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Sample records for monitor lizard rbc

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

    Science.gov (United States)

    Conrad, Jack L; Balcarcel, Ana M; Mehling, Carl M

    2012-01-01

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

    Directory of Open Access Journals (Sweden)

    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.

  3. 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. © 2011 The Author(s).

  4. Unidirectional pulmonary airflow patterns in the savannah monitor lizard.

    Science.gov (United States)

    Schachner, Emma R; Cieri, Robert L; Butler, James P; Farmer, C G

    2014-02-20

    The unidirectional airflow patterns in the lungs of birds have long been considered a unique and specialized trait associated with the oxygen demands of flying, their endothermic metabolism and unusual pulmonary architecture. However, the discovery of similar flow patterns in the lungs of crocodilians indicates that this character is probably ancestral for all archosaurs--the group that includes extant birds and crocodilians as well as their extinct relatives, such as pterosaurs and dinosaurs. Unidirectional flow in birds results from aerodynamic valves, rather than from sphincters or other physical mechanisms, and similar aerodynamic valves seem to be present in crocodilians. The anatomical and developmental similarities in the primary and secondary bronchi of birds and crocodilians suggest that these structures and airflow patterns may be homologous. The origin of this pattern is at least as old as the split between crocodilians and birds, which occurred in the Triassic period. Alternatively, this pattern of flow may be even older; this hypothesis can be tested by investigating patterns of airflow in members of the outgroup to birds and crocodilians, the Lepidosauromorpha (tuatara, lizards and snakes). Here we demonstrate region-specific unidirectional airflow in the lungs of the savannah monitor lizard (Varanus exanthematicus). The presence of unidirectional flow in the lungs of V. exanthematicus thus gives rise to two possible evolutionary scenarios: either unidirectional airflow evolved independently in archosaurs and monitor lizards, or these flow patterns are homologous in archosaurs and V. exanthematicus, having evolved only once in ancestral diapsids (the clade encompassing snakes, lizards, crocodilians and birds). If unidirectional airflow is plesiomorphic for Diapsida, this respiratory character can be reconstructed for extinct diapsids, and evolved in a small ectothermic tetrapod during the Palaeozoic era at least a hundred million years before the

  5. RBC count

    Science.gov (United States)

    ... by kidney disease) RBC destruction ( hemolysis ) due to transfusion, blood vessel injury, or other cause Leukemia Malnutrition Bone ... slight risk any time the skin is broken) Alternative Names Erythrocyte count; Red blood cell count; Anemia - RBC count Images Blood test ...

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

    Directory of Open Access Journals (Sweden)

    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.

  7. RBC nuclear scan

    Science.gov (United States)

    ... 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. using agama lizard as a biomaker in heavy metal pollution monitoring

    African Journals Online (AJOL)

    Oyekunle

    Key words: Agama lizard, environmental pollution, soil, heavy metals, liver, kidney. ... Despite the considerable weight of evidence that exists in favour of the ..... bioaccumulation capacity of heavy metals by the kidney. (59.2 ± 15.3 µg/g) was ...

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

    Science.gov (United States)

    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

  10. RBC micromotors carrying multiple cargos towards potential theranostic applications

    Science.gov (United States)

    Wu, Zhiguang; Esteban-Fernández de Ávila, Berta; Martín, Aída; Christianson, Caleb; Gao, Weiwei; Thamphiwatana, Soracha Kun; Escarpa, Alberto; He, Qiang; Zhang, Liangfang; Wang, Joseph

    2015-08-01

    Red blood cell (RBC)-based micromotors containing both therapeutic and diagnostic modalities are described as a means for potential theranostic applications. In this natural RBC-based multicargo-loaded micromotor system, quantum dots (QDs), anti-cancer drug doxorubicin (DOX), and magnetic nanoparticles (MNPs), were co-encapsulated into RBC micromotors. The fluorescent emission of both QDs and DOX provides direct visualization of their loading inside the RBC motors at two distinct wavelengths. The presence of MNPs within the RBCs allows for efficient magnetic guidance under ultrasound propulsion along with providing the potential for magnetic resonance imaging. The simultaneous encapsulation of the imaging nanoparticles and therapeutic payloads within the same RBC micromotor has a minimal effect upon its propulsion behavior. The ability of the RBC micromotors to transport imaging and therapeutic agents at high speed and spatial precision through a complex microchannel network is also demonstrated. Such ability to load and transport diagnostic imaging agents and therapeutic drugs within a single cell-based motor, in addition to a lower toxicity observed once the drug is encapsulated within the multicargo RBC motor, opens the door to the development of theranostic micromotors that may simultaneously treat and monitor diseases.Red blood cell (RBC)-based micromotors containing both therapeutic and diagnostic modalities are described as a means for potential theranostic applications. In this natural RBC-based multicargo-loaded micromotor system, quantum dots (QDs), anti-cancer drug doxorubicin (DOX), and magnetic nanoparticles (MNPs), were co-encapsulated into RBC micromotors. The fluorescent emission of both QDs and DOX provides direct visualization of their loading inside the RBC motors at two distinct wavelengths. The presence of MNPs within the RBCs allows for efficient magnetic guidance under ultrasound propulsion along with providing the potential for magnetic

  11. RBC micromotors carrying multiple cargos towards potential theranostic applications.

    Science.gov (United States)

    Wu, Zhiguang; Esteban-Fernández de Ávila, Berta; Martín, Aída; Christianson, Caleb; Gao, Weiwei; Thamphiwatana, Soracha Kun; Escarpa, Alberto; He, Qiang; Zhang, Liangfang; Wang, Joseph

    2015-08-28

    Red blood cell (RBC)-based micromotors containing both therapeutic and diagnostic modalities are described as a means for potential theranostic applications. In this natural RBC-based multicargo-loaded micromotor system, quantum dots (QDs), anti-cancer drug doxorubicin (DOX), and magnetic nanoparticles (MNPs), were co-encapsulated into RBC micromotors. The fluorescent emission of both QDs and DOX provides direct visualization of their loading inside the RBC motors at two distinct wavelengths. The presence of MNPs within the RBCs allows for efficient magnetic guidance under ultrasound propulsion along with providing the potential for magnetic resonance imaging. The simultaneous encapsulation of the imaging nanoparticles and therapeutic payloads within the same RBC micromotor has a minimal effect upon its propulsion behavior. The ability of the RBC micromotors to transport imaging and therapeutic agents at high speed and spatial precision through a complex microchannel network is also demonstrated. Such ability to load and transport diagnostic imaging agents and therapeutic drugs within a single cell-based motor, in addition to a lower toxicity observed once the drug is encapsulated within the multicargo RBC motor, opens the door to the development of theranostic micromotors that may simultaneously treat and monitor diseases.

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

    Directory of Open Access Journals (Sweden)

    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. 

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

    Science.gov (United States)

    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.

  14. Communication Signals in Lizards.

    Science.gov (United States)

    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)

  15. Reproductive Medicine in Lizards.

    Science.gov (United States)

    Knotek, Zdenek; Cermakova, Eva; Oliveri, Matteo

    2017-05-01

    Common reproductive problems in captive male lizards are hemipenile plugs in hemipenial sac, unilateral prolapse of hemipenis, or bilateral prolapse of hemipene. Although the orchiectomy is performed as a treatment for testicular disease, the effectiveness in reducing aggressive behavior is unclear. Female captive lizards suffer from cloacal prolapse, preovulatory follicular stasis, or dystocia. The veterinarian must differentiate between the disorders because the treatment differs. Mating, physical, or visual contact with the male stimulates ovulation and prevents preovulatory follicular stasis. Surgical intervention is usually required for dystocia. This article discusses selected procedures and use of ultrasonography and diagnostic endoscopy. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Notes on Scincid Lizards

    NARCIS (Netherlands)

    Brongersma, L.D.

    1942-01-01

    Lygosoma (Sphenomorphus) florense barbouri Dunn (Pl. VI fig. 1) Sphenomorphus florense barbouri Dunn, Amer. Mus. Nov., no. 288, 1927, p. 5, and Dunn, in: Burden, Dragon Lizards of Komodo, 1927, p. 203. 1 ♂, Noil Toko, Timor, 1937, leg. P. F. van West, Mus. Leiden, reg. no. 7033. 5 ♂ ♂, 6 ♀ ♀, Timor,

  17. Experimental evaluation of mechanical and electrical properties of RBC suspensions under flow. Role of RBC deformability

    Czech Academy of Sciences Publication Activity Database

    Antonova, N.; Říha, Pavel; Ivanov, I.

    2010-01-01

    Roč. 25, 3-4 (2010), s. 45-52 ISSN 1313-2458 Institutional research plan: CEZ:AV0Z20600510 Keywords : apparent viscosity * conductivity * RBC suspensions * dextran 70 * PEG 35 000 * glutaraldehyde Subject RIV: BK - Fluid Dynamics

  18. Erythrocyte survival studies in lymphomas : a prognostic appraisal. [/sup 51/Cr-labelled RBC

    Energy Technology Data Exchange (ETDEWEB)

    Sanyal, B; Subrahmanyam, K; Pant, G C [Banaras Hindu Univ. (India). Inst. of Medical Sciences

    1977-08-01

    Erythrocyte survival studies using /sup 51/Cr-labelled RBC's were conducted using 20 patients with Hodgkin's lymphoma and 10 control subjects. Hepatic, splenic, and cardiac areas were monitored for rapid detection of hypersplenism. The findings are discussed in relation to the prognosis of the disease in the patients.

  19. In vivo crossmatching with Tc-99m-RBC's and In-111-oxine-RBC's

    International Nuclear Information System (INIS)

    Marcus, C.S.; Myhre, B.A.; Angulo, M.C.; Salk, R.D.; Essex, C.E.

    1984-01-01

    In vitro crossmatching techniques are often inadequate for patients who have received multiple prior transfusions. These patients usually have multiple antibodies to minor blood groups, not all of which are necessarily important to vivo. It becomes increasingly difficult to obtain appropriate units for transfusion, and often units are used with hopes that a minor group antibody will not be significantly active in vivo. If a transfusion reaction occurs, the unit is stopped. The authors have developed and successfully tested a method whereby 1.5 to 3c of potential donor RBC's are labeled with 25-50 μCi of Tc-99m using the BNL kits. After injection, samples are drawn at 10, 20, 60, and 120 minutes and the RBC survival is measured. If it is desirable to test 2 units simultaneously, the authors use 400 μCi Tc-99m to label an RBC aliquot of one unit and 25 μCi In-111-oxine to label the other; both labeled aliquots are injected together. The method is simple and reliable. In addition to assessing compatibility, the authors may also estimate the % viability of transfused, compatible RBC's by starting with 400 μCi of Tc-99m and multiplying % survival at 24 hours by 1.2. For 24 hr. survival measurements of IN-111-oxine-RBC's, 25 μCi is adequate and no multiplication factor is necessary. The authors have performed 13 in vivo crossmatches, 4 of which were double, in 6 patients. One documented mild transfusion reaction occurred. There were no false positive or false negative results

  20. 99mTc-RBC subtraction scintigraphy

    International Nuclear Information System (INIS)

    Inagaki, Syoichi; Tonami, Syuichi; Yasui, Masakazu; Kuranishi, Makoto; Sugishita, Kouki; Nakamura, Mamoru

    1994-01-01

    Sequential abdominal scintigrams with 99m Tc-labelled red blood cells (RBC) were subtracted for observing a site of gastrointestinal bleeding and calculating the bleeding rate. This method is technically very easy and can detect the site of bleeding with the minimum rate, as low as 0.2 ml/min., in a phantom experiment. In 23 cases with final diagnosis of gastrointestinal bleeding, conventional non-subtraction scintigraphy detected only 30% (7/23), but subtraction scintigraphy detected 61% (14/23). It was concluded that subtraction scintigraphy had higher sensitivity than conventional scintigraphy for early diagnosing bleeding. A combination of non-subtraction and subtraction scintigraphy is recommended to detect a site of gastrointestinal bleeding in a clinical setting. (author)

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

    Science.gov (United States)

    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. Copyright © 2013 Elsevier B.V. All rights reserved.

  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...... of the auditory system, and can be used successfully for step control steering of mobile robots. We extend the work to the continuous steering case, implementing the same model on a Braitenberg vehicle-like robot. The performance of the robot is evaluated in a phonotaxis task. The robot shows strong directional...

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

  5. Lizard reproductive medicine and surgery.

    Science.gov (United States)

    Funk, Richard S

    2002-09-01

    Lizards are a diverse group of some 4470 species, a wide variety of which are now kept in captivity. Interest in captive lizards continues to increase, wild populations seem to be declining in some areas, and herpetoculturists continue to succeed in breeding more species; consequently, veterinarians must understand basic lizard reproductive biology to successfully treat lizard patients with reproductive problems. Just obtaining First Filial Generation (F1) offspring is an accomplishment. But we must look down the road to maintain a species in captivity for succeeding generations, and a lineage may not continue if attention is not given to details of appropriate husbandry and proper reproductive pursuits. One study documents the senescence of lineages in parthenogenetic lizards in captivity apparently associated with husbandry problems [99].

  6. Measurement of blood coagulation with considering RBC aggregation through a microchip-based light transmission aggregometer.

    Science.gov (United States)

    Lim, Hyunjung; Nam, Jeonghun; Xue, Shubin; Shin, Sehyun

    2011-01-01

    Even though blood coagulation can be tested by various methods and techniques, the effect of RBC aggregation on blood coagulation is not fully understood. The present study monitored clot formation in a microchip-based light transmission aggregometer. Citrated blood samples with and without the addition of calcium ion solution were initially disaggregated by rotating a stirrer in the microchip. After abrupt stop of the rotating stirrer, the transmitted light intensity over time was recorded. The syllectogram (light intensity vs. time graph) manifested a rapid increase that is associated with RBC aggregation followed by a decrease that is associated with blood coagulation. The time to reach the peak point was used as a new index of coagulation time (CT) and ranged from 200 to 500 seconds in the present measurements. The CT was inversely proportional to the concentration of fibrinogen, which enhances RBC aggregation. In addition, the CT was inversely proportional to the hematocrit, which is similar to the case of the prothrombin time (PT), as measured by a commercial coagulometer. Thus, we carefully concluded that RBC aggregation should be considered in tests of blood coagulation.

