognitive divide between ecto- and endotherms.

  7. Enter the Dragon: The Dynamic and Multifunctional Evolution of Anguimorpha Lizard Venoms

    Science.gov (United States)

    Koludarov, Ivan; Jackson, Timothy NW; op den Brouw, Bianca; Dobson, James; Dashevsky, Daniel; Clemente, Christofer J.; Stockdale, Edward J.; Cochran, Chip; Debono, Jordan; Stephens, Carson; Panagides, Nadya; Li, Bin; Roy Manchadi, Mary-Louise; Violette, Aude; Fourmy, Rudy; Hendrikx, Iwan; Nouwens, Amanda; Clements, Judith; Martelli, Paolo; Kwok, Hang Fai; Fry, Bryan G.

    2017-01-01

    While snake venoms have been the subject of intense study, comparatively little work has been done on lizard venoms. In this study, we have examined the structural and functional diversification of anguimorph lizard venoms and associated toxins, and related these results to dentition and predatory ecology. Venom composition was shown to be highly variable across the 20 species of Heloderma, Lanthanotus, and Varanus included in our study. While kallikrein enzymes were ubiquitous, they were also a particularly multifunctional toxin type, with differential activities on enzyme substrates and also ability to degrade alpha or beta chains of fibrinogen that reflects structural variability. Examination of other toxin types also revealed similar variability in their presence and activity levels. The high level of venom chemistry variation in varanid lizards compared to that of helodermatid lizards suggests that venom may be subject to different selection pressures in these two families. These results not only contribute to our understanding of venom evolution but also reveal anguimorph lizard venoms to be rich sources of novel bioactive molecules with potential as drug design and development lead compounds. PMID:28783084

  8. Carotenoid-Based Colours Reflect the Stress Response in the Common Lizard

    Science.gov (United States)

    Fitze, Patrick S.; Cote, Julien; San-Jose, Luis Martin; Meylan, Sandrine; Isaksson, Caroline; Andersson, Staffan; Rossi, Jean-Marc; Clobert, Jean

    2009-01-01

    Under chronic stress, carotenoid-based colouration has often been shown to fade. However, the ecological and physiological mechanisms that govern colouration still remain largely unknown. Colour changes may be directly induced by the stressor (for example through reduced carotenoid intake) or due to the activation of the physiological stress response (PSR, e.g. due to increased blood corticosterone concentrations). Here, we tested whether blood corticosterone concentration affected carotenoid-based colouration, and whether a trade-off between colouration and PSR existed. Using the common lizard (Lacerta vivipara), we correlatively and experimentally showed that elevated blood corticosterone levels are associated with increased redness of the lizard's belly. In this study, the effects of corticosterone did not depend on carotenoid ingestion, indicating the absence of a trade-off between colouration and PSR for carotenoids. While carotenoid ingestion increased blood carotenoid concentration, colouration was not modified. This suggests that carotenoid-based colouration of common lizards is not severely limited by dietary carotenoid intake. Together with earlier studies, these findings suggest that the common lizard's carotenoid-based colouration may be a composite trait, consisting of fixed (e.g. genetic) and environmentally elements, the latter reflecting the lizard's PSR. PMID:19352507

  9. Carotenoid-based colours reflect the stress response in the common lizard.

    Directory of Open Access Journals (Sweden)

    Patrick S Fitze

    Full Text Available Under chronic stress, carotenoid-based colouration has often been shown to fade. However, the ecological and physiological mechanisms that govern colouration still remain largely unknown. Colour changes may be directly induced by the stressor (for example through reduced carotenoid intake or due to the activation of the physiological stress response (PSR, e.g. due to increased blood corticosterone concentrations. Here, we tested whether blood corticosterone concentration affected carotenoid-based colouration, and whether a trade-off between colouration and PSR existed. Using the common lizard (Lacerta vivipara, we correlatively and experimentally showed that elevated blood corticosterone levels are associated with increased redness of the lizard's belly. In this study, the effects of corticosterone did not depend on carotenoid ingestion, indicating the absence of a trade-off between colouration and PSR for carotenoids. While carotenoid ingestion increased blood carotenoid concentration, colouration was not modified. This suggests that carotenoid-based colouration of common lizards is not severely limited by dietary carotenoid intake. Together with earlier studies, these findings suggest that the common lizard's carotenoid-based colouration may be a composite trait, consisting of fixed (e.g. genetic and environmentally elements, the latter reflecting the lizard's PSR.

  10. Carotenoid-based colours reflect the stress response in the common lizard.

    Science.gov (United States)

    Fitze, Patrick S; Cote, Julien; San-Jose, Luis Martin; Meylan, Sandrine; Isaksson, Caroline; Andersson, Staffan; Rossi, Jean-Marc; Clobert, Jean

    2009-01-01

    Under chronic stress, carotenoid-based colouration has often been shown to fade. However, the ecological and physiological mechanisms that govern colouration still remain largely unknown. Colour changes may be directly induced by the stressor (for example through reduced carotenoid intake) or due to the activation of the physiological stress response (PSR, e.g. due to increased blood corticosterone concentrations). Here, we tested whether blood corticosterone concentration affected carotenoid-based colouration, and whether a trade-off between colouration and PSR existed. Using the common lizard (Lacerta vivipara), we correlatively and experimentally showed that elevated blood corticosterone levels are associated with increased redness of the lizard's belly. In this study, the effects of corticosterone did not depend on carotenoid ingestion, indicating the absence of a trade-off between colouration and PSR for carotenoids. While carotenoid ingestion increased blood carotenoid concentration, colouration was not modified. This suggests that carotenoid-based colouration of common lizards is not severely limited by dietary carotenoid intake. Together with earlier studies, these findings suggest that the common lizard's carotenoid-based colouration may be a composite trait, consisting of fixed (e.g. genetic) and environmentally elements, the latter reflecting the lizard's PSR.

  11. Enter the Dragon: The Dynamic and Multifunctional Evolution of Anguimorpha Lizard Venoms

    Directory of Open Access Journals (Sweden)

    Ivan Koludarov

    2017-08-01

    Full Text Available While snake venoms have been the subject of intense study, comparatively little work has been done on lizard venoms. In this study, we have examined the structural and functional diversification of anguimorph lizard venoms and associated toxins, and related these results to dentition and predatory ecology. Venom composition was shown to be highly variable across the 20 species of Heloderma, Lanthanotus, and Varanus included in our study. While kallikrein enzymes were ubiquitous, they were also a particularly multifunctional toxin type, with differential activities on enzyme substrates and also ability to degrade alpha or beta chains of fibrinogen that reflects structural variability. Examination of other toxin types also revealed similar variability in their presence and activity levels. The high level of venom chemistry variation in varanid lizards compared to that of helodermatid lizards suggests that venom may be subject to different selection pressures in these two families. These results not only contribute to our understanding of venom evolution but also reveal anguimorph lizard venoms to be rich sources of novel bioactive molecules with potential as drug design and development lead compounds.

  12. Photographic capture-recapture sampling for assessing populations of the Indian gliding lizard Draco dussumieri.

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    Rachakonda Sreekar

    Full Text Available The usage of invasive tagging methods to assess lizard populations has often been criticised, due to the potential negative effects of marking, which possibly cause increased mortality or altered behaviour. The development of safe, less invasive techniques is essential for improved ecological study and conservation of lizard populations. In this study, we describe a photographic capture-recapture (CR technique for estimating Draco dussumieri (Agamidae populations. We used photographs of the ventral surface of the patagium to identify individuals. To establish that the naturally occurring blotches remained constant through time, we compared capture and recapture photographs of 45 pen-marked individuals after a 30 day interval. No changes in blotches were observed and individual lizards could be identified with 100% accuracy. The population density of D. dussumieri in a two hectare areca-nut plantation was estimated using the CR technique with ten sampling occasions over a ten day period. The resulting recapture histories for 24 individuals were analysed using population models in the program CAPTURE. All models indicated that nearly all individuals were captured. The estimated probability for capturing D. dussumieri on at least one occasion was 0.92 and the estimated population density was 13±1.65 lizards/ha. Our results demonstrate the potential for applying CR to population studies in gliding lizards (Draco spp. and other species with distinctive markings.

  13. Local enhancement and social foraging in a non-social insular lizard.

    Science.gov (United States)

    Pérez-Cembranos, Ana; Pérez-Mellado, Valentín

    2015-05-01

    Even in solitary foragers, conspecifics can provide reliable information about food location. The insular lizard Podarcis lilfordi is a solitary species with high population densities that sometimes aggregate around rich food patches. Its diet includes novel and unpredictable resources, such as carcasses or plants, whose exploitation quickly became widespread among the population. We tested the use of social information by lizards through some field experiments in which they had to choose one of the two pieces of fruit. Probably due to local enhancement, lizards preferred to feed on the piece of fruit where conspecifics or lizard-shaped models were already present. Conspecifics' behaviour, but also their mere presence, seems to be a valuable source of information to decide where to feed. Lizards also showed a strong attraction to conspecifics, even in the absence of food. Maybe the presence of a group is interpreted as an indirect cue for the presence of food. The group size was not important to females, but males had a significantly higher attraction towards groups with three conspecifics. We discuss some characteristics of P. lilfordi at Aire Island that can explain the development of the observed social foraging, as well as their possible consequences.

  14. Turn up the heat: thermal tolerances of lizards at La Selva, Costa Rica.

    Science.gov (United States)

    Brusch, George A; Taylor, Emily N; Whitfield, Steven M

    2016-02-01

    Global temperature increases over the next century are predicted to contribute to the extinction of a number of taxa, including up to 40% of all lizard species. Lizards adapted to living in lowland tropical areas are especially vulnerable because of their dependence on specific microhabitats, low vagility, and a reduced capacity to physiologically adjust to environmental change. To assess the potential effects of climate change on lizards in the lowland tropics, we measured the critical thermal maximum (CTmax) of ten species from La Selva, Costa Rica. We also examined how well body size, microhabitat type, and species predicted the CTmax. We used current temperature data along with projected temperature increases for 2080 to predict which species may be at the greatest risk at La Selva. Of the ten species sampled, four are at serious risk of lowland extirpation and three others might also be at risk under the highest predicted temperature-increase models. Forest floor lizards at La Selva have already experienced significant population declines over the past 40 years, and we found that each of the forest floor species we studied is at serious risk of local extirpation. We also found that microhabitat type is the strongest predictor of CTmax, demonstrating the profound impact habitat specialization has on the thermal limits of tropical lizards.

  15. Reproduction and morphology of the common lizard (Zootoca vivipara) from montane populations in Slovakia.

    Science.gov (United States)

    Horváthová, Terézia; Baláž, Michal; Jandzik, David

    2013-02-01

    The common lizard, Zootoca vivipara (Lichtenstein, 1823), shows high variation in life histories and morphology across its range, which comprises almost the entire Palearctic region. However, this variation is not congruent with the species phylogeny. This suggests an important role of the environment in shaping the variation in morphology and life histories of this species. As most data on life histories originate from only a small number of populations and do not cover the species' geographic range and phylogenetic diversity, to fill a gap and provide more information for future comparative studies we investigated reproduction and morphology in two montane populations from Slovakia, central Europe. This region is characterized by taxonomic and phylogenetic diversity and both montane and lowland ecological forms of the common lizard occur here. The common lizards from the Slovak populations are sexually dimorphic, with females having larger body and abdomen lengths and males having larger heads and longer legs. Female common lizards start to reproduce at a relatively large size compared to most other populations. This is consistent with a relatively short activity season, which has been shown to be the main factor driving variation in body size in the common lizard. Clutch size was also relatively high and positively correlated with body size, abdomen size and head size. One third of all females attaining the size of the smallest gravid female showed no signs of reproductive activity despite mating opportunities, suggesting that not all females reproduce annually in this population.

  16. High antipredatory efficiency of insular lizards: a warning signal of excessive specimen collection?

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    Miguel Delibes

    Full Text Available We live-captured lizards on islands in the Gulf of California and the Baja California peninsula mainland, and compared their ability to escape predation. Contrary to expectations, endemic lizard species from uninhabited islands fled from humans earlier and more efficiently than those from peninsular mainland areas. In fact, 58.2% (n=146 of the lizards we tried to capture on the various islands escaped successfully, while this percentage was only 14.4% (n=160 on the peninsular mainland. Separate evidence (e.g., proportion of regenerated tails, low human population at the collection areas, etc. challenges several potential explanations for the higher antipredatory efficiency of insular lizards (e.g., more predation pressure on islands, habituation to humans on the peninsula, etc.. Instead, we suggest that the ability of insular lizards to avoid predators may be related to harvesting by humans, perhaps due to the value of endemic species as rare taxonomic entities. If this hypothesis is correct, predation-related behavioral changes in rare species could provide early warning signals of their over-exploitation, thus encouraging the adoption of conservation measures.

  17. Population genetic structure, gene flow and sex-biased dispersal in frillneck lizards (Chlamydosaurus kingii).

    Science.gov (United States)

    Ujvari, Beata; Dowton, Mark; Madsen, Thomas

    2008-08-01

    By using both mitochondrial and nuclear multiloci markers, we explored population genetic structure, gene flow and sex-specific dispersal of frillneck lizards (Chlamydosaurus kingii) sampled at three locations, separated by 10 to 50 km, in a homogenous savannah woodland in tropical Australia. Apart from a recombinant lizard, the mitochondrial analyses revealed two nonoverlapping haplotypes/populations, while the nuclear markers showed that the frillneck lizards represented three separate clusters/populations. Due to the small population size of the mtDNA, fixation may occur via founder effects and/or drift. We therefore suggest that either of these two processes, or a combination of the two, are the most likely causes of the discordant results obtained from the mitochondrial and the nuclear markers. In contrast to the nonoverlapping mitochondrial haplotypes, in 12 out of 74 lizards, mixed nuclear genotypes were observed, hence revealing a limited nuclear gene flow. Although gene flow should ultimately result in a blending of the populations, we propose that the distinct nuclear population structure is maintained by frequent fires resulting in local bottlenecks, and concomitant spatial separation of the frillneck lizard populations. Limited mark-recapture data and the difference in distribution of the mitochondrial and nuclear markers suggest that the mixed nuclear genotypes were caused by juvenile male-biased dispersal.

  18. Symmetry recovery of cell-free layer after bifurcations of small arterioles in reduced flow conditions: effect of RBC aggregation.

    Science.gov (United States)

    Ng, Yan Cheng; Namgung, Bumseok; Tien, Sim Leng; Leo, Hwa Liang; Kim, Sangho

    2016-08-01

    Heterogeneous distribution of red blood cells (RBCs) in downstream vessels of arteriolar bifurcations can be promoted by an asymmetric formation of cell-free layer (CFL) in upstream vessels. Consequently, the CFL widths in subsequent downstream vessels become an important determinant for tissue oxygenation (O2) and vascular tone change by varying nitric oxide (NO) availability. To extend our previous understanding on the formation of CFL in arteriolar bifurcations, this study investigated the formation of CFL widths from 2 to 6 vessel-diameter (2D-6D) downstream of arteriolar bifurcations in the rat cremaster muscle (D = 51.5 ± 1.3 μm). As the CFL widths are highly influenced by RBC aggregation, the degree of aggregation was adjusted to simulate levels seen during physiological and pathological states. Our in vivo experimental results showed that the asymmetry of CFL widths persists along downstream vessels up to 6D from the bifurcating point. Moreover, elevated levels of RBC aggregation appeared to retard the recovery of CFL width symmetry. The required length of complete symmetry recovery was estimated to be greater than 11D under reduced flow conditions, which is relatively longer than interbifurcation distances of arterioles for vessel diameter of ∼50 μm. In addition, our numerical prediction showed that the persistent asymmetry of CFL widths could potentially result in a heterogeneous vasoactivity over the entire arteriolar network in such abnormal flow conditions.

  19. BGMUT: NCBI dbRBC database of allelic variations of genes encoding antigens of blood group systems.

    Science.gov (United States)

    Patnaik, Santosh Kumar; Helmberg, Wolfgang; Blumenfeld, Olga O

    2012-01-01

    Analogous to human leukocyte antigens, blood group antigens are surface markers on the erythrocyte cell membrane whose structures differ among individuals and which can be serologically identified. The Blood Group Antigen Gene Mutation Database (BGMUT) is an online repository of allelic variations in genes that determine the antigens of various human blood group systems. The database is manually curated with allelic information collated from scientific literature and from direct submissions from research laboratories. Currently, the database documents sequence variations of a total of 1251 alleles of all 40 gene loci that together are known to affect antigens of 30 human blood group systems. When available, information on the geographic or ethnic prevalence of an allele is also provided. The BGMUT website also has general information on the human blood group systems and the genes responsible for them. BGMUT is a part of the dbRBC resource of the National Center for Biotechnology Information, USA, and is available online at http://www.ncbi.nlm.nih.gov/projects/gv/rbc/xslcgi.fcgi?cmd=bgmut. The database should be of use to members of the transfusion medicine community, those interested in studies of genetic variation and related topics such as human migrations, and students as well as members of the general public.

  20. Can changes in the distribution of lizard species over the past 50 years be attributed to climate change?

    Science.gov (United States)

    Wu, Jianguo

    2016-08-01

    We analyzed changes in the distributions of nine lizard species in China over the past 50 years and identified whether these changes could be attributed to climate change. Long-term records of lizard distributions, grey relational analysis, fuzzy set classification techniques, and attribution methods were used. The distribution of nearly half of the lizard species primarily shifted northward, westward, or eastward since the 1970s, and most changes were related to the thermal index. In response to climate change over the past 50 years, the distribution boundary and center of some species have mainly shifted northward, westward, or eastward, with some irregular shifting during the process. The observed and predicted changes in distribution were highly consistent for some lizard species. The changes in the northern and eastern distribution limits of nearly half of the lizard species and the western limits and distribution centers of several species can be attributed to climate change.

  1. Immunohistochemical evidence of seasonal changes of gonadotropes in male ruin lizard (Podarcis sicula campestris De Betta

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    G De Metrio

    2009-12-01

    Full Text Available The pars distalis from the pituitary gland of adult male ruin lizards (Podarcis sicula campestris De Betta, captured during the five periods of the annual sexual cycle (emergence from hibernation, reproductive period, summer regression, autumnal recrudescence, winter arrest, was studied immunohistochemically using specific antibodies against hFSHb, hLHb, oFSHb, and oLHb with the avidinbiotin complex (ABC procedure to monitor the seasonal changes in shape, size and percentage area taken up from gonadotropes. FSH containing cells were specifically identified with anti-hFSHb and anti-oFSHb sera, whereas the LH cells were localized by anti-hLHb. The anti-oLHb serum showed cross-reactivity with the cells immunostained by the three above antisera (anti-hFSHb, anti-oFSHb, and anti-hLHb. None of the cells containing both gonadotropic hormones as shown by the doubleimmunostaining procedure. Generally, FSH cells were larger and more numerous than LH cells. FSH cells were elongated or pyriform in shape from spring to autumn, whereas they were round or oval during the winter stasis and until the emergence from hibernation. The size and the percentage area occupied by FSH cells showed an annual pattern with two distinct peaks in the reproductive and in the autumnal recrudescence periods. LH cells did not show seasonal changes in shape, being round or oval throughout the reproductive cycle, whereas their size and the area they occupied underwent seasonal variations. The LH cells reached the largest size during the reproductive period and the smallest size during the summer regression. The percentage area occupied by LH cells in the pars distalis peaked at the emergence from hibernation and during the summer refractory period, when FSH cells displayed their lowest values.

  2. Reflexiones sobre la estrategia de rehabilitación basada en la comunidad (RBC: la experiencia de un programa de RBC en Bolivia Reflections on community-based rehabilitation strategy (CBR: the experience of a CBR program in Bolivia

    Directory of Open Access Journals (Sweden)

    Urko Díaz-Aristizabal

    2012-01-01

    Full Text Available La Rehabilitación Basada en la Comunidad (RBC es una estrategia de desarrollo comunitario avalada por la Organización Mundial de la Salud (OMS, la Organización Internacional del Trabajo (OIT y la Organización de las Naciones Unidas para la Educación, la Ciencia y la Cultura (UNESCO, que persigue la rehabilitación, la igualdad de oportunidades y la integración social de las Personas con Discapacidad (PD en sus entornos. Con este objetivo promueve la colaboración entre las PD, sus familias y los diferentes actores de la comunidad involucrados, así como el liderazgo comunitario y la participación de las PD mediante el impulso de la colaboración multisectorial. Este artículo expone los antecedentes históricos y las características fundamentales de la estrategia de RBC a partir de un programa llevado a cabo por una fundación del departamento de Cochabamba (Bolivia, para después incidir en algunos aspectos referentes al contexto sociocultural, que especialmente en situaciones de interculturalidad, pueden determinar que un programa de RBC tenga éxito o esté abocado al fracaso.Community-Based Rehabilitation (CBR is a strategy for community development endorsed by the World Health Organization (WHO, the International Labor Office (ILO and the United Nations Educational, Scientific and Cultural Organization (UNESCO. It is designed to promote rehabilitation, equal opportunity and social inclusion of Disabled Persons (DP in their home communities by fostering cooperation among disabled individuals, their families, and other concerned social actors, it encourages community leadership and full social participation by DP through multi-sector cooperation. This article explores the historical antecedents and basic features of CBR strategy through an analysis of a directed culture change initiative developed by a foundation in the Cochabamba administrative region of Bolivia. Especially in intercultural environments, certain aspects of the socio

  3. Failure analysis in process of RBC switching based on Stochastic Petri Nets(SPN)%基于SPN的无线闭塞中心切换过程中的故障分析

    Institute of Scientific and Technical Information of China (English)

    李嘉懿; 王长林

    2011-01-01

    The paper analyzed the impaction of the RBC (Radio Block Center) switching under RBC2 (receiving RBC) different times of the fault condition, selected the formal description language of Stochastic Petri Nets (SPN), established the RBC switching model under RBC2 fault at different times, using mathematical modeling of SPN, the impaction of RBC switching at failure of the RBC2 and the effect of RBC failure on safety and efficiency of train traffic were analyzed by SPNP6. 0. The result of analysis provided people more realistic understanding of the actual situation in the RBC switching. This also had reference meaning of improving the equipment and perfecting the agreement.%分析在RBC2(接收无线闭塞中心(RBC))不同时段故障工况下,对RBC切换的影响,选取形式化描述语言随机Petri网(SPN),分别建立RBC2在不同时段故障下RBC的切换模型,采用SPN数学建模,通过SPNP6.0分析RBC故障对切换的影响以及对行车安全和行车效率等方面的影响.分析结果可使人们对实际情况中RBC切换有更真实的认识,并对设备的改进、协议的完善等有一定的借鉴意义.

  4. Mass extinction of lizards and snakes at the Cretaceous–Paleogene boundary

    Science.gov (United States)

    Longrich, Nicholas R.; Bhullar, Bhart-Anjan S.; Gauthier, Jacques A.

    2012-01-01

    The Cretaceous–Paleogene (K-Pg) boundary is marked by a major mass extinction, yet this event is thought to have had little effect on the diversity of lizards and snakes (Squamata). A revision of fossil squamates from the Maastrichtian and Paleocene of North America shows that lizards and snakes suffered a devastating mass extinction coinciding with the Chicxulub asteroid impact. Species-level extinction was 83%, and the K-Pg event resulted in the elimination of many lizard groups and a dramatic decrease in morphological disparity. Survival was associated with small body size and perhaps large geographic range. The recovery was prolonged; diversity did not approach Cretaceous levels until 10 My after the extinction, and resulted in a dramatic change in faunal composition. The squamate fossil record shows that the end-Cretaceous mass extinction was far more severe than previously believed, and underscores the role played by mass extinctions in driving diversification. PMID:23236177

  5. Mass extinction of lizards and snakes at the Cretaceous-Paleogene boundary.

    Science.gov (United States)

    Longrich, Nicholas R; Bhullar, Bhart-Anjan S; Gauthier, Jacques A

    2012-12-26

    The Cretaceous-Paleogene (K-Pg) boundary is marked by a major mass extinction, yet this event is thought to have had little effect on the diversity of lizards and snakes (Squamata). A revision of fossil squamates from the Maastrichtian and Paleocene of North America shows that lizards and snakes suffered a devastating mass extinction coinciding with the Chicxulub asteroid impact. Species-level extinction was 83%, and the K-Pg event resulted in the elimination of many lizard groups and a dramatic decrease in morphological disparity. Survival was associated with small body size and perhaps large geographic range. The recovery was prolonged; diversity did not approach Cretaceous levels until 10 My after the extinction, and resulted in a dramatic change in faunal composition. The squamate fossil record shows that the end-Cretaceous mass extinction was far more severe than previously believed, and underscores the role played by mass extinctions in driving diversification.

  6. Population and conservation strategies for the Chinese crocodile lizard (Shinisaurus crocodilurus in China

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    Huang, C. M.

    2008-12-01

    Full Text Available The Chinese crocodile lizard (Shinisaurus crocodilurus is an unusual anguimorph lizard found mainly in China. Transect surveys estimate a total wild population of about 950 individuals in China. This is a dramatic decrease compared with previous surveys. At present, there are only eight areas of distribution. No Chinese crocodile lizards have been found in four former areas for several years. Investigations have demonstrated that poaching has contributed directly to the population decline. Habitat destruction, and in particular water flow, is the second most important factor. Mining, small scale dam construction, electro-fishing and poisoning of fish in the stream also contribute to population decline. Therefore, educating local people, punishing illegal poaching, and strengthening scientific research are urgent.

  7. Mid-Cretaceous amber fossils illuminate the past diversity of tropical lizards.

    Science.gov (United States)

    Daza, Juan D; Stanley, Edward L; Wagner, Philipp; Bauer, Aaron M; Grimaldi, David A

    2016-03-01

    Modern tropical forests harbor an enormous diversity of squamates, but fossilization in such environments is uncommon and little is known about tropical lizard assemblages of the Mesozoic. We report the oldest lizard assemblage preserved in amber, providing insight into the poorly preserved but potentially diverse mid-Cretaceous paleotropics. Twelve specimens from the Albian-Cenomanian boundary of Myanmar (99 Ma) preserve fine details of soft tissue and osteology, and high-resolution x-ray computed tomography permits detailed comparisons to extant and extinct lizards. The extraordinary preservation allows several specimens to be confidently assigned to groups including stem Gekkota and stem Chamaleonidae. Other taxa are assignable to crown clades on the basis of similar traits. The detailed preservation of osteological and soft tissue characters in these specimens may facilitate their precise phylogenetic placement, making them useful calibration points for molecular divergence time estimates and potential keys for resolving conflicts in higher-order squamate relationships.

  8. Nutritional perfomance of Tupinambis merianae lizards fed with corn starch as source of energy

    Directory of Open Access Journals (Sweden)

    Harold Vega Parry

    2009-07-01

    Full Text Available Efficiency in processing complex carbohydrates as a source of energy was studied in Tupinambis merianae lizards. Four isoproteic and isoenergetic diets in which different percentages of corn starch substituted fat (0, 10, 20 and 30 dry matter in the diet were provided. Even though consumption was similar in all diets, growth and feeding conversion rates decreased significantly with corn starch supplies of 10% and more. At the end of the trial, pancreatic alpha-amylase activity showed correlated increases, yet these were insufficient to compensate corn starch supplies. Results suggest that Tupinambis merianae lizards have a restricted omnivorous capacity. Therefore, diet formulation for these lizards should exclude high molecular weight carbohydrates.

  9. A new Early Cretaceous lizard with well-preserved scale impressions from western Liaoning, China

    Institute of Scientific and Technical Information of China (English)

    JI Shu'an

    2005-01-01

    A new small lizard, Liaoningolacerta brevirostra gen. et sp. nov., from the Early Cretaceous Yixian Formation of western Liaoning is described in detail. The new specimen was preserved not only by the skeleton, but also by the exceptionally clear scale impressions. This lizard can be included within the taxon Scleroglossa based on its 26 or more presacrals, cruciform interclavicle with a large anterior process, moderately elongated pubis, and slightly notched distal end of tibia. The scales vary evidently in size and shape at different parts of body: small and rhomboid ventral scales, tiny and round limb scales, and large and longitudinally rectangular caudal scales that constitute the caudal whorls. This new finding provides us with more information on the lepidosis of the Mesozoic lizards.

  10. Effects of dexamethasone and gonadotropins on the testis of the adrenalectomized lizard Mabuya carinata (Schn.)

    Science.gov (United States)

    Yajurvedi, H N; Chandramohan, K

    1994-02-01

    The effects of gonadotropins (LH + FSH) and dexamethasone on the spermatogenic and steroidogenic activity in the adrenalectomized Mabuya carinata have been studied. Secondary spermatocytes, spermatids, and spermatozoa were absent, and there was a significant decrease in the activity levels of delta 5-3 beta-hydroxysteroid dehydrogenase (delta 5-3 beta-HSDH) and glucose-6-phosphate dehydrogenase in the adrenalectomized lizards compared with those of controls. Administration of either dexamethasone or LH + FSH to adrenalectomized lizards resulted in restoration of testicular activity as revealed by the appearance of secondary spermatocytes, spermatids, and spermatozoa and a significant increase in the activity level of delta 5-3 beta-HSDH compared to that of adrenalectomized lizards. The results indicate that impairment in gonadotropin secretion might be a major factor in inducing testicular regression following adrenalectomy in M. carinata.

  11. Causes of habitat divergence in two species of agamid lizards in arid central Australia.

    Science.gov (United States)

    Daly, Benjamin G; Dickman, Chris R; Crowther, Mathew S

    2008-01-01

    The deserts of central Australia contain richer communities of lizards than any other arid regions, with the highest diversity occurring in sand dune habitats dominated by hummock-forming spinifex grasses. To investigate the mechanisms that permit coexistence, we studied two species of coexisting agamid lizards that exhibit striking divergence in their use of habitat in the Simpson Desert of central Australia. Here, the military dragon Ctenophorus isolepis is restricted primarily to sites providing > 30% cover of hard spinifex Triodia basedowii, whereas the central netted dragon C. nuchalis occurs in areas with much sparser (thermal environments or different prey types and that each selects the habitats that maximize access to them. Both were supported. C. isolepis preferred lower temperatures when active and specialized in eating ants ecological interactions, allowing lizard species to partition biotic and abiotic resources and achieve the extraordinarily high levels of local diversity that are observed.

  12. Stable isotope ecology of a hyper-diverse community of scincid lizards from arid Australia.

    Science.gov (United States)

    Grundler, Maggie R; Pianka, Eric R; Pelegrin, Nicolás; Cowan, Mark A; Rabosky, Daniel L

    2017-01-01

    We assessed the utility of stable isotope analysis as a tool for understanding community ecological structure in a species-rich clade of scincid lizards from one of the world's most diverse lizard communities. Using a phylogenetic comparative framework, we tested whether δ15N and δ13C isotopic composition from individual lizards was correlated with species-specific estimates of diet and habitat use. We find that species are highly divergent in isotopic composition with significant correlations to habitat use, but this relationship shows no phylogenetic signal. Isotopic composition corresponds to empirical observations of diet for some species but much variation remains unexplained. We demonstrate the importance of using a multianalytical approach to questions of long-term dietary preference, and suggest that the use of stable isotopes in combination with stomach content analysis and empirical data on habitat use can potentially reveal patterns in ecological traits at finer scales with important implications for community structuring.

  13. Levels of helminth infection in the flat lizard Tropidurus semitaeniatus from north-eastern Brazil.

    Science.gov (United States)

    Bezerra, C H; Ávila, R W; Passos, D C; Zanchi-Silva, D; Galdino, C A B

    2016-11-01

    Parasites represent a great, unknown component of animal biodiversity. Recent efforts have begun to uncover patterns of infection by helminth parasites in several Neotropical lizards. The present study reports, for the first time, levels of helminth infection in a population of the flat lizard Tropidurus semitaeniatus. One hundred and thirty-nine lizards were examined and evidence of five intestinal helminth species was found, comprising four species of nematodes, one species of cestode and an unidentified encysted larval nematode. The most frequently occurring species was the intestinal nematode Parapharyngodon alvarengai, which did not exhibit differences in prevalence and intensity of infection relative to host sex or age/body size. Furthermore, helminth species richness was not related to host body size.

  14. Mass extinction of lizards and snakes at the Cretaceous-Paleogene boundary

    Science.gov (United States)

    Longrich, Nicholas R.; Bhullar, Bhart-Anjan S.; Gauthier, Jacques A.

    2012-12-01

    The Cretaceous-Paleogene (K-Pg) boundary is marked by a major mass extinction, yet this event is thought to have had little effect on the diversity of lizards and snakes (Squamata). A revision of fossil squamates from the Maastrichtian and Paleocene of North America shows that lizards and snakes suffered a devastating mass extinction coinciding with the Chicxulub asteroid impact. Species-level extinction was 83%, and the K-Pg event resulted in the elimination of many lizard groups and a dramatic decrease in morphological disparity. Survival was associated with small body size and perhaps large geographic range. The recovery was prolonged; diversity did not approach Cretaceous levels until 10 My after the extinction, and resulted in a dramatic change in faunal composition. The squamate fossil record shows that the end-Cretaceous mass extinction was far more severe than previously believed, and underscores the role played by mass extinctions in driving diversification.

  15. Patterns of sexual dimorphism in Mexican alligator lizards, Barisia imbricata

    Science.gov (United States)

    Dashevsky, Daniel; Meik, Jesse M; Mociño-Deloya, Estrella; Setser, Kirk; Schaack, Sarah

    2013-01-01

    We compare morphological characteristics of male and female Barisia imbricata, Mexican alligator lizards, and find that mass, head length, coloration, incidence of scars from conspecifics, tail loss, and frequency of bearing the color/pattern of the opposite sex are all sexually dimorphic traits. Overall size (measured as snout–vent length), on the other hand, is not different between the two sexes. We use data on bite scar frequency and fecundity to evaluate competing hypotheses regarding the selective forces driving these patterns. We contend that sexual selection, acting through male-male competition, may favor larger mass and head size in males, whereas large females are likely favored by natural selection for greater fecundity. In addition, the frequency of opposite-sex patterning in males versus females may indicate that the costs of agonistic interactions among males are severe enough to allow for an alternative mating strategy. Finally, we discuss how sexual and natural selective forces may interact to drive or mask the evolution of sexually dimorphic traits. PMID:23467394

  16. Sleep and wakefulness in the green iguanid lizard (Iguana iguana).

    Science.gov (United States)

    Ayala-Guerrero, F; Mexicano, G

    2008-11-01

    The reptile Iguana iguana exhibits four states of vigilance: active wakefulness (AW), quiet wakefulness (QW), quiet sleep (QS) and active sleep (AS). Cerebral activity decreases in amplitude and frequency when passing from wakefulness to QS. Both parameters show a slight increase during AS. Heart rate is at a maximum during AW (43.8+/-7.9 beats/min), decreases to a minimum in QS (25.3+/-3.2 beats/min) and increases in AS (36.1+/-5.7 beats/min). Tonical and phasical muscular activity is present in wakefulness, decreases or disappears in QS and reappears in AS. Single or conjugate ocular movements are observed during wakefulness, then disappear in QS and abruptly reappear in AS. Although these reptiles are polyphasic, their sleep shows a tendency to concentrate between 20:00 and 8:00 h. Quiet sleep occupies the greater percentage of the total sleep time. Active sleep episodes are of very short duration, showing an average of 21.5+/-4.9 (mean+/-SD). Compensatory increment of sleep following its total deprivation was significant only for QS. Reaction to stimuli decreased significantly when passing from wakefulness to sleep. It is suggested that the lizard I. iguana displays two sleep phases behaviorally and somatovegetatively similar to slow wave sleep and paradoxical sleep in birds and mammals.

  17. Incubation temperature modifies neonatal thermoregulation in the lizard Anolis carolinensis.

    Science.gov (United States)

    Goodman, Rachel M; Walguarnery, Justin W

    2007-08-01

    The thermal environment experienced during embryonic development can profoundly affect the phenotype, and potentially the fitness, of ectothermic animals. We examined the effect of incubation temperature on the thermal preferences of juveniles in the oviparous lizard, Anolis carolinensis. Temperature preference trials were conducted in a laboratory thermal gradient within 48 hr of hatching and after 22-27 days of maintenance in a common laboratory environment. Incubation temperature had a significant effect on the upper limit of the interquartile range (IQR) of temperatures selected by A. carolinensis within the first 2 days after hatching. Between the first and second trials, the IQR of selected temperatures decreased significantly and both the lower limit of the IQR and the median selected temperature increased significantly. This, along with a significant incubation temperature by time interaction in the upper limit of the IQR, resulted in a pattern of convergence in thermoregulation among treatment groups. The initial differences in selected temperatures, as well as the shift in selected temperatures between first and second trials, demonstrate plasticity in temperature selection. As a previous study failed to find environmentally induced plasticity in temperature selection in adult A. carolinensis, this study suggests that this type of plasticity is exclusive to the period of neonatal development.

  18. Female ornamentation influences male courtship investment in a lizard

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    Devi Meian Stuart-Fox

    2014-02-01

    Full Text Available Female signals of reproductive status often comprise both distinctive colour patches and behaviours but their relative influence on male courtship investment is unclear. We examined the role of female-specific colouration in signalling reproductive condition and quality to males in the Lake Eyre dragon lizard, Ctenophorus maculosus. Females of this species develop intense orange ventral coloration when sexually receptive, which fades to white only after laying. To separate the effect of colour and behaviour, we manipulated the presence of female orange ventral colouration within different periods of the reproductive cycle in which females display qualitatively different behaviours. In a separate manipulation, we tested whether the presence of an ultraviolet (UV component, size and intensity of female orange patches influenced male courtship investment. Males tended to chase, bite and copulate more with orange than white females, irrespective of reproductive state. However, males copulated much more frequently with receptive females than non-receptive or gravid females, consistent with females’ behavioural acceptance of copulations during this stage. Males courted females with small orange patches the most, and had an overall preference for intense colour patches (as opposed to pale orange patches, regardless of the presence of UV. Our results suggest that female orange coloration signals reproductive condition, specifically receptivity, and that small, intensely orange patches signal that females are more likely to be receptive. Female ornamentation therefore encodes information used by males to make decisions regarding courtship investment.

  19. Proximate determinants of bite force in Anolis lizards.

    Science.gov (United States)

    Wittorski, Antoine; Losos, Jonathan B; Herrel, Anthony

    2016-01-01

    Performance measures associated with the vertebrate jaw system may provide important insights into vertebrate ecology and evolution because of their importance in many ecologically relevant tasks. Previous studies have shown that in many taxa, evolution toward higher bite force has gone hand in hand with the evolution of larger body size. However, independent of differences in overall body size, bite force may vary depending on head size and shape as well. Moreover, the underlying musculature may also drive variation in bite force. Here, we investigate the proximate determinants of bite force in lizards of the genus Anolis. We dissected the jaw muscles and quantified muscle mass, fibre length, and cross-sectional area. Data were analysed for both sexes independently given the sexual dimorphism detected in the dataset. Our results show that the traits that explain bite force are similar in both males and females with overall body size and muscle mass being the principal determinants. Among the different muscles examined, the adductor externus and the pseudotemporalis groups were the best determinants of bite force. However, models run for males predicted the variation in bite force better than models for females, suggesting that selection on morphology improving bite force may be stronger in males. © 2015 Anatomical Society.

  20. Ground resistance influences lizard burial in dry and wet sand

    Science.gov (United States)

    Sharpe, Sarah; Kuckuk, Robyn; Goldman, Daniel

    2012-11-01

    Many terrestrial animals move within soil in which water content can vary, and little is known about how water content affects locomotor performance. To investigate the effect of water content on burial, we created controlled dry and wet substrates. We used 0.3 mm glass particles and varied water content W, the mass of water to mass of dry loosely packed sand. Drag force on a submerged 1.6 cm diameter rod increased by a factor of 4 as W increased from 0 to 0.03, after which force increases were small. Drag force in wet media periodically fluctuated with time and corresponded with surface fracturing. We characterized how W affected burial performance and strategy of a generalist burrower, the ocellated skink lizard (Chalcides ocellatus). High speed x-ray imaging was used to measure head, body and limb kinematics in substrates with W= 0 and W= 0.03. In both states during burial the body was maintained in a curved posture and the animal moved using a start-stop motion. During movement, the head oscillated and the forelimb on the convex side of the body was used to push the animal forward. Both speed and angular excursion of the head oscillation decreased in the W= 0.03 state. The differences in locomotion were attributed to the changing resistance force within the media.

  1. Evidence for facilitated lactate uptake in lizard skeletal muscle.

    Science.gov (United States)

    Donovan, E R; Gleeson, T T

    2001-12-01

    To understand more fully lactate metabolism in reptilian muscle, lactate uptake in lizard skeletal muscle was measured and its similarities to the monocarboxylate transport system found in mammals were examined. At 2 min, uptake rates of 15 mmol l(-1) lactate into red iliofibularis (rIF) were 2.4- and 2.2-fold greater than white iliofibularis (wIF) and mouse soleus, respectively. alpha-Cyano-4-hydroxycinnamate (15 mmol l(-1)) caused little inhibition of uptake in wIF but caused a 42-54 % reduction in the uptake rate of lactate into rIF, suggesting that much of the lactate uptake by rIF is via protein-mediated transport. N-ethymaleimide (ETH) (10 mmol l(-1)) also caused a reduction in the rate of uptake, but measurements of adenylate and phosphocreatine concentrations show that ETH had serious effects on rIF and wIF and may not be appropriate for transport inhibition studies in reptiles. The higher net uptake rate by rIF than by wIF agrees with the fact that rIF shows much higher rates of lactate utilization and incorporation into glycogen than wIF. This study also suggests that lactate uptake by reptilian muscle is similar to that by mammalian muscle and that, evolutionarily, this transport system may be relatively conserved even in animals with very different patterns of lactate metabolism.

  2. Cylindrotheca closterium Is a Species Complex as Was Evidenced by the Variations of rbcL Gene and SSU rDNA

    Institute of Scientific and Technical Information of China (English)

    LI Haitao; YANG Guanpin; SUN Ying; WU Suihan; ZHANG Xiufang

    2007-01-01

    The genus Cylindrotheca consists of a small group of marine diatoms with a few species described. Eleven isolates of diatoms identified as Cylindrotheca closterium morphologically were obtained from Jiaozhou Bay with their nuclear-encoded small-subunit ribosomal RNA (SSU rDNA) and chloroplast-encoded rbcL gene sequences determined in this study. Interestingly, very high sequence divergences of SSU rDNA and rbcL gene were found among these isolates, and numerous nucleotide variation of rbcL gene caused relatively few variation of deduced amino acid sequence. Phylogenetic analyses based on SSU rDNA and rbcL gene, respectively, grouped the isolates into 6 clades. Phylogenetic tree of SSU rDNA placed all the Cylindrotheca isolates together, separating them into two lineages clearly. LineageⅠ was composed of the eleven C. closterium isolates obtained in this study together with another C. closterium isolate, but some clades were not well supported. LineageⅡ contained two C. closterium isolates and one C. fusiformis isolate. Phylogenetic analysis of rbcL gene also separated the Cylindrotheca isolates into two well-defined lineages. The eleven C. closterium isolates formed a lineage and all clades were supported strongly. Statistical comparisons of SSU rDNA indicated that the average distance within lineage Ⅰ was significantly higher than that of other microalgae species (P < 0.01). These results suggested the existence of cryptic species within C. closterium.

  3. Use of mosquito preventive measures is associated with increased RBC CR1 levels in a malaria holoendemic area of western Kenya.

    Science.gov (United States)

    King, Christine; Du, Ping; Otieno, Walter; Stoute, José A

    2015-01-01

    Malaria is responsible for close to 1 million deaths each year, mostly among African children. Red blood cells (RBCs) of children with severe malarial anemia show loss of complement regulatory proteins such as complement receptor 1 (CR1). We carried out this study to identify socio-economic, environmental, and biological factors associated with the loss of RBC CR1. A cross-sectional study was conducted in a malaria holoendemic area of western Kenya. Twelve socioeconomic, environmental, and biological factors were examined for a relationship with RBC CR1 level using bivariate linear regression followed by creation of a multivariate linear regression model. A significant positive relationship between RBC CR1 level and use of mosquito countermeasures was found. However, there was no evidence of a significant relationship between RBC CR1 level and malaria infection or parasitemia level. Reducing mosquito exposure may aid in the prevention of severe malarial anemia by reducing the number of infections and thus preserving RBC CR1. © The American Society of Tropical Medicine and Hygiene.

  4. Cloning and Sequencing of a Full-Length cDNA Encoding the RuBPCase Small Subunit (RbcS)in Tea (Camellia sinensis)

    Institute of Scientific and Technical Information of China (English)

    YE Ai-hua; JIANG Chang-jun; ZHU Lin; YU Mei; WANG Zhao-xia; DENG Wei-wei; WEI Chao-lin

    2009-01-01

    This study was aimed to isolate ribulose-l,5-bisphosphate carboxylase/oxygenase small subunit (RbcS) from tea plant [Camellia sinensis (L.) O. Kuntze]. In the study of transcriptional profiling of gene expression from tea flower bud development stage by cDNA-AFLP (cDNA amplified fragment length polymorphism), we have isolated some transcript-derived fragments (TDFs) occurring in both the young and mature flower bud. One of them showed a high degree of similarity to RbcS. Based on the fragment, the full length of RbcS with 769-bp (EF011075) cDNA was obtained via rapid amplification of cDNA ends (RACE). It contained an open reading frame of 176 amino acids consisting of a chloroplast transit peptide with 52 amino acids and a mature protein of 124 amino acids. The amino acids sequence presented a high identity to those of other plant RbcS genes. It also contains three conserved domains and a protein kinase C phosphorylation site, one tyrosine kinase phosphorylation site and two N-myristoylation sites. Analysis by RT-PCR showed that the expression of RbcS in tea from high to low was leaf, young stem, young flower bud and mature flower bud, respectively. The isolation of the tea Rubisco small subunit gene establishes a good foundation for further study on the photosynthesis of tea plant.

  5. The importance of remnant native vegetation of Amazonian submontane forest for the conservation of lizards

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    DJ Silva

    Full Text Available Forest fragmentation affects animal population dynamics mainly by loss of habitat and disruption of animal movement. Lizard assemblages are affected by environmental changes, but, depending on their ecological needs, some species might be more vulnerable than others. The southern Amazon suffers accelerated anthropic actions replacing natural environments by farmland (crops and pasture. This region is considerably drier than most of the northern Amazon, with stational semi-deciduous forests fragmented and isolated by pasture, and crops to a lesser extent. Here we report data on lizard assemblages using semi-deciduous forests, forest edge and the surrounding pasture in the southern Amazon in Mato Grosso, Brazil. Lizards were collected in 21 forest fragments (41 to 7,035 ha surrounded by pasture; using pitfall traps placed on a degradation gradient – from pasture inwards forest fragment (up to 200 m. We collected 242 individuals (14 species, seven families in 6,300 trap-days. The pattern of species occurrence was largely nested and this nesting was associated with three habitat guilds (generalist, edge-tolerant, and forest species. Although there was no obvious fragmentation effect on lizards diversity community-wise, Hoplocercus spinosus, Bachia dorbignyi, Micrablepharus maximiliani and Kentropyx calcarta were more vulnerable to such effects than all other ten species collected. We verified that assemblages inhabiting pasture and forest edge are a nested subset of assemblages from the forest core. The remnant native vegetation is not distributed homogeneously and lizards species can persist in different parts of the landscape, therefore we recommend the protection of forest remnants as an important conservation action for lizards of the southern Amazon.

  6. Phenotypic shifts in urban areas in the tropical lizard Anolis cristatellus.

    Science.gov (United States)

    Winchell, Kristin M; Reynolds, R Graham; Prado-Irwin, Sofia R; Puente-Rolón, Alberto R; Revell, Liam J

    2016-05-01

    Urbanization is an increasingly important dimension of global change, and urban areas likely impose significant natural selection on the species that reside within them. Although many species of plants and animals can survive in urban areas, so far relatively little research has investigated whether such populations have adapted (in an evolutionary sense) to their newfound milieu. Even less of this work has taken place in tropical regions, many of which have experienced dramatic growth and intensification of urbanization in recent decades. In the present study, we focus on the neotropical lizard, Anolis cristatellus. We tested whether lizard ecology and morphology differ between urban and natural areas in three of the most populous municipalities on the island of Puerto Rico. We found that environmental conditions including temperature, humidity, and substrate availability differ dramatically between neighboring urban and natural areas. We also found that lizards in urban areas use artificial substrates a large proportion of the time, and that these substrates tend to be broader than substrates in natural forest. Finally, our morphological data showed that lizards in urban areas have longer limbs relative to their body size, as well as more subdigital scales called lamellae, when compared to lizards from nearby forested habitats. This shift in phenotype is exactly in the direction predicted based on habitat differences between our urban and natural study sites, combined with our results on how substrates are being used by lizards in these areas. Findings from a common-garden rearing experiment using individuals from one of our three pairs of populations provide evidence that trait differences between urban and natural sites may be genetically based. Taken together, our data suggest that anoles in urban areas are under significant differential natural selection and may be evolutionarily adapting to their human-modified environments.

  7. The importance of remnant native vegetation of Amazonian submontane forest for the conservation of lizards.

    Science.gov (United States)

    Silva, D J; Santos-Filho, M; Canale, G R

    2014-08-01

    Forest fragmentation affects animal population dynamics mainly by loss of habitat and disruption of animal movement. Lizard assemblages are affected by environmental changes, but, depending on their ecological needs, some species might be more vulnerable than others. The southern Amazon suffers accelerated anthropic actions replacing natural environments by farmland (crops and pasture). This region is considerably drier than most of the northern Amazon, with stational semi-deciduous forests fragmented and isolated by pasture, and crops to a lesser extent. Here we report data on lizard assemblages using semi-deciduous forests, forest edge and the surrounding pasture in the southern Amazon in Mato Grosso, Brazil. Lizards were collected in 21 forest fragments (41 to 7,035 ha) surrounded by pasture; using pitfall traps placed on a degradation gradient - from pasture inwards forest fragment (up to 200 m). We collected 242 individuals (14 species, seven families) in 6,300 trap-days. The pattern of species occurrence was largely nested and this nesting was associated with three habitat guilds (generalist, edge-tolerant, and forest species). Although there was no obvious fragmentation effect on lizards diversity community-wise, Hoplocercus spinosus, Bachia dorbignyi, Micrablepharus maximiliani and Kentropyx calcarta were more vulnerable to such effects than all other ten species collected. We verified that assemblages inhabiting pasture and forest edge are a nested subset of assemblages from the forest core. The remnant native vegetation is not distributed homogeneously and lizards species can persist in different parts of the landscape, therefore we recommend the protection of forest remnants as an important conservation action for lizards of the southern Amazon.

  8. Male Texas Horned Lizards increase daily movements and area covered in spring: A mate searching strategy?

    Science.gov (United States)

    Stark, Richard C.; Fox, S. F.; David, M.L.

    2005-01-01

    Texas Horned Lizards, Phrynosoma cornutum, were tracked using fluorescent powder to determine exact daily movements. Daily linear movements and daily space use were compared between adult males and females. Lizards that traveled the greatest linear distances also covered the largest areas. In Oklahoma, adults emerge from hibernation in late April and early May and mate soon afterward. Males traveled significantly greater distances (and covered significantly larger areas in a day) than females in May but not after May. We propose that males move more and cover more area than females early in the mating season to intercept receptive females. Copyright 2005 Society for the Study of Amphibians and Reptiles.

  9. Beta-endorphin disrupts seasonal and FSH-induced ovarian recrudescence in the lizard Mabuya carinata.

    Science.gov (United States)

    Ganesh, C B; Yajurvedi, H N

    2003-10-01

    Administration (ip) of an opioid peptide, beta-endorphin (beta-EP) (0.1, 0.5, or 1 microg beta-EP/day/lizard for 30 days) during seasonal recrudescence phase of the ovarian cycle inhibited ovarian recrudescence as shown by the absence of vitellogenic follicles in the ovary in contrast to their presence in treatment controls in the lizard Mabuya carinata. In the germinal bed, treatment of 0.1 microg beta-EP did not affect primordial follicles, whereas their mean number was significantly lower in lizards treated with 0.5 or 1 microg beta-EP compared to those of treatment controls. There was also suppression of oviductal development as shown by a significantly lower relative weight of the oviduct and regressed oviductal glands in lizards treated with all the dosages of beta-EP compared to treatment controls. In another experiment, administration of FSH (10 IU FSH/alternate day/lizard for 30 days) during the regression phase of the ovarian cycle induced development of vitellogenic follicles, whereas the treatment controls showed only previtellogenic follicles. In addition, there was a significant increase in the ovarian and oviductal weights compared to initial and treatment controls. However, simultaneous administration of similar dosage of FSH and beta-EP (0.5 microg/day/lizard) did not induce ovarian recrudescence as shown by the absence of vitellogenic follicles in the ovary and significantly lower weight of the ovary and the oviduct and the mean number of oogonia, oocytes, and primordial follicles compared to those of FSH-treated lizards. The results indicate that beta-EP inhibits seasonal as well as FSH-induced ovarian recrudescence. Inhibitory effect of beta-EP on follicular development despite FSH administration implies its effect at the ovarian level in M. carinata. While adversely affecting the ovarian follicular development, beta-EP did not affect the adrenal gland as there was no significant variation in the mean nuclear diameter of the adrenocortical cells

  10. Natural history of Xenosaurus phalaroanthereon (Squamata, Xenosauridae, a Knob-scaled Lizard from Oaxaca, Mexico

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    Julio A. Lemos-Espinal

    2005-12-01

    Full Text Available We made observations on the natural history of a population of the lizard Xenosaurus phalaroanthereon from Oaxaca, Mexico. Females were larger than males (SVL. Most lizards were found completely inside rock crevices. Mean body temperature was 20.3°C. Body temperature wasrelated primarily to substrate temperature. Body temperature was not influenced by any crevice characteristic. Based on abdominal palpation, the size at maturity for females appears to be 117-119 mm SVL. Sex ratio did not differ from 1:1. We compare the ecology of this population to that of other Xenosaurus.

  11. Muscle fiber-type variation in lizards (Squamata) and phylogenetic reconstruction of hypothesized ancestral states.

    Science.gov (United States)

    Bonine, Kevin E; Gleeson, Todd T; Garland, Theodore

    2005-12-01

    Previously, we found that phrynosomatid lizards, a diverse group common in the southwestern USA, vary markedly in fiber-type composition of the iliofibularis (a hindlimb muscle important in locomotion). Phrynosomatidae comprises three subclades: the closely related sand and horned lizards, and their relatives the Sceloporus group. The variation in muscle fiber-type composition for 11 phrynosomatid species is attributable mainly to differences between the sand- and horned-lizard subclades. Here, we expand the phrynosomatid database with three additional species and compare these results with data collected for 10 outgroup (distantly related) species. Our goal was to determine if the patterns found in Phrynosomatidae hold across a broader phylogenetic range of the extant lizards and to elucidate the evolution of muscle fiber-type composition and related traits. To allow for meaningful comparisons, data were collected from species that are primarily terrestrial and relatively small in size (3.5-65 g body mass). Results indicate that the fiber-type variation observed within the Phrynosomatidae almost spans the range of variation observed in our sample of 24 species from eight families. However, one species of Acanthodactylus (Lacertidae) had a consistent region of large tonic fibers (that did not stain darkly for either succinic dehydrogenase or myosin ATPase activity), a fiber-type only occasionally seen in the other 23 species examined. Many species have a large proportion of either fast-twitch glycolytic (FG; e.g. sand lizards and Aspidoscelis) or fast-twitch oxidative-glycolytic (FOG) fibers (e.g. horned lizards), with the slow-oxidative proportion occupying only 1-17% of the iliofibularis. Importantly, the negative relationship between FG and FOG composition observed in Phrynosomatidae appears to be a characteristic of lizards in general, and could lead to functional trade-offs in aspects of locomotor performance, as has previously been reported for Lacertidae

  12. Identification key to species of the flying lizard genus Draco Linnaeus, 1758 (Squamata: Agamidae in Thailand

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    Nattawut Srichairat

    2017-02-01

    Full Text Available A species identification key of flying lizards in the genus Draco from Thailand was constructed based on 521 preserved specimens from collections during 1967–2012 in the Natural History Museum (THNHM, National Science Museum, Technopolis, Pathum Thani, Thailand. Regardless of sexual characters, four characters were used to identify Draco spp. lizards: 1 nostril direction; 2 type of tympanum; 3 pattern of patagium; and 4 snout with or without a series of scales forming a Y-shaped figure. The specimens were identified into nine species—Draco blanfordii, Draco fimbriatus, Draco maculatus, Draco maximus, Draco melanopogon, Draco obscurus, Draco quinquefasciatus, Draco taeniopterus and Draco volans.

  13. Prediction of RBC aggregability and deformability by whole body bioimpedance measurements analyzed according to Hanai's mixture conductivity theory.

    Science.gov (United States)

    Varlet-Marie, Emmanuelle; Brun, Jean-Frédéric

    2011-01-01

    Bioelectrical impedancemetry (BIA) has been used to evaluate hemorheological parameters in vitro, and whole body impedance measurements are also correlated to some hemorheologic factors, due to their close relationship with determinants of electric properties of blood. In previous studies, we have determined a set of predictive equations for hematocrit, whole blood viscosity and plasma viscosity in both sedentary and trained individuals. Recent developments of the interpretation of BIA analysis based on Hanai's mixture conductivity theory allows a more interpretative analysis of the relationships between these electric measurements and body composition. Impedance can be analyzed in terms of resistance and resistivity of the whole body and even more, assuming some simplifications, resistance R and resistivity ρ of total body water (TBW), extracellular water (ECW) and intracellular water (ICW). In this study we thus investigated relationships between blood rheology and these calculations of R and ρ in a sample of 83 subjects (age: 9-64 yr; BMI: 17-44 kg/m(2)). BIA was performed with a multifrequency bioelectrical impedancemeter using low intensity at the following frequencies: 1, 5, 10, 50 and 100 kHz. Viscometric measurements were done with a falling ball viscometer. Hematocrit was measured with microcentrifuge. We found a new prediction of Quemada's viscometric index of RBC rigidity "k" which was positively correlated to the resistance of ECW (R(e)) and even more if it was related to this volume: k = 0.005809 R(e)/ECW + 1.1784 (r = 0.487; Bland-Altman mean difference: 0.0124; range: -0.00481 to 0.00296). A new finding was that red blood cells (RBC) aggregability, that in the previous studies was not related to whole body impedance, despite its in vitro measurability with such measurements, was correlated to extracellular resistance and resistivity. The Myrenne index "M" was negatively correlated to the resistivity of the extracellular fluid ρe and is predicted

  14. Importance of Heparin Provocation and SPECT/CT in Detecting Obscure Gastrointestinal Bleeding on 99mTc-RBC Scintigraphy: A Case Report.

    Science.gov (United States)

    Haghighatafshar, Mahdi; Gheisari, Farshid; Ghaedian, Tahereh

    2015-08-01

    We presented a pediatric case with a history of intermittent melena for 3 years because of angiodyplasia of small intestine. The results of frequent upper gastrointestinal endoscopies and colonoscopies as well as both Tc-red blood cell (RBC) and Meckel's scintigraphies for several times were negative in detection of bleeding site. However, Tc-RBC scintigraphy with single-photon emission computed tomography (SPECT)/computed tomography (CT) after heparin augmentation detected a site of bleeding in the distal ileum which later was confirmed during surgery with final diagnosis of angiodysplasia.It could be stated that heparin provocation of bleeding before Tc-RBC scintigraphy accompanied by fused SPECT/CT images should be kept in mind for management of intestinal bleeding especially in difficult cases.

  15. Implications of rbcL phylogeny for historical biogeography of genus Mercurialis L.: Estimating age and center of origin

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    Jovanović V.