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

    International Nuclear Information System (INIS)

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

    2016-01-01

    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)

  8. 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)

  9. 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.

  10. Towards the ecology and conservation of sand lizard (Lacerta agilis) populations in Southern England

    OpenAIRE

    Fearnley, Helen

    2009-01-01

    The sand lizard (Lacerta agilis) is a rare, elusive and cryptic reptile species of conservation importance in the UK. Knowledge of its ecology and behaviour has limited the development of a reliable and effective methodology for population monitoring; this threatens to compromise conservation effort. The behaviour of sand lizards varies seasonally, with sex and with environmental conditions, none of which are fully understood. This aim of this thesis is to further our ecological knowledge of ...

  11. 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 indirect sound components on the eardrum. The ensuing pressure-difference characteristics generate the highest directionality of any similar-sized terrestrial vertebrate ear. The aim of the present study was to measure the gain of the direct and indirect sound components in three lizard species: Anolis...... sagrei and Basiliscus vittatus (iguanids) and Hemidactylus frenatus (gekkonid) by laser vibrometry, using either free-field sound or a headphone and coupler for stimulation. The directivity of the ear of these lizards is pronounced in the frequency range from 2 to 5 kHz. The directivity is ovoidal...

  12. Strategi Perancangan Mutu Ripe Banana Chip (RBC Berbasis Harapan Konsumen

    Directory of Open Access Journals (Sweden)

    Bambang Herry P

    2016-11-01

    Full Text Available Ripe Banana Chip (RBC, merupakan salah satu jenis kripik yang dibuat dari pisang masak. RBC dapat dilakukan dengan menggunakan teknologi penggorengan vakum (vacum frying ataupun pembekuan (freezing. RBC pisang mas cukup banyak memiliki keunggulan dari nilai gizinya. Produk ini masih belum diketahui tingkat kesesuain mutunya dengan keinginan konsumen dilihat dari aspek fisik ataupun organoleptik. Tujuan penelitian ini agar dapat mengetahui rancangan mutu yang tepat untuk produk RBC pisang mas. Penelitian ini menggunakan tiga metode, diantaranya metode skoring, Customer Satisfaction Index (CSI, dan metode diagram tulang ikan. Hasil dari penelitian, yaitu : warna RBC dengan intensitas 5,56 (kuning dan skor 3,862 (suka ; informasi kemasan dengan intensitas 4,5 (setuju dan skor 3,534 (suka ; kenyamanan kemasan dengan intensitas 8,58 (nyaman dan skor 4,155 (suka ; keamanan kemasan dengan intensitas 8,15 (sangat aman dan skor 4,086 (suka ; ketebalan dengan intensitas 8,31(sangat tebal dan skor 1,604 (sangat tidak suka ; Oil dengan intensitas 4,86 (banyak dan skor 2,483 (tidak suka ; kerenyahan dengan intensitas 7,32 (keras dan skor 2,843 (cukup suka ; Easy of breaking dengan intensitas 5,17 (mudah dipatahkan dan skor 3,158 (cukup suka ; rasa manis dengan intensitas 7,89 (manis dan skor 3,208 (cukup suka ; rasa asam dengan intensitas 4,84 (agak asam dan skor 3,309 (cukup suka. Nilai CSI yang dihasilkan, yaitu sebesar 64% (puas. Strategi untuk meningkatkan mutu RBC diantaranya: mengurangi ukuran ketebalan bahan baku sebelum diproses; lebih dipertimbangkan lagi tingkat kematangan pisang; memberi pengarahan dan motivasi kepada pekerja; melakukan pengawasan saat produksi berlangsung; lebih memperhatikan keseragaman ukuran pisang, dan menggunakan alternatif lain dalam penirisan minyak, misalnya sentrifuse agar keberadaan minyak berkurang.

  13. Placentography with technetium-99m labelled RBC - an evaluation

    International Nuclear Information System (INIS)

    Jayachandran, C.A.; Benjamin, C.S.; Balakrishnan; Narasimhan

    1983-01-01

    During 1979-80, placentography was performed in 40 cases of pregnant women with third trimester bleeding. Random labelled RBC with sup(99m)Tc of activity 2-3 mci was used, depending upon the weight of the patient. In 98% of cases, the isotope finding was confirmed. (author)

  14. Experimental evaluation of mechanical and electrical properties of RBC suspensions under flow. Role of RBC aggregating agent

    Czech Academy of Sciences Publication Activity Database

    Antonova, N.; Říha, Pavel; Ivanov, I.

    2010-01-01

    Roč. 45, 2-4 (2010), s. 253-261 ISSN 1386-0291 R&D Projects: GA AV ČR IAA200600803 Institutional research plan: CEZ:AV0Z20600510 Keywords : apparent viscosity * conductivity * unsteady flow * RBC suspensions * dextrans * PEG Subject RIV: BK - Fluid Dynamics Impact factor: 2.838, year: 2010

  15. Temporal overlap of humans and giant lizards (Varanidae; Squamata) in Pleistocene Australia

    Science.gov (United States)

    Price, Gilbert J.; Louys, Julien; Cramb, Jonathan; Feng, Yue-xing; Zhao, Jian-xin; Hocknull, Scott A.; Webb, Gregory E.; Nguyen, Ai Duc; Joannes-Boyau, Renaud

    2015-10-01

    An obvious but key prerequisite to testing hypotheses concerning the role of humans in the extinction of late Quaternary 'megafauna' is demonstrating that humans and the extinct taxa overlapped, both temporally and spatially. In many regions, a paucity of reliably dated fossil occurrences of megafauna makes it challenging, if not impossible, to test many of the leading extinction hypotheses. The giant monitor lizards of Australia are a case in point. Despite commonly being argued to have suffered extinction at the hands of the first human colonisers (who arrived by 50 ka), it has never been reliably demonstrated that giant monitors and humans temporally overlapped in Australia. Here we present the results of an integrated U-Th and 14C dating study of a late Pleistocene fossil deposit that has yielded the youngest dated remains of giant monitor lizards in Australia. The site, Colosseum Chamber, is a cave deposit in the Mt Etna region, central eastern Australia. Sixteen new dates were generated and demonstrate that the bulk of the material in the deposit accumulated since ca. 50 ka. The new monitor fossil is, minimally, 30 ky younger than the previous youngest reliably dated record for giant lizards in Australia and for the first time, demonstrates that on a continental scale, humans and giant lizards overlapped in time. The new record brings the existing geochronological dataset for Australian giant monitor lizards to seven dated occurrences. With such sparse data, we are hesitant to argue that our new date represents the time of their extinction from the continent. Rather, we suspect that future fossil collecting will yield new samples both older and younger than 50 ka. Nevertheless, we unequivocally demonstrate that humans and giant monitor lizards overlapped temporally in Australia, and thus, humans can only now be considered potential drivers for their extinction.

  16. DNA damage and micronuclei in parthenogenetic and bisexual Darevskia rock lizards from the areas with different levels of soil pollution.

    Science.gov (United States)

    Simonyan, Anna; Hovhannisyan, Galina; Sargsyan, Anzhela; Arakelyan, Marine; Minasyan, Seyran; Aroutiounian, Rouben

    2018-06-15

    Natural species are widely used as indicator organisms to estimate of the impact of environmental pollution. Here we present the results of first study of a reliability of parthenogenetic Darevskia аrmeniaca and bisexual Darevskia raddei rock lizards as sentinels for monitoring of environmental genotoxicity. The comet assay and micronucleus test were applied to the lizards sampled in six areas in Armenia and Artsakh with different levels of soil contamination. The results obtained showed a clear relationship between the pollution level of lizards' habitats and the frequency of DNA damage in the comet assay. Low baseline frequency of micronuclei in D. аrmeniaca and D. raddei, however, makes this parameter ineffective for environmental genotoxicity evaluation. The parthenogenetic lizards D. аrmeniaca showed higher sensitivity toward genotoxic pollutions compared with bisexual D. raddei living in the same environment. The correlations between soil content of heavy metals Cr, Cu, Zn, Mo, Pb and DNA damage in D. аrmeniaca and between Cu, As, Mo, Pb and DNA damage in D. raddei were revealed. Overall, the lizards D. raddei and D. аrmeniaca appeared to be sensitive species in detecting soil pollution in natural environment. The application of the comet assay in Darevskia lizard species can be considered as a more appropriate method than a micronucleus test. The use of parthenogenetic lizards D. аrmeniaca as bioindicator will permit to assess the environmental genotoxicity independent of the genetic polymorphism of bisexual species. Copyright © 2018. Published by Elsevier Inc.

  17. Detection of Borrelia burgdorferi DNA in Lizards from Southern Maryland

    OpenAIRE

    SWANSON, KATHERINE I.; NORRIS, DOUGLAS E.

    2007-01-01

    Lizards serve as hosts for Ixodes ticks in the western and southeastern United States and may affect the transmission cycles of Borrelia burgdorferi in these regions. In Maryland, the role of lizards in the maintenance and transmission cycle of this pathogen has not been examined. We tested 29 lizards (Sceloporus undulatus and Eumeces spp.) and 21 ticks from these lizards for the presence of B. burgdorferi. Eight lizards were positive by polymerase chain reaction (PCR) for at least one B. bur...

  18. The hematology of captive Bobtail lizards (Tiliqua rugosa): blood counts, light microscopy, cytochemistry, and ultrastructure.

    Science.gov (United States)

    Moller, Cheryl A; Gaál, Tibor; Mills, Jennifer N

    2016-12-01

    Bobtail lizards (Tiliqua rugosa) are native to Australia. The only previous study on the hematology of this species documented just 6 animals. The aims of this study were to characterize the light microscopy, ultrastructure and cytochemistry of blood cells, and evaluate CBCs of captive Bobtail lizards. Over 2 consecutive summers, heparinized venous blood was collected from the ventral coccygeal vein of 46 clinically healthy, captive indoor- or outdoor-housed adult Bobtails. Complete blood cell counts and smear evaluations were performed, and cytochemical stains and transmission electron microscopy were used to further characterize blood cells. The eosinophils of this species were uniformly vacuolated: a unique feature not previously reported in reptiles. Heterophils were the predominant leukocyte, with fewer lymphocytes, azurophilic and nonazurophilic monocytes, occasional eosinophils, and basophils. Thrombocytes were frequently clumped. Slight polychromasia (0-15% of erythrocytes) was typically present. Hemogregarine parasites were seen on some smears. The range of CBC results was often wide. The PCV ranged from 11% to 38%. Total plasma proteins by refractometry were between 3.5 and 7.8 g/dL. Hemoglobin ranged between 2.6 and 12.6 g/dL by the modified hemoglobin-hydroxylamine method. Manual RBC count was 0.35-1.27 × 10 6 /μL, and WBC count was 2.86-22.66 × 10 3 /μL. Bobtail lizards housed outdoors had lower PCVs than indoor-housed animals. Bobtails with hemogregarine infections had lower PCVs than noninfected lizards. Ranges for CBC data were often very wide, influenced by preanalytic and analytic factors. Hemogregarine infection is associated with a decreased PCV, suggesting that some hemogregarine species are pathogenic in this population. © 2016 American Society for Veterinary Clinical Pathology.

  19. 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.

  20. 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

  1. Effect of Processing and Storage on RBC function in vivo

    Science.gov (United States)

    Doctor, Allan; Spinella, Phil

    2012-01-01

    Red Blood Cell (RBC) transfusion is indicated to improve oxygen delivery to tissue, and for no other purpose. We have come to appreciate that donor RBCs are fundamentally altered during processing and storage, in a fashion that both impairs oxygen transport efficacy and introduces additional risk by perturbing both immune and coagulation systems. The protean biophysical and physiologic changes in RBC function arising from storage are termed the ‘storage lesion’; many have been understood for some time; for example, we know that the oxygen affinity of stored blood rises during the storage period1 and that intracellular allosteric regulators, notably 2,3-bisphosphoglyceric acid (DPG) and ATP, are depleted during storage. Our appreciation of other storage lesion features has emerged with improved understanding of coagulation, immune and vascular signaling systems. Herein we review key features of the ‘storage lesion’. Additionally, we call particular attention to the newly appreciated role of RBCs in regulating linkage between regional blood flow and regional O2 consumption by regulating the bioavailability of key vasoactive mediators in plasma, as well as discuss how processing and storage disturbs this key signaling function and impairs transfusion efficacy. PMID:22818545

  2. Unique structural features facilitate lizard tail autotomy.

    Science.gov (United States)

    Sanggaard, Kristian W; Danielsen, Carl Chr; Wogensen, Lise; Vinding, Mads S; Rydtoft, Louise M; Mortensen, Martin B; Karring, Henrik; Nielsen, Niels Chr; Wang, Tobias; Thøgersen, Ida B; Enghild, Jan J

    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 of Gekko gecko was pre-severed at distinct sites and that its structural integrity depended on the adhesion between these segments.

  3. Unique structural features facilitate lizard tail autotomy

    DEFF Research Database (Denmark)

    Sanggaard, Kristian W; Danielsen, Carl Chr; Wogensen, Lise

    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...

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

    Directory of Open Access Journals (Sweden)

    Mehregan Ebrahimi

    Full Text Available 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.

  5. Conservation of sex chromosomes in lacertid lizards

    Czech Academy of Sciences Publication Activity Database

    Rovatsos, M.; Vukič, J.; Altmanová, M.; Johnson Pokorná, Martina; Moravec, J.; Kratochvíl, L.

    2016-01-01

    Roč. 25, č. 13 (2016), s. 3120-3126 ISSN 0962-1083 Institutional support: RVO:67985904 Keywords : lizards * molecular sex ing * reptiles * sex chromosomes Subject RIV: EG - Zoology Impact factor: 6.086, year: 2016

  6. Accurate measurement of peripheral blood mononuclear cell concentration using image cytometry to eliminate RBC-induced counting error.

    Science.gov (United States)

    Chan, Leo Li-Ying; Laverty, Daniel J; Smith, Tim; Nejad, Parham; Hei, Hillary; Gandhi, Roopali; Kuksin, Dmitry; Qiu, Jean

    2013-02-28

    Peripheral blood mononuclear cells (PBMCs) have been widely researched in the fields of immunology, infectious disease, oncology, transplantation, hematological malignancy, and vaccine development. Specifically, in immunology research, PBMCs have been utilized to monitor concentration, viability, proliferation, and cytokine production from immune cells, which are critical for both clinical trials and biomedical research. The viability and concentration of isolated PBMCs are traditionally measured by manual counting with trypan blue (TB) using a hemacytometer. One of the common issues of PBMC isolation is red blood cell (RBC) contamination. The RBC contamination can be dependent on the donor sample and/or technical skill level of the operator. RBC contamination in a PBMC sample can introduce error to the measured concentration, which can pass down to future experimental assays performed on these cells. To resolve this issue, RBC lysing protocol can be used to eliminate potential error caused by RBC contamination. In the recent years, a rapid fluorescence-based image cytometry system has been utilized for bright-field and fluorescence imaging analysis of cellular characteristics (Nexcelom Bioscience LLC, Lawrence, MA). The Cellometer image cytometry system has demonstrated the capability of automated concentration and viability detection in disposable counting chambers of unpurified mouse splenocytes and PBMCs stained with acridine orange (AO) and propidium iodide (PI) under fluorescence detection. In this work, we demonstrate the ability of Cellometer image cytometry system to accurately measure PBMC concentration, despite RBC contamination, by comparison of five different total PBMC counting methods: (1) manual counting of trypan blue-stained PBMCs in hemacytometer, (2) manual counting of PBMCs in bright-field images, (3) manual counting of acetic acid lysing of RBCs with TB-stained PBMCs, (4) automated counting of acetic acid lysing of RBCs with PI-stained PBMCs

  7. The clinical sequence of hematological effects in the lizard Uromastix hardwickii subjected to gamma radiation

    International Nuclear Information System (INIS)

    Ahmad, M.; Taqawi, I.H.

    1979-01-01

    Changes of the peripheral RBC levels in the lizard Uromastix hardwickii were studied for a period of six weeks following exposure to 0.774 C/kg, 0.903 C/kg, and 1.032 C/kg gamma rays. The recovery in erythrocyte count was more rapid after exposure to 0.774 C/kg than to 0.903 C/kg. New red cells started appearing in the circulation from the 4th weeks in 0.774 C/kg and the 6th week postradiation in 0.903 C/kg. Anemia developed more severely following a dose of 1.032 C/kg. (author)

  8. The medical care of iguanas and other common pet lizards.

    Science.gov (United States)

    Barten, S L

    1993-11-01

    The majority of health problems in captive lizards result from improper diets, caging, and environmental conditions. This article discusses recommended husbandry and management techniques. A clinical approach to evaluating the health status of lizards, including assessing patient history, physical examination, clinical pathology, anesthesia, and surgery, is reviewed. Common health maladies of captive lizards are discussed, and rapid diagnosis and treatment are emphasized.

  9. Unique structural features facilitate lizard tail autotomy.

    Directory of Open Access Journals (Sweden)

    Kristian W Sanggaard

    Full Text Available 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 of Gekko gecko was pre-severed at distinct sites and that its structural integrity depended on the adhesion between these segments.

  10. Perpetuation of the Lyme Disease Spirochete Borrelia lusitaniae by Lizards

    Science.gov (United States)

    Richter, Dania; Matuschka, Franz-Rainer

    2006-01-01

    To determine whether the Lyme disease spirochete Borrelia lusitaniae is associated with lizards, we compared the prevalence and genospecies of spirochetes present in rodent- and lizard-associated ticks at a site where this spirochete frequently infects questing ticks. Whereas questing nymphal Ixodes ricinus ticks were infected mainly by Borrelia afzelii, one-half of the infected adult ticks harbored B. lusitaniae at our study site. Lyme disease spirochetes were more prevalent in sand lizards (Lacerta agilis) and common wall lizards (Podarcis muralis) than in small rodents. Although subadult ticks feeding on rodents acquired mainly B. afzelii, subadult ticks feeding on lizards became infected by B. lusitaniae. Genetic analysis confirmed that the spirochetes isolated from ticks feeding on lizards are members of the B. lusitaniae genospecies and resemble type strain PotiB2. At our central European study site, lizards, which were previously considered zooprophylactic for the agent of Lyme disease, appear to perpetuate B. lusitaniae. PMID:16820453

  11. 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.

  12. 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.

  13. Molecular cloning of RBCS genes in Selaginella and the evolution of the rbcS gene family

    Directory of Open Access Journals (Sweden)

    Wang Bo

    2015-01-01

    Full Text Available Rubisco small subunits (RBCS are encoded by a nuclear rbcS multigene family in higher plants and green algae. However, owing to the lack of rbcS sequences in lycophytes, the characteristics of rbcS genes in lycophytes is unclear. Recently, the complete genome sequence of the lycophyte Selaginella moellendorffii provided the first insight into the rbcS gene family in lycophytes. To understand further the characteristics of rbcS genes in other Selaginella, the full length of rbcS genes (rbcS1 and rbcS2 from two other Selaginella species were isolated. Both rbcS1 and rbcS2 genes shared more than 97% identity among three Selaginella species. RBCS proteins from Selaginella contained the Pfam RBCS domain F00101, which was a major domain of other plant RBCS proteins. To explore the evolution of the rbcS gene family across Selaginella and other plants, we identified and performed comparative analysis of the rbcS gene family among 16 model plants based on a genome-wide analysis. The results showed that (i two rbcS genes were obtained in Selaginella, which is the second fewest number of rbcS genes among the 16 representative plants; (ii an expansion of rbcS genes occurred in the moss Physcomitrella patens; (iii only RBCS proteins from angiosperms contained the Pfam PF12338 domains, and (iv a pattern of concerted evolution existed in the rbcS gene family. Our study provides new insights into the evolution of the rbcS gene family in Selaginella and other plants.

  14. The study of x-ray photo-electron spectroscopy of 99mTc-RBC

    International Nuclear Information System (INIS)

    Song Chunyi

    1994-01-01

    99m Tc-RBC are widely used as visualization agents for a blood pool. In this research 99m Tc-RBC was prepared by in vivo labeling. The chemical state and changes of 99m Tc atoms in 99m Tc-RBC was determined by x-ray photo-electron spectroscopy (XPS). The stability of 99m Tc-RBC is best shown by the determination of XPS at one hour or at two hours after labeling. There are two ways of coordination of bonding of RBC and 99m Tc: One is the coordination of 99m Tc with the oxygen atom which carries a negative charge of the carboxyl radical on the polypeptide bond, the other is the coordination of 99m Tc with a sulfur atom which caries the negative charge of cysteine. From the E b value of 99m Tc-RBC 99m Tc 3d5/2, it can be inferred that 99m Tc of 99m Tc-RBC is less than a trivalent. At the same time, the results of the determination by XPS with the compounds containing 99 TcO 4 - , 99 Tc(V), 99 Tc(IV) and 99 Tc(III) show that the chemical shift is lowered as the reduction state is lowered. Experimental results coincide with theoretical inferences

  15. 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.

  16. Quantity Discrimination in Trained Lizards (Podarcis sicula

    Directory of Open Access Journals (Sweden)

    Maria Elena Miletto Petrazzini

    2018-03-01

    Full Text Available Quantitative abilities have been reported in many animal species. Two main methods have been extensively used: spontaneous choice tests and training procedures. A recent study showed that ruin lizards are capable of spontaneously discriminating between the surface area of two food items of different size, but failed when food was presented in sets of discrete items differing in number. In the present study, we used a training procedure to further investigate quantitative abilities in ruin lizards. Subjects were presented with two sets of yellow disks differing either in number (Experiment 1 or in area (Experiment 2 and were trained on different discriminations of increasing difficulty (1 vs. 4, 2 vs. 4, and 2 vs. 3. Results showed that lizards were more accurate in discriminating sets of discrete items differing in number than the area of two individual items, in contrast to what had earlier been observed in spontaneous choice tests. Although we cannot exclude other factors that affected the performance of ruin lizards, the poor accuracy here observed in both experiments might reflect a true limit in lizards’ quantitative abilities.

  17. 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.

  18. 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 th...... range is reviewed in the light of current theories of sound localization....

  19. Diets Alter the Gut Microbiome of Crocodile Lizards

    Directory of Open Access Journals (Sweden)

    Hai-Ying Jiang

    2017-10-01

    Full Text Available The crocodile lizard is a critically endangered reptile, and serious diseases have been found in this species in recent years, especially in captive lizards. Whether these diseases are caused by changes in the gut microbiota and the effect of captivity on disease remains to be determined. Here, we examined the relationship between the gut microbiota and diet and disease by comparing the fecal microbiota of wild lizards with those of sick and healthy lizards in captivity. The gut microbiota in wild crocodile lizards was consistently dominated by Proteobacteria (∼56.4% and Bacteroidetes (∼19.1%. However, the abundance of Firmicutes (∼2.6% in the intestine of the wild crocodile lizards was distinctly lower than that in other vertebrates. In addition, the wild samples from Guangdong Luokeng Shinisaurus crocodilurus National Nature Reserve also had a high abundance of Deinococcus–Thermus while the wild samples from Guangxi Daguishan Crocodile Lizard National Nature Reserve had a high abundance of Tenericutes. The gut microbial community in loach-fed crocodile lizards was significantly different from the gut microbial community in the earthworm-fed and wild lizards. In addition, significant differences in specific bacteria were detected among groups. Notably, in the gut microbiota, the captive lizards fed earthworms resulted in enrichment of Fusobacterium, and the captive lizards fed loaches had higher abundances of Elizabethkingia, Halomonas, Morganella, and Salmonella, all of which are pathogens or opportunistic pathogens in human or other animals. However, there is no sufficient evidence that the gut microbiota contributes to either disease A or disease B. These results provide a reference for the conservation of endangered crocodile lizards and the first insight into the relationship between disease and the gut microbiota in lizards.

  20. RBC-choline: changes by lithium and relation to prophylactic response

    International Nuclear Information System (INIS)

    Haag, M.; Haag, H.; Eisenried, F.; Greil, W.

    1984-01-01

    Red blod cell (RBC)- and plasma-choline levels were measured in patients on lithium (n=96), antidepressants (n=32) and neuroleptics (n=51) and in 25 healthy drug-free controls. Lithium patients exhibited highly increased RBC- and slightly increased plasma-choline levels compared with controls (P<0.001 and P<0.05, respectively); the choline ratio (RBC-/plasma-choline) was elevated almost to the same extent as RBC-choline (P<0.001). With antidepressants RBC-choline and choline ratios were slightly reduced (P<0.05), whereas neuroleptics showed no effect on choline levels. 79% of lithium patients were responders (reduction in hospitalizations with lithium) 21% were non-responders (no reduction or increase in hospitalizations). Choline ratio exhibited a significant relation to prophylactic lithium response, but lithium ratio did not. The percentage of non-responders was significantly higher in patients with a choline ratio exceeding 100 than in patients with a choline ratio below this cut-off (P<0.01). Thus, the increase of RBC-choline and choline ratios appears to be an effect specific for lithium and might be related to the outcome of lithium prophylaxis. (author)

  1. Isolation, expression and characterization of rbcL gene from Ulva prolifera J. Agardh (Ulvophyceae, Chlorophyta)

    Science.gov (United States)

    Shao, Zhanru; Li, Wei; Guo, Hui; Duan, Delin

    2015-12-01

    Ulva prolifera is a typical green alga in subtidal areas and can grow tremendously fast. A highly efficient Rubisco enzyme which is encoded by UpRbcL gene may contribute to the rapid growth. In this study, the full-length UpRbcL open reading frame (ORF) was identified, which encoded a protein of 474 amino acids. Phylogenetic analysis of UpRbcL sequences revealed that Chlorophyta had a closer genetic relationship with higher plants than with Rhodophyta and Phaeophyta. The two distinct residues (aa11 and aa91) were presumed to be unique for Rubisco catalytic activity. The predicted three-dimensional structure showed that one α/β-barrel existed in the C-terminal region, and the sites for Mg2+ coordination and CO2 fixation were also located in this region. Gene expression profile indicated that UpRbcL was expressed at a higher level under light exposure than in darkness. When the culture temperature reached 35°C, the expression level of UpRbcL was 2.5-fold lower than at 15°C, and the carboxylase activity exhibited 13.8-fold decrease. UpRbcL was heterologously expressed in E. coli and was purified by Ni2+ affinity chromatography. The physiological and biochemical characterization of recombinant Rubisco will be explored in the future.

  2. Experimental evaluation of mechanical and electrical properties of RBC suspensions in Dextran and PEG under flow II. Role of RBC deformability and morphology

    Czech Academy of Sciences Publication Activity Database

    Antonova, N.; Říha, Pavel; Ivanov, I.; Gluhcheva, Y.

    2011-01-01

    Roč. 49, 1-4 (2011), s. 441-450 ISSN 1386-0291 Institutional research plan: CEZ:AV0Z20600510 Keywords : RBC suspensions * conductivity * Dextran 70 * Polyethylene glycol 35 000 (PEG) Subject RIV: BK - Fluid Dynamics Impact factor: 3.398, year: 2011

  3. Experimental evaluation of mechanical and electrical properties of RBC suspensions in Dextran and PEG under flow II. Role of RBC deformability and morphology

    Czech Academy of Sciences Publication Activity Database

    Antonova, N.; Říha, Pavel; Ivanov, I.; Gluhcheva, Y.