    2010-01-01

    Full Text Available The aim of this study was to address questions concerning the historical biogeography of the genus Mercurialis in the subfamily Acalyphoideae. Applying a molecular clock to obtained rbcL phylogeny, we estimated the minimal age of divergence of genus Mercurialis to ~65-66 Ma, placing it at the Cretaceous/Paleogene boundary. We used ancestral area analysis and dispersal-vicariance analysis to infer the center of origin of the genus. Contrary to previous hypothesis, our results show that Mercurialis originated in Indomalaya and migrated westward, while the Mediterranean area was most probably the center of ecological diversification and further speciation. Evolutionary events of vicariance and dispersals were reconstructed in a proposed scenario of divergence of Mercurialis within Acalyphoideae. .

  16. Conversion to Paradoxical Finding on Technetium-99m-labeled RBC Scintigraphy after Treatment for Secondary Raynaud's Phenomenon.

    Science.gov (United States)

    Chong, Ari; Ha, Jung-Min; Song, Ho-Chun; Kim, Jahae; Choi, Soo Jin Na

    2013-12-01

    An 18-year-old woman reported that after exposure to cold temperatures her fingers appeared blue and her hands and feet felt cold. Secondary Raynaud's phenomenon (RP) associated with peripheral vascular disease was suspected. Technetium (Tc)-99m-labeled RBC hand scintigraphy after cold change showed decreased blood pool activity in her fingers. The patient's symptoms improved after she received sarpogrelate HCL (200 mg/day) and nifedifine (40 mg/day). Follow-up scintigraphy performed 7 months after the patient started treatment showed paradoxically increased blood pool activity in her fingers after cold challenge. To the best of our knowledge, this is the first case report of a patient with secondary RP showing paradoxical change on scintigraphy after she received medication that improved her symptoms.

  17. RBC acetyl cholinesterase: A poor man′s early diagnostic biomarker for familial alzheimer′s and Parkinson′s disease dementia

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    Himmatrao Saluba Bawaskar

    2015-01-01

    Full Text Available Objective: Analysis of red blood cell acetyl cholinesterase (AChE in a familial Alzheimer′s diseases (AD Parkinson′s disease dementia (PDD and their first generation. Setting: General hospital, Mahad district, Raigad. Patients and Methods: Clinically diagnosed patients of AD and PDD and their asymptomatic relatives. Their blood was collected in EDTA tube and transferred to laboratory at Mumbai. Result: Median red blood cell (RBC cholinesterase levels amongst PDD, their first generation asymptomatic relatives, familial AD, asymptomatic relatives of AD, healthy controls, farmers exposed to pesticides (positive control and other neurological condition without dementia (hypertension with TIA 1, sub-dural hematoma 2, hypothyroid 1, non-familial unilateral parkinsonism without dementia 3, writers cramps 2, hyponitremia 1 and cerebral palsy with non-fluent aphasia 1. Median values of RBC AChE were 19086.78 U/L, 15666.05 U/L, 9013.11 U/L, 7806.19 U/L, 14334.57 U/L, 9785.05 U/L and 13162.60 U/L, respectively. As compared to controls, RBC AChE levels were statistically significant among PDD (P = 0.004 and significantly lowered among familial AD patients (P = 0.010, relatives of patients (P = 0.010. Interpretations: Below the normal RBC AChE level is a potential biomarker in asymptomatic relatives of familial AD patients. RBC AChE is raised than normal level in patients suffering from PDD, where AChE inhibitors are helpful. However, RBC AChE level below the normal where AChE inhibitor may not be effective.

  18. Are Invasive Species Stressful? The Glucocorticoid Profile of Native Lizards Exposed to Invasive Fire Ants Depends on the Context.

    Science.gov (United States)

    Graham, Sean P; Freidenfelds, Nicole A; Thawley, Christopher J; Robbins, Travis R; Langkilde, Tracy

    Invasive species represent a substantial threat to native species worldwide. Research on the impacts of invasive species on wild living vertebrates has focused primarily on population-level effects. The sublethal, individual-level effects of invaders may be equally important but are poorly understood. We investigated the effects of invasive fire ants (Solenopsis invicta) on the physiological stress response of a native lizard (Sceloporus undulatus) within two experimental contexts: directly exposing lizards to a fire ant attack and housing lizards with fire ants in seminatural field enclosures. Lizards directly exposed to brief attack by fire ants had elevated concentrations of the stress hormone corticosterone (CORT), suggesting that these encounters can be physiologically stressful. However, lizards exposed for longer periods to fire ants in field enclosures had lower concentrations of CORT. This may indicate that the combined effects of confinement and fire ant exposure have pushed lizards into allostatic overload. However, lizards from fire ant enclosures appeared to have intact negative feedback controls of the stress response, evidenced by functioning adrenocorticotropic hormone responsiveness and lack of suppression of innate immunity (plasma bactericidal capacity). We review previous studies examining the stress response of wild vertebrates to various anthropogenic stressors and discuss how these-in combination with our results-underscore the importance of considering context (the length, frequency, magnitude, and types of threat) when assessing these impacts.

  19. Effects of wildfire, rainfall and region on desert lizard assemblages: the importance of multi-scale processes.

    Science.gov (United States)

    Pastro, Louise A; Dickman, Christopher R; Letnic, Mike

    2013-10-01

    Vertebrate populations are influenced by environmental processes that operate at a range of spatial and temporal scales. Wildfire is a disturbance that can affect vertebrate populations across large spatial scales, although vertebrate responses are frequently influenced by processes operating at smaller spatial scales such as topography, interspecific interactions and regional history. Here, we investigate the effects of a broad-scale wildfire on lizard assemblages in a desert region. We predicted that a rainfall gradient within the region affected by the wildfire would influence lizard responses to the fire by encouraging post-fire succession to proceed more rapidly in high-rainfall areas, and would be enabled in turn by more rapid vegetation recovery. To test our prediction, we censused lizards, measured rainfall, undertook vegetation surveys and sampled invertebrate abundance across burnt and unburnt habitat ecotones within three regional areas situated along a gradient of long-term annual rainfall. Lizard diversity was not affected by fire or region and lizard abundance was influenced only by region. Lizard assemblage composition was also only influenced by region, but this did not relate to differences in rainfall or habitat as we had predicted. Regional differences in lizard assemblages related instead to food availability. The observed differences also likely reflected regional differences in the strength of biotic interactions with predators and changes in land use. Our study shows that assemblage responses to a disturbance were not uniform within a large desert region and instead were influenced by other environmental processes operating simultaneously at multiple temporal and spatial scales.

  20. Effects of CO2 and iron availability on rbcL gene expression in Bering Sea diatoms

    Science.gov (United States)

    Endo, H.; Sugie, K.; Yoshimura, T.; Suzuki, K.

    2015-04-01

    Iron (Fe) can limit phytoplankton productivity in approximately 40% of the global ocean, including in high-nutrient, low-chlorophyll (HNLC) waters. However, there is little information available on the impact of CO2-induced seawater acidification on natural phytoplankton assemblages in HNLC regions. We therefore conducted an on-deck experiment manipulating CO2 and Fe using Fe-deficient Bering Sea water during the summer of 2009. The concentrations of CO2 in the incubation bottles were set at 380 and 600 ppm in the non-Fe-added (control) bottles and 180, 380, 600, and 1000 ppm in the Fe-added bottles. The phytoplankton assemblages were primarily composed of diatoms followed by haptophytes in all incubation bottles as estimated by pigment signatures throughout the 5-day (control) or 6-day (Fe-added treatment) incubation period. At the end of incubation, the relative contribution of diatoms to chlorophyll a biomass was significantly higher in the 380 ppm CO2 treatment than in the 600 ppm treatment in the controls, whereas minimal changes were found in the Fe-added treatments. These results indicate that, under Fe-deficient conditions, the growth of diatoms could be negatively affected by the increase in CO2 availability. To further support this finding, we estimated the expression and phylogeny of rbcL (which encodes the large subunit of RuBisCO) mRNA in diatoms by quantitative reverse transcription polymerase chain reaction (PCR) and clone library techniques, respectively. Interestingly, regardless of Fe availability, the transcript abundance of rbcL decreased in the high CO2 treatments (600 and 1000 ppm). The present study suggests that the projected future increase in seawater pCO2 could reduce the RuBisCO transcription of diatoms, resulting in a decrease in primary productivity and a shift in the food web structure of the Bering Sea.

  1. Quantitative Evaluation of Therapeutic Efficacy of Endovenous Laser Treatment for Distal Varicose Veins by Tc-99m RBC Venography

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Do Young; Song, Ki Hoon; Sim, Seung Joo; Kim, Ki Ho [College of Medicine, Univ. of Donga, Busan (Korea, Republic of)

    2003-07-01

    Endovenous laser treatment (EVLT) has been shown to be effective for elimination of greater saphenous (GSV) incompetence. While the result of GSV closure has been studied in detail, the effects in distal GSV and its tributaries following EVLT are still not completely understood. In addition, the optimal time for treatment of remaining varicose veins is not established. We evaluated the clinical and radiological changes of distal varicose veins after EVLT and determined the optimal time for additional treatment of distal varicose veins following EVLT by Tc-99m RBC. Forty GSV (30 patients) were treated with 940 nm or 810 nm diode laser at usual energy setting. Clinical and Duplex evaluation were performed at I week, and at various monthly intervals (2-6 months) following the initial treatment. Tc-99m venography was performed as usual protocol at I month and at every 3 months after EVLT. The distal varicose veins were quantified by determining the ratio of mean counts per pixel in the target and background areas and then comparing the pre-EVLT and post-EVLT values. Thirty-eight (95.0%) GSV were closed following EVLT and remained closed at 1-21 months follow-up examination. The reduction rate of distal varicose veins measured by Tc-99m venography was 22.8% at l month, 42.7% at 3 months, 61.5% at 6 months, and 72.4% at 9 months after EVLT. Fifteen legs (37.5%) required additional phlebectomy at 1 to 3 months after EVLT, while the others (62.5%) showed spontaneous regression of distal veins from one month during follow-up period. Therapeutic efficacy of EVLT for distal varicose vein can be well-evaluated quantitatively by Tc-99m RBC venography. Theses results suggest that after EVLT for GSV, the 'wait' policy would be necessary, rather than the 'wasting' of distal veins concurrently with EVLT.

  2. Lizard movement tracks: variation in path re-use behaviour is consistent with a scent-marking function

    Directory of Open Access Journals (Sweden)

    Stephan T. Leu

    2016-03-01

    Full Text Available Individual movement influences the spatial and social structuring of a population. Animals regularly use the same paths to move efficiently to familiar places, or to patrol and mark home ranges. We found that Australian sleepy lizards (Tiliqua rugosa, a monogamous species with stable pair-bonds, repeatedly used the same paths within their home ranges and investigated whether path re-use functions as a scent-marking behaviour, or whether it is influenced by site familiarity. Lizards can leave scent trails on the substrate when moving through the environment and have a well-developed vomeronasal system to detect and respond to those scents. Path re-use would allow sleepy lizards to concentrate scent marks along these well-used trails, advertising their presence. Hypotheses of mate attraction and mating competition predict that sleepy lizard males, which experience greater intra-sexual competition, mark more strongly. Consistent with those hypotheses, males re-used their paths more than females, and lizards that showed pairing behaviour with individuals of the opposite sex re-used paths more than unpaired lizards, particularly among females. Hinterland marking is most economic when home ranges are large and mobility is low, as is the case in the sleepy lizard. Consistent with this strategy, re-used paths were predominantly located in the inner 50% home range areas. Together, our detailed movement analyses suggest that path re-use is a scent marking behaviour in the sleepy lizard. We also investigated but found less support for alternative explanations of path re-use behaviour, such as site familiarity and spatial knowledge. Lizards established the same number of paths, and used them as often, whether they had occupied their home ranges for one or for more years. We discuss our findings in relation to maintenance of the monogamous mating system of this species, and the spatial and social structuring of the population.

  3. Role of sand lizards in the ecology of Lyme and other tick-borne diseases in the Netherlands

    Directory of Open Access Journals (Sweden)

    Spitzen - van der Sluijs Annemarieke

    2010-05-01

    Full Text Available Abstract Background Lizards are considered zooprophylactic for almost all Borrelia burgdorferi species, and act as dilution hosts in parts of North America. Whether European lizards significantly reduce the ability of B. burgdorferi to maintain itself in enzootic cycles, and consequently decrease the infection rate of Ixodes ricinus ticks for B. burgdorferi and other tick-borne pathogens in Western Europe is not clear. Results Ticks were collected from sand lizards, their habitat (heath and from the adjacent forest. DNA of tick-borne pathogens was detected by PCR followed by reverse line blotting. Tick densities were measured at all four locations by blanket dragging. Nymphs and adult ticks collected from lizards had a significantly lower (1.4% prevalence of B. burgdorferi sensu lato, compared to questing ticks in heath (24% or forest (19%. The prevalence of Rickettsia helvetica was significantly higher in ticks from lizards (19% than those from woodland (10% whereas neither was significantly different from the prevalence in ticks from heather (15%. The prevalence of Anaplasma and Ehrlichia spp in heather (12% and forest (14% were comparable, but significantly lower in ticks from sand lizards (5.4%. The prevalence of Babesia spp in ticks varied between 0 and 5.3%. Tick load of lizards ranged from 1 - 16. Tick densities were ~ 5-fold lower in the heather areas than in woodlands at all four sites. Conclusions Despite their apparent low reservoir competence, the presence of sand lizards had insignificant impact on the B. burgdorferi s.l. infection rate of questing ticks. In contrast, sand lizards might act as reservoir hosts for R. helvetica. Remarkably, the public health risk from tick-borne diseases is approximately five times lower in heather than in woodland, due to the low tick densities in heather.

  4. The relationship between the lizard eye and associated bony features: a cautionary note for interpreting fossil activity patterns.

    Science.gov (United States)

    Hall, Margaret I

    2009-06-01

    Activity pattern, the time of day when an animal is active, is associated with ecology. There are two major activity patterns: diurnal (awake during the day in a photopic environment) and nocturnal (awake at night in a scotopic environment). Lizards exhibit characteristic eye shapes associated with activity pattern, with scotopic-adapted lizard eyes optimized for visual sensitivity with large corneal diameters relative to their eye axial lengths, and photopic-adapted lizards optimized for visual acuity, with larger axial lengths of the eye relative to their corneal diameters. This study: (1) quantifies the relationship between the lizard eye and its associated bony anatomy (the orbit, sclerotic ring, and associated skull widths); (2) investigates how activity pattern is reflected in that bony anatomy; and (3) determines if it is possible to reliably interpret activity pattern for a lizard that does not have the soft tissue available for study, specifically, for a fossil. Knowledge of extinct lizards' activity patterns would be useful in making paleoecological interpretations. Here, 96 scotopic- and photopic-adapted lizard species are analyzed in a phylogenetic context. Although there is a close relationship between the lepidosaur eye and associated bony anatomy, based on these data activity pattern cannot be reliably interpreted for bony-only specimens, such as a fossil, possibly because of the limited ossification of the lepidosaur skull. Caution should be exercised when utilizing lizard bony anatomy to interpret light-level adaptation, either for a fossil lizard or as part of an extant phylogenetic bracket to interpret other extinct animals with sclerotic rings, such as dinosaurs.

  5. Lizard movement tracks: variation in path re-use behaviour is consistent with a scent-marking function.

    Science.gov (United States)

    Leu, Stephan T; Jackson, Grant; Roddick, John F; Bull, C Michael

    2016-01-01

    Individual movement influences the spatial and social structuring of a population. Animals regularly use the same paths to move efficiently to familiar places, or to patrol and mark home ranges. We found that Australian sleepy lizards (Tiliqua rugosa), a monogamous species with stable pair-bonds, repeatedly used the same paths within their home ranges and investigated whether path re-use functions as a scent-marking behaviour, or whether it is influenced by site familiarity. Lizards can leave scent trails on the substrate when moving through the environment and have a well-developed vomeronasal system to detect and respond to those scents. Path re-use would allow sleepy lizards to concentrate scent marks along these well-used trails, advertising their presence. Hypotheses of mate attraction and mating competition predict that sleepy lizard males, which experience greater intra-sexual competition, mark more strongly. Consistent with those hypotheses, males re-used their paths more than females, and lizards that showed pairing behaviour with individuals of the opposite sex re-used paths more than unpaired lizards, particularly among females. Hinterland marking is most economic when home ranges are large and mobility is low, as is the case in the sleepy lizard. Consistent with this strategy, re-used paths were predominantly located in the inner 50% home range areas. Together, our detailed movement analyses suggest that path re-use is a scent marking behaviour in the sleepy lizard. We also investigated but found less support for alternative explanations of path re-use behaviour, such as site familiarity and spatial knowledge. Lizards established the same number of paths, and used them as often, whether they had occupied their home ranges for one or for more years. We discuss our findings in relation to maintenance of the monogamous mating system of this species, and the spatial and social structuring of the population.

  6. Thermal dependence of passive electrical properties of lizard muscle fibres.

    Science.gov (United States)

    Adams, B A

    1987-11-01

    1. The thermal dependence of passive electrical properties was determined for twitch fibres from the white region of the iliofibularis (IF) muscle of Anolis cristatellus (15-35 degrees C) and Sceloporus occidentalis (15-40 degrees C), and for twitch fibres from the white (15-45 degrees C) and red (15-40 degrees C) regions of the IF of Dipsosaurus dorsalis. These species differ in thermal ecology, with Anolis being the least thermophilic and Dipsosaurus the most thermophilic. 2. Iliofibularis fibres from the three species reacted similarly to changing temperature. As temperature was increased, input resistance (Rin) decreased (average R10 = 0.7), length constant (L) decreased (average R10 = 0.9), time constant (tau) decreased (average R10 = 0.8), sarcoplasmic resistivity (Rs) decreased (average R10 = 0.8) and apparent membrane resistance (Rm) decreased (average R10 = 0.7). In contrast, apparent membrane capacitance (Cm) increased with increasing temperature (average R10 = 1.3). 3. Rin, L, tau and apparent Rm were lowest in fibres from Anolis (the least thermophilic species) and highest in fibres from Dipsosaurus (the most thermophilic species). Anolis had the largest and Dipsosaurus the smallest diameter fibres (126 and 57 micron, respectively). Apparent Cm was highest in fibres from Sceloporus, which had fibres of intermediate diameter (101 micron). Rs did not differ significantly among species. 4. The effect of temperature on the passive electrical properties of these lizard fibres was similar to that reported for muscle fibres from other ectothermic animals (crustaceans, insects, fish and amphibians) but qualitatively different from that reported for some mammalian (cat tenuissimus, goat intercostal) fibres. The changes that occur in the passive electrical properties render the fibres less excitable as temperature increases.

  7. Anolis lizards as biocontrol agents in mainland and island agroecosystems.

    Science.gov (United States)

    Monagan, Ivan V; Morris, Jonathan R; Davis Rabosky, Alison R; Perfecto, Ivette; Vandermeer, John

    2017-04-01

    Our knowledge of ecological interactions that bolster ecosystem function and productivity has broad applications to the management of agricultural systems. Studies suggest that the presence of generalist predators in agricultural landscapes leads to a decrease in the abundance of herbivorous pests, but our understanding of how these interactions vary across taxa and along gradients of management intensity and eco-geographic space remains incomplete. In this study, we assessed the functional response and biocontrol potential of a highly ubiquitous insectivore (lizards in the genus Anolis) on the world's most important coffee pest, the coffee berry borer (Hypothalemus hampei). We conducted field surveys and laboratory experiments to examine the impact of land-use intensification on species richness and abundance of anoles and the capacity of anoles to reduce berry borer infestations in mainland and island coffee systems. Our results show that anoles significantly reduce coffee infestation rates in laboratory settings (Mexico, p = .03, F = 5.13 df = 1, 35; Puerto Rico, p = .014, F = 8.82, df = 1, 10) and are capable of consuming coffee berry borers in high abundance. Additionally, diversified agroecosystems bolster anole abundance, while high-intensity practices, including the reduction of vegetation complexity and the application of agrochemicals were associated with reduced anole abundance. The results of this study provide supporting evidence of the positive impact of generalist predators on the control of crop pests in agricultural landscapes, and the role of diversified agroecosystems in sustaining both functionally diverse communities and crop production in tropical agroecosystems.

  8. Convergent evolution of brain morphology and communication modalities in lizards

    Institute of Scientific and Technical Information of China (English)

    Christopher D.ROBINSON; Michael S.PATTON; Brittney M.ANDRE; Michele A.JOHNSON

    2015-01-01

    Animals communicate information within their environments via visual,chemical,auditory,and/or tactile modalities.The use of each modalityis generally linked to particular brain regions,but it is not yet known whether the cellular morphology of neurons in these regions has evolved in association with the relative use of a modality.We investigated relationships between the behavioral use of communication modalities and neural morphologies in six lizard species.Two of these species (Anolis carolinensis and Leiocephalus carinatus) primarily use visual signals to communicate with conspecifics and detect potential prey,and two (Aspidoscelis gularis and Scincella lateralis) communicate and forage primarily using chemical signals.Two other species (Hemidactylus turcicus and Sceloporus olivaceus) use both visual and chemical signals.For each species,we performed behavioral observations and quantified rates of visual and chemical behaviors.We then cryosectioned brain tissues from 9-10 males of each species and measured the soma size and density of neurons in two brain regions associated with visual behaviors (the lateral geniculate nucleus and the nucleus rotundus) and one region associated with chemical behaviors (the nucleus sphericus).With analyses conducted in a phylogenetic context,we found that species that performed higher rates of visual displays had a denser lateral geniculatc nucleus,and species that used a higher proportion of chemical displays had larger somas in the nucleus sphericus.These relationships suggest that neural morphologies in the brain have evolved convergently in species with similar communication behaviors [Current Zoology 61 (2):281-291,2015].

  9. Survey of the reptilian fauna of the Kingdom of Saudi Arabia. V. The lizard fauna of Turaif region.

    Science.gov (United States)

    Al-Sadoon, Mohammed K; Paray, Bilal Ahmad; Al-Otaibi, Hamad S

    2016-09-01

    Turaif area located in the Northern border region of Saudi Arabia is one of the most important regions of the Kingdom. This work was proposed to throw light on the diversity of lizard fauna investigated through the collection and subsequent identification of specimens from different localities of Turaif region of Kingdom of Saudi Arabia. Sixteen species of lizards belonging to 5 families (Agamidae, Gekkonidae, Lacertidae, Scincidae and Varanidae) were recorded. Lacertidae was the most common family. Three species of lizards namely Acanthodactylus orientalis, Acanthodactylus scutellatus and Acanthodactylus grandis were reported for the first time in the Turaif region of Saudi Arabia. The geographical distribution of the collected species within this province was mapped.

  10. Reservoir Role of Lizard Psammodromus algirus in Transmission Cycle of Borrelia burgdorferi Sensu Lato (Spirochaetaceae) in Tunisia

    OpenAIRE

    Dsouli, Najla; Younsi-kabachii, Hend; Postic, Danièle; Nouira, Said; Gern, Lise; Bouattour, Ali

    2017-01-01

    To investigate the reservoir role of the lizard Psammodromus algirus for the Lyme disease spirochete, 199 lizards were trapped from April to October 2003 in El Jouza, northwestern Tunisia. In this site, the infection rate of free-living Ixodes ricinus (L.) by Borrelia was evaluated by immunofluorescence as 34.6% for adult ticks and 12.5% for nymphs. Eighty percent of P. algirus (117/146) captured during this study were infested by I. ricinus, the predominant tick species collected from lizard...

  11. Does diet in lacertid lizards reflect prey availability? Evidence for selective predation in the Aeolian wall lizard, Podarcis raffonei (Mertens, 1952 (Reptilia, Lacertidae

    Directory of Open Access Journals (Sweden)

    Pietro Lo Cascio

    2011-06-01

    Full Text Available In this paper the invertebrate fauna occurring on Scoglio Faraglione, a tiny Aeolian island (AeolianArchipelago, NE Sicily inhabited by a population of the critically endangered lacertid lizard Podarcis raffonei(Mertens, 1952, was censused at different seasons and the resulting data were then compared with dataobtained analysing prey composition and prey abundance in the diet of the lizards occurring on the same islet.The diet of Podarcis raffonei was mainly based on insects and other arthropods. The results indicate that dietcomposition is not directly influenced by prey availability and temporal prey abundance, and that there isstrong evidence indicating selective predation. Lizards prey upon a number of arthropod categories fewer thanthat recorded in field. Some invertebrate taxa (e.g. Diptera and Gastropoda are really less attractive for lizardsand are rarely preyed or not preyed at all despite their spatial and/or temporal abundance. This suggests thatPodarcis raffonei is able to operate a hierarchical choice within the range of prey items constituting its preyspectrum, probably through the ability to discriminate between prey chemicals or visually oriented predation.

  12. A potential recovery of a population of the sand lizard Liolaemus lutzae Mertens, 1938 in an area within its range: a lizard endemic and threatened with extinction

    Directory of Open Access Journals (Sweden)

    CFD. Rocha

    Full Text Available The endemic and threatened lizard Liolaemus lutzae has a relatively small geographic range restricted to only 200 km of along the coast of Rio de Janeiro State, Brazil, which are habitats under intensive anthropic disturbance. At the Barra da Tijuca beach, in Rio de Janeiro city an estimate of the population abundance made in 1991, compared to a previous estimate made in 1984, showed a considerable decrease (about 65%. Most of the decrease was attributed to anthropic disturbances that locally affected the beach vegetation, the species habitat. In this study we present estimates made in 2002 and in 2006 at the same area and compare them with the estimates of 1984 and 1991, using the same methodology in order to make comparable the data from different samplings years and to evaluate the present status of the local population. The estimated indexes of L. lutzae abundance in 2002 and in 2006 were higher than that of 1991. There was a significant increase in the mean number of recorded lizards in 2002 compared to 1991, but the mean number of lizards sighted in 2006 remained stable when compared with that of 2002. Our data based on the index of abundance recorded suggested that the number of L. lutzae at Barra da Tijuca beach recorded increased, which can be indicative of a potential recovery of the local population.

  13. Does the conceptus of the viviparous lizard Barisia imbricata imbricata participates in the regulation of progesterone production and the control of luteolysis?

    Science.gov (United States)

    Martínez-Torres, Martín; Salcedo-Álvarez, Martha; Alvarez-Rodríguez, Carmen; Cárdenas-León, Mario; Luis, Juana; Moreno-Fierros, Leticia

    2014-08-01

    It is generally accepted that progesterone is necessary to maintain gestation; however, the mechanisms that control the production of this steroid remain unknown. The corpus luteum has been assigned a central role in the maintenance of gestation based on its capacity to produce progesterone. A pseudopregnancy model was performed in a viviparous lizard, Barisia imbricata imbricata, to determine whether the absence of embryos would affect the pattern of progesterone production or the corpus luteum histology. Blood samples were obtained prior to ovulation and at 8, 16, and 24 weeks after ovulation (pseudopregnant and pregnant lizards), as well as one day after parturition (pregnant lizards) or 32 weeks after ovulation (pseudopregnant lizards). The corpus luteum was surgically removed one day after blood samples were obtained. Blood aliquots from nongravid females were obtained at similar timepoints. We found a significant reduction in plasma progesterone concentrations at 24 and 32 weeks post-ovulation in pseudopregnant lizards compared with those observed at similar times in intact pregnant lizards, whereas the progesterone levels in non-gestant lizards remained significantly lower than in either pseudopregnant or pregnant lizards. Moreover, we observed that the histological appearance of the corpus luteum from pseudogestational females (obtained 24 and 32 weeks post-ovulation) differed from the corpora lutea from lizards in late gestation and intact parturient lizards. These observations suggest that the conceptus participates in the regulation of progesterone production in late gestation and also in luteolysis control.

  14. Acetaminophen and zinc phosphide for lethal management of invasive lizards Ctenosaura similis

    Institute of Scientific and Technical Information of China (English)

    Michael L. AVERY; John D. EISEMANN; Kandy L. KEACHER; Peter J. SAVARIE

    2011-01-01

    Reducing populations of invasive lizards through trapping and shooting is feasible in many cases but effective integrated management relies on a variety of tools,including toxicants.In Florida,using wild-caught non-native black spiny-tailed iguanas Ctenosaura similis,we screened acetaminophen and zinc phosphide to determine their suitability for effective population management of this prolific invasive species.Of the animals that received acetaminophen,none died except at the highest test dose,240 mg per lizard,which is not practical for field use.Zinc phosphide produced 100% mortality at dose levels as little as 25 mg per lizard,equivalent to about 0.5% in bait which is lower than currently used in commercial baits for eommensal rodent control.We conclude that zinc phosphide has potential as a useful tool for reducing populations of invasive lizards such as the black spiny-tailed iguana provided target-selective delivery methods are developed [Current Zoology 57 (5):625-629,2011].

  15. A body temperature model for lizards as estimated from the thermal environment

    NARCIS (Netherlands)

    Fei, T.; Skidmore, A.K.; Venus, V.; Wang, T.; Schlerf, M.; Toxopeus, A.G.; Overjijk, van S.; Bian, B.M.; Liu, Y.

    2012-01-01

    A physically based model was built to predict the transient body temperature of lizards in a thermally heterogeneous environment. Six heat transfer terms were taken into account in this model: solar radiation, convective heat flow, longwave radiation, conductive heat flow, metabolic heat gain and re

  16. 75 FR 77801 - Endangered and Threatened Wildlife and Plants; Endangered Status for Dunes Sagebrush Lizard

    Science.gov (United States)

    2010-12-14

    ... and Snell 1997, p. 1; Laurencio et al. 2007, p. 1; Chan et al. 2007, p. 337). In Texas, dunes... New Mexico, Sias and Snell (1998, p. 3) reported a negative relationship between oil well density and... sagebrush lizards declined by 50 percent when there were 29 pads per section (Sias and Snell 1998, p. 3...