    2011-01-01

    Roč. 49, 1-4 (2011), s. 441-450 ISSN 1386-0291 Institutional research plan: CEZ:AV0Z20600510 Keywords : RBC suspensions * conductivity * Dextran 70 * Polyethylene glycol 35 000 ( PEG ) Subject RIV: BK - Fluid Dynamics Impact factor: 3.398, year: 2011

  4. 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.

  5. 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.

  6. 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.

  7. Diagnostic Imaging in Snakes and Lizards

    OpenAIRE

    Banzato , Tommaso

    2013-01-01

    The increasing popularity of snakes and lizards as pets has led to an increasing demand of specialised veterinary duties in these animals. Diagnostic imaging is often a fundamental step of the clinical investigation. The interpretation of diagnostic images is complex and requires a broad knowledge of anatomy, physiology and pathology of the species object of the clinical investigation. Moreover, in order to achieve a correct diagnosis, the comparison between normal and abnormal diagnostic im...

  8. 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.

  9. Red blood cell (RBC) suspensions in confined microflows: Pressure-flow relationship.

    Science.gov (United States)

    Stauber, Hagit; Waisman, Dan; Korin, Netanel; Sznitman, Josué

    2017-10-01

    Microfluidic-based assays have become increasingly popular to explore microcirculation in vitro. In these experiments, blood is resuspended to a desired haematocrit level in a buffer solution, where frequent choices for preparing RBC suspensions comprise notably Dextran and physiological buffer. Yet, the rational for selecting one buffer versus another is often ill-defined and lacks detailed quantification, including ensuing changes in RBC flow characteristics. Here, we revisit RBC suspensions in microflows and attempt to quantify systematically some of the differences emanating between buffers. We measure bulk flow rate (Q) of RBC suspensions, using PBS- and Dextran-40, as a function of the applied pressure drop (ΔP) for two hematocrits (∼0% and 23%). Two distinct microfluidic designs of varying dimensions are employed: a straight channel larger than and a network array similar to the size of individual RBCs. Using the resulting pressure-flow curves, we extract the equivalent hydrodynamic resistances and estimate the relative viscosities. These efforts are a first step in rigorously quantifying the influence of the 'background' buffer on RBC flows within microfluidic devices and thereby underline the importance of purposefully selecting buffer suspensions for microfluidic in vitro assays. Copyright © 2017. Published by Elsevier Ltd.

  10. Preoperative diagnosis of orbital cavernous hemangioma: a 99mTc-RBC SPECT study.

    Science.gov (United States)

    Burroni, Luca; Borsari, Giulia; Pichierri, Patrizia; Polito, Ennio; Toscano, Olga; Grassetto, Gaia; Al-Nahhas, Adil; Rubello, Domenico; Vattimo, Angelo Giuseppe

    2012-11-01

    This study aimed to describe 99mTc-labeled RBC scintigraphy as a diagnostic method for orbital cavernous hemangiomas and to evaluate this diagnostic tool according to surgical outcomes. Fifty-five patients with clinical and radiological (US, CT, and/or MRI) suspicion of unilateral cavernous hemangioma of the orbit underwent 99mTc-RBC SPECT study.Qualitative and semiquantitative evaluations were performed, and results were statistically analyzed. SPECT images showed focal uptake in the orbital mass in 36 of 55 patients. Nineteen patients had a negative scintigraphic pattern, with concordance of early and late absence of uptake of 99mTc-RBC.Our procedure showed 100% sensitivity and 88.9% specificity for the diagnosis of orbital cavernous hemangioma, with a positive predictive value of 90.9% and a negative predictive value of 100%. 99mTc-RBC imaging is safe, easy to perform, and highly accurate in providing adequate clinical and surgical management. As a noninvasive and highly specific method for diagnosing orbital hemangioma, 99mTc-RBC scintigraphy can avoid more invasive imaging or biopsy.

  11. 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.

  12. Agama lizard: A potential biomarker of environmental heavy metal ...

    African Journals Online (AJOL)

    In this study, the suitability of Agama lizard as a biomarker in assessing environmental pollution levels of arsenium (As), barium (Ba), cadmium (Cd), copper (Cu), manganese (Mn), lead (Pb) and zinc (Zn) was investigated. Samples of top soil and agama lizards were taken from five sites within a university community in ...

  13. 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...

  14. Observations on sexual dimorphism and social structure in the lizard ...

    African Journals Online (AJOL)

    Angolosaurus skoogi is a large, herbivorous lizard of the northern Namib dune sea. Adults are sexually dimorphic in body size and colouration and these differences may be related to social organization. Whether the observed dimorphism is a result of the mating system, as is the case with several other herbivorous lizards, ...

  15. Tc-99m Labeled Red Blood Cell by Ultra Tag RBC Kit in Patients Suspected of Gastrointestinal Bleeding

    International Nuclear Information System (INIS)

    Pusuwan, Pawana; Leaungwutiwong, Suraphong; Tocharoenchai, Chiraporn; Chaiwatanarat, Tawatchai; Sirisatipoch, Sasitorn; Rajadara, Samart; Naktong, Thanyada; Thanyarak, Sucheera

    2001-06-01

    Twenty patients suspected of gastrointestinal bleeding who underwent Tc-99m labeled red blood cell (RBC) by ultraTag RBC kit at Division of Nuclear Medicine, Bumrungrad Hospital between January 2000 and December 2002 were studied. The histories of patients together with either endoscopic results or angiographic findings or pathological reports were used as gold standards. Two by Two decision matrix was used for data analysis and the sensitivity together with specificity were calculated. The results show that the sensitivity and specificity of Tc-99m labeled RBC by ultraTag RBC kit are 87.5% and 91.7%, respectively. We conclude that Tc-99m labeled RBC by ultraTag RBC kit gives high percentages of sensitivity and specificity. Moreover, the image quality is improved because of the absence of free Tc-99m pertechnetate uptake in the stomach in all patients

  16. 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.

  17. 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.

  18. 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

    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....... Compared to before transfusion, patients had slightly reduced coagulability 1 h after RBC transfusion, assessed by TEG. However, transfusion of older RBC products (>14 days) was associated with increased coagulability (all P level of syndecan-1 increased slightly 24 h after transfusion (median....... The changes observed were small to moderate and the clinical relevance of these findings should be investigated in larger studies....

  19. Estimation of adult and neonatal RBC lifespans in anemic neonates using RBCs labeled at several discrete biotin densities.

    Science.gov (United States)

    Kuruvilla, Denison J; Widness, John A; Nalbant, Demet; Schmidt, Robert L; Mock, Donald M; An, Guohua; Veng-Pedersen, Peter

    2017-06-01

    Prior conclusions that autologous neonatal red blood cells (RBC) have substantially shorter lifespans than allogeneic adult RBCs were not based on direct comparison of autologous neonatal vs. allogeneic adult RBCs performed concurrently in the same infant. Biotin labeling of autologous neonatal RBCs and allogeneic adult donor RBCs permits concurrent direct comparison of autologous vs. allogeneic RBC lifespan. RBCs from 15 allogeneic adult donors and from 15 very-low-birth-weight (VLBW) neonates were labeled at separate biotin densities and transfused simultaneously into the 15 neonates. Two mathematical models that account for the RBC differences were employed to estimate lifespans for the two RBC populations. Mean ± SD lifespan for adult allogeneic RBC was 70.1 ± 19.1 d, which is substantially shorter than the 120 d lifespan of both autologous and adult allogeneic RBC in healthy adults. Mean ± SD lifespan for neonatal RBC was 54.2 ± 11.3 d, which is only about 30% shorter than that of the adult allogeneic RBCs. This study provides evidence that extrinsic environmental factors primarily determine RBC survival (e.g., small bore of the capillaries of neonates, rate of oxygenation/deoxygenation cycles) rather than factors intrinsic to RBC.

  20. Time dependent variation of human blood conductivity as a method for an estimation of RBC aggregation

    Czech Academy of Sciences Publication Activity Database

    Antonova, N.; Říha, Pavel; Ivanov, I.

    2008-01-01

    Roč. 39, č. 1 (2008), s. 69-78 ISSN 1386-0291 Institutional research plan: CEZ:AV0Z20600510 Keywords : RBC aggregation * blood conductivity * low shear rate viscometry Subject RIV: BO - Biophysics Impact factor: 1.814, year: 2008

  1. 40 CFR 35.2035 - Rotating biological contractor (RBC) replacement grants.

    Science.gov (United States)

    2010-07-01

    ... treatment works owner, the applicant, its engineers, contractors, equipment manufacturers or suppliers; (b) The RBC failure has significantly increased the project's capital or operation and maintenance costs; (c) The modification/replacement project meets all requirements of EPA's construction grant and other...

  2. A gene phylogeny of the red algae (Rhodophyta) based on plastid rbcL.

    Science.gov (United States)

    Freshwater, D W; Fredericq, S; Butler, B S; Hommersand, M H; Chase, M W

    1994-01-01

    A phylogeny for the Rhodophyta has been inferred by parsimony analysis of plastid rbcL sequences representing 81 species, 68 genera, 38 families, and 17 orders of red algae; rbcL encodes the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase. Levels of sequence divergence among species, genera, and families are high in red algae, typically much greater than those reported for flowering plants. The Rhodophyta traditionally consists of one class, Rhodophyceae, and two subclasses, Bangiophycidae and Florideophycidae. The Bangiophycidae with three orders (Porphyridiales, Compsopogonales, and Bangiales) appears to be polyphyletic, and the Florideophycidae with 17 orders is monophyletic in this study. The current classification of the Florideophycidae based on ultrastructure of pit connections is supported. With the exception of the Rhodogorgonales, which appears to be misplaced, orders with one or two pit-plug cap layers (Hildenbrandiales, Corallinales, Acrochaetiales, Palmanales, Batrachospermales, and Nemaliales) terminate long branches of basal position within Florideophycidae in the most parsimonious rbcL tree. Orders that lack typical cap layers but possess a cap membrane are resolved as a monophyletic clade sister to the Ahnfeltiales. The large order Gigartinales, which is distributed among five rbcL clades, is polyphyletic. Families that possess typical carrageenan in their cell walls are resolved as a terminal clade containing two family complexes centered around the Solieriaceae and Gigartinaceae. PMID:8041781

  3. 77 FR 50487 - Application To Export Electric Energy; RBC Energy Services LP

    Science.gov (United States)

    2012-08-21

    ... DEPARTMENT OF ENERGY [OE Docket No. EA-328-A] Application To Export Electric Energy; RBC Energy... electric energy from the United States to Canada pursuant to section 202(e) of the Federal Power Act (FPA... to transmit electric energy from the United States to Canada as a power marketer for a five-year term...

  4. Rheological and electrical properties of polymeric nanoparticle solutions and their influence on RBC suspensions

    Czech Academy of Sciences Publication Activity Database

    Antonova, N.; Koseva, N.; Kowalczyk, A.; Říha, Pavel; Ivanov, I.

    2014-01-01

    Roč. 24, č. 3 (2014), s. 35190 ISSN 1430-6395 Institutional support: RVO:67985874 Keywords : nanoparticles and RBC suspensions * poly(acrylic acid) * rheology * electrical conductivity Subject RIV: BK - Fluid Dynamics Impact factor: 1.078, year: 2014 http://www.ar.ethz.ch/TMPPDF/24308140293.696/ApplRheol_24_35190.pdf

  5. Development of a kit for RBC labelling with 99mTc and its clinic evaluation

    International Nuclear Information System (INIS)

    Marafuschi, A.M.; Nowotny, G.A.; Palcos, M.C.; Rotta, M. del C.

    1980-01-01

    A kit for labelling red blood cells (RBC) with 99m Tc based on a Tin Pyrophosphate mixture freeze-dried and a saline solution saturated with nitrogen has been prepared for spleen and placenta scanning, circulatory studies and blood volume determinations. The stannous tin is intended to reduce the 99m Tc pertechnetate, obtained either from generators or from solvent extraction, to the appropriate valence state suitable for labelling. The technique is as follows: Add to the heparinized blood sample the Tin-Pyrophosphate mixture dissolved in the saline solution. After five minutes incubation time at room temperature the plasma is discarded by centrifugation. Following the addition of the tracer activity to the separated RBC, the supernatant is discarded after a second centrifugation. Depending on the test to be performed, the RBC are either resuspended in saline solution for blood pool or circulation studies or denaturalized at 49.5 deg C for spleen scanning. The labelling yield (95-88%) and its stability has been checked by in vitro measurements, up to four hours after labelling. The biological distribution and spleen uptake have been determined in rats and rabbits. The developed method proved to be adequate for labelling RBC with good labelling retention. An interesting application is shown in babies with congenital cardiac defects and suspected absence of the spleen, where the scan gave a good image of the existing spleen. (author) [es

  6. 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. Copyright © 2015

  7. Antioxidant activity of citrullus colocynthis pulp extract in the RBC's of alloxan-induced diabetic rats

    International Nuclear Information System (INIS)

    Dallak, M.; Jaliah, B.I.

    2010-01-01

    Previous studies in our laboratory showed that Citrullus colocynthis pulp seedless extract have antihyperglycemic and insulinotropic effects in alloxan induced diabetes. Reactive oxygen species have been implicated in the mechanism of damage of red blood cells and anaemia in diabetic patients. So the current study was carried out to investigate the protective role of citrullus colocynthis against oxidative stress in the RBC's of alloxan induced diabetic rats. Methods: Rats were divided into four groups each of ten rats, the first group was normal non diabetic rats given normal saline orally and was named control group, the second group was diabetic rats given normal saline orally and were named normal saline treated-diabetic rats, the third and fourth group were diabetic rats treated with the pulp extract or glibenclamide (a positive control) orally. Evaluations were made for haematological parameters in the blood and for lipid peroxidation and oxidative stress enzymes activities in the RBC's of all experimental rats. Results: The diabetic rats had a significant decrease (p<0.05) in total erythrocytes count and Packed Cell Volume (PCV) and a normal Haemoglobin (Hb) value in the blood. They also showed decreased levels of Thiobarbituric Acid Reactive Substances (TBARS) and decreased activities of Superoxide Dismutase (SOD) and Catalase (CAT) in the RBC's hemolysate. On other hand, oral administration of citrullus colocynthis or glibenclamide alleviated these altered parameters in the treated rats, they resulted in a significant increase (p<0.05) in the in total erythrocytes count and PCV (Haematocrit) values in the blood and caused a significant decreased levels of TBARS and increased activities of SOD and CAT in the RBC's of those diabetic treated rats when compared to diabetic rats given normal saline. The effect was more profound in citrullus colocynthis treated diabetic rats. Conclusion: Citrullus colocynthis pulp extract possesses a potent antioxidant property

  8. 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.

  9. Phylogeny of Neotropical Cercosaura (Squamata: Gymnophthalmidae) lizards.

    Science.gov (United States)

    Torres-Carvajal, Omar; Lobos, Simón E; Venegas, Pablo J

    2015-12-01

    Among Neotropical lizards, the geographically widespread gymnophthalmid Cercosaura as currently defined includes lowland and highland taxa from Panama to Argentina, with some species occurring in the northern Andes. In this study we analyze three mitochondrial (12S, 16S, ND4) and one nuclear (c-mos) gene using Bayesian methods to clarify the phylogenetic relationships among most species of Cercosaura based on a well-supported phylogenetic hypothesis that also includes a large sample of other taxa within Cercosaurini. The phylogenetic tree obtained in this paper shows that Cercosaura as currently defined is not monophyletic. Two species from the northern Andes (C. dicra and C. vertebralis) are nested within Pholidobolus, which has been formerly recognized as a major radiation along the Andes of Ecuador and Colombia. Therefore, Cercosaura has probably not diversified in the northern Andes, although the phylogenetic position of C. hypnoides from the Andes of Colombia remains unknown. Tree topology and genetic distances support both recognition of C. ocellata bassleri as a distinct species, C. bassleri, and recognition of C. argula and C. oshaughnessyi as two different species. In the interest of promoting clarity and precision regarding the names of clades of gymnophthalmid lizards, we propose a phylogenetic definition of Cercosaura. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. How lizards fly: A novel type of wing in animals.

    Science.gov (United States)

    Dehling, J Maximilian

    2017-01-01

    Flying lizards of the genus Draco are renowned for their gliding ability, using an aerofoil formed by winglike patagial membranes and supported by elongated thoracic ribs. It remains unknown, however, how these lizards manoeuvre during flight. Here, I present the results of a study on the aerial behaviour of Dussumier's Flying Lizard (Draco dussumieri) and show that Draco attaches the forelimbs to the leading edge of the patagium while airborne, forming a hitherto unknown type of composite wing. The attachment of the forelimbs to the patagium suggests that that aerofoil is controlled through movements of the forelimbs. One major advantage for the lizards is that the forelimbs retain their complete range of movement and functionality for climbing and running when not used as a part of the wing. These findings not only shed a new light on the flight of Draco but also have implications for the interpretation of gliding performance in fossil species.

  11. Dietary pathways through lizards of the Alligator Rivers Region

    International Nuclear Information System (INIS)

    James, C.D.; Morton, S.R.; Braithwaite, R.W.; Wombey, J.C.

    1984-07-01

    A broad survey of the diets of 46 species of terrestrial and arboreal lizards from the families Gekkonidae, Pygopodidae, Agamidae and Scincidae was carried out in the Alligator Rivers Region, and the diets of three of the species were examined in detail by monthly sampling near the Ranger uranium mine. The study shows that, in the event of contamination of the waterbodies, only two species of lizards face any risk of contamination through their food

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

    Directory of Open Access Journals (Sweden)

    Jack L Conrad

    Full Text Available 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.

  13. Mate familiarity and social learning in a monogamous lizard.

    Science.gov (United States)

    Munch, Kirke L; Noble, Daniel W A; Wapstra, Erik; While, Geoffrey M

    2018-05-08

    Social learning is thought to be advantageous as it allows an animal to gather information quickly without engaging in costly trial-and-error learning. However, animals should be selective about when and whom they learn from. Familiarity is predicted to positively influence an animal's reliance on social learning; yet, few studies have empirically tested this theory. We used a lizard (Liopholis whitii) that forms long-term monogamous pair bonds to examine the effects of partner familiarity on social learning in two novel foraging tasks, an association and a reversal task. We allowed female lizards to observe trained conspecifics that were either familiar (social mate) or unfamiliar execute these tasks and compared these two groups with control females that did not receive social information. Lizards preferentially relied on trial-and-error learning in the association task. In the reversal task, lizards that were demonstrated by familiar partners learnt in fewer trials compared to control lizards and made more correct choices. Our results provide some evidence for context-dependent learning with lizards differentiating between when they utilize social learning, and, to a limited degree, whom they learnt from. Understanding the role of the social context in which learning occurs provides important insights into the benefits of social learning and sociality more generally.

  14. 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.

  15. 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.

  16. 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 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.

  17. Rotational dynamics of C60 in Na2RbC60

    International Nuclear Information System (INIS)

    Christides, C.; Prassides, K.; Neumann, D.A.; Copley, J.R.D.; Mizuki, J.; Tanigaki, K.; Hirosawa, I.; Ebbesen, T.W.

    1993-01-01

    We have measured the low-energy neutron inelastic-scattering (NIS) spectra of superconducting Na 2 RbC 60 in the temperature range 50-350 K. Well-defined librational peaks are observed at 50 K at 2.83(17) meV (FWHM = 1.7(5) meV). They soften and broaden with increasing temperature. Their behaviour mimics that found in solid C 60 and differs markedly from K 3 C 60 . The rotational barrier for C 60 reorientations in Na 2 RbC 60 is somewhat higher than in pristine C 60 and approximately half as large as in K 3 C 60 . An order-disorder transition is anticipated at a temperature higher than that found in C 60 . (orig.)

  18. Studies on RBC lipid and protein phosphorylation during blood bank storage

    International Nuclear Information System (INIS)

    Dumaswala, U.J.; Bryan, D.J.; Greenwalt, T.J.

    1986-01-01

    Recent evidence has suggested that phosphoinositides play a significant role in maintaining membrane structure and function. Their importance during blood bank storage is not understood. They have performed preliminary studies of the phosphoinositide synthetic pathway enzymes of RBC during blood bank storage. At 0 and 35 days of storage leaky ghosts were prepared and incubated with [γ- 32 P]ATP for 5 minutes at 30 C. One aliquot was subjected to acidified solvent extraction and thin layer chromatography. The labeled phosphoinositide -4,5 biphosphate (PIP 2 ), phosphoinositide-4 phosphate (PIP) and phosphatidic acid (PA) spots were scraped and counted by liquid scintillation spectrometry. Another aliquot was used for SDS-PAGE and the radioactivity associated with the β-spectrin was measured. These experiments suggest a decrease in RBC phosphoinositol and PIP-Kinases and β-spectrin kinase activities during blood bank storage. Further studies are being done to evaluate significance of these observations

  19. "Sexual" behavior in parthenogenetic lizards (Cnemidophorus).

    Science.gov (United States)

    Crews, D; Fitzgerald, K T

    1980-01-01

    All-female, parthenogenetic species afford a unique test of hypotheses regarding the nature and evolution of sexuality. Basic data on the behavior of parthenogens are lacking, however. We have discovered, from observations of captive Cnemidophorus uniparens, C. velox, and C. tesselatus, behavior patterns remarkably similar to the courtship and copulatory behavior of closely related sexual species. Briefly, in separately housed pairs, one lizard was repeatedly seen to mount and ride its cagemate and appose the cloacal regions. Dissection or palpation revealed that, in each instance, the courted animal was reproductively active, having ovaries containing large, preovulatory follicles, while the courting animal was either reproductively inactive or postovulatory, having ovaries containing only small, undeveloped follicles. These observations are significant for the questions they raise. For example, is this behavior a nonfunctional vestige of the species' ancestry, or is this behavior necessary for successful reproduction in the species (e.g., by priming reproductive neuroendocrine mechanisms as has been demonstrated in sexual species)?

  20. rbcL gene sequences provide evidence for the evolutionary lineages of leptosporangiate ferns.

    OpenAIRE

    Hasebe, M; Omori, T; Nakazawa, M; Sano, T; Kato, M; Iwatsuki, K

    1994-01-01

    Pteriodophytes have a longer evolutionary history than any other vascular land plant and, therefore, have endured greater loss of phylogenetically informative information. This factor has resulted in substantial disagreements in evaluating characters and, thus, controversy in establishing a stable classification. To compare competing classifications, we obtained DNA sequences of a chloroplast gene. The sequence of 1206 nt of the large subunit of the ribulose-bisphosphate carboxylase gene (rbc...

  1. Experimental method for the study of blood and RBC suspension conductivity under flow

    Czech Academy of Sciences Publication Activity Database

    Antonova, N.; Říha, Pavel; Ivanov, I.

    2014-01-01

    Roč. 67, č. 7 (2014), s. 995-1004 ISSN 1310-1331 Grant - others:The Ministry of Education and Science of Bulgaria(BG) BG051PO001-3.3-05/0001; The Ministry of Education, Youth and Science of Bulgaria(BG) DO-805/2012 Institutional support: RVO:67985874 Keywords : viscometric flow * conductivity * blood/RBC suspension microstructural changes Subject RIV: BK - Fluid Dynamics Impact factor: 0.284, year: 2014

  2. Neem leaf extract as potential modifier of free radical interaction with RBC membrane

    International Nuclear Information System (INIS)

    Patil, Shilpa M.; Kulkarni, Satish G.; Rane, Charusheela

    2004-01-01

    Full text: Neem tree (Azadirachta indica) is well known as village pharmacy due to its multifaceted medicinal action in curing countless health problems. The leaf extract of Neem is known to purify blood by removing toxins and neutralizing free radicals. Using gamma irradiation as free radical generation process the efficacy of neem leaf extract in combating free radical attack on RBC membrane has been explored. The results narrating role of concentration and dose dependency in this radio modulation will be discussed

  3. Phylogeny and intraspecific variability of holoparasitic Orobanche (Orobanchaceae) inferred from plastid rbcL sequences.

    Science.gov (United States)

    Manen, Jean-François; Habashi, Christine; Jeanmonod, Daniel; Park, Jeong-Mi; Schneeweiss, Gerald M

    2004-11-01

    The rbcL sequences of 106 specimens representing 28 species of the four recognized sections of Orobanche were analyzed and compared. Most sequences represent pseudogenes with premature stop codons. This study confirms that the American lineage (sects. Gymnocaulis and Myzorrhiza) contains potentially functional rbcL-copies with intact open reading frames and low rates of non-synonymous substitutions. For the first time, this is also shown for a member of the Eurasian lineage, O. coerulescens of sect. Orobanche, while all other investigated species of sects. Orobanche and Trionychon contain pseudogenes with distorted reading frames and significantly higher rates of non-synonymous substitutions. Phylogenetic analyses of the rbcL sequences give equivocal results concerning the monophyly of Orobanche, and the American lineage might be more closely related to Boschniakia and Cistanche than to the other sections of Orobanche. Additionally, species of sect. Trionychon phylogenetically nest in sect. Orobanche. This is in concordance with results from other plastid markers (rps2 and matK), but in disagreement with other molecular (nuclear ITS), morphological, and karyological data. This might indicate that the ancestor of sect. Trionychon has captured the plastid genome, or parts of it, of a member of sect. Orobanche. Apart from the phylogenetically problematic position of sect. Trionychon, the phylogenetic relationships within sect. Orobanche are similar to those inferred from nuclear ITS data and are close to the traditional groupings traditionally recognized based on morphology. The intraspecific variation of rbcL is low and is neither correlated with intraspecific morphological variability nor with host range. Ancestral character reconstruction using parsimony suggests that the ancestor of O. sect. Orobanche had a narrow host range.

  4. Effect of RBC concentrate transfusions on serum ferritin content in children with acute leukaemia.

    Science.gov (United States)

    Bebeshko, V G; Bruslova, E M; Tsvietkova, N M; Iatsemirskii, S M; Puchkareva, T I; Gonchar, L A; Krukovska, V V; Zelinska, A V; Mishchenko, L P

    2013-01-01

    To study the serum ferritin levels in children with acute leukemia, depending on the number of transfusions of RBC concentrate and period of disease. We studied the red blood count, serum iron and ferritin levels in 54 patients with acute leukemia before chemotherapy, at the time of a standardized treatment protocol, and after transfusions of RBC concentrates. In the debute of acute leukemia just before treatment lauch the serum ferritin in 81.5% of children was 2.3-2.5 higher than normal. The need for transfusion of RBC concentrates was higher under serum ferritin level exceeding 500 ng/mL. The association was established between ferritin content and age of the children, variant of acute leukemia and period of the disease. The level of serum ferritin can be used as a marker of ferrokinetic status for timely diagnosis of iron overload in children with acute leukemias and for application of treatment-and-prophylactic actions. Bebeshko V. G., Bruslova K. M., Cvjetkova N. M., Jacemyrskyj S. M., Pushkarova T. I., Gonchar L. O., Krukovska V. V., Zelinska A. V., Mishhenko L. P., 2013.

  5. Illustrating ontogenetic change in the dentition of the Nile monitor lizard, Varanus niloticus: a case study in the application of geometric morphometric methods for the quantification of shape-size heterodonty.