  17. UV-deprived coloration reduces success in mate acquisition in male sand lizards (Lacerta agilis.

    Directory of Open Access Journals (Sweden)

    Mats Olsson

    Full Text Available BACKGROUND: Recent work on animal signals has revealed a wide occurrence of UV signals in tetrapods, in particular birds, but also in lizards (and perhaps other Squamate reptiles. Our previous work on the Swedish sand lizard (Lacerta agilis has verified, both in correlative selection analyses in the wild and with laboratory and field experiments, the importance of the green 'badge' on the body sides of adult males for securing mating opportunities, probably mostly through deterring rival males rather than attracting females. The role of UV in communication has, however, never been examined. METHODOLOGY/PRINCIPAL FINDINGS: Here we show that when measured immediately after spring skin shedding, there is also signaling in the UV. By UV-depriving the signal (reflectance with sun block chemicals fixated with permeable, harmless spray dressing, we show that males in the control group (spray dressing only had significantly higher success in mate acquisition than UV-deprived males. CONCLUSIONS/SIGNIFICANCE: These results suggest that at least two colour traits in sand lizards, badge area and UV, contribute to rival deterrence and/or female choice on UV characters, which elevates success in mate acquisition in UV intact male sand lizards.

  18. A body temperature model for lizards as estimated from the thermal environment

    NARCIS (Netherlands)

    Fei, T.; Skidmore, A.K.; Venus, V.; Wang, T.; Schlerf, M.; Toxopeus, A.G.; Overjijk, van S.; Bian, B.M.; Liu, Y.

    2012-01-01

    A physically based model was built to predict the transient body temperature of lizards in a thermally heterogeneous environment. Six heat transfer terms were taken into account in this model: solar radiation, convective heat flow, longwave radiation, conductive heat flow, metabolic heat gain and re

  19. Biogeographic history and cryptic diversity of saxicolous Tropiduridae lizards endemic to the semiarid Caatinga

    OpenAIRE

    Werneck, Fernanda P.; Leite, Rafael N; Silvia R Geurgas; Rodrigues, Miguel T

    2015-01-01

    Abstract Background Phylogeographic research has advanced in South America, with increasing efforts on taxa from the dry diagonal biomes. However, the diversification of endemic fauna from the semiarid Caatinga biome in northeastern Brazil is still poorly known. Here we targeted saxicolous lizards of the Tropidurus semitaeniatus species group to better understand the evolutionary history of these endemic taxa and the Caatinga. We estimat...

  20. Distinct Patterns of Desynchronized Limb Regression in Malagasy Scincine Lizards (Squamata, Scincidae)

    NARCIS (Netherlands)

    Miralles, A.; Hipsley, C.A.; Erens, J.; Gehara, M.; Rakotoarison, A.; Glaw, F.; Müller, J.; Vences, M.

    2015-01-01

    Scincine lizards in Madagascar form an endemic clade of about 60 species exhibiting a variety of ecomorphological adaptations. Several subclades have adapted to burrowing and convergently regressed their limbs and eyes, resulting in a variety of partial and completely limbless morphologies among ext

  1. Effects of bacterial lipopolysaccharide on thermoregulation in green anole lizards (Anolis carolinensis).

    Science.gov (United States)

    Merchant, Mark; Fleury, Lauren; Rutherford, Renee; Paulissen, Mark

    2008-09-15

    Fever is a non-specific host defense mechanism that comprises part of the innate immune response. Innate immune function is thought to be an important adaptive immunological response to infection because it occurs across a broad diversity of phyla. Some reptiles can mount a febrile response, despite the fact that their internal body temperatures (T(b)s) are, to some extent, controlled by the environmental temperatures in which they live. This study was undertaken to determine if LPS would induce fever in green anole lizards (Anolis carolinensis). Lizards were maintained in thermal gradients (22-45 degrees C) with a 12-h diurnal cycle. anoles were injected with LPS, pyrogen-free saline, or left untreated, and their T(b)s were recorded every 15min using internal cloacal probes. All lizards showed a diurnal periodicity in T(b) characterized by decreased temperatures during the scotophase (dark hours) and higher temperatures during the photophase (light phase). Anoles injected with LPS exhibited a hypothermic response, relative to untreated and saline-injected animals. The response varied from 2.1 to 4.6 degrees C lower than control lizards. The hypothermic response was initiated within 12-24h of LPS injection, and continued for 3 days after treatment. However, the anapyrexic response was observed primarily during scotophases, with photophase hypothermia observed only on the first day after LPS injection.

  2. Tail autotomy affects bipedalism but not sprint performance in a cursorial Mediterranean lizard

    Science.gov (United States)

    Savvides, Pantelis; Stavrou, Maria; Pafilis, Panayiotis; Sfenthourakis, Spyros

    2017-02-01

    Running is essential in all terrestrial animals mainly for finding food and mates and escaping from predators. Lizards employ running in all their everyday functions, among which defense stands out. Besides flight, tail autotomy is another very common antipredatory strategy within most lizard families. The impact of tail loss to sprint performance seems to be species dependent. In some lizard species, tail shedding reduces sprint speed, in other species, increases it, and, in a few species, speed is not affected at all. Here, we aimed to clarify the effect of tail autotomy on the sprint performance of a cursorial lizard with particular adaptations for running, such as bipedalism and spike-like protruding scales (fringes) on the toepads that allow high speed on sandy substrates. We hypothesized that individuals that performed bipedalism, and have more and larger fringes, would achieve higher sprint performance. We also anticipated that tail shedding would affect sprint speed (though we were not able to define in what way because of the unpredictable effects that tail loss has on different species). According to our results, individuals that ran bipedally were faster; limb length and fringe size had limited effects on sprint performance whereas tail autotomy affected quadrupedal running only in females. Nonetheless, tail loss significantly affected bipedalism: the ability for running on hindlimbs was completely lost in all adult individuals and in 72.3% of juveniles.

  3. Spatial and social organization in a burrow-dwelling lizard (Phrynocephalus vlangalii from China.

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    Yin Qi

    Full Text Available Shared ecological resources such as burrow complexes can set the stage for social groupings and the evolution of more complex social behavior such as parental care. Paternity testing is increasingly revealing cases of kin-based groupings, and lizards may be a good system to inform on the early evolution of sociality. We examined spatial and social organization in the lizard Phrynocephalus vlangalii from China and tested genetic relatedness (based on eight microsatellite DNA loci between offspring and parents that shared burrow complexes. Adult males and females had similar spatial patterns: they overlapped most with members of the opposite sex and least with their own sex. Males in better body condition overlapped with more females, and both sexes showed high site fidelity. Most lizards used a single burrow, but some individuals used two or three burrows. While high site fidelity is consistent with sociality in lizards, juveniles did not preferentially share burrows with parents, and we documented only a few cases of parent-offspring associations through burrow sharing. We suggest that P. vlangalii conforms to a classical polygynous mating system in which the burrow forms the core of the male's territory and may be offered as an important resource for females, but this remains to be determined.

  4. Exotic trees modify the thermal landscape and food resources for lizard communities.

    Science.gov (United States)

    Schreuder, E; Clusella-Trullas, S

    2016-12-01

    Increasing numbers of invasive plant species are establishing around the globe, and these species frequently form dense stands that alter habitat structure in critical ways. Nevertheless, little is known about the mechanisms underlying the impacts of invasive alien plant species on native fauna. We first ask whether alien pine trees impact lizard species richness in the Cape Floristic Region of South Africa, a world-renowned biodiversity hotspot, by examining differences in lizard species richness, abundance, and diversity between native mountain fynbos and exotic pine tree-dominated habitats. We then examine two mutually non-exclusive processes: (i) changes in the thermal quality of the habitat and (ii) changes in the availability of food resources, to explain differences in lizard assemblages among habitat types. Lizard richness, abundance, and diversity were greater in fynbos habitat than in fynbos heavily invaded by pine and in pine plantations. The thermal quality of the environment and food resources was consistently higher in native fynbos than in pine forests, but these responses were more varied when comparisons were made along an invasion gradient and among seasons. Our results suggest that management strategies must consider spatially and temporally detailed measurements of thermal regimes and resources to assess the impacts of invasive vegetation on reptile diversity.

  5. A new species of Andean semiaquatic lizard of the genus Potamites (Sauria, Gymnophtalmidae from southern Peru

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    Germán Chávez

    2012-01-01

    Full Text Available We describe a new lizard species of the genus Potamites from the montane forests of the Cordillera de Vilcabamba (Cusco region and Apurimac River valley (Ayacucho region, between 1500 and 2000 meters of elevation, in southern Peru. The new species is distinguishable from all other species of the genus mainly byhighly keeled scattered scales on dorsum and females lacking femoral pores.

  6. Effects of DDT ground-spraying against tsetse flies on lizards in NW Zimbabwe.

    Science.gov (United States)

    Lambert, M R

    1993-01-01

    The impact of DDT ground-spraying against tsetse flies on lizards was investigated in NW Zimbabwe. Nineteen species were recorded, 17 in mopane woodland and 11 on gritstone outcrops: Mabuya striata wahlbergii dominated trees and Mabuya quinquetaeniata margaritifer rocks. Mean frequency of M. s. wahlbergii declined significantly from 76% of lizards at untreated sites (n = 8), through 72% after three annual treatments (n = 4), to 48% after 4-6 treatments (n = 6). Sighting rates and proportion of trees occupied were also significantly lower at treated than untreated sites. Numbers on trunks (99% > 15 cm diameter) above 3 m increased significantly with years of treatment relative to those in the spray target area below 3 m. Total DDT loads rose significantly with number of annual treatments and were up to 263 microg g(-1) lipid (7 microg g(-1) wet body weight) after 3-6 years. The percentage of unaltered DDT increased with load, which was proportionately higher in thin than in fat lizards. The geometric mean total DDT level in M. s. wahlbergii was significantly higher than in outcrop species, and from treated woodland was elevated 21 times above that in lizards from treated outcrops. Frequency and sighting rates of Lygodactylus chobiensis in woodland and immature Agama kirkii on outcrops were significantly higher in treated than in untreated areas.

  7. Corticosterone inhibits normal and FSH-induced testicular recrudescence in the lizard, Mabuya carinata.

    Science.gov (United States)

    Yajurvedi, H N; Nijagal, B S

    2000-12-01

    Administration (ip) of 1, 10, or 20 microg corticosterone (alternate days for 30 days) to adult male Mabuya carinata did not affect the seasonal recrudescence of spermatogenesis whereas administration of 40 microg corticosterone did result in inhibition of spermatogenesis. Further, administration of FSH (10 IU/lizard/alternate day for 30 days) during the quiescent phase of the testicular cycle stimulated spermatogenetic and steroidogenic activity of the testis as shown by significant increases in the mean number of spermatogonia, spermatocytes, and spermatids and serum levels of testosterone. In addition there were abundant spermatozoa in the lumen of the tubules in FSH-treated lizards. Administration of 10 IU FSH + 40 microg corticosterone (per lizard on alternate days for 30 days) increased the mean number of primary and secondary spermatocytes whereas the mean number of spermatids did not show significant variation compared with that of controls. Further, the mean numbers of spermatocytes and spermatids and serum levels of testosterone were significantly less when compared to those of FSH alone treated lizards. In addition, FSH-induced development of epididymis was also inhibited by corticosterone treatment. The results indicate that corticosterone inhibits FSH-induced testicular recrudescence, possibly by suppressing testosterone secretion in M. carinata.

  8. Stress inhibits seasonal and FSH-induced ovarian recrudescence in the lizard,Mabuya carinata.

    Science.gov (United States)

    Ganesh, C B; Yajurvedi, H N

    2002-06-01

    Stressors (handling, chasing, and noise) applied randomly five times per day for one month to lizards during the recrudescence phase of the ovarian cycle caused a significant reduction in mean number of oocytes and primordial follicles when compared to those of controls. Further, vitellogenic follicles were absent in the ovary of lizards subjected to stressors. Administration of bovine FSH during post-breeding regression phase of the ovarian cycle induced ovarian recrudescence as shown by significant increases in the mean number of oogonia, oocytes, and primordial follicles compared to controls, as well as vitellogenic growth of follicles. However, lizards treated with FSH and exposed to stressors did not exhibit ovarian recrudescence. Furthermore, FSH administration during the post-breeding regression phase caused a significant increase in serum levels of estradiol compared to controls, which was accompanied by significant increases in the relative weight of the liver and oviduct, as well as vitellogenic growth of follicles. Despite administration of FSH to lizards subjected to stressors, there was neither any increase in serum levels of estradiol and weight of the liver nor vitellogenic growth of follicles. The results indicate that repeated application of stressors inhibits vitellogenic growth of follicles by suppression of steroidogenic activity in M. carinata. This is the first report revealing that the ovary does not respond to gonadotrophin treatment under stressful conditions in reptiles.

  9. Thermal and energetic constraints on ectotherm abundance: a global test using lizards.

    Science.gov (United States)

    Buckley, Lauren B; Rodda, Gordon H; Jetz, Walter

    2008-01-01

    Population densities of birds and mammals have been shown to decrease with body mass at approximately the same rate as metabolic rates increase, indicating that energetic needs constrain endotherm population densities. In ectotherms, the exponential increase of metabolic rate with body temperature suggests that environmental temperature may additionally constrain population densities. Here we test simple bioenergetic models for an ecologically important group of ectothermic vertebrates by examining 483 lizard populations. We find that lizard population densities decrease as a power law of body mass with a slope approximately inverse to the slope of the relationship between metabolic rates and body mass. Energy availability should limit population densities. As predicted, environmental productivity has a positive effect on lizard density, strengthening the relationship between lizard density and body mass. In contrast, the effect of environmental temperature is at most weak due to behavioral thermoregulation, thermal evolution, or the temperature dependence of ectotherm performance. Our results provide initial insights into how energy needs and availability differentially constrain ectotherm and endotherm density across broad spatial scales.

  10. A new scincid lizard of the genus Leiolopisma from New Guinea

    NARCIS (Netherlands)

    Zweifel, R.G.

    1972-01-01

    The lizard fauna of New Guinea numbers over 150 species (for a list, now well out-dated, see Loveridge, 1948), and probably more than two-thirds of these belong to the family Scincidae. With the exception of studies by Brown (1953, 1954) on the genus Emoia, the large and diverse scincid fauna has re

  11. Ecological explanations to island gigantism: dietary niche divergence, predation, and size in an endemic lizard.

    Science.gov (United States)

    Runemark, Anna; Sagonas, Kostas; Svensson, Erik I

    2015-08-01

    Although rapid evolution of body size on islands has long been known, the ecological mechanisms behind this island phenomenon remain poorly understood. Diet is an important selective pressure for morphological divergence. Here we investigate if selection for novel diets has contributed to the multiple independent cases of island gigantism in the Skyros wall lizard (Podarcis gaigeae) and if diet, predation, or both factors best explain island gigantism. We combined data on body size, shape, bite force, and realized and available diets to address this. Several lines of evidence suggest that diet has contributed to the island gigantism. The larger islet lizards have relatively wider heads and higher bite performance in relation to mainland lizards than would be expected from size differences alone. The proportions of consumed and available hard prey are higher on islets than mainland localities, and lizard body size is significantly correlated with the proportion of hard prey. Furthermore, the main axis of divergence in head shape is significantly correlated with dietary divergence. Finally, a model with only diet and one including diet and predation regime explain body size divergence equally well. Our results suggest that diet is an important ecological factor behind insular body size divergence, but could be consistent with an additional role for predation.

  12. Fifty years of chasing lizards: new insights advance optimal escape theory.

    Science.gov (United States)

    Samia, Diogo S M; Blumstein, Daniel T; Stankowich, Theodore; Cooper, William E

    2016-05-01

    Systematic reviews and meta-analyses often examine data from diverse taxa to identify general patterns of effect sizes. Meta-analyses that focus on identifying generalisations in a single taxon are also valuable because species in a taxon are more likely to share similar unique constraints. We conducted a comprehensive phylogenetic meta-analysis of flight initiation distance in lizards. Flight initiation distance (FID) is a common metric used to quantify risk-taking and has previously been shown to reflect adaptive decision-making. The past decade has seen an explosion of studies focused on quantifying FID in lizards, and, because lizards occur in a wide range of habitats, are ecologically diverse, and are typically smaller and differ physiologically from the better studied mammals and birds, they are worthy of detailed examination. We found that variables that reflect the costs or benefits of flight (being engaged in social interactions, having food available) as well as certain predator effects (predator size and approach speed) had large effects on FID in the directions predicted by optimal escape theory. Variables that were associated with morphology (with the exception of crypsis) and physiology had relatively small effects, whereas habitat selection factors typically had moderate to large effect sizes. Lizards, like other taxa, are very sensitive to the costs of flight.

  13. Sound Localization in Lizards: Functioning of a Pressure-Gradient Receiver

    Science.gov (United States)

    van Hemmen, J. Leo

    2009-03-01

    Because of their small interaural distance, lizards as well as some other animals have developed a special hearing mechanism, the ``pressure-gradient receiver''. The lizard peripheral auditory system differs from the mammalian one by a coupling of the two eardrums through the internal mouth cavity. We present a three-dimensional analytical model of the pressure-gradient receiver. The central aspect of the coupling of the membranes through the mouth cavity is realized by means of the boundary conditions. Moreover, the lizard's middle ear, a simple lever construction called columella, is asymmetrically attached to the tympanic membrane. This has motivated us to solve the problem of how the middle ear influences the spatial-amplitude profile and the frequency distribution of the tympanic membrane vibration. Finally, we show results from numerical simulations of the eigenfunctions and eigenfrequencies in a lizard's internal mouth cavity bounded by the eardrums. To this end, we have constructed the complex geometry from a cast imprint of the cavity with the help of three-dimensional scans. Our results led to an interesting speculation regarding the neurobiological use of the pressure-gradient system.

  14. Estrogenic contamination by manure fertilizer in organic farming: a case study with the lizard Podarcis sicula.

    Science.gov (United States)

    Verderame, Mariailaria; Limatola, Ermelinda; Scudiero, Rosaria

    2016-01-01

    In the last years, worldwide organic farming has grown exponentially; as a consequence, the use of animal manure as a soil fertility source has become the principal agricultural choice. However, the use of manure as fertilizer can increase the amount of steroid hormone metabolites in the soil. In southern Italy, lacertidae lizards are the most abundant vertebrate group in agroecosystems and have been identified as potential model species for ecotoxicological studies. The aim of this study was to understand if the manure applied in organic farming has estrogen-like effects in the lizard Podarcis sicula. Adult male lizards were captured in two organic agricultural fields (manure-treated sites) and in an uncultivated field (control site). Lizards from the two organic farms displayed hepatic biosynthetic alterations typical of an estrogenic contamination; hepatocytes contained both vitellogenin and estrogen receptor alpha transcripts and proteins, detected by in situ hybridization and immunocytochemistry. The same cells did not show cadmium, lead and metallothionein accumulation, indicative of the lack of inorganic contamination. These findings suggest that exogenous estrogens, arising from the use of manure, could affect the welfare of wild animals and animal breeding, leading to bioaccumulation of estrogens in food chain, with possible risk for human consumers. For this reason, organic farming should implement the use of sustainable practices such as crop rotation to preserve the soil biological activity, rather than organic manure as fertilizer.

  15. The regeneration blastema of lizards: an amniote model for the study of appendage replacement.

    Science.gov (United States)

    Gilbert, E A B; Delorme, S L; Vickaryous, M K

    2015-04-01

    Although amniotes (reptiles, including birds, and mammals) are capable of replacing certain tissues, complete appendage regeneration is rare. Perhaps the most striking example is the lizard tail. Tail loss initiates a spontaneous epimorphic (blastema-mediated) regenerative program, resulting in a fully functional but structurally non-identical replacement. Here we review lizard tail regeneration with a particular focus on the blastema. In many lizards, the original tail has evolved a series of fracture planes, anatomical modifications that permit the tail to be self-detached or autotomized. Following tail loss, the wound site is covered by a specialized wound epithelium under which the blastema develops. An outgrowth of the spinal cord, the ependymal tube, plays a key role in governing growth (and likely patterning) of the regenerate tail. In some species (e.g., geckos), the blastema forms as an apical aggregation of proliferating cells, similar to that of urodeles and teleosts. For other species (e.g., anoles) the identification of a proliferative blastema is less obvious, suggesting an unexpected diversity in regenerative mechanisms among tail-regenerating lizards.

  16. Thermal sensitivity of cold climate lizards and the importance of distributional ranges.

    Science.gov (United States)

    Bonino, Marcelo F; Moreno Azócar, Débora L; Schulte, James A; Abdala, Cristian S; Cruz, Félix B

    2015-08-01

    One of the fundamental goals in macroecology is to understand the relationship among species' geographic ranges, ecophysiology, and climate; however, the mechanisms underlying the distributional geographic patterns observed remain unknown for most organisms. In the case of ectotherms this is particularly important because the knowledge of these interactions may provide a robust framework for predicting the potential consequences of climate change in these organisms. Here we studied the relationship of thermal sensitivity and thermal tolerance in Patagonian lizards and their geographic ranges, proposing that species with wider distributions have broader plasticity and thermal tolerance. We predicted that lizard thermal physiology is related to the thermal characteristics of the environment. We also explored the presence of trade-offs of some thermal traits and evaluated the potential effects of a predicted scenario of climate change for these species. We examined sixteen species of Liolaemini lizards from Patagonia representing species with different geographic range sizes. We obtained thermal tolerance data and performance curves for each species in laboratory trials. We found evidence supporting the idea that higher physiological plasticity allows species to achieve broader distribution ranges compared to species with restricted distributions. We also found a trade-off between broad levels of plasticity and higher optimum temperatures of performance. Finally, results from contrasting performance curves against the highest environmental temperatures that lizards may face in a future scenario (year 2080) suggest that the activity of species occurring at high latitudes may be unaffected by predicted climatic changes.

  17. A model for the relation between stimulus frequency and spontaneous otoacoustic emissions in lizard papillae

    NARCIS (Netherlands)

    Wit, Hero P.; van Dijk, Pim; Manley, Geoffrey A.

    2012-01-01

    Spontaneous otoacoustic emissions (SOAEs) and stimulus frequency otoacoustic emissions (SFOAEs) have been described from lizard ears. Although there are several models for these systems, none has modeled the characteristics of both of these types of otoacoustic emissions based upon their being deriv

  18. The Effects of Air Pressure on Spontaneous Otoacoustic Emissions of Lizards

    NARCIS (Netherlands)

    van Dijk, Pim; Manley, Geoffrey A.

    2013-01-01

    Small changes of air pressure outside the eardrum of five lizard species led to changes in frequency, level, and peak width of spontaneous otoacoustic emissions (SOAE). In contrast to humans, these changes generally occurred at very small pressures (<20 mbar). As in humans, SOAE amplitudes were gene

  19. Impact and intrusion of the foot of a lizard running rapidly on sand

    Science.gov (United States)

    Li, Chen; Hsieh, Tonia; Umbanhowar, Paul; Goldman, Daniel

    2012-11-01

    The desert-dwelling zebra-tailed lizard (Callisaurus draconoides, 10 cm, 10 g) runs rapidly (~10 BL/s) on granular media (GM) like sand and gravel. On loosely packed GM, its large hind feet penetrate into the substrate during each step. Based on above-ground observation, a previous study (Li et al., JEB 2012) hypothesized that the hind foot rotated in the vertical plane subsurface to generate lift. To explain the observed center-of-mass dynamics, the model assumed that ground reaction force was dominated by speed-independent frictional drag. Here we use x-ray high speed video to obtain subsurface foot kinematics of the lizard running on GM, which confirms the hypothesized subsurface foot rotation following rapid foot impact at touchdown. However, using impact force measurements, a resistive force model, and the observed foot kinematics, we find that impact force during initial foot touchdown and speed-independent frictional drag during rotation only account for part of the required lift to support locomotion. This suggests that the rapid foot rotation further allows the lizard to utilize inertial forces from the local acceleration of the substrate (particles), similar to small robots running on GM (Qian et al., RSS 2012) and the basilisk (Jesus) lizard running on water.

  20. Tail loss and narrow surfaces decrease locomotor stability in the arboreal green anole lizard (Anolis carolinensis).

    Science.gov (United States)

    Hsieh, Shi-Tong Tonia

    2016-02-01

    Tails play an important role in dynamic stabilization during falling and jumping in lizards. Yet tail autotomy (the voluntary loss of an appendage) is a common mechanism used for predator evasion in these animals. How tail autotomy has an impact on locomotor performance and stability remains poorly understood. The goal of this study was to determine how tail loss affects running kinematics and performance in the arboreal green anole lizard, Anolis carolinensis. Lizards were run along four surface widths (9.5 mm, 15.9 mm, 19.0 mm and flat), before and following 75% tail autotomy. Results indicate that when perturbed with changes in surface breadth and tail condition, surface breadth tends to have greater impacts on locomotor performance than tail loss. Furthermore, while tail loss does have a destabilizing effect during regular running in these lizards, its function during steady locomotion is minimal. Instead, the tail probably plays a more active role during dynamic maneuvers that require dramatic changes in whole body orientation or center of mass trajectories.

  1. Original and regenerating lizard tail cartilage contain putative resident stem/progenitor cells.

    Science.gov (United States)

    Alibardi, Lorenzo

    2015-11-01

    Regeneration of cartilaginous tissues is limited in mammals but it occurs with variable extension in lizards (reptiles), including in their vertebrae. The ability of lizard vertebrae to regenerate cartilaginous tissue that is later replaced with bone has been analyzed using tritiated thymidine autoradiography and 5BrdU immunocytochemistry after single pulse or prolonged-pulse and chase experiments. The massive cartilage regeneration that can restore broad vertebral regions and gives rise to a long cartilaginous tube in the regenerating tail, depends from the permanence of some chondrogenic cells within adult vertebrae. Few cells that retain tritiated thymidine or 5-bromodeoxy-uridine for over 35 days are mainly localized in the inter-vertebral cartilage and in sparse chondrogenic regions of the neural arch of the vertebrae, suggesting that they are putative resident stem/progenitor cells. The study supports previous hypothesis indicating that the massive regeneration of the cartilaginous tissue in damaged vertebrae and in the regenerating tail of lizards derive from resident stem cells mainly present in the cartilaginous areas of the vertebrae including in the perichondrium that are retained in adult lizards as growing centers for most of their lifetime.

  2. Early Holocene turnover, followed by stability, in a Caribbean lizard assemblage

    Science.gov (United States)

    Kemp, Melissa E.; Hadly, Elizabeth A.

    2016-03-01

    Understanding how communities are impacted by environmental perturbations is integral for addressing the ongoing biodiversity crisis that impacts ecosystems worldwide. The fossil record serves as a window into ancient interactions and the responses of communities to past perturbations. Here, we re-examine paleontological data from Katouche Bay, Anguilla, a Holocene site in the Lesser Antilles. We reveal that the site was more diverse than previously indicated, with long-term, continuous records of three genera of extant lizards (Anolis, Ameiva, and Thecadactylus), and the early Holocene presence of Leiocephalus, a large ground-dwelling lizard that has since been completely extirpated from the Lesser Antilles. The disappearance of Leiocephalus from Katouche Bay resulted in high turnover, decreased evenness, and decreased species richness-a trend that continues to the present day. Our body size reconstructions for the most abundant genus, Anolis, are consistent with the presence of only one species, Anolis cf. gingivinus, at Katouche Bay throughout the Holocene, contrary to previously published studies. Additionally, we find no evidence of dwarfism in A. cf. gingivinus, which contrasts with a global study of contemporary insular lizards. Our data reveal that the impacts of diversity loss on lizard communities are long lasting and irreversible over millennia.

  3. Functional characterization and expression analysis of myoglobin in high-altitude lizard Phrynocephalus erythrurus.

    Science.gov (United States)

    Xin, Ying; Tang, Xiaolong; Wang, Huihui; Lu, Songsong; Wang, Yan; Zhang, Yang; Chen, Qiang

    2015-10-01

    Myoglobin (Mb) is a monomeric hemoprotein which plays an important role in oxygen storage and transport in cardiac and skeletal muscle under hypoxia. The red tail toad-headed lizard Phrynocephalus erythrurus (Lacertilia: Agamidae), which inhabits at an elevation of 4500-5300 m on the Qinghai-Tibetan plateau, is known to be the highest living lizard in the world. To investigate the characters of myoglobin of this unique species, another low altitude lizard Phrynocephalus przewalskii (Lacertilia: Agamidae) was selected as a reference. The open reading frame (ORF) of myoglobin in two lizards was 465 bp which encodes a polypeptide of 154 amino acids with different theoretical molecular weight and isoelectric point. The amino acid substitutions of myoglobin between two species were found at Thr13Ile, Lys87Thr and His118Asn. Homology modeling results indicated that P. erythrurus myoglobin has a greater heme pocket, which may be more favorable to oxygen binding and unloading. On the other hand, the mRNA levels of myoglobin in both cardiac and skeletal muscle in P. erythrurus were significantly larger than those in low altitude P. przewalskii. At protein level, myoglobin concentration in skeletal muscle in P. erythrurus was notably increased, but no significant difference was observed in cardiac muscle.

  4. Diet of the lizard Ecpleopus gaudichaudii (Gymnophthalmidae in Atlantic Rainforest, state of Rio de Janeiro, Brazil

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    Thiago Maia

    2011-10-01

    Full Text Available In this study we analyzed the diet of the gymnophthalmid lizard Ecpleopus gaudichaudii Duméril & Bibron, 1839, a typical inhabitant of the forest-floor leaf litter, in an Atlantic Forest area in the state of Rio de Janeiro, southeastern Brazil. The 26 individuals sampled during the study had a mean snout-vent length (SVL of 36.2 ± 4.2 mm and a mean jaw width (JW of 4.1 ± 0.5 mm. We did not find differences in SVL between males and females, though the sexes differed in JW when the effect of body size was factored out, with females presenting higher values. The diet of the lizards was composed exclusively of arthropods, especially isopods and orthopterans. The similarity in trophic niches among seasons (volumetric and numerical proportions of prey categories consumed were 0.096 and to 0.43, respectively. There were also no detectable seasonal differences in mean number and mean volume of prey ingested, as well as no significant influence of lizard SVL on prey number and of lizard JW on mean prey volume, which may reflect the tendency of E. gaudichaudii to feed on few, relatively large prey.