    Science.gov (United States)

    D'Amore, Domenic C

    2015-05-01

    Many recent attempts have been made to quantify heterodonty in non-mammalian vertebrates, but the majority of these are limited to Euclidian measurements. One taxon frequently investigated is Varanus niloticus, the Nile monitor. Juveniles possess elongate, pointed teeth (caniniform) along the entirety of the dental arcade, whereas adults develop large, bulbous distal teeth (molariform). The purpose of this study was to present a geometric morphometric method to quantify V. niloticus heterodonty through ontogeny that may be applied to other non-mammalian taxa. Data were collected from the entire tooth row of 19 dry skull specimens. A semilandmark analysis was conducted on the outline of the photographed teeth, and size and shape were derived. Width was also measured with calipers. From these measures, sample ranges and allometric functions were created using multivariate statistical analyses for each tooth position separately, as well as overall measures of heterodonty for each specimen based on morphological disparity. The results confirm and expand upon previous studies, showing measurable shape-size heterodonty in the species with significant differences at each tooth position. Tooth size increases with body size at most positions, and the allometric coefficient increases at more distal positions. Width shows a dramatic increase at the distal positions with ontogeny, often displaying pronounced positive allometry. Dental shape varied in two noticeable ways, with the first composing the vast majority of shape variance: (i) caniniformy vs. molariformy and (ii) mesially leaning, 'rounded' apices vs. distally leaning, 'pointed' apices. The latter was twice as influential in the mandible, a consequence of host bone shape. Mesial teeth show no significant shape change with growth, whereas distal teeth change significantly due primarily to an increase in molariformy. Overall, heterodonty increases with body size concerning both tooth size and shape, but shape

  6. Hotter nests produce hatchling lizards with lower thermal tolerance.

    Science.gov (United States)

    Dayananda, Buddhi; Murray, Brad R; Webb, Jonathan K

    2017-06-15

    In many regions, the frequency and duration of summer heatwaves is predicted to increase in future. Hotter summers could result in higher temperatures inside lizard nests, potentially exposing embryos to thermally stressful conditions during development. Potentially, developmentally plastic shifts in thermal tolerance could allow lizards to adapt to climate warming. To determine how higher nest temperatures affect the thermal tolerance of hatchling geckos, we incubated eggs of the rock-dwelling velvet gecko, Amalosia lesueurii , at two fluctuating temperature regimes to mimic current nest temperatures (mean 23.2°C, range 10-33°C, 'cold') and future nest temperatures (mean 27.0°C, range 14-37°C, 'hot'). Hatchlings from the hot incubation group hatched 27 days earlier and had a lower critical thermal maximum (CT max 38.7°C) and a higher critical thermal minimum (CT min 6.2°C) than hatchlings from cold incubation group (40.2 and 5.7°C, respectively). In the field, hatchlings typically settle under rocks near communal nests. During the hatching period, rock temperatures ranged from 13 to 59°C, and regularly exceeded the CT max of both hot- and cold-incubated hatchlings. Because rock temperatures were so high, the heat tolerance of lizards had little effect on their ability to exploit rocks as retreat sites. Instead, the timing of hatching dictated whether lizards could exploit rocks as retreat sites; that is, cold-incubated lizards that hatched later encountered less thermally stressful environments than earlier hatching hot-incubated lizards. In conclusion, we found no evidence that CT max can shift upwards in response to higher incubation temperatures, suggesting that hotter summers may increase the vulnerability of lizards to climate warming. © 2017. Published by The Company of Biologists Ltd.

  7. The influence of irradiation potential on the degree of conversion and mechanical properties of two bulk-fill flowable RBC base materials.

    Science.gov (United States)

    Finan, Leah; Palin, William M; Moskwa, Natalia; McGinley, Emma Louise; Fleming, Garry J P

    2013-08-01

    To assess the depth of cure claims of two bulk-fill flowable RBC bases (SDR and x-tra base) using Fourier transform infrared (FTIR) spectroscopy, biaxial flexure strength (BFS), and Vickers hardness number (VHN) for specimen depths of 8mm (in 1mm increments). The degree of conversion (DC) was measured by monitoring the peak height (6164cm(-1)) of specimens (11.0±0.1mm diameter, 1.0±0.1mm thickness) during light irradiation for 20s using a quartz tungsten halogen light curing unit at 650±26mW/cm(2). DC was measured up to 120s post irradiation and repeated (n=3) for irradiation depths up to 8mm (in 1mm increments). Further series (n=20) of eight discs were prepared, stacked, light irradiated and numbered from one to eight (distance from the LCU). The specimens were stored at 37±1°C for 24h and BFS tested with the fracture fragments used to determine the VHN for each specimen. X-tra base can be irradiated to 8mm without a change in DC, something the SDR material cannot claim. However, the DC results confirm both bulk-fill flowable RBC bases have a depth of cure in excess of 4mm. One-way ANOVAs of BFS and VHN data showed significant differences between irradiation depths for x-tra base and SDR with increasing irradiation depth (4mm) resulting in significant reductions in mean BFS and VHN. The claims that the bulk-fill flowable RBC bases have a depth of cure in excess of 4mm can be confirmed but the differing chemistry of the resin formulations and filler characteristics contribute to significant differences in DC, BFS and VHN data between the two materials tested. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  8. 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…

  9. 76 FR 62087 - Draft Conservation Plan and Draft Environmental Assessment; Dunes Sagebrush Lizard, Texas

    Science.gov (United States)

    2011-10-06

    ...] Draft Conservation Plan and Draft Environmental Assessment; Dunes Sagebrush Lizard, Texas AGENCY: Fish... draft Texas Conservation Plan for the Dunes Sagebrush Lizard (TCP). The draft TCP will function as a... the Applicant for the dunes sagebrush lizard (Sceloporus arenicolus) throughout its range in Texas...

  10. 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

  11. 76 FR 19304 - Endangered and Threatened Wildlife and Plants; Endangered Status for Dunes Sagebrush Lizard

    Science.gov (United States)

    2011-04-07

    ... for Dunes Sagebrush Lizard AGENCY: Fish and Wildlife Service, Interior. ACTION: Proposed rule... list the dunes sagebrush lizard (Sceloporus arenicolus) under the Endangered Species Act of 1973, as... dunes sagebrush lizard (Sceloporus arenicolus) that was published in the Federal Register on December 14...

  12. Genotoxicity induced by Roundup® (Glyphosate) in tegu lizard (Salvator merianae) embryos.

    Science.gov (United States)

    Schaumburg, Laura G; Siroski, Pablo A; Poletta, Gisela L; Mudry, Marta D

    2016-06-01

    Environmental contaminants produce multiple adverse consequences at individual, population and ecosystem levels. High volumes of agrochemicals applied to great variety of crops, together with agricultural expansion, generate great concerns due to the impact for the environment and large risk implicated for wildlife. The lack of data on these threats is striking. The tegu lizard (Salvator merianae) is one of the species that live in environments under contaminant effects. Several characteristics allow proposing this species as a potential sentinel organism for the monitoring of pesticides in their habitat. The present study is the first report about genotoxicity in tegu lizard neonates after embryonic exposure to Roundup® (glyphosate 66.2%). The micronucleus test (MN), nuclear abnormalities (NAs) assay and comet assay (CA) were used as biomarkers of genotoxic effects induced in erythrocytes by topical exposure of the eggs to the glyphosate commercial formulation Roundup® (RU), in laboratory controlled conditions. A total of 96 eggs were distributed in six groups exposed to RU (50, 100, 200, 400, 800, 1600μg/egg), one positive control (PC; 200μg cyclophosphamide/egg) and one negative control (NC; distilled water). No teratogenic effects were observed in any of the exposed or control neonates. A significant increase in DNA damage was observed in all concentrations higher than 100μg/egg with respect to NC (p0.05). Our results provide new information about the undesirable effects of the glyphosate-based herbicide formulations RU on this lizard species that inhabits areas permanently exposed to several pesticide formulations. We consider of utmost necessity a strict regulation of the agrochemical application conditions in those environments near to places where wild populations of terrestrial and aquatic species live, in order to minimize the adverse effects on ecosystems. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. 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.

  14. Why tropical forest lizards are vulnerable to climate warming

    Science.gov (United States)

    Huey, Raymond B.; Deutsch, Curtis A.; Tewksbury, Joshua J.; Vitt, Laurie J.; Hertz, Paul E.; Álvarez Pérez, Héctor J.; Garland, Theodore

    2009-01-01

    Biological impacts of climate warming are predicted to increase with latitude, paralleling increases in warming. However, the magnitude of impacts depends not only on the degree of warming but also on the number of species at risk, their physiological sensitivity to warming and their options for behavioural and physiological compensation. Lizards are useful for evaluating risks of warming because their thermal biology is well studied. We conducted macrophysiological analyses of diurnal lizards from diverse latitudes plus focal species analyses of Puerto Rican Anolis and Sphaerodactyus. Although tropical lowland lizards live in environments that are warm all year, macrophysiological analyses indicate that some tropical lineages (thermoconformers that live in forests) are active at low body temperature and are intolerant of warm temperatures. Focal species analyses show that some tropical forest lizards were already experiencing stressful body temperatures in summer when studied several decades ago. Simulations suggest that warming will not only further depress their physiological performance in summer, but will also enable warm-adapted, open-habitat competitors and predators to invade forests. Forest lizards are key components of tropical ecosystems, but appear vulnerable to the cascading physiological and ecological effects of climate warming, even though rates of tropical warming may be relatively low. PMID:19324762

  15. 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.

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

    International Nuclear Information System (INIS)

    Salice, Christopher J.; Suski, Jamie G.; Bazar, Matthew A.; Talent, Larry G.

    2009-01-01

    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.

  17. Bone indicators of grasping hands in lizards

    Directory of Open Access Journals (Sweden)

    Gabriela Fontanarrosa

    2016-05-01

    Full Text Available Grasping is one of a few adaptive mechanisms that, in conjunction with clinging, hooking, arm swinging, adhering, and flying, allowed for incursion into the arboreal eco-space. Little research has been done that addresses grasping as an enhanced manual ability in non-mammalian tetrapods, with the exception of studies comparing the anatomy of muscle and tendon structure. Previous studies showed that grasping abilities allow exploitation for narrow branch habitats and that this adaptation has clear osteological consequences. The objective of this work is to ascertain the existence of morphometric descriptors in the hand skeleton of lizards related to grasping functionality. A morphological matrix was constructed using 51 morphometric variables in 278 specimens, from 24 genera and 13 families of Squamata. To reduce the dimensions of the dataset and to organize the original variables into a simpler system, three PCAs (Principal Component Analyses were performed using the subsets of (1 carpal variables, (2 metacarpal variables, and (3 phalanges variables. The variables that demonstrated the most significant contributions to the construction of the PCA synthetic variables were then used in subsequent analyses. To explore which morphological variables better explain the variations in the functional setting, we ran Generalized Linear Models for the three different sets. This method allows us to model the morphology that enables a particular functional trait. Grasping was considered the only response variable, taking the value of 0 or 1, while the original variables retained by the PCAs were considered predictor variables. Our analyses yielded six variables associated with grasping abilities: two belong to the carpal bones, two belong to the metacarpals and two belong to the phalanges. Grasping in lizards can be performed with hands exhibiting at least two different independently originated combinations of bones. The first is a combination of a highly

  18. Multiple and Periodic Measurement of RBC Aggregation and ESR in Parallel Microfluidic Channels under On-Off Blood Flow Control

    Directory of Open Access Journals (Sweden)

    Yang Jun Kang

    2018-06-01

    Full Text Available Red blood cell (RBC aggregation causes to alter hemodynamic behaviors at low flow-rate regions of post-capillary venules. Additionally, it is significantly elevated in inflammatory or pathophysiological conditions. In this study, multiple and periodic measurements of RBC aggregation and erythrocyte sedimentation rate (ESR are suggested by sucking blood from a pipette tip into parallel microfluidic channels, and quantifying image intensity, especially through single experiment. Here, a microfluidic device was prepared from a master mold using the xurography technique rather than micro-electro-mechanical-system fabrication techniques. In order to consider variations of RBC aggregation in microfluidic channels due to continuous ESR in the conical pipette tip, two indices (aggregation index (AI and erythrocyte-sedimentation-rate aggregation index (EAI are evaluated by using temporal variations of microscopic, image-based intensity. The proposed method is employed to evaluate the effect of hematocrit and dextran solution on RBC aggregation under continuous ESR in the conical pipette tip. As a result, EAI displays a significantly linear relationship with modified conventional ESR measurement obtained by quantifying time constants. In addition, EAI varies linearly within a specific concentration of dextran solution. In conclusion, the proposed method is able to measure RBC aggregation under continuous ESR in the conical pipette tip. Furthermore, the method provides multiple data of RBC aggregation and ESR through a single experiment. A future study will involve employing the proposed method to evaluate biophysical properties of blood samples collected from cardiovascular diseases.

  19. 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

  20. 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.

  1. 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. PMID:26844295

  2. 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.

  3. Did Lizards Follow Unique Pathways in Sex Chromosome Evolution?

    Science.gov (United States)

    Gleeson, Dianne; Georges, Arthur

    2018-01-01

    Reptiles show remarkable diversity in modes of reproduction and sex determination, including high variation in the morphology of sex chromosomes, ranging from homomorphic to highly heteromorphic. Additionally, the co-existence of genotypic sex determination (GSD) and temperature-dependent sex determination (TSD) within and among sister clades makes this group an attractive model to study and understand the evolution of sex chromosomes. This is particularly so with Lizards (Order Squamata) which, among reptiles, show extraordinary morphological diversity. They also show no particular pattern of sex chromosome degeneration of the kind observed in mammals, birds and or even in snakes. We therefore speculate that sex determination sensu sex chromosome evolution is labile and rapid and largely follows independent trajectories within lizards. Here, we review the current knowledge on the evolution of sex chromosomes in lizards and discuss how sex chromosome evolution within that group differs from other amniote taxa, facilitating unique evolutionary pathways. PMID:29751579

  4. A forebrain atlas of the lizard Gekko gecko.

    Science.gov (United States)

    Smeets, W J; Hoogland, P V; Lohman, A H

    1986-12-01

    An atlas of the forebrain of the lizard Gekko gecko has been provided, which will serve as the basis for subsequent experimental tracing and immunohistochemical studies. Apart from a strongly developed medial cortex and septal area, the Tokay gecko shows all the main features of the forebrain of the lacertid-type lizards. When its convenience as an experimental animal is also taken into account, this species seems to be very suitable for studying the limbic system in reptiles. The atlas comprises topographical reconstructions of the telencephalon and diencephalon and a series of transverse sections of which the levels have been indicated in the reconstructions. The results obtained in the Gekko are briefly compared with those found in other lizards studied.

  5. 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...... animals, known for their loud vocalizations) and the green anole (Anolis carolinensis, diurnal, non-vocal animals). Hearing sensitivity was measured in 5 geckos and 7 anoles. The lizards were sedated with isoflurane, and ABRs were measured at levels of 1 and 3% isoflurane. The typical ABR waveform......). Above 5 kHz, however, anoles were more than 20 dB more sensitive than geckos and showed a wider range of sensitivity (1-7 kHz). Generally, thresholds from ABR audiograms were comparable to those of small birds. Best hearing sensitivity, however, extended over a larger frequency range in lizards than...

  6. Nematodes Parasites of Teiid Lizards from the Brazilian Amazon Rainforest.

    Science.gov (United States)

    Macedo, L C; Gardner, S L; Melo, F T V; Giese, E G; Santos, J N

    2017-04-01

    This study presents the helminth composition and parameters of infection by several species of nematodes in teiid lizards, Ameiva ameiva ameiva (Linnaeus, 1758), Cnemidophorus cryptus Cole and Dessauer, 1993, and Kentropyx calcarata Spix, 1825 from the Brazilian Amazonian Rainforest. The population of lizards studied were parasitized by 6 species of Phylum Nemata including: Spinicauda spinicauda (Olfers, 1919), Parapharyngodon alvarengai Freitas, 1957, Physaloptera sp. (adults), Physaloptera sp. (larvae), Piratuba digiticauda Lent and Freitas, 1941, and Anisakidae (larvae). The overall prevalence was 66.17% and the mean intensity of infection was 19.40 ± 25.48. The association between the body-length of lizards and the abundance and richness of parasitic nematodes was statistically significant only in Ameiva a. ameiva. A new host record is reported here with 1 specimen of the family Anasakidae in Ameiva a. ameiva. Both S. spinicauda and Physaloptera sp. represent new records from C. cryptus.

  7. Did Lizards Follow Unique Pathways in Sex Chromosome Evolution?

    Directory of Open Access Journals (Sweden)

    Shayer Mahmood Ibney Alam

    2018-05-01

    Full Text Available Reptiles show remarkable diversity in modes of reproduction and sex determination, including high variation in the morphology of sex chromosomes, ranging from homomorphic to highly heteromorphic. Additionally, the co-existence of genotypic sex determination (GSD and temperature-dependent sex determination (TSD within and among sister clades makes this group an attractive model to study and understand the evolution of sex chromosomes. This is particularly so with Lizards (Order Squamata which, among reptiles, show extraordinary morphological diversity. They also show no particular pattern of sex chromosome degeneration of the kind observed in mammals, birds and or even in snakes. We therefore speculate that sex determination sensu sex chromosome evolution is labile and rapid and largely follows independent trajectories within lizards. Here, we review the current knowledge on the evolution of sex chromosomes in lizards and discuss how sex chromosome evolution within that group differs from other amniote taxa, facilitating unique evolutionary pathways.

  8. 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.

  9. 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. © The Author 2014. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  10. 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...

  11. Radiation induced leukemia and leukopenia in the lizard Uromastix hardwickii

    International Nuclear Information System (INIS)

    Ahmad, M.; Taqawi, I.H.

    1978-01-01

    The effect of 3,000 R, 3,500 R and 4,000 R on the total leukocyte counts of the lizard Uromastix hardwickii was observed for a period of six weeks. Exposure to 3,000 R resulted in ever rising leukocyte counts and the cells showed abnormal morphology. There was no primary transient leukocytosis prior to leukopenia after exposure to 3,500 R, and no abortive leukocytosis prior to leukopenia in the 4,000 R lizards. Thus, the dose of 3,000 R induces leukemia and the doses of 3,500 and 4,000 R produce leukopenia. (author)

  12. Pampean lizard assemblage from subtropical Brazil: a temporal analysis

    Directory of Open Access Journals (Sweden)

    Gisele R. Winck

    2011-12-01

    Full Text Available The increasing human occupation of natural environments is one of the greatest threats to biodiversity. To mitigate the negative anthropogenic effects, it is necessary to understand the characteristics of natural populations and the natural history of species. A study was conducted with an assemblage of lizards from a disturbed area of the Pampa biome, from February 2001 to January 2004. The assemblage showed a unimodal seasonal pattern, with the recruitment period occurring during the warmer months. The captures were seasonal for two of the three monitored years, and concentrated within warmer months. The minimum temperature explained the number of catches for the assemblage as a whole. However, when the species were analyzed individually, the temperature only explained the seasonal occurrence of Teius oculatus. The abundance of species was significantly different in the third year of study for Cercosaura schreibersii and Ophiodes striatus. This latter species was no longer registered in the study area from May 2003 until the end of the study. Therefore, O. striatus may be more sensitive to environmental changes, considering the events of change in vegetation during the study. With frequent and increasing environmental disturbances, it is necessary to take conservation measures and encourage the increase of knowledge on Pampean lizards.O crescimento da ocupação humana sobre ambientes naturais é uma das maiores ameaças à biodiversidade. Para amenizar os efeitos negativos antropogênicos, é necessário entender as características das populações naturais, e a história natural das espécies. Um estudo foi conduzido com uma assembeia de lagartos de uma área perturbada do Pampa, de fevereiro de 2002 a janeiro de 2004. A assembleia apresentou padrão sazonal unimodal, com recrutamento ocorrendo durante os meses mais quentes. As capturas foram sazonais durante dois dos três anos monitorados, e concentradas nos meses mais quentes. A

  13. 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

  14. Tissue Characterization of Lemna gibba rbcS Promoter%浮萍rbcS启动子组织特性研究

    Institute of Scientific and Technical Information of China (English)

    黄凤珍; 李倩; 王友如

    2015-01-01

    A new rbcS (ribulose-1,5-bisphosphate carboxylase small subunit) promoter with the size of 1 438 bp (named SSU5C promoter) was cloned from Lemna gibba. SSU5C promoter was fused with the GUS reporter gene to construct a plant binary vector (pSSU5C-IGUS), and introduced into duckweed by agrogacterium-mediated trans-formation. The transgenic plantlets were generated. This study was focused on the tissue characterization of SSU5C promoter. GUS staining showed that SSU5C promoter drove GUS to express in the green tissue in leaf, stem and petiole of T1 tobacco, whereas no GUS activity was observed in root. In reproductive organs, the GUS activity was observed in corolla lobes, anther and stigma, no GUS activity was observed in other parts. It was obvious that rbcS promoter can not only express in the green tissue, but also can express in reproductive organs. The results lay a good doundation for the application of SSU5C in plant genetic engineering.%SSU5C启动子(全长1438 bp)是从浮萍基因组中新克隆的一个rb c S (ribulose-1,5-bisphosphate carbo-xylase small subunit)启动子。本研究将 SSU5C 启动子与GUS基因融合,成功构建植物双元表达载p SSU5C-IGUS,并利用农杆菌介导法转化烟草,获得转基因植株,探究SSU5C启动子在烟草中的组织表达特点。GUS检测结果表明:在T1烟草的营养器官中,SSU5C启动子主要驱动GUS基因在烟草叶片和叶柄、茎等绿色组织中表达,而在根部不表达;在生殖器官中,GUS基因主要在花冠裂片以及花药和柱头中表达。本研究首次发现浮萍rb c S启动子不仅在绿色组织中表达,而且在生殖器官中的花冠裂片以及花药和柱头中表达,这一发现可为SSU5C启动子在植物基因工程中的应用奠定基础。

  15. Discriminatory power of rbcL barcode locus for authentication of some of United Arab Emirates (UAE) native plants.

    Science.gov (United States)

    Maloukh, Lina; Kumarappan, Alagappan; Jarrar, Mohammad; Salehi, Jawad; El-Wakil, Houssam; Rajya Lakshmi, T V

    2017-06-01

    DNA barcoding of United Arab Emirates (UAE) native plants is of high practical and scientific value as the plants adapt to very harsh environmental conditions that challenge their identification. Fifty-one plant species belonged to 22 families, 2 monocots, and 20 eudicots; a maximum number of species being legumes and grasses were collected. To authenticate the morphological identification of the wild plant taxa, rbcL and matK regions were used in the study. The primer universality and discriminatory power of rbcL is 100%, while it is 35% for matK locus for these plant species. The sequences were submitted to GenBank; accession numbers were obtained for all the rbcL sequences and for 6 of matK sequences. We suggest rbcL as a promising barcode locus for the tested group of 51 plants. In the present study, an inexpensive, simple method of identification of rare desert plant taxa through rbcL barcode is being reported.

  16. Prey, but not plant, chemical discrimination by the lizard ...

    African Journals Online (AJOL)

    We experimentally studied responses to food chemicals by Gerrhosaurus nigrolineatus, amember of a lizard genus endemic to subsaharan Africa. Gerrhosaur diets vary from insectivorous to omnivorous with a very large plant portion. The omnivorous G. validus responds strongly to chemical cues from prey and food plants.

  17. Ecological release in lizard assemblages of neotropical savannas.

    Science.gov (United States)

    Mesquita, Daniel Oliveira; Colli, Guarino Rinaldi; Vitt, Laurie J

    2007-08-01

    We compare lizard assemblages of Cerrado and Amazonian savannas to test the ecological release hypothesis, which predicts that niche dimensions and abundance should be greater in species inhabiting isolated habitat patches with low species richness (Amazonian savannas and isolated Cerrado patches) when compared with nonisolated areas in central Cerrado with greater species richness. We calculated microhabitat and diet niche breadths with data from 14 isolated Cerrado patches and Amazon savanna areas and six central Cerrado populations. Morphological data were compared using average Euclidean distances, and lizard abundance was estimated using the number of lizards captured in pitfall traps over an extended time period. We found no evidence of ecological release with respect to microhabitat use, suggesting that historical factors are better microhabitat predictors than ecological factors. However, data from individual stomachs indicate that ecological release occurs in these areas for one species (Tropidurus) but not others (Ameiva ameiva, Anolis, Cnemidophorus, and Micrablepharus), suggesting that evolutionary lineages respond differently to environmental pressures, with tropidurids being more affected by ecological factors than polychrotids, teiids, and gymnophthalmids. We found no evidence that ecological release occurs in these areas using morphological data. Based on abundance data, our results indicate that the ecological release (density compensation) hypothesis is not supported: lizard species are not more abundant in isolated areas than in nonisolated areas. The ecology of species is highly conservative, varying little from assemblage to assemblage. Nevertheless, increases in niche breadth for some species indicate that ecological release occurs as well.

  18. The female reproductive cycle of the lizard, Cordylus polyzonus ...

    African Journals Online (AJOL)

    1987-11-13

    Nov 13, 1987 ... mass of the embryos versus newly ovulated eggs indica- ted that a loss of 15,9% ... Figure 4 Summary of follicular (dark shaded) and luteal activity (light shaded) during gestation in the lizard, C. p. polyzonus. AIl values are .... inadequate energy intake to meet the increased metabo- lic demand during this ...

  19. Paradoxical reproduction and body size in the rock lizard, Agama ...

    African Journals Online (AJOL)

    1993-07-05

    Jul 5, 1993 ... The rock lizard Agama atra atra from Namaqualand differs in both body size and reproduction from other populations of this species occurring elsewhere in southern Africa. Both sexes from Namaqualand are significantly larger than their counterparts in the south-western Cape. While reproduction in this ...

  20. A survey of the mammals, lizards and mollusks

    NARCIS (Netherlands)

    NN,

    1940-01-01

    This annotated list of the mammals, lizards and mollusks of the Leeward Group, is based on author’s collection and therefore includes additional mainland-records of the island-species. As a rule a short commentary is given only as a guide to the adopted nomenclature and classification, in case of

  1. 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.…

  2. 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...

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

    NARCIS (Netherlands)

    Erens, Jesse; Miralles, A.; Glaw, F.; Chatrou, L.W.; Vences, M.

    2017-01-01

    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

  4. 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...

  5. Rain-harvesting behavior in agamid lizards (Trapelus)

    Czech Academy of Sciences Publication Activity Database

    Veselý, M.; Modrý, David

    2002-01-01

    Roč. 36, č. 2 (2002), s. 311-314 ISSN 0022-1511 Institutional research plan: CEZ:AV0Z6022909 Keywords : lizards * ethology * rain-harvesting behavior Subject RIV: EG - Zoology Impact factor: 0.649, year: 2002

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

    NARCIS (Netherlands)

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

    2014-01-01

    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

  7. Reproductive strategies in males of the world's southernmost lizards.

    Science.gov (United States)

    Fernández, Jimena B; Medina, Marlin; Kubisch, Erika L; Scolaro, José A; Ibargüengoytía, Nora R

    2017-03-01

    Reproductive and life history patterns in reptiles are tightly related to the environmental conditions, so male reproductive cycles have been historically characterized as continuous, for tropical lizards, or seasonal, for temperate lizards. However, males of Liolaemus and Phymaturus lizards (Liolaemidae), from cold temperate climates of high altitudes or latitudes in Argentina and Chile, have developed a variety of reproductive cycles to coordinate with the short female reproductive season and to deal with the low frequency of reproductive females in the population. Using gonadal histology and morphological analysis, we describe the male reproductive biology, fat storage and sexual dimorphism of the viviparous lizards Liolaemus sarmientoi and Liolaemus magellanicus that inhabit an austral grass steppe at 51°S, in the southern limit of the American continent. Males of L. sarmientoi and L. magellanicus are reproductively available during the entire activity season of approximately 5 months. In addition, males of both species exhibit greater body sizes than females in morphological variables relevant in sexual selection. Meanwhile, females of both species exhibit larger inter-limb length than conspecific males, which suggests fecundity selection to increase space for a larger litter size. The continuous sperm production throughout the activity season allows these liolaemids to mate at any time when females ovulate, representing a selective advantage to deal with the short activity season and the adversities of the cold environment they inhabit. © 2016 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

  8. Leaping Lizards And Learning. In the Curriculum: Science

    Science.gov (United States)

    Petersen, Diane; Nelson, Cathi

    2004-01-01

    In the broad fields that stretch toward the horizon in the Columbia Basin region of Washington state, the land is just right for at least two purposes: growing dryland wheat and providing habitat for shorthorned lizards, also known as horny toads. Our elementary school, enrolling 150 children from this rural farming community, has become a hub for…

  9. 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.