  5. Thermal and energetic constraints on ectotherm abundance: A global test using lizards

    Science.gov (United States)

    Buckley, L.B.; Rodda, G.H.; Jetz, W.

    2008-01-01

    Population densities of birds and mammals have been shown to decrease with body mass at approximately the same rate as metabolic rates increase, indicating that energetic needs constrain endotherm population densities. In ectotherms, the exponential increase of metabolic rate with body temperature suggests that environmental temperature may additionally constrain population densities. Here we test simple bioenergetic models for an ecologically important group of ectothermic vertebrates by examining 483 lizard populations. We find that lizard population densities decrease as a power law of body mass with a slope approximately inverse to the slope of the relationship between metabolic rates and body mass. Energy availability should limit population densities. As predicted, environmental productivity has a positive effect on lizard density, strengthening the relationship between lizard density and body mass. In contrast, the effect of environmental temperature is at most weak due to behavioral thermoregulation, thermal evolution, or the temperature dependence of ectotherm performance. Our results provide initial insights into how energy needs and availability differentially constrain ectotherm and endotherm density across broad spatial scales. ?? 2008 by the Ecological Society of America.

  6. The dragon lizard Pogona vitticeps has ZZ/ZW micro-sex chromosomes.

    Science.gov (United States)

    Ezaz, Tariq; Quinn, Alexander E; Miura, Ikuo; Sarre, Stephen D; Georges, Arthur; Marshall Graves, Jennifer A

    2005-01-01

    The bearded dragon, Pogona vitticeps (Agamidae: Reptilia) is an agamid lizard endemic to Australia. Like crocodilians and many turtles, temperature-dependent sex determination (TSD) is common in agamid lizards, although many species have genotypic sex determination (GSD). P. vitticeps is reported to have GSD, but no detectable sex chromosomes. Here we used molecular cytogenetic and differential banding techniques to reveal sex chromosomes in this species. Comparative genomic hybridization (CGH), GTG- and C-banding identified a highly heterochromatic microchromosome specific to females, demonstrating female heterogamety (ZZ/ZW) in this species. We isolated the P. vitticeps W chromosome by microdissection, re-amplified the DNA and used it to paint the W. No unpaired bivalents were detected in male synaptonemal complexes at meiotic pachytene, confirming male homogamety. We conclude that P. vitticeps has differentiated previously unidentifable W and Z micro-sex chromosomes, the first to be demonstrated in an agamid lizard. Our finding implies that heterochromatinization of the heterogametic chromosome occurred during sex chromosome differentiation in this species, as is the case in some lizards and many snakes, as well as in birds and mammals. Many GSD reptiles with cryptic sex chromosomes may also prove to have micro-sex chromosomes. Reptile microchromosomes, long dismissed as non-functional minutiae and often omitted from karyotypes, therefore deserve closer scrutiny with new and more sensitive techniques.

  7. Thermal preference, thermal tolerance and the thermal dependence of digestive performance in two Phrynocephalus lizards (Agamidae), with a review of species studied

    Institute of Scientific and Technical Information of China (English)

    Yanfu QU; Hong LI; Jianfang GAO; Xuefeng XU; Xiang JI

    2011-01-01

    We reported data on thermal preference,thermal tolerance and the thermal dependence of digestive performance for two Phrynocephalus lizards (P.frontalis and P.versicolor),and compared data among lizards so far studied worldwide.Mean values for selected body temperature (Tsel) and critical thermal maximum (CTMax) were greater in P.versicolor,whereas mean values for critical thermal minimum (CTMin) did not differ between the two species.The two lizards differed in food intake,but not in food passage time,apparent digestive coefficient (ADC) and assimilation efficiency (AE),across the experimental temperatures.Four general conclusions can be drawn from published data.Firstly,thermal preference and thermal tolerance differ among lizards differing in distribution,temporal activity pattern and habitat use.Lizards in thermally more variable regions are better able to tolerate low and high temperatures.Diurnal lizards generally select higher body temperatures than nocturnal lizards,and lizards using habitats with direct sun exposure generally selected higher body temperatures and are better able to tolerate high temperatures.Secondly,CTMax is positively correlated with Tsel.Lizards more likely exposed to extremely high temperatures while active select higher body temperatures than those using shaded habitats.Thirdly,the effects of body temperature on food intake,food passage time,ADC and AE differ among lizards,but it seems to be common among lizards that ADC and AE are less thermally sensitive than food intake and food passage time.Lastly,ADC is dependent on the type of food ingested,with insectivorous lizards digesting food more efficiently than herbivorous lizards [Current Zoology 57 (6):684-700,2011].

  8. Regeneration of Articular Cartilage in Lizard Knee from Resident Stem/Progenitor Cells

    Directory of Open Access Journals (Sweden)

    Lorenzo Alibardi

    2015-09-01

    Full Text Available The epiphysis of femur and tibia in the lizard Podarcis muralis can extensively regenerate after injury. The process involves the articular cartilage and metaphyseal (growth plate after damage. The secondary ossification center present between the articular cartilage and the growth plate is replaced by cartilaginous epiphyses after about one month of regeneration at high temperature. The present study analyzes the origin of the chondrogenic cells from putative stem cells located in the growing centers of the epiphyses. The study is carried out using immunocytochemistry for the detection of 5BrdU-labeled long retaining cells and for the localization of telomerase, an enzyme that indicates stemness. The observations show that putative stem cells retaining 5BrdU and positive for telomerase are present in the superficial articular cartilage and metaphyseal growth plate located in the epiphyses. This observation suggests that these areas represent stem cell niches lasting for most of the lifetime of lizards. In healthy long bones of adult lizards, the addition of new chondrocytes from the stem cells population in the articular cartilage and the metaphyseal growth plate likely allows for slow, continuous longitudinal growth. When the knee is injured in the adult lizard, new populations of chondrocytes actively producing chondroitin sulfate proteoglycan are derived from these stem cells to allow for the formation of completely new cartilaginous epiphyses, possibly anticipating the re-formation of secondary centers in later stages. The study suggests that in this lizard species, the regenerative ability of the epiphyses is a pre-adaptation to the regeneration of the articular cartilage.

  9. NADPH diaphorase-positive neurons in the lizard hippocampus: a distinct subpopulation of GABAergic interneurons.

    Science.gov (United States)

    Dávila, J C; Megías, M; Andreu, M J; Real, M A; Guirado, S

    1995-01-01

    We analyzed the distribution and light-microscopic features of the NADPH diaphorase-containing structures in the lizard hippocampus, likely to correspond to nitric oxide synthase-containing cells and fibers, and thus likely to release nitric oxide. We also studied co-localization of NADPH diaphorase with the neurotransmitter GABA, the calcium-binding protein parvalbumin, and the neuropeptide somatostatin, in order to examine whether putative nitric oxide-synthesizing neurons represent a different subpopulation of GABA cells, on which the authors recently reported in lizards. We also studied co-localization of NADPH diaphorase with parvalbumin or somatostatin in mice to ascertain whether the characteristics of this population in reptiles parallel the situation in mammals. Most of the positive NADPH diaphorase neurons were stained in a Golgi-like manner and were in the plexiform layers of the lizard hippocampus with morphologies ranging from bipolar to multipolar. Co-localization with GABA was 100%, and NADPH diaphorase-positive neurons in the lizard hippocampus did not contain parvalbumin or somatostatin. The results indicate that putative nitric oxide-synthesizing neurons represent a distinct subpopulation of GABA interneurons in the lizard hippocampus. Two different types of fibers were described in the plexiform layers: one type bearing thick varicosities, and the other thinner ones. We discuss the possibility that at least part of the positive fibers arise from a hypothalamic aminergic nucleus contacting the third ventricle, the periventricular hypothalamic organ. Most radial glia were stained almost completely and formed typical end-feet both at the pia and around capillaries. The results of this study confirm that the capacity for synthesizing nitric oxide is linked to a determined set of neuronal markers depending on the specific brain region, and they provide new resemblances between hippocampal regions in different classes of vertebrates.

  10. Behavioral buffering of global warming in a cold-adapted lizard.

    Science.gov (United States)

    Ortega, Zaida; Mencía, Abraham; Pérez-Mellado, Valentín

    2016-07-01

    Alpine lizards living in restricted areas might be particularly sensitive to climate change. We studied thermal biology of Iberolacerta cyreni in high mountains of central Spain. Our results suggest that I. cyreni is a cold-adapted thermal specialist and an effective thermoregulator. Among ectotherms, thermal specialists are more threatened by global warming than generalists. Alpine lizards have no chance to disperse to new suitable habitats. In addition, physiological plasticity is unlikely to keep pace with the expected rates of environmental warming. Thus, lizards might rely on their behavior in order to deal with ongoing climate warming. Plasticity of thermoregulatory behavior has been proposed to buffer the rise of environmental temperatures. Therefore, we studied the change in body and environmental temperatures, as well as their relationships, for I. cyreni between the 1980s and 2012. Air temperatures have increased more than 3.5°C and substrate temperatures have increased by 6°C in the habitat of I. cyreni over the last 25 years. However, body temperatures of lizards have increased less than 2°C in the same period, and the linear relationship between body and environmental temperatures remains similar. These results show that alpine lizards are buffering the potential impact of the increase in their environmental temperatures, most probably by means of their behavior. Body temperatures of I. cyreni are still cold enough to avoid any drop in fitness. Nonetheless, if warming continues, behavioral buffering might eventually become useless, as it would imply spending too much time in shelter, losing feeding, and mating opportunities. Eventually, if body temperature exceeds the thermal optimum in the near future, fitness would decrease abruptly.

  11. Regeneration of Articular Cartilage in Lizard Knee from Resident Stem/Progenitor Cells.

    Science.gov (United States)

    Alibardi, Lorenzo

    2015-09-01

    The epiphysis of femur and tibia in the lizard Podarcis muralis can extensively regenerate after injury. The process involves the articular cartilage and metaphyseal (growth) plate after damage. The secondary ossification center present between the articular cartilage and the growth plate is replaced by cartilaginous epiphyses after about one month of regeneration at high temperature. The present study analyzes the origin of the chondrogenic cells from putative stem cells located in the growing centers of the epiphyses. The study is carried out using immunocytochemistry for the detection of 5BrdU-labeled long retaining cells and for the localization of telomerase, an enzyme that indicates stemness. The observations show that putative stem cells retaining 5BrdU and positive for telomerase are present in the superficial articular cartilage and metaphyseal growth plate located in the epiphyses. This observation suggests that these areas represent stem cell niches lasting for most of the lifetime of lizards. In healthy long bones of adult lizards, the addition of new chondrocytes from the stem cells population in the articular cartilage and the metaphyseal growth plate likely allows for slow, continuous longitudinal growth. When the knee is injured in the adult lizard, new populations of chondrocytes actively producing chondroitin sulfate proteoglycan are derived from these stem cells to allow for the formation of completely new cartilaginous epiphyses, possibly anticipating the re-formation of secondary centers in later stages. The study suggests that in this lizard species, the regenerative ability of the epiphyses is a pre-adaptation to the regeneration of the articular cartilage.

  12. A randomized phase 3 study of lenalidomide versus placebo in RBC transfusion-dependent patients with Low-/Intermediate-1-risk myelodysplastic syndromes with del5q

    NARCIS (Netherlands)

    Fenaux, P.; Giagounidis, A.; Selleslag, D.; Beyne-Rauzy, O.; Mufti, G.; Mittelman, M.; Muus, P.; Boekhorst, P. Te; Sanz, G.; Del Canizo, C.; Guerci-Bresler, A.; Nilsson, L.; Platzbecker, U.; Lubbert, M.; Quesnel, B.; Cazzola, M.; Ganser, A.; Bowen, D.; Schlegelberger, B.; Aul, C.; Knight, R.; Francis, J.; Fu, T.; Hellstrom-Lindberg, E.

    2011-01-01

    This phase 3, randomized, double-blind study assessed the efficacy and safety of lenalidomide in 205 red blood cell (RBC) transfusion-dependent patients with International Prognostic Scoring System Low-/Intermediate-1-risk del5q31 myelodysplastic syndromes. Patients received lenalidomide 10 mg/day o

  13. Use of rbcL and trnL-F as a two-locus DNA barcode for identification of NW-European ferns: an ecological perspective

    NARCIS (Netherlands)

    Groot, de G.A.; During, H.J.; Maas, J.W.; Schneider, H.; Erkens, R.H.J.

    2011-01-01

    Although consensus has now been reached on a general two-locus DNA barcode for land plants, the selected combination of markers (rbcL + matK) is not applicable for ferns at the moment. Yet especially for ferns, DNA barcoding is potentially of great value since fern gametophytes—while playing an esse

  14. Phylogenetic analyses of four species of Ulva and Monostroma grevillei using ITS, rbcL and 18S rDNA sequence data

    Institute of Scientific and Technical Information of China (English)

    LIN Zhongheng; SHEN Songdong; CHEN Weizhou; LI Huihui

    2013-01-01

    Chlorophyta species are common in the southern and northern coastal areas of China.In recent years,frequent green tide incidents in Chinese coastal waters have raised concerns and attracted the attention of scientists.In this paper,we sequenced the 18S rDNA genes,the internal transcribed spacer (ITS) regions and the rbcL genes in seven organisms and obtained 536-566 bp long ITS sequences,1 377-1 407 bp long rbcL sequences and 1 718-1 761 bp long partial 18S rDNA sequences.The GC base pair content was highest in the ITS regions and lowest in the rbcL genes.The sequencing results showed that the three Ulvaprolifera (or U.pertusa) gene sequences from Qingdao and Nan'ao Island were identical.The ITS,18S rDNA and rbcL genes in U.prolifera and U.pertusa from different sea areas in China were unchanged by geographic distance.U.flexuosa had the least evolutionary distance from U.californica in both the ITS regions (0.009) and the 18S rDNA (0.002).These data verified that Ulva and Enteromorpha are not separate genera.

  15. Molecular phylogenetics of Caryophyllales based on nuclear 18S rDNA and plastid rbcL, atpB,and matK DNA sequences

    NARCIS (Netherlands)

    Cuénoud, P.; Savolainen, V.; Chatrou, L.W.; Powell, M.; Grayer, R.J.; Chase, M.W.

    2002-01-01

    To study the inter- and infrafamilial phylogenetic relationships in the order Caryophyllales sensu lato (s.l.), 930 base pairs of the matK plastid gene have been sequenced and analyzed for 127 taxa. In addition, these sequences have been combined with the rbcL plastid gene for 53 taxa and with the r

  16. Phylogenetic analyses of four species of Ulva and Monostroma grevillei using ITS, rbc L and 18S rDNA sequence data

    Science.gov (United States)

    Lin, Zhongheng; Shen, Songdong; Chen, Weizhou; Li, Huihui

    2013-01-01

    Chlorophyta species are common in the southern and northern coastal areas of China. In recent years, frequent green tide incidents in Chinese coastal waters have raised concerns and attracted the attention of scientists. In this paper, we sequenced the 18S rDNA genes, the internal transcribed spacer (ITS) regions and the rbc L genes in seven organisms and obtained 536-566 bp long ITS sequences, 1 377-1 407 bp long rbc L sequences and 1 718-1 761 bp long partial 18S rDNA sequences. The GC base pair content was highest in the ITS regions and lowest in the rbc L genes. The sequencing results showed that the three Ulva prolifera (or U. pertusa) gene sequences from Qingdao and Nan'ao Island were identical. The ITS, 18S rDNA and rbc L genes in U. prolifera and U. pertusa from different sea areas in China were unchanged by geographic distance. U. flexuosa had the least evolutionary distance from U. californica in both the ITS regions (0.009) and the 18S rDNA (0.002). These data verified that Ulva and Enteromorpha are not separate genera.

  17. Chloroplast phylogeny of asplenioid ferns based on rbcL and trnL-F Spacer sequences (Polypodiidae, aspleniaceae) and its implications for biogeography

    NARCIS (Netherlands)

    Schneider, H.; Russell, S.J.; Cox, C.J.; Bakker, F.T.; Henderson, S.; Rumsey, F.; Barrett, J.; Gibby, M.; Vogel, J.C.

    2004-01-01

    Molecular phylogenies have been generated to investigate relationships among species and putative segregates in Asplenium, one of the largest genera in ferns. Of the ~700 described taxa, 71 are included in a phylogenetic analysis using the chloroplast rbcL gene and trnL-F spacer. Our results support

  18. Studies on Dasyaceae. 3. Towards a phylogeny of the Dasyaceae (Ceramiales, Rhodophyta), based on comparative rbcL gene sequences and morphology

    NARCIS (Netherlands)

    de Jong, Y.S D M; van der Wurff, A.W G; Stam, W.T.; Olsen, J.L.

    1998-01-01

    Phylogenetic analyses of the Dasyaceae based on sequence analysis of the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (rbcL) and 42 morphological characters are presented. Comparative sequence analysis confirms the general view of the Ceramiaceae as a primitive, paraphyletic grou

  19. RBC-coupled tPA prevents cerebrovasodilatory impairment and tissue injury in pediatric cerebral hypoxia/ischemia through inhibition of ERK MAPK unregulation

    Energy Technology Data Exchange (ETDEWEB)

    Ganguly, Kumkum [Los Alamos National Laboratory; Armstead, William M [U PENNSYLVANIA; Kiessling, J W [U PENNSYLVANIA; Chen, Xiao - Han [U PENNSYLVANIA; Smith, Douglas H [U PENNSYLVANA; Higazi, Abd Ar [U PENNSYLVANIA; Cines, Douglas B [U PENNSYLVANIA; Bdeir, Khalil [U PENNSYLVANIA; Zaitsev, Sergei [U PENNSYLVANIA; Muzykantov, Vladimir R [U PENNSYLVANIA

    2008-01-01

    Babies experience hypoxia (H) and ischemia (I) from stroke. The only approved treatment for stroke is fibrinolytic therapy with tissue-type plasminogen activator (tPA). However, tPA potentiates H/I-induced impairment of responses to cerebrovasodilators such as hypercapnia and hypotension, and blockade of tPA-mediated vasoactivity prevents this deleterious effect. Coupling tPA to RBCs reduces its CNS toxicity through spatially confining the drug to the vasculature. Mitogen activated protein kinase (MAPK), a family of at least 3 kinases, is upregulated after H/I. In this study we determined if RBC-tPA given before or after cerebral H/I would preserve responses to cerebrovasodilators and prevent neuronal injury mediated through the ERK MAPK pathway. Animals given RBC-tPA maintained responses to cerebrovasodilators at levels equivalent to pre-H/I values. CSF and brain parenchymal ERK MAPK was elevated by H/I and this upregulation was potentiated by tPA, but blunted by RBC-tPA. U 0126, an ERK MAPK antagonist, also maintained cerebrovasodilation post H/I. Neuronal degeneration in CA1 hippocampus and parietal cortex after H/I was exacerbated by tPA, but ameliorated by RBC-tPA and U 0126. These data suggest that coupling tPA to RBCs may offer a novel approach towards increasing the benefit/risk ratio of thrombolytic therapy for CNS disorders associated with H/I.

  20. Differences in Chemical Sexual Signals May Promote Reproductive Isolation and Cryptic Speciation between Iberian Wall Lizard Populations

    Directory of Open Access Journals (Sweden)

    Marianne Gabirot

    2012-01-01

    Full Text Available Interpopulational variation in sexual signals may lead to premating reproductive isolation and speciation. Genetic and morphological studies suggest that the Iberian wall lizard, Podarcis hispanica, forms part of a “species complex” with several cryptic species. We explored the role of chemical sexual signals in interpopulational recognition between five distinct populations of Iberian wall lizards in Central Spain. Results showed that these populations differed in morphology and in composition and proportion of chemical compounds in femoral gland secretions of males. Tongue-flick experiments indicated that male and female lizards discriminated and were more interested in scents of lizards from their own area (i.e., Northern versus Southern populations, but did not discriminate between all populations. Moreover, only males from the populations that are geographically located more far away preferred scent of females from their own population. These data suggest that, at least between some populations, there may be reproductive isolation mediated by chemical signals and cryptic speciation.

  1. Population structure of Blunt-nosed leopard lizards Gambelia silus at Pixley National Wildlife Refuge Tulare County California

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Abstract. Seasonal mark-recapture population estimates and relative abundance indices for the blunt-nosed leopard lizard (Gambelia silus) were calculated on eight...

  2. Homology of the jaw muscles in lizards and snakes-a solution from a comparative gnathostome approach.

    Science.gov (United States)

    Johnston, Peter

    2014-03-01

    Homology or shared evolutionary origin of jaw adductor muscles in lizards and snakes has been difficult to establish, although snakes clearly arose within the lizard radiation. Lizards typically have temporal adductors layered lateral to medial, and in snakes the muscles are arranged in a rostral to caudal pattern. Recent work has suggested that the jaw adductor group in gnathostomes is arranged as a folded sheet; when this theory is applied to snakes, homology with lizard morphology can be seen. This conclusion revisits the work of S.B. McDowell, J Herpetol 1986; 20:353-407, who proposed that homology involves identity of m. levator anguli oris and the loss of m. adductor mandibulae externus profundus, at least in "advanced" (colubroid) snakes. Here I advance the folded sheet hypothesis across the whole snake tree using new and literature data, and provide a solution to this homology problem.

  3. Chemosensory recognition of the marbled whiptail lizard, Aspidoscelis marmorata (Squamata: Teiidae) to odors of sympatric lizards (Crotophytus collaris, Coleonyx brevis, Eumeces obsoletus and Uta stansburiana) that represent different predation risks.

    Science.gov (United States)

    Punzo, F

    2008-01-01

    The ability of the whiptail lizard Aspidoscelis marmorata (Teiidae) to detect and discriminate chemical stimuli associated with the integument of a sympatric saurophagous lizard (Crotaphytus collaris) was tested. Females of A. marmorata were presented with cotton swabs containing chemical cues from C. collaris and three species of nonsaurophagous lizards, as well as water and cologne (pungency control), and total number of tongue-flick (TF) recorded. Other responses were assessed including directed TF rate, time from initial presentation of the stimulus to first TF (latency), time spent fleeing from the stimulus, and number of flight bouts. The number of TFs, directed TF rate, and number of attempts at fleeing exhibited by were significantly greater when females were presented with swabs containing cues from C. collaris as compared to nonsaurophagous lizards and both control treatments. A. marmorata required significantly less time to elicit their first TF when presented with cues from C. collaris as compared to all other treatments. Most previous studies have focused on the responses of lizards to cues associated with snake predators. This study provides the first available data on responses of a teiid to cues associated with a saurophagous lizard.

  4. Evolution of viviparity: what can Australian lizards tell us?

    Science.gov (United States)

    Thompson, Michael B; Stewart, James R; Speake, Brian K; Hosie, Margot J; Murphy, Christopher R

    2002-04-01

    Historically, Australia has been important in the study of, and the development of hypotheses aimed at understanding, the evolution of viviparity in amniote vertebrates. Part of the importance of Australia in the field results from a rich fauna of skinks, including one of the broadest ranges of diversity of placental structures within one geographic region. During the last decade, we have focussed our studies on one lineage, the Eugongylus group of skinks of the subfamily Lygosominae because it contains oviparous species and some that exhibit complex placentae. Our specific objective has been to attempt to understand the fundamental steps required when viviparity, and ultimately complex placentae, evolve from oviparous ancestors. We have taken a three-prong approach: (1) detailed study of the morphology and ontogeny of the placentae of key species at the light microscope level; (2) study of changes in the uterus associated with pregnancy, or the plasma membrane transformation; and (3) measures of the net exchange of nutrients across the placenta or eggshell of key species. In turn, we have found that: (1) details of the morphology and ontogeny of placentae are more complex that originally envisaged, and that the early conclusions about a sequence in the evolution of complex placentae was naïve; (2) a plasma membrane transformation occurs in viviparous, but not oviparous lizards, and thus may be a fundamental feature of the evolution of viviparity in amniotes; and (3) species with more complex chorioallantoic placentae tend to transport more nutrients across the placenta during pregnancy than those with simpler chorioallantoic placentae but, because the correlation is not tight, the importance of the omphaloplacenta in transporting nutrients may have been overlooked. Also, the composition of yolk of highly matrotrophic species is broadly similar, but not identical, to the yolk of oviparous species. Some of the interpretation of our data within the context of our

  5. Dose-dependent effect of N′-Nitrosodiethylamine on hepatic architecture, RBC rheology and polypeptide repertoire in Wistar rats

    Directory of Open Access Journals (Sweden)

    Mukherjee Devoshree

    2015-03-01

    Full Text Available N′-Nitrosodiethylamine (NDEA is an effective hepatotoxicant, carcinogen and mutagen. NDEA-induced hepatic necrosis, through metabolic activation by CYP2E1, is an extensively used experimental model. In the present study, we analysed the dose- and time-dependent effect of NDEA on hepatic damage, RBC rheology and proteomic profile in male Wistar rats. The rats, 5–6 weeks old, were divided into four groups: Group-1 served as control and received normal saline, Group-2 received a single dose of 200 mg/kg body weight NDEA intraperitoneally (i.p. and the animals were sacrificed after one week; the rats of Group-3 received a single dose of 100 mg/kg body weight NDEA and were sacrificed after one week; Group-4 received 100 mg/kg body weight/wk NDEA for two weeks and were then sacrificed. Various biochemical parameters such as ALT, AST, ALP and bilirubin were determined. Further, RBC rheology, histopathology (H&E staining of liver biopsies and polypeptide profiling (SDS-PAGE in sera and liver sections were also carried out both in control and NDEA treated groups. Our results showed a significant increase in all the biochemical parameters of the liver function test (p<0.05. In NDEA treated categories dacryocytes (tear drop cells, schistocytes (fragmented cells, codocytes (target cells, acanthocytes (spur cells and ovalocytes (oval cells were observed. H & E stained liver biopsies treated with NDEA showed abnormal liver architecture with severe haemorrhage, neutrophilic infiltration and dysplastic hepatocytes manifested in a dose-dependent manner. Software analysis of SDS-PAGE of control and NDEA treated rat sera and liver revealed qualitative and quantitative differences in polypeptide composition. Based on the presence/absence, polypeptides were classified in three different categories: (1 house-keeping, present in all the groups investigated; (2 novel, present in either control or NDEA treated group at any given time; (3 differential expression

  6. The binding of Aβ1-42 to lipid rafts of RBC is enhanced by dietary docosahexaenoic acid in rats: Implicates to Alzheimer's disease.

    Science.gov (United States)

    Hashimoto, Michio; Hossain, Shahdat; Katakura, Masanori; Al Mamun, Abdullah; Shido, Osamu

    2015-06-01

    Once amyloid β peptides (Aβs) of the Alzheimer's disease build up in blood circulation, they are capable of binding to red blood cell (RBC) and inducing hemolysis of RBC. The mechanisms of the interactions between RBC and Aβ are largely unknown; however, it is very important for the therapeutic target of Aβ-induced hemolysis. In the present study, we investigated whether Aβ1-42 interacts with caveolin-1-containing detergent-resistant membranes (DRMs) of RBC and whether the interaction could be modulated by dietary pre-administration of docosahexaenoic acid (DHA). DHA pre-administration to rats inhibited hemolysis by Aβ1-42. This activity was accompanied by increased DHA levels and membrane fluidity and decreased cholesterol level, lipid peroxidation, and reactive oxygen species in the RBCs of the DHA-pretreated rats, suggesting that the antioxidative property of DHA may rescue RBCs from oxidative damage by Aβ1-42. The level of caveolin-1 was augmented in the DRMs of DHA-pretreated rats. Binding between Aβ1-42 and DRMs of RBC significantly increased in DHA-rats. When fluorescently labeled Aβ1-42 (TAMRA-Aβ1-42) was directly infused into the bloodstream, it again occupied the caveolin-1-containing DRMs of the RBCs from the DHA-rats to a greater extent, indicating that circulating Aβs interact with the caveolin-1-rich lipid rafts of DRMs and the interaction is stronger in the DHA-enriched RBCs. The levels of TAMRA-Aβ1-42 also increased in liver DRMs, whereas it decreased in plasma of DHA-pretreated rats. DHA might help clearance of circulating Aβs by increased lipid raft-dependent degradation pathways and implicate to therapies in Alzheimer's disease.

  7. Sequence Analysis and Potentials of the Native RbcS Promoter in the Development of an Alternative Eukaryotic Expression System Using Green Microalga Ankistrodesmus convolutus

    Directory of Open Access Journals (Sweden)

    Suhaimi Napis

    2012-02-01

    Full Text Available The availability of highly active homologous promoters is critical in the development of a transformation system and improvement of the transformation efficiency. To facilitate transformation of green microalga Ankistrodesmus convolutus which is considered as a potential candidate for many biotechnological applications, a highly-expressed native promoter sequence of ribulose-1,5-bisphosphate carboxylase/oxygenase small subunit (AcRbcS has been used to drive the expression of β-glucuronidase (gusA gene in this microalga. Besides the determination of the transcription start site by 5¢-RACE, sequence analysis revealed that AcRbcS promoter contained consensus TATA-box and several putative cis-acting elements, including some representative light-regulatory elements (e.g., G-box, Sp1 motif and SORLIP2, which confer light responsiveness in plants, and several potential conserved motifs (e.g., CAGAC-motif, YCCYTGG-motifs and CACCACA-motif, which may be involved in light responsiveness of RbcS gene in green microalgae. Using AcRbcS promoter::gusA translational fusion, it was demonstrated that this promoter could function as a light-regulated promoter in transgenic A. convolutus, which suggested that the isolated AcRbcS promoter was a full and active promoter sequence that contained all cis-elements required for developmental and light-mediated control of gene expression, and this promoter can be used to drive the expression of heterologous genes in A. convolutus. This achievement therefore advances the development of A. convolutus as an alternative expression system for the production of recombinant proteins. This is the first report on development of gene manipulation system for unicellular green alga A. convolutus.

  8. Historical colonization and dispersal limitation supplement climate and topography in shaping species richness of African lizards (Reptilia: Agaminae)

    OpenAIRE

    Daniel Kissling, W.; Anne Blach-Overgaard; Zwaan, Roelof E.; Philipp Wagner

    2016-01-01

    To what extent deep-time dispersal limitation shapes present-day biodiversity at broad spatial scales remains elusive. Here, we compiled a continental dataset on the distributions of African lizard species in the reptile subfamily Agaminae (a relatively young, Neogene radiation of agamid lizards which ancestors colonized Africa from the Arabian peninsula) and tested to what extent historical colonization and dispersal limitation (i.e. accessibility from areas of geographic origin) can explain...

  9. Thermal ecology of the lizard Sceloporus gadoviae (Squamata: Phrynosomatidae) in a semiarid region of southern Puebla, Mexico

    OpenAIRE

    Guillermo A. Woolrich-Piña; Lemos-Espinal, Julio A; GEOFFREY R. SMITH; Luis Oliver-López; Felipe Correa-Sánchez; Tizoc A. Altamirano-Álvarez; Raymundo Montoya-Ayala

    2012-01-01

    We studied the thermal ecology of the lizard Sceloporus gadoviae from Puebla, Mexico. Mean body temperature (Tb) was 31.5 ± 0.3˚C. A multiple regression suggested that Tb was affected by substrate temperature and solar insolation, and minimally affected by ambient temperature (Ta), sex, and body size. However, body temperature was higher in females than males, and higher in gravid females than non-gravid females. We also found significant differences in Tbs of lizards occupying microhabitats ...

  10. The effect of chronic seaweed subsidies on herbivory: plant-mediated fertilization pathway overshadows lizard-mediated predator pathways.

    Science.gov (United States)

    Piovia-Scott, Jonah; Spiller, David A; Takimoto, Gaku; Yang, Louie H; Wright, Amber N; Schoener, Thomas W

    2013-08-01

    Flows of energy and materials link ecosystems worldwide and have important consequences for the structure of ecological communities. While these resource subsidies typically enter recipient food webs through multiple channels, most previous studies focussed on a single pathway of resource input. We used path analysis to evaluate multiple pathways connecting chronic marine resource inputs (in the form of seaweed deposits) and herbivory in a shoreline terrestrial ecosystem. We found statistical support for a fertilization effect (seaweed increased foliar nitrogen content, leading to greater herbivory) and a lizard numerical response effect (seaweed increased lizard densities, leading to reduced herbivory), but not for a lizard diet-shift effect (seaweed increased the proportion of marine-derived prey in lizard diets, but lizard diet was not strongly associated with herbivory). Greater seaweed abundance was associated with greater herbivory, and the fertilization effect was larger than the combined lizard effects. Thus, the bottom-up, plant-mediated effect of fertilization on herbivory overshadowed the top-down effects of lizard predators. These results, from unmanipulated shoreline plots with persistent differences in chronic seaweed deposition, differ from those of a previous experimental study of the short-term effects of a pulse of seaweed deposition: while the increase in herbivory in response to chronic seaweed deposition was due to the fertilization effect, the short-term increase in herbivory in response to a pulse of seaweed deposition was due to the lizard diet-shift effect. This contrast highlights the importance of the temporal pattern of resource inputs in determining the mechanism of community response to resource subsidies.

  11. Joeropsididae Nordenstam, 1933 (Crustacea, Isopoda, Asellota) from the Lizard Island region of the Great Barrier Reef, Queensland, Australia.

    Science.gov (United States)

    Bruce, Niel L

    2015-01-01

    The marine isopod family Joeropsididae (Asellota) is documented for the Lizard Island region of the Great Barrier Reef, Australia. Fifteen species of Joeropsis are recorded, including ten new species; descriptive notes are provided for five species that lacked adequate material for description. A revised family and genus diagnosis is presented together with comments on the most useful characters for species identification and a key to Joeropsis of the Lizard Island region.

  12. Joeropsididae Nordenstam, 1933 (Crustacea, Isopoda, Asellota from the Lizard Island region of the Great Barrier Reef, Queensland, Australia

    Directory of Open Access Journals (Sweden)

    Niel L. Bruce

    2015-03-01

    Full Text Available The marine isopod family Joeropsididae (Asellota is documented for the Lizard Island region of the Great Barrier Reef, Australia. Fifteen species of Joeropsis are recorded, including ten new species; descriptive notes are provided for five species that lacked adequate material for description. A revised family and genus diagnosis is presented together with comments on the most useful characters for species identification and a key to Joeropsis of the Lizard Island region.

  13. Orientation of lizards in a Morris water-maze: roles of the sun compass and the parietal eye.

    Science.gov (United States)

    Foà, Augusto; Basaglia, Francesca; Beltrami, Giulia; Carnacina, Margherita; Moretto, Elisa; Bertolucci, Cristiano

    2009-09-15

    The present study examined for the first time whether a Morris water-maze can be used to explore compass and other orientation mechanisms in the ruin lizard Podarcis sicula. In the open field, during sunny days, lizards were individually trained to swim from the center of the water maze onto a hidden platform (the goal), positioned at the periphery of the maze in a single compass direction. The goal was invisible because it was placed just beneath the water surface and the water was rendered opaque. The results showed that lizards learn to swim directly towards the hidden goal under the sun in the absence of visual feature cues. We further examined whether the observed orientation response would be due to lizards learning the spatial position of the goal relative to the sun's azimuth, i.e. to the use of a time-compensated sun compass. Lizards reaching learning criteria were subjected to 6 h clock-shift (fast or slow), and tested for goal orientation in the Morris water-maze. Results demonstrated that the learned orientation response is mediated by a time-compensated sun compass. Further investigations provided direct evidence that in ruin lizards an intact parietal eye is required to perform goal orientation under the sun inside a Morris water-maze, and that other brain photoreceptors, like the pineal or deep brain photoreceptors, are not involved in orientation.

  14. Supplementation of male pheromone on rock substrates attracts female rock lizards to the territories of males: a field experiment.

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    José Martín

    Full Text Available BACKGROUND: Many animals produce elaborated sexual signals to attract mates, among them are common chemical sexual signals (pheromones with an attracting function. Lizards produce chemical secretions for scent marking that may have a role in sexual selection. In the laboratory, female rock lizards (Iberolacerta cyreni prefer the scent of males with more ergosterol in their femoral secretions. However, it is not known whether the scent-marks of male rock lizards may actually attract females to male territories in the field. METHODOLOGY/PRINCIPAL FINDINGS: In the field, we added ergosterol to rocks inside the territories of male lizards, and found that this manipulation resulted in increased relative densities of females in these territories. Furthermore, a higher number of females were observed associated to males in manipulated plots, which probably increased mating opportunities for males in these areas. CONCLUSIONS/SIGNIFICANCE: These and previous laboratory results suggest that female rock lizards may select to settle in home ranges based on the characteristics of scent-marks from conspecific males. Therefore, male rock lizards might attract more females and obtain more matings by increasing the proportion of ergosterol when scent-marking their territories. However, previous studies suggest that the allocation of ergosterol to secretions may be costly and only high quality males could afford it, thus, allowing the evolution of scent-marks as an honest sexual display.

  15. Total lactate dehydrogenase activity of tail muscle is not cold-adapted in nocturnal lizards from cool-temperate habitats.

    Science.gov (United States)

    Hare, K M; Miller, J H; Clark, A G; Daugherty, C H

    2005-12-01

    The dependence of metabolic processes on temperature constrains the behavior, physiology and ecology of many ectothermic animals. The evolution of nocturnality in lizards, especially in temperate regions, requires adaptations for activity at low temperatures when optimal body temperatures are unlikely to be obtained. We examined whether nocturnal lizards have cold-adapted lactate dehydrogenase (LDH). LDH was chosen as a representative metabolic enzyme. We measured LDH activity of tail muscle in six lizard species (n=123: three nocturnal, two diurnal and one crepuscular) between 5 and 35 degrees C and found no differences in LDH-specific activity or thermal sensitivity among the species. Similarly, the specific activity and thermal sensitivity of LDH were similar between skinks and geckos. Similar enzyme activities among nocturnal and diurnal lizards indicate that there is no selection of temperature specific LDH enzyme activity at any temperature. As many nocturnal lizards actively thermoregulate during the day, LDH may be adapted for a broad range of temperatures rather than adapted specifically for the low temperatures encountered when the animals are active. The total activity of LDH in tropical and temperate lizards is not cold-adapted. More data are required on biochemical adaptations and whole animal thermal preferences before trends can be established.

  16. Pentastomid, Raillietiella mottae Almeida, Freire and Lopes, 2008, infecting lizards in an area of caatinga, northeast, Brazil.

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    Almeida, W O; Santana, G G; Vieira, W L S; Wanderley, I C; Freire, E M X; Vasconcellos, A

    2008-05-01

    Pentastomids can infect the respiratory tract of lizards, causing their death and as a result influencing the population size of hosts. Despite this, studies on rates of pulmonary infection of Brazilian lizards, including those living in Caatinga ecosystems of northeastern Brazil are scarce. Active collections of lizards were performed from October to December 2004 in an area of Caatinga of the Estação Experimental de São João do Cariri -- EESJC (07 masculine 25' S and 36 masculine 30' W), located in the state of Paraíba, Northeast of Brazil. Forty-five lizards inhabiting granite outcrops in an area of Caatinga were captured, belonging to the following species: Tropidurus hispidus (Spix, 1825) (18 individuals), T. semitaeniatus (Spix, 1825) (15 individuals), Phyllopezus periosus Rodrigues, 1986 (6 individuals), and P. pollicaris (Spix, 1825) (6 individuals). Laboratory examination revealed that all species had some degree of pulmonary infection caused by Raillietiella mottae. The highest rates of prevalence (66.7%) and mean intensity of infection (5.25 +/- 2.01, range of 2-11) were observed in P. periosus. The results obtained in this study show that lizards of the Brazilian semi-arid region are infected by a generalist species of pentastomid. The most likely cause for such pattern is the similarity in lizards' diets (ants and termites). It is particularly noteworthy that T. semitaeniatus, P. periosus, and P. pollicaris represent new host records for R. mottae.

  17. The functional significance of aposematic signals: geographic variation in the responses of widespread lizard predators to colourful invertebrate prey.

    Science.gov (United States)

    Tseng, Hui-Yun; Lin, Chung-Ping; Hsu, Jung-Ya; Pike, David A; Huang, Wen-San

    2014-01-01

    Conspicuous colouration can evolve as a primary defence mechanism that advertises unprofitability and discourages predatory attacks. Geographic overlap is a primary determinant of whether individual predators encounter, and thus learn to avoid, such aposematic prey. We experimentally tested whether the conspicuous colouration displayed by Old World pachyrhynchid weevils (Pachyrhynchus tobafolius and Kashotonus multipunctatus) deters predation by visual predators (Swinhoe's tree lizard; Agamidae, Japalura swinhonis). During staged encounters, sympatric lizards attacked weevils without conspicuous patterns at higher rates than weevils with intact conspicuous patterns, whereas allopatric lizards attacked weevils with intact patterns at higher rates than sympatric lizards. Sympatric lizards also attacked masked weevils at lower rates, suggesting that other attributes of the weevils (size/shape/smell) also facilitate recognition. Allopatric lizards rapidly learned to avoid weevils after only a single encounter, and maintained aversive behaviours for more than three weeks. The imperfect ability of visual predators to recognize potential prey as unpalatable, both in the presence and absence of the aposematic signal, may help explain how diverse forms of mimicry exploit the predator's visual system to deter predation.

  18. The importance of ultraviolet and near-infrared sensitivity for visual discrimination in two species of lacertid lizards.

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    Martin, Mélissa; Le Galliard, Jean-François; Meylan, Sandrine; Loew, Ellis R

    2015-02-01

    Male and female Lacertid lizards often display conspicuous coloration that is involved in intraspecific communication. However, visual systems of Lacertidae have rarely been studied and the spectral sensitivity of their retinal photoreceptors remains unknown. Here, we characterise the spectral sensitivity of two Lacertid species from contrasting habitats: the wall lizard Podarcis muralis and the common lizard Zootoca vivipara. Both species possess a pure-cone retina with one spectral class of double cones and four spectral classes of single cones. The two species differ in the spectral sensitivity of the LWS cones, the relative abundance of UVS single cones (potentially more abundant in Z. vivipara) and the coloration of oil droplets. Wall lizards have pure vitamin A1-based photopigments, whereas common lizards possess mixed vitamin A1 and A2 photopigments, extending spectral sensitivity into the near infrared, which is a rare feature in terrestrial vertebrates. We found that spectral sensitivity in the UV and near infrared improves discrimination of small variations in throat coloration among Z. vivipara. Thus, retinal specialisations optimise chromatic resolution in common lizards, indicating that the visual system and visual signals might co-evolve.

  19. Genetic diversity and its seasonal variation of Jiaozhou Bay phytoplankton determined by rbcL gene sequencing

    Institute of Scientific and Technical Information of China (English)

    LIU Yongjian; YANG Guanpin; GUAN Xiaojing; MEN Rongxin

    2006-01-01

    Ribulose-1, 5-bisphosphate carboxynase/oxygenase large subunit gene (rbcL) of Jiaozhou Bay phytoplankton was amplified from spring, summer and autumn surface seawater DNAs and cloned respectively. About 50 clones were randomly selected from each library and sequenced. If identical amino acid sequences are considered as the same operational taxonomy unit (OTU), 61 OTUs are identified according to inferred amino acid sequences, among them, 21 from spring seawater, 15 from summer seawater and 25 from autumn seawater. Shannon index calculated from OTU abundances reflects the genetic diversity of a community. The indexes of spring, summer and autumn surface seawater phytoplankton are 2.69, 2.44 and 2.76 respectively, indicating that phytoplankton genetic diversity of autumn seawater is the richest. Seasonal variation of phytoplankton community is significant; the community compositions of three seasons are almost completely different except for the two OTUs shared by summer and autumn. Surface seawater phytoplankton communities are possibly metacommunities different spatially and temporally.

  20. Phylogeny and divergence of Chinese Angiopteridaceae based on chloroplast DNA sequence data (rbcL and trnL-F)

    Institute of Scientific and Technical Information of China (English)

    LI ChunXiang; LU ShuGang

    2007-01-01

    Marattioid ferns are an ancient lineage of primitive vascular plants that first appeared in the middle Carboniferous. Extant members are almost exclusively restricted to tropical regions, and the species-rich family Angiopteridaceae are limited in their distribution to the eastern hemisphere; relationships within the group are currently vague. Here the phylogenetic relationship between Angiopteris Hoffm. and Archangiopteris Christ et Gies. was evaluated based on the sequence analysis of chloroplast rbcL gene and trnL-F intergenic spacer with MEGA2 and MrBayes v3.0b4. On the basis of the phylogenetic pattern and fossil record, we further estimated the divergence time for the two genera. The phylogenetic trees revealed that all species of Angiopteris and Archangiopteris in this study formed a monophyletic group with strong statistical support, but the relationship between the two genera remained unresolved based on individual sequence analysis. On the other hand, the sequence analyses of combined data set revealed that Archangiopteris species diverged first, indicating that Archangiopteris may not be a direct derivative as traditionally assumed. The clade of Angiopteris and Archangiopteris appears to have diversified in the late Oligocene (≈26 Ma) based on the molecular estimate. Thus, the evolutionary history of extant Angiopteris and Archangiopteris has been characterized by ancient origin and recent diversification, and these groups are not relic and endangered lineages as traditionally considered.

  1. Re-identifying Grateloupia yangjiangensis (Rhodophyta, Halymeniaceae) based on morphological observations, life history and rbcL sequence analyses

    Institute of Scientific and Technical Information of China (English)

    WANG Hongwei; GUO Shaoru; ZHANG Xiaoming; ZHAO Dan; ZHANG Wen; LUAN Rixiao

    2014-01-01

    On the basis of morphological observations, life history and molecular phylogeny, Grateloupia yangjiangen-sis, which is similar to G. filicina, G. orientalis, G. catenata, and G. ramosissima in appearance, was re-exam-ined. The results are as follows:(1) the auxiliary-cell ampullae of G. yangjiangensis were of Grateloupia type, thalli was fleshy and gelatinous in texture, and the erect axes were compressed;the cortex was 0.25-0.30 mm thick, consisting of five to seven outer layers, and there were five inner layers of triangular or stellate cells;(2) there was no filamentous stage in the development of the carpospores;(3) the ribulose-1,5-bisphosphate carboxylase/oxygenase gene (rbcL) sequence of four G. yangjiangensis examined showed that there was no intergeneric divergence among them, and for the phylogenetic tree, four sequences of G. yangjiangensis formed a single monophyletic subclade within the large Grateloupia clade of Halymeniaceae. In conclusion, G. yangjiangensis was a single species within the genus Grateloupia. This research provided criterion for identification and cultivation of G. yangjiangensis.

  2. Helminths infection patterns in a lizard (Tropidurus hispidus) population from a semiarid neotropical area: associations between female reproductive allocation and parasite loads.

    Science.gov (United States)

    Galdino, Conrado A B; Ávila, Robson W; Bezerra, Castiele H; Passos, Daniel C; Melo, Gabriela C; Zanchi-Silva, Djan

    2014-12-01

    This study reports helminth infection patterns of the lizard Tropidurus hispidus from an area of semiarid caatinga in northeastern Brazil (Ceará state). The lizard population was parasitized by 8 helminth species, and the species composition of the component community resembles that found for other Neotropical lizards. The prevalence of parasites was higher for males compared with females, whereas no relation was found between intensity of infection of 2 parasites (Parapharyngodon alvarengai and Physaloptera lutzi) and the lizards body size. For reproductive females, parasite infection intensity was negatively correlated to reproductive investment.

  3. Anatomy, morphology and evolution of the patella in squamate lizards and tuatara (Sphenodon punctatus).

    Science.gov (United States)

    Regnault, Sophie; Jones, Marc E H; Pitsillides, Andrew A; Hutchinson, John R

    2016-05-01

    The patella (kneecap) is the largest and best-known of the sesamoid bones, postulated to confer biomechanical advantages including increasing joint leverage and reinforcing the tendon against compression. It has evolved several times independently in amniotes, but despite apparently widespread occurrence in lizards, the patella remains poorly characterised in this group and is, as yet, completely undescribed in their nearest extant relative Sphenodon (Rhynchocephalia). Through radiography, osteological and fossil studies we examined patellar presence in diverse lizard and lepidosauromorph taxa, and using computed tomography, dissection and histology we investigated in greater depth the anatomy and morphology of the patella in 16 lizard species and 19 Sphenodon specimens. We have found the first unambiguous evidence of a mineralised patella in Sphenodon, which appears similar to the patella of lizards and shares several gross and microscopic anatomical features. Although there may be a common mature morphology, the squamate patella exhibits a great deal of variability in development (whether from a cartilage anlage or not, and in the number of mineralised centres) and composition (bone, mineralised cartilage or fibrotendinous tissue). Unlike in mammals and birds, the patella in certain lizards and Sphenodon appears to be a polymorphic trait. We have also explored the evolution of the patella through ancestral state reconstruction, finding that the patella is ancestral for lizards and possibly Lepidosauria as a whole. Clear evidence of the patella in rhynchocephalian or stem lepidosaurian fossil taxa would clarify the evolutionary origin(s) of the patella, but due to the small size of this bone and the opportunity for degradation or loss we could not definitively conclude presence or absence in the fossils examined. The pattern of evolution in lepidosaurs is unclear but our data suggest that the emergence of this sesamoid may be related to the evolution of secondary

  4. The ecological cost of morphological specialization: feeding by a fossorial lizard.

    Science.gov (United States)

    Andrews, R M; Pough, F H; Collazo, A; de Queiroz, A

    1987-08-01

    Head size and shape of reptiles may reflect selection for multiple uses. For example, sexual selection for large head size may enhance feeding efficiency. In contrast, morphological characteristics of the heads of fossorial reptiles suggests that fossoriality may have evolved at the expense of reduced effectiveness in feeding. Our research focused on the question: Does a fossorial lizard feed less effectively than a non-fossorial lizard? To answer this question, we measured the time, number of bites, and oxygen consumption by sand-swimming (Chalcides ocellatus) and epigeal (Eumeces inexpectatus) skinks feeding on crickets. These lizard species were similar in mass, but different in body form: Chalcides had longer bodies and smaller heads than Eumeces. For lizards of the same mass, Chalcides were unable to eat prey as large as those eaten by Eumeces, Chalcides took longer to eat prey of the same size than did Eumeces, and the aerobic energy cost of eating crickets of the same relative size (cricket mass/lizard mass) tended to be greater for Chalcides than for Eumeces. The ecologically relevant costs of feeding appear to be the upper limit to the size of prey and the time of feeding. Both costs would restrict the energy intake per unit time of Chalcides. Moreover, given the same energy requirements and prey community, Chalcides would have to feed more often and would take longer to feed than would Eumeces. Both factors would increase the exposure of Chalcides to predators relative to that of Eumeces. To reduce the risk of predation, Chalcides would have to reduce energy intake or fulfill its energy requirements with relatively small prey, or both. These conclusions are potentially confounded in two ways. The first is that male Eumeces have relatively large heads as a result of sexual selection. Thus, the differences we observed between Chalcides and Eumeces (most of our specimens were males) could have been the result of reduced costs of feeding for Eumeces due to

  5. Prey-handling and the evolutionary ecology of sand-swimming lizards (Lerista : Scincidae).

    Science.gov (United States)

    Pough, F Harvey; Preest, Marion R; Fusari, Margaret H

    1997-10-01

    Fossorial lizards differ in morphology from their surface-dwelling relatives. The Australian sphenomorphine skink genus Ctenotus consists of surface-dwelling species, and is closely related to the genus Lerista, which includes both surface-dwelling and fossorial species. Sand-swimming represents the derived condition and has evolved independently in several lineages of Lerista. The heads of lizards in the two genera differ in shape (blunt snout for Ctenotus versus wedge-shaped for Lerista) and in length relative to the body (approximately 20% of snout-vent length for Ctenotus versus 12% for sand-swimming Lerista). Do these specializations affect the sizes or types of prey that can be consumed by Lerista? We compared prey-handling by Ctenotus and Lerista to correlate morphological differences with differences in prey-handling ability, and to distinguish the effects of snout shape and head length. Feeding trials included three categories of insect prey that the lizards normally eat: soft-bodied larvae (Lepidoptera), hard-bodied larvae (Coleoptera), and roaches (Blatoidea). In comparisons based on the mass of a prey item relative to the mass of a lizard, Lerista had longer handling times for all prey categories and were limited to smaller prey than were Ctenotus. However, when comparisons were based on the length of prey relative to the length of a lizard's head, Lerista ate some elongate prey as fast or faster than did Ctenotus, and both genera successfully swallowed prey more than twice the length of their own head. Thus, the differences in prey-handling performance of Ctenotus and Lerista probably result from the fact that Lerista have a relatively shorter head than Ctenotus. All Lerista species, surface-dwelling and fossorial, have short heads compared to primitive sphenomorphine lizards. Fossorial species of Lerista have elongate trunks, and consequently their heads are shorter in proportion to trunk length than those of surface-dwelling Lerista. However, most

  6. 从叶绿体DNA rbcL序列分析探讨五味子科的系统发育%Phylogeny of Schisandraceae Based on the cpDNA rbcL Sequences

    Institute of Scientific and Technical Information of China (English)

    王彦涵; 张寿州; 高建平; 李晓波; 陈道峰

    2003-01-01

    以广玉兰Magnolia grandiflora,蝙蝠葛Menispermum dauricum,牡丹Paeonia suffruticosa和Illicium parviflorum为外类群,对五味子科的叶绿体rbcL基因进行序列分析,探讨其系统发育关系. 结果表明,五味子科为一单系类群,与八角科关系最近,与木兰科关系较远. 在严格一致性树中(Length=256, CI=0.872 5,RI=0.819 2),五味子科被分为二支,一支由五味子属中的中华五味子亚属Subgen. Sinoschisandra,多蕊五味子亚属Subgen. Pleiostema和少蕊五味子亚属Subgen. Maximowixzia构成,支持率82%;另一支包括南五味子属和五味子属中的团蕊五味子亚属Subgen. Sphaerostema,重瓣五味子亚属Subgen. Plenischisandra. 由此推断,五味子属和南五味子属关系密切,它们之间存在交叉和重叠,两属可能起源于共同的祖先. 通过基因树分析,结合形态学、解剖学和化学证据认为,五味子S. chinensis和红花五味子S. rubriflora是五味子属中的原始类群.

  7. Lineage-specific variations of congruent evolution among DNA sequences from three genomes, and relaxed selective constraints on rbcL in Cryptomonas (Cryptophyceae

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    Tran Hoang-Dung

    2005-10-01

    Full Text Available Abstract Background Plastid-bearing cryptophytes like Cryptomonas contain four genomes in a cell, the nucleus, the nucleomorph, the plastid genome and the mitochondrial genome. Comparative phylogenetic analyses encompassing DNA sequences from three different genomes were performed on nineteen photosynthetic and four colorless Cryptomonas strains. Twenty-three rbcL genes and fourteen nuclear SSU rDNA sequences were newly sequenced to examine the impact of photosynthesis loss on codon usage in the rbcL genes, and to compare the rbcL gene phylogeny in terms of tree topology and evolutionary rates with phylogenies inferred from nuclear ribosomal DNA (concatenated SSU rDNA, ITS2 and partial LSU rDNA, and nucleomorph SSU rDNA. Results Largely congruent branching patterns and accelerated evolutionary rates were found in nucleomorph SSU rDNA and rbcL genes in a clade that consisted of photosynthetic and colorless species suggesting a coevolution of the two genomes. The extremely accelerated rates in the rbcL phylogeny correlated with a shift from selection to mutation drift in codon usage of two-fold degenerate NNY codons comprising the amino acids asparagine, aspartate, histidine, phenylalanine, and tyrosine. Cysteine was the sole exception. The shift in codon usage seemed to follow a gradient from early diverging photosynthetic to late diverging photosynthetic or heterotrophic taxa along the branches. In the early branching taxa, codon preferences were changed in one to two amino acids, whereas in the late diverging taxa, including the colorless strains, between four and five amino acids showed changes in codon usage. Conclusion Nucleomorph and plastid gene phylogenies indicate that loss of photosynthesis in the colorless Cryptomonas strains examined in this study possibly was the result of accelerated evolutionary rates that started already in photosynthetic ancestors. Shifts in codon usage are usually considered to be caused by changes in functional

  8. Development of Lifting and Propulsion Mechanism for Biped Robot Inspired by Basilisk Lizards

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    Linsen Xu

    2013-01-01

    Full Text Available The lifting and propulsion mechanism of a novel biped robot inspired by the basilisk lizard's water-walking function has been developed. The movement trajectories of the Watt-I planar linkage are brought out by combining the movement equations of the four-bar mechanism and the coordinate transformation equations, which are used to simulate the foot trajectories of the basilisk lizard, and the lifting and propulsion mechanism of the biped robot walking on water is carried out. The links' parameters are optimized by taking the trajectories overlap ratio as the objective function. The prototype of the biped robot walking on water is manufactured by the results of the kinematic analysis on the robot. And the lifting and propulsion force curve on the robot from water is measured. The experiment results show that the lifting and propulsion system can satisfy the function requirement of the biped robot walking on water.

  9. Prevalence and molecular identification of Cryptosporidium isolates from pet lizards and snakes in Italy

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    Rinaldi L.

    2012-11-01

    Full Text Available In order to acquire prevalence and genetic data on Cryptosporidium infections in captive lizards and snakes kept as pets, a survey was conducted on 150 individual reptiles from southern Italy. Fecal samples were preserved in 5% formalin and analyzed using a commercial immunofluorescence assay (IFA for the detection of Cryptosporidium oocysts and Giardia cysts. IFA revealed the presence of Cryptosporidium oocysts in nine of the 150 samples examined (6.0%, precisely in 6/125 snakes (4.8% and in 3/25 lizards (12.0%; all fecal samples tested negative for the presence of Giardia cysts. Molecular characterization based on nested PCR amplification and sequencing of the SSU-rRNA gene, revealed the presence of Cryptosporidium serpentis in three samples from snakes (Boa constrictor constrictor, Elapheguttata guttata guttata and Python molurus.

  10. Testis of the lizard Mabuya carinata: a light microscopic and ultrastructural seasonal study.

    Science.gov (United States)

    Aranha, I; Bhagya, M; Yajurvedi, H N

    2006-01-01

    Histomorphology and ultrastructure of the testis during breeding and nonbreeding phases of the reproductive cycle of the lizard Mabuya carinata are studied. Observations of the ultrastructural features of the testis during breeding and nonbreeding phases of the reproductive cycle reveal a prenuptial type of spermatogenesis and a clearcut discontinuous spermatogenic cycle. Seminiferous tubules are enlarged and there is active spermatogenesis as shown by the presence of all the stages of spermatogenesis (spermatogonia to spermatids) and spermatozoa during the breeding phase (November). During the nonbreeding phase (April) only spermatogonia and Sertoli cells are seen in the shrunken seminiferous tubules. Leydig cells and Sertoli cells show distinct changes in the morphological appearance with hypertrophy of the cells in breeding phase and atrophy of the cells in the nonbreeding phase of the reproductive cycle. The present study suggests that Sertoli cells and Leydig cells functions are synchronous in the lizard M. carinata.

  11. Telothelepodidae, Thelepodidae and Trichobranchidae (Annelida, Terebelliformia) from Lizard Island, Great Barrier Reef, Australia.

    Science.gov (United States)

    Hutchings, Pat; de Matos Nogueira, João Miguel; Carrerette, Orlemir

    2015-09-18

    In a survey of the polychaetes of the Lizard Island region, six species of polychaetes belonging to the families Telothelepodidae Nogueira, Fitzhugh & Hutchings, 2013, Thelepodidae Hessle, 1917 and Trichobranchidae Malmgren, 1866 were found, from material collected during the Lizard Island Polychaete Taxonomic Workshop, and material collected by previous projects undertaken by the Australian Museum. This material includes one new species of Rhinothelepus Hutchings, 1974 (Telothelepodidae); one new species of each of the genera, Euthelepus McIntosh, 1885, Streblosoma Sars, 1872, and Thelepus Leuckart, 1849 (Thelepodidae); and one new species of Terebellides Sars, 1835 and another of Trichobranchus Malmgren, 1866 (Trichobranchidae). Keys for identification of these species are provided, together with full descriptions for all species, as well as comparisons with the morphologically most similar congeners.

  12. A revised key to the lizards of Iran (Reptilia: Squamata: Lacertilia).

    Science.gov (United States)

    Nasrabadi, Reza; Rastegar-Pouyani, Nasrullah; Rastegar-Pouyani, Eskandar; Gharzi, Ahmad

    2017-02-03

    During recent years several lizard taxa have been added to the faunal list of Iran. Descriptions and new records are scattered in different publications in the herpetological literature. We here present species accounts for 152 species belonging to 43 genera and 10 families up to July 2016. The most diverse family is Lacertidae with 9 genera, 49 species and 2 subspecies, followed by Gekkonidae with 13 genera and 43 species, Agamidae with 5 genera, 18 species and 4 subspecies, Scincidae with 7 genera, 18 species and 2 subspecies, Phyllodactylidae with 1 genus and 10 species, Sphaerodactylidae with 2 genera and 4 species, Varanidae with 1 genus, 3 species and 2 subspecies, Uromastycidae with 2 genera and 3 species, Eublepharidae with 1 genus and 3 species, and Anguidae with 2 genera and 2 species. The current paper provides a dichotomous key including all of the currently recognized lizards of Iran.

  13. Checklist of helminths from lizards and amphisbaenians (Reptilia, Squamata of South America

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    RW Ávila

    2010-01-01

    Full Text Available A comprehensive and up to date summary of the literature on the helminth parasites of lizards and amphisbaenians from South America is herein presented. One-hundred eighteen lizard species from twelve countries were reported in the literature harboring a total of 155 helminth species, being none acanthocephalans, 15 cestodes, 20 trematodes and 111 nematodes. Of these, one record was from Chile and French Guiana, three from Colombia, three from Uruguay, eight from Bolivia, nine from Surinam, 13 from Paraguay, 12 from Venezuela, 27 from Ecuador, 17 from Argentina, 39 from Peru and 103 from Brazil. The present list provides host, geographical distribution (with the respective biome, when possible, site of infection and references from the parasites. A systematic parasite-host list is also provided.

  14. Ultrasonic-assisted extraction of phenolic and antioxidative compounds from lizard tail (Houttuynia cordata Thunb.

    Directory of Open Access Journals (Sweden)

    Trakul Prommajak

    2014-02-01

    Full Text Available Lizard tail (Houttuynia cordata Thunb. is an Asian herb which has many biological activities, including antioxidative property from polyphenolic compounds. Response surface methodology and Box-Behnken design were employed to study the effect of extraction temperature (30 to 70°C, extraction time (10 to 30 min, ethanol concentration (30 to 70%, and solvent to sample ratio (2 to 6 ml/g on ultrasonic-assisted extraction of phenolic compounds from lizard tail and antioxidant capacity of the herb extract. Extraction temperature was the most relevant factor on the responses. Optimal condition was the extraction temperature of 70°C for 30 min, using 60% ethanol concentration at the solvent to sample ratio of 5 ml/g. Model adequacies were confirmed by extraction at the optimal condition and normality of standardized residuals.

  15. Lung infection rates in two sympatric Tropiduridae lizard species by pentastomids and nematodes in northeastern Brazil

    Directory of Open Access Journals (Sweden)

    WO. Almeida

    Full Text Available We present data on pulmonary infection rates by parasites in the lizards Tropidurus hispidus Spix, 1825 and T. semitaeniatus (Spix, 1825 living sympatrically in the Chapada do Araripe mountain Range, northeastern Brazil. We found no parasite pulmonary infection in T. semitaeniatus. However, two pulmonary parasite species were found in the T. hispidus hosts, the pentastomid Raillietiella mottae Almeida, Freire and Lopes, 2008 and the nematode Rhabdias sp. Overall prevalence was 5%. Prevalence of R. mottae was 2.5% and corresponded to only one parasite on each infected host. Prevalence of Rhabdias sp. was 2.5% and the range of infection was 1-2 parasites per host. This represents the first record of Rhabdias infecting lizards of the family Tropiduridae in the Neotropical region. Furthermore, we present a comparison of parameters of infection by pulmonary parasites including some recent studies in Brazil.

  16. Helminths infecting the parthenogenetic whiptail lizard Cnemidophorus nativo in a restinga habitat of Bahia State, Brazil.

    Science.gov (United States)

    Menezes, V A; Vrcibradic, D; Vicente, J J; Dutra, G F; Rocha, C F D

    2004-12-01

    A sample of 101 specimens of the unisexual whiptail lizard Cnemidophorus nativo (Squamata; Teiidae) from a coastal site in Bahia State, Brazil were examined for the presence of endoparasites. Of these, 35 (34.7%) harboured helminths. Six helminth species were recovered from C. nativo, including five nematodes (Physaloptera retusa, Physalopteroides venancioi, Subulura lacertilia, Skrjabinelazia intermedia and Parapharyngodon sp., and one cestode (Oochoristica ameivae), all representing new host records. Most lizards were infected by a single species of helminth and none by more than three. Infection rates were neither significantly influenced by host body size nor by environmental factors. The results are compared with data from studies on other whiptail species in both South and North America.

  17. Modifications of the dermis during scale regeneration in the lizard tail

    OpenAIRE

    1994-01-01

    During scale morphogenesis in the regenerating tail of lizards (Anolis and Lampropholis) the structure of the dermis undergoes changes in relation to the ingrowth of epidermal papillae to form the new scales. Cell proliferation in the dermis, as revealed by the uptake of 3~-thymidinei,s high in the prescaling region of the regenerating tail but lower than the proliferation in the epidermis. Under the epidermis of the scaling region dermal cell proliferation rap...

  18. From tameness to wariness: chemical recognition of snake predators by lizards in a Mediterranean island

    Directory of Open Access Journals (Sweden)

    Abraham Mencía

    2017-01-01

    Full Text Available Antipredatory defenses are maintained when benefit exceeds cost. A weak predation pressure may lead insular lizards to tameness. Podarcis lilfordi exhibits a high degree of insular tameness, which may explain its extinction from the main island of Menorca when humans introduced predators. There are three species of lizards in Menorca: the native P. lilfordi, only on the surrounding islets, and two introduced lizards in the main island, Scelarcis perspicillata and Podarcis siculus. In addition, there are three species of snakes, all introduced: one non-saurophagous (Natrix maura, one potentially non-saurophagous (Rhinechis scalaris and one saurophagous (Macroprotodon mauritanicus. We studied the reaction to snake chemical cues in five populations: (1 P. lilfordi of Colom, (2 P. lilfordi of Aire, (3 P. lilfordi of Binicodrell, (4 S. perspicillata, and (5 P. siculus, ordered by increasing level of predation pressure. The three snakes are present in the main island, while only R. scalaris is present in Colom islet, Aire and Binicodrell being snake-free islets. We aimed to assess the relationship between predation pressure and the degree of insular tameness regarding scent recognition. We hypothesized that P. lilfordi should show the highest degree of tameness, S. perspicillata should show intermediate responses, and P. siculus should show the highest wariness. Results are clear: neither P. lilfordi nor S. perspicillata recognize any of the snakes, while P. siculus recognizes the scent of M. mauritanicus and reacts to it with typical well-defined antipredatory behaviours as tail waving and slow motion. These results rise questions about the loss of chemical recognition of predators during island tameness and its related costs and benefits for lizards of insular habitats. In addition, this highlights the necessity for strong conservation measures to avoid the introduction of alien predators.

  19. Inferring responses to climate dynamics from historical demography in neotropical forest lizards

    OpenAIRE

    2016-01-01

    We apply a comparative framework to test for concerted demographic changes in response to climate shifts in the neotropical lowland forests, learning from the past to inform projections of the future. Using reduced genomic (SNP) data from three lizard species codistributed in Amazonia and the Atlantic Forest (Anolis punctatus, Anolis ortonii, and Polychrus marmoratus), we first reconstruct former population history and test for assemblage-level responses to cycles of moisture transport recent...

  20. Ontogenetic Variation in the Thermal Biology of Yarrow's Spiny Lizard, Sceloporus jarrovii

    OpenAIRE

    Anthony L Gilbert; Lattanzio, Matthew S.

    2016-01-01

    Climate change is rapidly altering the way current species interact with their environment to satisfy life-history demands. In areas anticipated to experience extreme warming, rising temperatures are expected to diminish population growth, due either to environmental degradation, or the inability to tolerate novel temperature regimes. Determining how at risk ectotherms, and lizards in particular, are to changes in climate traditionally emphasizes the thermal ecology and thermal sensitivity of...

  1. Length of activity season drives geographic variation in body size of a widely distributed lizard

    OpenAIRE

    Horváthová, Terézia; Cooney, Christopher R.; Fitze, Patrick S; Oksanen, Tuula; Jelic, Dusan; Ghira, Ioan; Uller, Tobias; Jandzik, David

    2013-01-01

    Understanding the factors that drive geographic variation in life history is an important challenge in evolutionary ecology. Here, we analyze what predicts geographic variation in life-history traits of the common lizard, Zootoca vivipara, which has the globally largest distribution range of all terrestrial reptile species. Variation in body size was predicted by differences in the length of activity season, while we found no effects of environmental temperature per se. Females experiencing r...

  2. The role of habitat shift in the evolution of lizard morphology: evidence from tropical Tropidurus

    OpenAIRE

    Vitt, Laurie J.; Caldwell, Janalee P; Zani, Peter A.; Titus, Tom A.

    1997-01-01

    We compared morphology of two geographically close populations of the tropical lizard Tropidurus hispidus to test the hypothesis that habitat structure influences the evolution of morphology and ecology at the population level. T. hispidus isolated on a rock outcrop surrounded by tropical forest use rock crevices for refuge and appear dorsoventrally compressed compared with those in open savanna. A principal components analysis revealed that the populations were differentially distributed alo...

  3. Predation or Scavenging of Giant Otter (Pteronura brasiliensis Cubs by Lizards?

    Directory of Open Access Journals (Sweden)

    Fernando César Weber Rosas

    2008-10-01

    Full Text Available Despite the fact that several species have been mentioned as being giant otter predators, there is no direct evidence of most of them actually preying on P. brasiliensis. In this study we report for the first time a lizard (Tupinambis teguixin, commonly known as a tegu, either preying or scavenging on a giant otter cub. We also present some interactions of free-ranging giant otters with other potential predators, showing that their interactions are not always negative.

  4. Neosabellides lizae, a new species of Ampharetidae (Annelida) from Lizard Island, Great Barrier Reef, Australia.

    Science.gov (United States)

    Alvestad, Tom; Budaeva, Nataliya

    2015-09-18

    Neosabellides lizae, a new species of Ampharetidae, is described from the intertidal zone off Lizard Island, Great Barrier Reef, Queensland, Australia. The new species is referred to the genus Neosabellides based on the shape of the prostomium, three pairs of branchiae, 14 thoracic segments with notopodia, 12 thoracic uncinigerous segments, and the first two pairs of abdominal uncinigers of thoracic type. The new species differs from all known species of Neosabellides in having 14 abdominal uncinigerous segments.

  5. Glyceriformia Fauchald, 1977 (Annelida: "Polychaeta") from Lizard Island, Great Barrier Reef, Australia.

    Science.gov (United States)

    Böggemann, Markus

    2015-09-18

    Eight species of Glyceridae (Glycera brevicirris, Glycera cf. lapidum, Glycera onomichiensis, Glycera sagittariae, Glycera tesselata, Glycera tridactyla, Glycerella magellanica, Hemipodia cf. simplex) and six species of Goniadidae (Goniada antipoda, Goniada cf. brunnea, Goniada echinulata, Goniada emerita, Goniada grahami, Goniada paucidens) have been collected during several expeditions to the vicinity of Lizard Island (Australia, Queensland). An identification key to the Glyceriformia that inhabit the region is presented. Detailed and illustrated morphological descriptions are given for all investigated species.

  6. Moisture harvesting and water transport through specialized micro-structures on the integument of lizards

    Directory of Open Access Journals (Sweden)

    Philipp Comanns

    2011-04-01

    Full Text Available Several lizard species that live in arid areas have developed special abilities to collect water with their bodies' surfaces and to ingest the so collected moisture. This is called rain- or moisture-harvesting. The water can originate from air humidity, fog, dew, rain or even from humid soil. The integument (i.e., the skin plus skin derivatives such as scales has developed features so that the water spreads and is soaked into a capillary system in between the reptiles' scales. Within this capillary system the water is transported to the mouth where it is ingested. We have investigated three different lizard species which have developed the ability for moisture harvesting independently, viz. the Australian thorny devil (Moloch horridus, the Arabian toadhead agama (Phrynocephalus arabicus and the Texas horned lizard (Phrynosoma cornutum. All three lizards have a honeycomb like micro ornamentation on the outer surface of the scales and a complex capillary system in between the scales. By investigation of individual scales and by producing and characterising polymer replicas of the reptiles' integuments, we found that the honeycomb like structures render the surface superhydrophilic, most likely by holding a water film physically stable. Furthermore, the condensation of air humidity is improved on this surface by about 100% in comparison to unstructured surfaces. This allows the animals to collect moisture with their entire body surface. The collected water is transported into the capillary system. For Phrynosoma cornutum we found the interesting effect that, in contrast to the other two investigated species, the water flow in the capillary system is not uniform but directed to the mouth. Taken together we found that the micro ornamentation yields a superhydrophilic surface, and the semi-tubular capillaries allow for an efficient passive – and for Phrynosoma directed – transport of water.

  7. From tameness to wariness: chemical recognition of snake predators by lizards in a Mediterranean island

    Science.gov (United States)

    Pérez-Mellado, Valentín

    2017-01-01

    Antipredatory defenses are maintained when benefit exceeds cost. A weak predation pressure may lead insular lizards to tameness. Podarcis lilfordi exhibits a high degree of insular tameness, which may explain its extinction from the main island of Menorca when humans introduced predators. There are three species of lizards in Menorca: the native P. lilfordi, only on the surrounding islets, and two introduced lizards in the main island, Scelarcis perspicillata and Podarcis siculus. In addition, there are three species of snakes, all introduced: one non-saurophagous (Natrix maura), one potentially non-saurophagous (Rhinechis scalaris) and one saurophagous (Macroprotodon mauritanicus). We studied the reaction to snake chemical cues in five populations: (1) P. lilfordi of Colom, (2) P. lilfordi of Aire, (3) P. lilfordi of Binicodrell, (4) S. perspicillata, and (5) P. siculus, ordered by increasing level of predation pressure. The three snakes are present in the main island, while only R. scalaris is present in Colom islet, Aire and Binicodrell being snake-free islets. We aimed to assess the relationship between predation pressure and the degree of insular tameness regarding scent recognition. We hypothesized that P. lilfordi should show the highest degree of tameness, S. perspicillata should show intermediate responses, and P. siculus should show the highest wariness. Results are clear: neither P. lilfordi nor S. perspicillata recognize any of the snakes, while P. siculus recognizes the scent of M. mauritanicus and reacts to it with typical well-defined antipredatory behaviours as tail waving and slow motion. These results rise questions about the loss of chemical recognition of predators during island tameness and its related costs and benefits for lizards of insular habitats. In addition, this highlights the necessity for strong conservation measures to avoid the introduction of alien predators. PMID:28123905

  8. Elevational variation in body-temperature response to immune challenge in a lizard

    Directory of Open Access Journals (Sweden)

    Francisco Javier Zamora-Camacho

    2016-04-01

    Full Text Available Immunocompetence benefits animal fitness by combating pathogens, but also entails some costs. One of its main components is fever, which in ectotherms involves two main types of costs: energy expenditure and predation risk. Whenever those costs of fever outweigh its benefits, ectotherms are expected not to develop fever, or even to show hypothermia, reducing costs of thermoregulation and diverting the energy saved to other components of the immune system. Environmental thermal quality, and therefore the thermoregulation cost/benefit balance, varies geographically. Hence, we hypothesize that, in alpine habitats, immune-challenged ectotherms should show no thermal response, given that (1 hypothermia would be very costly, as the temporal window for reproduction is extremely small, and (2 fever would have a prohibitive cost, as heat acquisition is limited in such habitat. However, in temperate habitats, immune-challenged ectotherms might show a febrile response, due to lower cost/benefit balance as a consequence of a more suitable thermal environment. We tested this hypothesis in Psammodromus algirus lizards from Sierra Nevada (SE Spain, by testing body temperature preferred by alpine and non-alpine lizards, before and after activating their immune system with a typical innocuous pyrogen. Surprisingly, non-alpine lizards responded to immune challenge by decreasing preferential body-temperature, presumably allowing them to save energy and reduce exposure to predators. On the contrary, as predicted, immune-challenged alpine lizards maintained their body-temperature preferences. These results match with increased costs of no thermoregulation with elevation, due to the reduced window of time for reproduction in alpine environment.

  9. Comparative modeling and molecular dynamics suggest high carboxylase activity of the Cyanobium sp. CACIAM14 RbcL protein.

    Science.gov (United States)

    Siqueira, Andrei Santos; Lima, Alex Ranieri Jerônimo; Dall'Agnol, Leonardo Teixeira; de Azevedo, Juliana Simão Nina; da Silva Gonçalves Vianez, João Lídio; Gonçalves, Evonnildo Costa

    2016-03-01

    Rubisco catalyzes the first step reaction in the carbon fixation pathway, bonding atmospheric CO2/O2 to ribulose 1,5-bisphosphate; it is therefore considered one of the most important enzymes in the biosphere. Genetic modifications to increase the carboxylase activity of rubisco are a subject of great interest to agronomy and biotechnology, since this could increase the productivity of biomass in plants, algae and cyanobacteria and give better yields in crops and biofuel production. Thus, the aim of this study was to characterize in silico the catalytic domain of the rubisco large subunit (rbcL gene) of Cyanobium sp. CACIAM14, and identify target sites to improve enzyme affinity for ribulose 1,5-bisphosphate. A three-dimensional model was built using MODELLER 9.14, molecular dynamics was used to generate a 100 ns trajectory by AMBER12, and the binding free energy was calculated using MM-PBSA, MM-GBSA and SIE methods with alanine scanning. The model obtained showed characteristics of form-I rubisco, with 15 beta sheets and 19 alpha helices, and maintained the highly conserved catalytic site encompassing residues Lys175, Lys177, Lys201, Asp203, and Glu204. The binding free energy of the enzyme-substrate complexation of Cyanobium sp. CACIAM14 showed values around -10 kcal mol(-1) using the SIE method. The most important residues for the interaction with ribulose 1,5-bisphosphate were Arg295 followed by Lys334. The generated model was successfully validated, remaining stable during the whole simulation, and demonstrated characteristics of enzymes with high carboxylase activity. The binding analysis revealed candidates for directed mutagenesis sites to improve rubisco's affinity.

  10. Defense behavior and tail loss in the endemic lizard Eurolophosaurus nanuzae (Squamata, Tropiduridae from southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Conrado A. B. Galdino

    2006-09-01

    Full Text Available Defense behavior of the endemic tropidurid lizard Eurolophosaurus nanuzae was studied in an area of rocky outcrops at Serra do Cipó, Minas Gerais State, southeastern Brazil. Tail loss aspects of this species were also studied in lizards from three populations (Diamantina, Serra do Cipó, and Serro, Minas Gerais State, Brazil. Lizards relied primarily on crypsis to avoid detection by predators. Secondary defense strategies involved a complex set of behaviors. Mean maximum distance of flight was 1.68 ± 1.70 m. When captured,individuals attempted to flee, lifted the tail, produced distress calls, discharged the cloacal contents, waived their tails, and bit. Frequency of tail autotomy was 13.2% (n = 53 in Diamantina, 11.9% (n = 42 in Serra do Cipó, and 4.1% (n = 49 in Serro. Tail autotomy frequency did not differ among the three populations (X2 = 3.3, DF =2, p = 0.19. Tail autotomy did not vary between the years of the study (X2 = 1.32, p = 0.35 and did not differ between males and females among the studied populations.

  11. Assessing the reliability of thermography to infer internal body temperatures of lizards.

    Science.gov (United States)

    Barroso, Frederico M; Carretero, Miguel A; Silva, Francisco; Sannolo, Marco

    2016-12-01

    For many years lizard thermal ecology studies have relied on the use of contact thermometry to obtain internal body temperature (Tb) of the animals. However, with progressing technology, an interest grew in using new, less invasive methods, such as InfraRed (IR) pyrometry and thermography, to infer Tb of reptiles. Nonetheless few studies have tested the reliability of these new tools. The present study tested the use of IR cameras as a non-invasive tool to infer Tb of lizards, using three differently body-sized lacertid species (Podarcis virescens, Lacerta schreiberi and Timon lepidus). Given the occurrence of regional heterothermy, we pairwise compared thermography readings of six body parts (snout, eye, head, dorsal, hind limb, tail base) to cloacal temperature (measured by a thermometer-associated thermocouple probe) commonly employed to measure Tb in field and lab studies. The results showed moderate to strong correlations (R(2)=0.84-0.99) between all body parts and cloacal temperature. However, despite the readings on the tail base showed the strongest correlation in all three species, it was the eye where the absolute values and pattern of temperature change most consistently followed the cloacal measurements. Hence, we concluded that the eye would be the body location whose IR camera readings more closely approximate that of the animal's internal environment. Alternatively, other body parts can be used, provided that a careful calibration is carried out. We provide guidelines for future research using thermography to infer Tb of lizards.

  12. Light reflection from crystal platelets in iridophores determines green or brown skin coloration in Takydromus lizards.

    Science.gov (United States)

    Kuriyama, Takeo; Esashi, Jyunko; Hasegawa, Masami

    2017-04-01

    Brown and green are the most commonly imitated colors in prey animals because both colors occur in a range of habitats. Many researchers have evaluated survival with respect to background color matching, but the pigment cell mechanisms underlying such coloration are not known. Dorsal coloration of East Asian Takydromus lizards has shifted from green to brown or from brown to green on multiple occasions during the diversification of the genus, thus giving us an opportunity to examine the cellular mechanisms of background color matching. Brown and green skin were found to differ with respect to the morphological characteristics of iridophores, with different thicknesses of the reflecting platelets and the cytoplasmic spacing between platelets, despite a shared vertical arrangement of pigment cells, i.e., xanthophores in the upper layer, iridophores in the middle layer, and melanophores at the bottom of the dermal layer, among the different Takydromus lizards. Iridophores of brown skin reflected longer wavelengths of light than those of green skin, which may be attributed to the thicker platelets and longer distances between platelets in brown skin. We discuss the potential role of genetic and intracellular mechanisms explaining the thickness and orientation of the light-reflecting platelets of iridophores in Takydromus lizards. Copyright © 2016 Elsevier GmbH. All rights reserved.

  13. Pre- and Postcopulatory Traits of Salvator Male Lizards in Allopatry and Sympatry

    Directory of Open Access Journals (Sweden)

    Sergio Naretto

    2016-01-01

    Full Text Available The reproductive traits of males are under influence of sexual pressures before and after copulation. The strength of sexual selection varies across populations because they undergo varying competition for mating opportunities. Besides intraspecific pressures, individuals seem to be subjected to pressures driven by interspecific interactions in sympatry. Lizards may vary their reproductive strategies through varying sexual characters, body size, gonadal investment, and sperm traits. We evaluated the reproductive traits, involved in pre- and postcopulatory competition, in allopatric and sympatric populations of Salvator lizards. We observed a spatial gradient of male competition among populations, with the following order: allopatric zone of S. rufescens; sympatric zone; and allopatric zone of S. merianae. Accordingly, variation in secondary sexual character, the relative testis mass, and the length of sperm component was observed between allopatry and sympatry in each species, suggesting differences in the investment of reproductive traits. However, we found that these two Salvator species did not differ in secondary sexual characters in sympatry. Interestingly, the trade-off between testes and muscle varied differently from allopatry to sympatry between these Salvator species, suggesting that the influence of social context on reproductive traits investment would affect lizard species differently.

  14. [Mortality from contact with poisonous snakes and lizards in Mexico from 1979 to 2003].

    Science.gov (United States)

    Frayre-Torres, María José; Sevilla-Godínez, Elizabeth; Orozco-Valerio, Maria de Jesús; Armas, Jesús; Celis, Alfredo

    2006-01-01

    To describe the trend of standardized mortality by contact with poisonous snakes and lizards in Mexico from 1979 to 2003. We describe the standardized mortality trend by contact with poisonous snakes and lizards occurring in Mexico from 1979 to 2003, and report the mortality data bases from the INEGI (Instituto Nacional de Estadística, Geografía e Informática). We determined frequencies, percentages, mortality rates, standardized mortality rates and mortality relative risks with 95% confidence intervals. The general trend shows a statistically significant descent of 63.8%. The highest mortality rate within the 2000-2003 period was reported in Quintana Roo (7.47/1,000,000), Oaxaca (4.01/1,000,000), Veracruz (1.56/1,000,000), Chiapas (1.48/1,000,000), Campeche (1.43/1,000,000) and Yucatan (1.29/1,000,000). The groups with the highest risk are those older than 60 years and males. In spite of the detected decrease in mortality, the contact with poisonous snakes and lizards still is a public health problem in Mexico. As timely treatment saves lives, it is necessary to include and offer treatment in all emergency units of the country.

  15. Survey of birds and lizards for ixodid ticks (Acari) and spirochetal infection in northern California.

    Science.gov (United States)

    Manweiler, S A; Lane, R S; Block, W M; Morrison, M L

    1990-11-01

    A total of 138 birds (24 species) was captured in an oak woodland between December 1988 and June 1989 at the University of California, Sierra Foothill Range Field Station, Yuba County, Calif. Ticks were not found on 71 birds captured between December 1988 and March 1989. Five subadult Ixodes pacificus Cooley & Kohls were removed from 3 of 67 birds caught between April and June 1989. These three birds, an orange-crowned warbler (Vermivora celata (Say], a lazuli bunting (Passerina amoena (Say], and a chipping sparrow (Spizella passerina (Bechstein], represent new host records for I. pacificus in California. Tissues from two ticks and thick blood films prepared from 126 birds tested negative for spirochetes by direct immunofluorescence (DI). A total of 172 larval and 197 nymphal I. pacificus was removed from 15 of 16 western fence lizards (Sceloporus occidentalis Baird & Girard) caught between April and June 1989 in the same location as were birds. Thick blood films prepared from all 16 lizards and tissue smears from 334 of the ticks (143 larvae and 191 nymphs) were DI test-negative for spirochetes. One (1.1%) of 93 adult I. pacificus collected at the bird-lizard capture site in February 1989 was infected with spirochetes that resembled B. burgdorferi.

  16. The anatomy and histology of caudal autotomy and regeneration in lizards.

    Science.gov (United States)

    Gilbert, Emily A B; Payne, Samantha L; Vickaryous, Matthew K

    2013-01-01

    Abstract Caudal autotomy-the ability to self-detach the tail-is a dramatic adaptation common to many structural-grade lizards. For most species, tail loss is followed by the equally dramatic phenomenon of tail regeneration. Here we review the anatomy and histology of caudal autotomy and regeneration in lizards, drawing heavily from research published over the past 2 decades. The autotomous tail is characterized by various structural adaptations, which act to minimize blood loss and trauma to adjacent tissues. The early phase of wound healing involves a leukocytic response but limited inflammation. Reepithelialization via a specialized wound epithelium is not only critical for scar-free healing but also necessary for subsequent tissue patterning and regenerative outgrowth. Regeneration begins with the formation of the blastema, a mass of proliferating mesenchymal-like cells. As the blastema expands, it is invaded by blood vessels and the spinal cord. Whereas the replacement tail outwardly resembles the original appendage, it differs in several notable respects, including the tissue composition and organization of the skeleton, muscular system, and spinal cord. Increasingly, the lizard tail is being recognized among biomedical scientists as an important model for the study of wound healing and multitissue restoration.

  17. How phylogeny and foraging ecology drive the level of chemosensory exploration in lizards and snakes.

    Science.gov (United States)

    Baeckens, S; Van Damme, R; Cooper, W E

    2017-03-01

    The chemical senses are crucial for squamates (lizards and snakes). The extent to which squamates utilize their chemosensory system, however, varies greatly among taxa and species' foraging strategies, and played an influential role in squamate evolution. In lizards, 'Scleroglossa' evolved a state where species use chemical cues to search for food (active foragers), whereas 'Iguania' retained the use of vision to hunt prey (ambush foragers). However, such strict dichotomy is flawed as shifts in foraging modes have occurred in all clades. Here, we attempted to disentangle effects of foraging ecology from phylogenetic trait conservatism as leading cause of the disparity in chemosensory investment among squamates. To do so, we used species' tongue-flick rate (TFR) in the absence of ecological relevant chemical stimuli as a proxy for its fundamental level of chemosensory investigation, that is baseline TFR. Based on literature data of nearly 100 species and using phylogenetic comparative methods, we tested whether and how foraging mode and diet affect baseline TFR. Our results show that baseline TFR is higher in active than ambush foragers. Although baseline TFRs appear phylogenetically stable in some lizard taxa, that is a consequence of concordant stability of foraging mode: when foraging mode shifts within taxa, so does baseline TFR. Also, baseline TFR is a good predictor of prey chemical discriminatory ability, as we established a strong positive relationship between baseline TFR and TFR in response to prey. Baseline TFR is unrelated to diet. Essentially, foraging mode, not phylogenetic relatedness, drives convergent evolution of similar levels of squamate chemosensory investigation.

  18. Influence of corticosterone on FSH-induced ovarian recrudescence in the lizard Mabuya carinata.

    Science.gov (United States)

    Nijagal, B S; Yajurvedi, H N

    1999-09-01

    Administration of bovine FSH (10 IU/lizard/alternate day for 30 days) in the postbreeding quiescent phase of the ovarian cycle caused a significant increase in the mean number of oogonia and oocytes, the relative weight of the oviduct, and the liver and serum estradiol levels compared to those of controls. In addition, the FSH-treated lizards showed a vitellogenic growth of follicles and development through to preovulatory follicles. However, the administration of corticosterone simultaneously with FSH (10 IU FSH + 40 microgram corticosterone/lizard/alternate day for 30 days) did not result in these changes and the ovaries resembled those of controls. The results indicate the absence of ovarian refractoriness to gonadotropic stimulation during the quiescent phase of the reproductive cycle and inhibition of FSH-induced ovarian recrudescence by corticosterone. It is suggested that corticosterone treatment reduces FSH-induced steroidogenic activity of the ovary, leads to impairment in vitellogenin secretion by the liver, and results as well in the failure of vitellogenic follicular growth in Mabuya carinata.

  19. Evolution of placental specializations in viviparous African and South American lizards.

    Science.gov (United States)

    Flemming, Alexander F; Blackburn, Daniel G

    2003-09-01

    Phylogenetic information offers an important resource in analyses of reproductive diversity, including interpretations of fetal membrane evolution. In this paper, we draw upon ongoing studies of South American and African lizards to consider the value of combining phylogenetic and reproductive evidence in the construction of evolutionary interpretations. South American lizards of the genus Mabuya exhibit several reproductive specializations that are convergent on those of eutherian mammals, including viviparity, long gestation periods, ovulation of tiny eggs, and placental supply of the nutrients for development. Studies of placental morphology and development indicate that New World Mabuya share several other derived features, including chorionic areolae and a "Type IV" epitheliochorial placenta with a villous, mesometrial placentome. Some characteristics of these lizards are shared by two African skinks, M. ivensii and Eumecia anchietae, including minuscule eggs, placentotrophy, an absorptive chorioallantois, and features of the yolk sac. Available evidence is consistent with two explanations: (1) placentotrophy originated in Africa, predating a trans-Atlantic colonization by Mabuya of the New World; and (2) placentotrophy arose two or three separate times among these closely related skinks. As illustrated by analysis of these animals, not only can data on fetal membrane morphology yield phylogenetic information, but phylogenetic evidence in turn provides a valuable way to reconstruct the evolution of fetal membranes in a biogeographic context. When appropriately interpreted, morphological and phylogenetic evidence can be combined to yield robust evolutionary conclusions that avoid the pitfalls of circular reasoning.

  20. Ontogenetic Variation in the Thermal Biology of Yarrow's Spiny Lizard, Sceloporus jarrovii.

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    Gilbert, Anthony L; Lattanzio, Matthew S

    2016-01-01

    Climate change is rapidly altering the way current species interact with their environment to satisfy life-history demands. In areas anticipated to experience extreme warming, rising temperatures are expected to diminish population growth, due either to environmental degradation, or the inability to tolerate novel temperature regimes. Determining how at risk ectotherms, and lizards in particular, are to changes in climate traditionally emphasizes the thermal ecology and thermal sensitivity of physiology of adult members of a population. In this study, we reveal ontogenetic differences in thermal physiological and ecological traits that have been used to anticipate how ectotherms will respond to climate change. We show that the thermal biological traits of juvenile Yarrow's Spiny Lizards (Sceloporus jarrovii) differ from the published estimates of the same traits for adult lizards. Juvenile S. jarrovii differ in their optimal performance temperature, field field-active body temperature, and critical thermal temperatures compared to adult S. jarrovii. Within juvenile S. jarrovii, males and females exhibit differences in field-active body temperature and desiccation tolerance. Given the observed age- and sex-related variation in thermal physiology, we argue that not including physiological differences in thermal biology throughout ontogeny may lead to misinterpretation of patterns of ecological or evolutionary change due to climate warming. Further characterizing the potential for ontogenetic changes in thermal biology would be useful for a more precise and accurate estimation of the role of thermal physiology in mediating population persistence in warmer environments.

  1. The importance of habitat resistance for movement decisions in the common lizard, Lacerta vivipara

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    Zajitschek Susanne RK

    2012-07-01

    Full Text Available Abstract Background Movement behaviour can be influenced by a multitude of biotic and abiotic factors. Here, we investigate the speed of movement in relation to environmental and individual phenotypic properties in subadult common lizards (Lacerta vivipara. We aim to disentangle the importance of substrate, cover, humidity, basking opportunity and individual phenotype on moving tendencies in 12 treatment combinations, at which each lizard was tested. Results We find that movement behaviour depends on the starting conditions, the physical properties of the dispersal corridor, and on the individuals’ phenotype. Specifically, the presence of cover and substrate providing suitable traction in the corridor had positive effects on individual movement decisions. Additionally, we find high phenotypic variation in the propensity to move dependent on the presence of cover. Individual back patterns also strongly affected movement decisions in interaction with the physical properties of the dispersal corridor. Conclusions Our results highlight the importance of understanding the habitat resistance for movement patterns, with humid habitats with covering vegetation providing the best conditions to initiate movement in the common lizard. In addition, population effects, differences in back pattern phenotype and individual plasticity were identified as key parameters influencing movement behaviour.

  2. Directional evolution of stockiness coevolves with ecology and locomotion in lizards.

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    Bergmann, Philip J; Meyers, Jay J; Irschick, Duncan J

    2009-01-01

    Although studied in many taxa, directional macroevolution remains difficult to detect and quantify. We present an approach for detecting directional evolution in subclades of species when relatively few species are sampled, and apply it to studying the evolution of stockiness in Phrynosomatine lizards. Our approach is more sensitive to detecting the tempo of directional evolution than other available approaches. We use ancestral reconstruction and phylogenetic mapping of morphology to characterize the direction and magnitude of trait evolution. We demonstrate a directional trend toward stockiness in horned lizards, but not their sister groups, finding that stockier species tend to have relatively short and wide bodies, and relatively short heads, tails, and limbs. Ornstein-Uhlenbeck models show that the directional trend in horned lizards is due to a shift in selective regime and stabilizing selection as opposed to directional selection. Bayesian evolutionary correlation analyses indicate that stockier species run more slowly and eat a larger proportion of ants. Furthermore, species with larger horns tend to be slower and more ant-specialized. Directional evolution toward a stocky body shape has evolved in conjunction with changes in a suite of traits, representing a complex example of directional macroevolution.

  3. The effect of light on melatonin secretion in the cultured pineal glands of Anolis lizards.

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    Moore, Ashli F; Menaker, Michael

    2011-10-01

    Melatonin, a hormone produced by the pineal gland, is important for regulating circadian rhythms in many animals. Light at night causes an acute suppression of melatonin in nearly all vertebrate species. A previous study found that light failed to suppress melatonin in the lizard Anolis carolinensis. This is a surprising result given that the Anolis pineal gland is intrinsically photosensitive, is a key pacemaker controlling locomotor activity, and can be directly entrained to a light-dark cycle. To find out if the lack of photic suppression is widespread in the Anolis genus, we investigated the acute effects of light on melatonin secretion in five different species of Anolis using flow-through tissue culture. We administered a two-hour pulse of bright light to isolated pineal glands during the night. The results show photic suppression of melatonin in all five Anolis species, but the suppression is weak relative to that seen in other vertebrates. Moreover, Anolis species differ in the magnitude of the effect. These findings are discussed in the context of vertebrate pineal evolution and the ecology of Anolis lizards. Given their extensive phylogenetic and ecological divergence, Anolis lizards provide a promising system for investigating the ecology and evolution of circadian organization.

  4. Life on the rocks: habitat use drives morphological and performance evolution in lizards.

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    Goodman, Brett A; Miles, Donald B; Schwarzkopf, Lin

    2008-12-01

    As a group, lizards occupy a vast array of habitats worldwide, yet there remain relatively few cases where habitat use (ecology), morphology, and thus, performance, are clearly related. The best known examples include: increased limb length in response to increased arboreal perch diameter in anoles and increased limb length in response to increased habitat openness for some skinks. Rocky habitats impose strong natural selection on specific morphological characteristics, which differs from that imposed on terrestrial species, because moving about on inclined substrates of irregular sizes and shapes constrains locomotor performance in predictable ways. We quantified habitat use, morphology, and performance of 19 species of lizards (family Scincidae, subfamily Lygosominae) from 23 populations in tropical Australia. These species use habitats with considerable variation in rock availability. Comparative phylogenetic analyses revealed that occupation of rock-dominated habitats correlated with the evolution of increased limb length, compared to species from forest habitats that predominantly occupied leaf litter. Moreover, increased limb length directly affected performance, with species from rocky habitats having greater sprinting, climbing, and clinging ability than their relatives from less rocky habitats. Thus, we found that the degree of rock use is correlated with both morphological and performance evolution in this group of tropical lizards.

  5. Giant lizards occupied herbivorous mammalian ecospace during the Paleogene greenhouse in Southeast Asia.

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    Head, Jason J; Gunnell, Gregg F; Holroyd, Patricia A; Hutchison, J Howard; Ciochon, Russell L

    2013-07-22

    Mammals dominate modern terrestrial herbivore ecosystems, whereas extant herbivorous reptiles are limited in diversity and body size. The evolution of reptile herbivory and its relationship to mammalian diversification is poorly understood with respect to climate and the roles of predation pressure and competition for food resources. Here, we describe a giant fossil acrodontan lizard recovered with a diverse mammal assemblage from the late middle Eocene Pondaung Formation of Myanmar, which provides a historical test of factors controlling body size in herbivorous squamates. We infer a predominately herbivorous feeding ecology for the new acrodontan based on dental anatomy, phylogenetic relationships and body size. Ranking body masses for Pondaung Formation vertebrates indicates that the lizard occupied a size niche among the larger herbivores and was larger than most carnivorous mammals. Paleotemperature estimates of Pondaung Formation environments based on the body size of the new lizard are approximately 2-5°C higher than modern. These results indicate that competitive exclusion and predation by mammals did not restrict body size evolution in these herbivorous squamates, and elevated temperatures relative to modern climates during the Paleogene greenhouse may have resulted in the evolution of gigantism through elevated poikilothermic metabolic rates and in response to increases in floral productivity.

  6. Foraging behaviors of two sympatric ant species in response to lizard eggs.

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    Huang, Wen-San

    2010-03-01

    The trade-off between behavioral dominance and resource discovery ability represents a mechanism which could facilitate the coexistence of species, but evidence of the existence of this trade-off is limited and is often derived from experiments using artificial bait. In this study, I performed a field experiment to investigate the outcome of potential food competition between an encounter species (Paratrechina longicornis) and an exploitative one (Pheidole taivanensis) and to examine the factors that may explain the behavior of P. taivanensis when obtaining food (lizard eggs) without being attacked by P. longicornis. When P. longicornis was experimentally introduced to eggs occupied by P. taivanensis for 1 day, it displaced P. taivanensis. However, P. longicornis ignored lizard eggs which had been occupied by P. taivanensis for 2 or more days, and did not displace P. taivanensis, because by that time the eggshells had been damaged by P. taivanensis so they could no longer be used by P. longicornis. Eggshells were damaged more quickly by P. taivanensis at Santimen, southwestern Taiwan, than at four other study sites where there were lower intensities of food competition between P. taivanensis and P. longicornis. The displacement percentage was higher at Santimen which had higher ant population densities. The present study shows that lizard eggs may constitute a natural, ephemeral resource for which ants compete in space and time. Comparisons between study sites with and without ants suggest the existence of a trade-off between resource discovery and territorial defense.

  7. Immunocalization of telomerase in cells of lizard tail after amputation suggests cell activation for tail regeneration.

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    Alibardi, L

    2016-02-01

    Tail amputation (autotomy) in most lizards elicits a remarkable regenerative response leading to a new although simplified tail. No information on the trigger mechanism following wounding is known but cells from the stump initiate to proliferate and form a regenerative blastema. The present study shows that telomerases are mainly activated in the nuclei of various connective and muscle satellite cells of the stump, and in other tissues, probably responding to the wound signals. Western blotting detection also indicates that telomerase positive bands increases in the regenerating blastema in comparison to the normal tail. Light and ultrastructural immunocytochemistry localization of telomerase shows that 4-14 days post-amputation in lizards immunopositive nuclei of sparse cells located among the wounded tissues are accumulating into the forming blastema. These cells mainly include fibroblasts and fat cells of the connective tissue and satellite cells of muscles. Also some immature basophilic and polychromatophilic erytroblasts, lymphoblasts and myelocytes present within the Bone Marrow of the vertebrae show telomerase localization in their nuclei, but their contribution to the formation of the regenerative blastema remains undetermined. The study proposes that one of the initial mechanisms triggering cell proliferation for the formation of the blastema in lizards involve gene activation for the production of telomerase that stimulates the following signaling pathways for cell division and migration.

  8. Comparing alignment methods for inferring the history of the new world lizard genus Mabuya (Squamata: Scincidae).

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    Whiting, Alison S; Sites, Jack W; Pellegrino, Katia C M; Rodrigues, Miguel T

    2006-03-01

    The rapid increase in the ability to generate molecular data, and the focus on model-based methods for tree reconstruction have greatly advanced the use of phylogenetics in many fields. The recent flurry of new analytical techniques has focused almost solely on tree reconstruction, whereas alignment issues have received far less attention. In this paper, we use a diverse sampling of gene regions from lizards of the genus Mabuya to compare the impact, on phylogeny estimation, of new maximum likelihood alignment algorithms with more widely used methods. Sequences aligned under different optimality criteria are analyzed using partitioned Bayesian analysis with independent models and parameter settings for each gene region, and the most strongly supported phylogenetic hypothesis is then used to test the hypothesis of two colonizations of the New World by African scincid lizards. Our results show that the consistent use of model-based methods in both alignment and tree reconstruction leads to trees with more optimal likelihood scores than the use of independent criteria in alignment and tree reconstruction. We corroborate and extend earlier evidence for two independent colonizations of South America by scincid lizards. Relationships within South American Mabuya are found to be in need of taxonomic revision, specifically complexes under the names M. heathi, M. agilis, and M. bistriata (sensu, M.T. Rodrigues, Papeis Avulsos de Zoologia 41 (2000) 313).

  9. Pre- and Postcopulatory Traits of Salvator Male Lizards in Allopatry and Sympatry

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    Naretto, Sergio; Blengini, Cecilia S.; Cardozo, Gabriela; Chiaraviglio, Margarita

    2016-01-01

    The reproductive traits of males are under influence of sexual pressures before and after copulation. The strength of sexual selection varies across populations because they undergo varying competition for mating opportunities. Besides intraspecific pressures, individuals seem to be subjected to pressures driven by interspecific interactions in sympatry. Lizards may vary their reproductive strategies through varying sexual characters, body size, gonadal investment, and sperm traits. We evaluated the reproductive traits, involved in pre- and postcopulatory competition, in allopatric and sympatric populations of Salvator lizards. We observed a spatial gradient of male competition among populations, with the following order: allopatric zone of S. rufescens; sympatric zone; and allopatric zone of S. merianae. Accordingly, variation in secondary sexual character, the relative testis mass, and the length of sperm component was observed between allopatry and sympatry in each species, suggesting differences in the investment of reproductive traits. However, we found that these two Salvator species did not differ in secondary sexual characters in sympatry. Interestingly, the trade-off between testes and muscle varied differently from allopatry to sympatry between these Salvator species, suggesting that the influence of social context on reproductive traits investment would affect lizard species differently. PMID:27110428

  10. Correlation between ovarian steroidogenesis and beta-endorphin in the Lizard Uromastyx acanthinura: Immunohistochemical approach.

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    Jean Marie Exbrayat

    2010-01-01

    Full Text Available In Mammals, opioid peptides are involved in various physiological processes including the reproductive function. The knowledge of the distribution of beta-endorphin, one of opioid peptides in Reptiles ovaries is very limited. Therefore, the present study used the lizard ovarian follicles to further elucidate the role of this peptide in steroidogenesis. In Uromastyx acanthinura, the localization of both this peptide and sex steroid hormone was investigated by the immunohistochemical approach. This technique was used to evaluate the distribution of these substances and their relationship. The beta-endorphin is strongly distributed in the granulosa cells and oocyte cytoplasm of the previtellogenic follicles in sexually quiescent lizards (winter when steroidogenesis was interrupted. In spring, the signal became weak, or even absent, in the vitellogenic and previtellogenic follicles. The granulosa cells of the previtellogenic follicles showed an important synthesis of 17beta-estradiol. Females that did not undergo in vitellogenesis in spring showed the same profile than quiescent females of winter. These findings represent the first evidence of the presence of beta-endorphin in the ovary of this lizard. The seasonal variations observed in the reproductive cycle suggest that this opioid peptide is involved in the modulation of seasonal steroidogenesis.

  11. Living in sympatry: The effect of habitat partitioning on the thermoregulation of three Mediterranean lizards.

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    Sagonas, Kostas; Kapsalas, Grigoris; Valakos, Efstratios; Pafilis, Panayiotis

    2017-04-01

    The ability for effective, accurate and precise thermoregulation is of paramount importance for ectotherms. Sympatric lizards often partition their niche and select different microhabitats. These microhabitats, however, usually differ in their thermal conditions and lizards have to adapt their thermoregulation behavior accordingly. Here, we evaluated the impact of habitat partitioning on the thermal biology of three syntopic, congeneric lacertids (Podarcis peloponnesiacus, P. tauricus and P. muralis) from central Peloponnese, Greece. We assessed thermoregulation effectiveness (E) using the three standard thermal parameters: body (Tb), operative (Te) and preferred (Tpref) temperatures. We hypothesized that the microhabitats used by each species would differ in thermal quality. We also predicted that all species would effectively thermoregulate, as they inhabit a thermally challenging mountain habitat. As expected, the partition of the habitat had an effect on the thermoregulation of lizards since microhabitats had different thermal qualities. All three species were effective and accurate thermoregulators but one of them achieved smaller E values as a result of the lower Tb in the field. This discrepancy could be attributed to the cooler (but more benign) thermal microhabitats that this species occupies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Some coccidial parasites of the lizard Amphisbaena alba (Reptilia: Amphisbaenia: Amphisbaenidae

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    Ralph Lainson

    2003-10-01

    Full Text Available Five parasites are described in the lizard Amphisbaena alba (Amphisbaenidae from the state of Pará, North Brazil. Mature oocysts of Choleoeimeria amphisbaenae n. sp., are passed already mature in the faeces. They are ellipsoidal-cylindrical, average 33.7 x 22.8 µm and are devoid of micropyle, oocyst residuum or polar body. The colourless wall is smooth and of 2 layers. The 4 dizoic sporocysts have no Stieda body and average 13 x 9.3 µm. Endogenous stages develop in the epithelial cells of the gall-bladder in the manner described for the genus and may cause extensive tissue damage. Sporulation of Isospora capanemaensis n. sp., is completed 3 days after the oocysts are voided in the faeces. They average 14.8 x 14.5 µm and have no micropyle, oocyst residuum or polar body. The 2 tetrazoic sporocysts are pear-shaped, average 8.6 x 6.6 and have an inconspicuous Stieda body. Endogenous development is in the epithelial cells of the ileum, and heavy infections cause considerable tissue destruction. Multisporocystic oocysts passed in the faeces of one A. alba possibly originated from an invertebrate host ingested by the lizard. A globidium-like cyst in the digestive tract of A. alba measured 105 x 85 µm and contained many hundreds of merozoites. A stained kidney smear of the same lizard revealed the presence of an unidentified parasite producing multinucleate cyst-like stages.

  13. Ontogenic development of spermatids during spermiogenesis in the high altitude bunchgrass lizard (Sceloporus bicanthalis).

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    Rheubert, Justin; Touzinsky, Katherine; Hernández-Gallegos, Oswaldo; Granados-González, Gisela; Gribbins, Kevin

    2012-04-01

    The body of ultrastructural data on spermatid characters during spermiogenesis continues to grow in reptiles, but is still relatively limited within the squamates. This study focuses on the ontogenic events of spermiogenesis within a viviparous and continually spermatogenic lizard, from high altitude in Mexico. Between the months of June and August, testicular tissues were collected from eight spermatogenically active bunchgrass lizards (Sceloporus bicanthalis) from Nevado de Toluca, México. The testicular tissues were processed for transmission electron microscopy and analyzed to access the ultrastructural differences between spermatid generations during spermiogenesis. Interestingly, few differences exist between S. bicanthalis spermiogenesis when compared with what has been described for other saurian squamates. Degrading and coiling membrane structures similar to myelin figures were visible within the developing acrosome that are likely remnants from Golgi body vesicles. During spermiogenesis, an electron lucent area between the subacrosomal space and the acrosomal medulla was observed, which has been observed in other squamates but not accurately described. Thus, we elect to term this region the acrosomal lucent ridge. This study furthers the existing knowledge of spermatid development in squamates, which could be useful in future work on the reproductive systems in high altitude viviparous lizard species.

  14. Evidence for a carotid body homolog in the lizard Tupinambis merianae.

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    Reichert, Michelle N; Brink, Deidre L; Milsom, William K

    2015-01-15

    The homolog to the mammalian carotid body has not yet been identified in lizards. Observational studies and evolutionary history provide indirect evidence for the existence of a chemoreceptor population at the first major bifurcation of the common carotid artery in lizards, but a chemoreceptive role for this area has not yet been definitively demonstrated. We explored this possibility by measuring changes in cardiorespiratory variables in response to focal arterial injections of the hypoxia mimic sodium cyanide (NaCN) into the carotid artery of 12 unanesthetized specimens of Tupinambis merianae. These injections elicited increases in heart rate (f(H); 101±35% increase) and respiratory rate (f(R); 620±119% increase), but not mean arterial blood pressure (MAP). These responses were eliminated by vagal denervation. Similar responses were elicited by injections of the neurotransmitters acetylcholine (ACh) and serotonin (5-HT) but not norepinephrine. Heart rate and respiratory rate increases in response to NaCN could be blocked or reduced by antagonists to ACh (atropine) and/or 5-HT (methysergide). Finally, using immunohistochemistry, we demonstrate the presence of putative chemoreceptive cells immunopositive for the cholinergic cell marker vesicular ACh transporter (VAChT) and 5-HT on internal lattice-like structures at the carotid bifurcation. These results provide evidence in lizards for the existence of dispersed chemoreceptor cells at the first carotid bifurcation in the central cardiovascular area that have similar properties to known carotid body homologs, adding to the picture of chemoreceptor evolution in vertebrates.

  15. A gravid lizard from the Cretaceous of China and the early history of squamate viviparity

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    Wang, Yuan; Evans, Susan E.

    2011-09-01

    Although viviparity is most often associated with mammals, roughly one fifth of extant squamate reptiles give birth to live young. Phylogenetic analyses indicate that the trait evolved more than 100 times within Squamata, a frequency greater than that of all other vertebrate clades combined. However, there is debate as to the antiquity of the trait and, until now, the only direct fossil evidence of squamate viviparity was in Late Cretaceous mosasauroids, specialised marine lizards without modern equivalents. Here, we document viviparity in a specimen of a more generalised lizard, Yabeinosaurus, from the Early Cretaceous of China. The gravid female contains more than 15 young at a level of skeletal development corresponding to that of late embryos of living viviparous lizards. This specimen documents the first occurrence of viviparity in a fossil reptile that was largely terrestrial in life, and extends the temporal distribution of the trait in squamates by at least 30 Ma. As Yabeinosaurus occupies a relatively basal position within crown-group squamates, it suggests that the anatomical and physiological preconditions for viviparity arose early within Squamata.

  16. Allelic expression of mammalian imprinted genes in a matrotrophic lizard, Pseudemoia entrecasteauxii.

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    Griffith, Oliver W; Brandley, Matthew C; Belov, Katherine; Thompson, Michael B

    2016-03-01

    Genomic imprinting is a process that results in the differential expression of genes depending on their parent of origin. It occurs in both plants and live-bearing mammals, with imprinted genes typically regulating the ability of an embryo to manipulate the maternal provision of nutrients. Genomic imprinting increases the potential for selection to act separately on paternally and maternally expressed genes, which increases the number of opportunities that selection can facilitate embryonic control over maternal nutrient provision. By looking for imprinting in an independent matrotrophic lineage, the viviparous lizard Pseudemoia entrecasteauxii (Scincidae), we test the hypothesis that genomic imprinting facilitates the evolution of substantial placental nutrient transport to embryos (matrotrophy). We sequenced transcriptomes from the embryonic component of lizard placentae to determine whether there are parent-of-origin differences in expression of genes that are imprinted in mammals. Of these genes, 19 had sufficiently high expression in the lizard to identify polymorphisms in transcribed sequences. We identified bi-allelic expression in 17 genes (including insulin-like growth factor 2), indicating that neither allele was imprinted. These data suggest that either genomic imprinting has not evolved in this matrotrophic skink or, if it has, it has evolved in different genes to mammals. We outline how these hypotheses can be tested. This study highlights important differences between mammalian and reptile pregnancy and the absence of any shared imprinting genes reflects fundamental differences in the way that pregnancy has evolved in these two lineages.

  17. Controlled preparation of wet granular media reveals limits to lizard burial ability

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    Sharpe, Sarah S.; Kuckuk, Robyn; Goldman, Daniel I.

    2015-07-01

    Many animals move within ground composed of granular media (GM); the resistive properties of such substrates can depend on water content and compaction, but little is known about how such parameters affect locomotion or the physics of drag and penetration. Using apparatus to control compaction of GM, our recent studies of movement in dry GM have revealed locomotion strategies of specialized dry-sand-swimming reptiles. However, these animals represent a small fraction of the diversity and presumed burial strategies of fossorial reptilian fauna. Here we develop a system to create states of wet GM of varying moisture content and compaction in quantities sufficient to study the burial and subsurface locomotion of the Ocellated skink (C. ocellatus), a generalist lizard. X-ray imaging revealed that in wet and dry GM the lizard slowly buried (≈ 30 s) propagating a wave from head to tail, while moving in a start-stop motion. During forward movement, the head oscillated, and the forelimb on the convex side of the body propelled the animal. Although body kinematics and ‘slip’ were similar in both substrates, the burial depth was smaller in wet GM. Penetration and drag force experiments on smooth cylinders revealed that wet GM was ≈ 4× more resistive than dry GM. In total, our measurements indicate that while the rheology of the dry and wet GM differ substantially, the lizard's burial motor pattern is conserved across substrates, while its burial depth is largely constrained by environmental resistance.

  18. Baseline values of immunologic parameters in the lizard Salvator merianae (Teiidae, Squamata

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    Ana Paula Mestre

    2017-05-01

    Full Text Available The genus Salvator is widely distributed throughout South America. In Argentina, the species most abundant widely distributed is Salvator merianae. Particularly in Santa Fe province, the area occupied by populations of these lizards overlaps with areas where agriculture was extended. With the aim of established baseline values for four immunologic biomarkers widely used, 36 tegu lizards were evaluated tacking into account different age classes and both sexes. Total leukocyte counts were not different between age classes. Of the leucocytes count, eosinophils levels were higher in neonates compared with juvenile and adults; nevertheless, the heterophils group was the most prevalent leukocyte in the peripheral blood in all age classes. Lymphocytes, monocytes, heterophils, azurophils and basophils levels did not differ with age. Natural antibodies titres were higher in the adults compared with neonates and juveniles lizards. Lastly, complement system activity was low in neonates compared with juveniles and adults. Statistical analysis within each age group showed that gender was not a factor in the outcomes. Based on the results, we concluded that S. merianae demonstrated age (but not gender related differences in the immune parameters analyzed. Having established baseline values for these four widely-used immunologic biomarkers, ongoing studies will seek to optimize the use of the S. merianae model in future research.

  19. Ontogenetic Variation in the Thermal Biology of Yarrow's Spiny Lizard, Sceloporus jarrovii.

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    Anthony L Gilbert

    Full Text Available Climate change is rapidly altering the way current species interact with their environment to satisfy life-history demands. In areas anticipated to experience extreme warming, rising temperatures are expected to diminish population growth, due either to environmental degradation, or the inability to tolerate novel temperature regimes. Determining how at risk ectotherms, and lizards in particular, are to changes in climate traditionally emphasizes the thermal ecology and thermal sensitivity of physiology of adult members of a population. In this study, we reveal ontogenetic differences in thermal physiological and ecological traits that have been used to anticipate how ectotherms will respond to climate change. We show that the thermal biological traits of juvenile Yarrow's Spiny Lizards (Sceloporus jarrovii differ from the published estimates of the same traits for adult lizards. Juvenile S. jarrovii differ in their optimal performance temperature, field field-active body temperature, and critical thermal temperatures compared to adult S. jarrovii. Within juvenile S. jarrovii, males and females exhibit differences in field-active body temperature and desiccation tolerance. Given the observed age- and sex-related variation in thermal physiology, we argue that not including physiological differences in thermal biology throughout ontogeny may lead to misinterpretation of patterns of ecological or evolutionary change due to climate warming. Further characterizing the potential for ontogenetic changes in thermal biology would be useful for a more precise and accurate estimation of the role of thermal physiology in mediating population persistence in warmer environments.

  20. Intersexual chemo-sensation in a “visually-oriented” lizard, Anolis sagrei

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    Simon Baeckens

    2016-03-01

    Full Text Available While the conspicuous visual displays of anoles have been studied in great depth, the possibility that these lizards may also interact through chemical signalling has received hardly any consideration. In this study, we observed the behaviour of male brown anoles (Anolis sagrei when introduced into an environment previously inhabited by female conspecifics, and compared it to when they were introduced into an untreated environment. The males in our tests exhibited significantly more elaborate display behaviour (i.e., greater number of dewlap extensions and head-nods and a significantly greater number of tongue extrusions while in the cage formerly occupied by females than when placed in the untreated, control cage. The absolute numbers of tongue extrusions, however, were relatively low in comparison to average tongue-flick rates of ‘true’ chemically-oriented lizards. Our results strongly suggest that the males were capable of detecting chemical cues left behind by the females. These observations provide the first evidence of intersexual chemo-sensation in an anole lizard.