  10. 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.

  11. [sup 99m]Tc-RBC subtraction scintigraphy; Assessmet of bleeding site and rate

    Energy Technology Data Exchange (ETDEWEB)

    Inagaki, Syoichi; Tonami, Syuichi; Yasui, Masakazu; Kuranishi, Makoto; Sugishita, Kouki; Nakamura, Mamoru (Toyama Medical and Pharmaceutical Univ. (Japan). Hospital)

    1994-03-01

    Sequential abdominal scintigrams with [sup 99m]Tc-labelled red blood cells (RBC) were subtracted for observing a site of gastrointestinal bleeding and calculating the bleeding rate. This method is technically very easy and can detect the site of bleeding with the minimum rate, as low as 0.2 ml/min., in a phantom experiment. In 23 cases with final diagnosis of gastrointestinal bleeding, conventional non-subtraction scintigraphy detected only 30% (7/23), but subtraction scintigraphy detected 61% (14/23). It was concluded that subtraction scintigraphy had higher sensitivity than conventional scintigraphy for early diagnosing bleeding. A combination of non-subtraction and subtraction scintigraphy is recommended to detect a site of gastrointestinal bleeding in a clinical setting. (author).

  12. The ability of lizards to identify an artificial Batesian mimic.

    Science.gov (United States)

    Beneš, Josef; Veselý, Petr

    2017-08-01

    Birds are usually considered the main predators shaping the evolution of aposematic signals and mimicry. Nevertheless, some lizards also represent predominately visually oriented predators, so they may also play an important role in the evolution of aposematism. Despite this fact, experimental evidence regarding the responses of lizards to aposematic prey is very poor compared to such evidence in birds. Lizards possess very similar sensory and cognitive abilities to those of birds and their response to aposematic prey may thus be affected by very similar processes. We investigated the reactions of a lizard, the Gran Canaria skink (Chalcides sexlineatus), to an aposematic prey and its artificial Batesian mimic. Further, we attempted to ascertain whether the lizard's food experience has any effect on its ability to recognise an artificial Batesian mimic, by using two groups of predators differing in their prior experience with the prey from which the mimic was fabricated. The red firebug (Pyrrhocoris apterus) was used as an aposematic model, and the Guyana spotted roach (Blaptica dubia) as the palatable prey from which the mimic was fabricated. The appearance of the roach was modified by a paper sticker placed on its back. The skinks showed a strong aversion towards the model firebug. They also avoided attacking the cockroaches with the firebug pattern sticker. This suggests that a visual rather than a chemical signal is responsible for this aversion. The protection provided by the firebug sticker was even effective when the skinks were familiar with unmodified cockroaches (previous food experience). Copyright © 2017 Elsevier GmbH. All rights reserved.

  13. Physiologic Impact of Circulating RBC Microparticles upon Blood-Vascular Interactions

    Directory of Open Access Journals (Sweden)

    Ahmed S. Said

    2018-01-01

    Full Text Available Here, we review current data elucidating the role of red blood cell derived microparticles (RMPs in normal vascular physiology and disease progression. Microparticles (MPs are submicron-size, membrane-encapsulated vesicles derived from various parent cell types. MPs are produced in response to numerous stimuli that promote a sequence of cytoskeletal and membrane phospholipid changes and resulting MP genesis. MPs were originally considered as potential biomarkers for multiple disease processes and more recently are recognized to have pleiotropic biological effects, most notably in: promotion of coagulation, production and handling of reactive oxygen species, immune modulation, angiogenesis, and in initiating apoptosis. RMPs, specifically, form normally during RBC maturation in response to injury during circulation, and are copiously produced during processing and storage for transfusion. Notably, several factors during RBC storage are known to trigger RMP production, including: increased intracellular calcium, increased potassium leakage, and energy failure with ATP depletion. Of note, RMP composition differs markedly from that of intact RBCs and the nature/composition of RMP components are affected by the specific circumstances of RMP genesis. Described RMP bioactivities include: promotion of coagulation, immune modulation, and promotion of endothelial adhesion as well as influence upon vasoregulation via influence upon nitric oxide (NO bioavailability. Of particular relevance, RMPs scavenge NO more avidly than do intact RBCs; this physiology has been proposed to contribute to the impaired oxygen delivery homeostasis that may be observed following transfusion. In summary, RMPs are submicron particles released from RBCs, with demonstrated vasoactive properties that appear to disturb oxygen delivery homeostasis. The clinical impact of RMPs in normal and patho-physiology and in transfusion recipients is an area of continued investigation.

  14. 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.

  15. 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. Copyright © 2013 Elsevier GmbH. All rights reserved.

  16. Decision Tree Algorithm-Generated Single-Nucleotide Polymorphism Barcodes of rbcL Genes for 38 Brassicaceae Species Tagging.

    Science.gov (United States)

    Yang, Cheng-Hong; Wu, Kuo-Chuan; Chuang, Li-Yeh; Chang, Hsueh-Wei

    2018-01-01

    DNA barcode sequences are accumulating in large data sets. A barcode is generally a sequence larger than 1000 base pairs and generates a computational burden. Although the DNA barcode was originally envisioned as straightforward species tags, the identification usage of barcode sequences is rarely emphasized currently. Single-nucleotide polymorphism (SNP) association studies provide us an idea that the SNPs may be the ideal target of feature selection to discriminate between different species. We hypothesize that SNP-based barcodes may be more effective than the full length of DNA barcode sequences for species discrimination. To address this issue, we tested a r ibulose diphosphate carboxylase ( rbcL ) S NP b arcoding (RSB) strategy using a decision tree algorithm. After alignment and trimming, 31 SNPs were discovered in the rbcL sequences from 38 Brassicaceae plant species. In the decision tree construction, these SNPs were computed to set up the decision rule to assign the sequences into 2 groups level by level. After algorithm processing, 37 nodes and 31 loci were required for discriminating 38 species. Finally, the sequence tags consisting of 31 rbcL SNP barcodes were identified for discriminating 38 Brassicaceae species based on the decision tree-selected SNP pattern using RSB method. Taken together, this study provides the rational that the SNP aspect of DNA barcode for rbcL gene is a useful and effective sequence for tagging 38 Brassicaceae species.

  17. 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

    -related liver disease were matched with 20 CF patients without. Blood samples were analysed for liver biochemistry and haematology. Granulocytes, mononuclear cells, and RBC were separated by density gradient centrifugation, and fatty acid composition was measured by gas chromatography. Hepatic ultrasound...

  18. Partial characterization of new adenoviruses found in lizards.

    Science.gov (United States)

    Ball, Inna; Behncke, Helge; Schmidt, Volker; Geflügel, F T A; Papp, Tibor; Stöhr, Anke C; Marschang, Rachel E

    2014-06-01

    In the years 2011-2012, a consensus nested polymerase chain reaction was used for the detection of adenovirus (AdV) infection in reptiles. During this screening, three new AdVs were detected. One of these viruses was detected in three lizards from a group of green striped tree dragons (Japalura splendida). Another was detected in a green anole (Anolis carolinensis). A third virus was detected in a Jackson's chameleon (Chamaeleo jacksonii). Analysis of a portion of the DNA-dependent DNA polymerase genes of each of these viruses revealed that they all were different from one another and from all previously described reptilian AdVs. Phylogenetic analysis of the partial DNA polymerase gene sequence showed that all newly detected viruses clustered within the genus Atadenovirus. This is the first description of AdVs in these lizard species.

  19. 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.

  20. Isoniazid-Associated Uric Acid Retention in the Lizard, Uromastix ...

    African Journals Online (AJOL)

    Reduction in uric acid excretion was observed following oral administration of 0.06 mg isoniazid per day for 5, 10 and 15 days to three groups of Uromastix hardwickii lizards. The rise of serum uric acid levels in the treated groups was 60 per cent higher on day 5, and about 4 and 5 times greater than in control groups on day ...

  1. “Sexual” behavior in parthenogenetic lizards (Cnemidophorus)

    OpenAIRE

    Crews, David; Fitzgerald, Kevin T.

    1980-01-01

    All-female, parthenogenetic species afford a unique test of hypotheses regarding the nature and evolution of sexuality. Basic data on the behavior of parthenogens are lacking, however. We have discovered, from observations of captive Cnemidophorus uniparens, C. velox, and C. tesselatus, behavior patterns remarkably similar to the courtship and copulatory behavior of closely related sexual species. Briefly, in separately housed pairs, one lizard was repeatedly seen to mount and ride its cagema...

  2. 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.

  3. The auditory brainstem response in two lizard species.

    Science.gov (United States)

    Brittan-Powell, Elizabeth F; Christensen-Dalsgaard, Jakob; Tang, Yezhong; Carr, Catherine; Dooling, Robert J

    2010-08-01

    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 animals, known for their loud vocalizations) and the green anole (Anolis carolinensis, diurnal, non-vocal animals). Hearing sensitivity was measured in 5 geckos and 7 anoles. The lizards were sedated with isoflurane, and ABRs were measured at levels of 1 and 3% isoflurane. The typical ABR waveform in response to click stimulation showed one prominent and several smaller peaks occurring within 10 ms of the stimulus onset. ABRs to brief tone bursts revealed that geckos and anoles were most sensitive between 1.6-2 kHz and had similar hearing sensitivity up to about 5 kHz (thresholds typically 20-50 dB SPL). Above 5 kHz, however, anoles were more than 20 dB more sensitive than geckos and showed a wider range of sensitivity (1-7 kHz). Generally, thresholds from ABR audiograms were comparable to those of small birds. Best hearing sensitivity, however, extended over a larger frequency range in lizards than in most bird species.

  4. 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.

  5. 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.

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

    Science.gov (United States)

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

    2015-01-01

    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. PMID:25937911

  7. 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 lost/regenerating tails for nocturnal lizards (all 246 spp., P pressure.

  8. 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.

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

    Science.gov (United States)

    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. PMID:28792983

  10. 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

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

    Directory of Open Access Journals (Sweden)

    Breanna J Putman

    Full Text Available 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.

  12. rbcL gene sequences provide evidence for the evolutionary lineages of leptosporangiate ferns.

    Science.gov (United States)

    Hasebe, M; Omori, T; Nakazawa, M; Sano, T; Kato, M; Iwatsuki, K

    1994-06-07

    Pteriodophytes have a longer evolutionary history than any other vascular land plant and, therefore, have endured greater loss of phylogenetically informative information. This factor has resulted in substantial disagreements in evaluating characters and, thus, controversy in establishing a stable classification. To compare competing classifications, we obtained DNA sequences of a chloroplast gene. The sequence of 1206 nt of the large subunit of the ribulose-bisphosphate carboxylase gene (rbcL) was determined from 58 species, representing almost all families of leptosporangiate ferns. Phlogenetic trees were inferred by the neighbor-joining and the parsimony methods. The two methods produced almost identical phylogenetic trees that provided insights concerning major general evolutionary trends in the leptosporangiate ferns. Interesting findings were as follows: (i) two morphologically distinct heterosporous water ferns, Marsilea and Salvinia, are sister genera; (ii) the tree ferns (Cyatheaceae, Dicksoniaceae, and Metaxyaceae) are monophyletic; and (iii) polypodioids are distantly related to the gleichenioids in spite of the similarity of their exindusiate soral morphology and are close to the higher indusiate ferns. In addition, the affinities of several "problematic genera" were assessed.

  13. OpenRBC: Redefining the Frontier of Red Blood Cell Simulations at Protein Resolution

    Science.gov (United States)

    Tang, Yu-Hang; Lu, Lu; Li, He; Grinberg, Leopold; Sachdeva, Vipin; Evangelinos, Constantinos; Karniadakis, George

    We present a from-scratch development of OpenRBC, a coarse-grained molecular dynamics code, which is capable of performing an unprecedented in silico experiment - simulating an entire mammal red blood cell lipid bilayer and cytoskeleton modeled by 4 million mesoscopic particles - on a single shared memory node. To achieve this, we invented an adaptive spatial searching algorithm to accelerate the computation of short-range pairwise interactions in an extremely sparse 3D space. The algorithm is based on a Voronoi partitioning of the point cloud of coarse-grained particles, and is continuously updated over the course of the simulation. The algorithm enables the construction of a lattice-free cell list, i.e. the key spatial searching data structure in our code, in O (N) time and space space with cells whose position and shape adapts automatically to the local density and curvature. The code implements NUMA/NUCA-aware OpenMP parallelization and achieves perfect scaling with up to hundreds of hardware threads. The code outperforms a legacy solver by more than 8 times in time-to-solution and more than 20 times in problem size, thus providing a new venue for probing the cytomechanics of red blood cells. This work was supported by the Department of Energy (DOE) Collaboratory on Mathematics for Mesoscopic Model- ing of Materials (CM4). YHT acknowledges partial financial support from an IBM Ph.D. Scholarship Award.

  14. 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.

  15. Lizard activity and abundance greater in burned habitat of a xeric montane forest

    Science.gov (United States)

    Fouts, Kevin L.; Moore, Clinton; Johnson, Kristine D.; Maerz, John C.

    2017-01-01

    Restoring the natural or historical state of ecosystems is a common objective among resource managers, but determining whether desired system responses to management actions are occurring is often protracted and challenging. For wildlife, the integration of mechanistic habitat modeling with population monitoring may provide expedited measures of management effectiveness and improve understanding of how management actions succeed or fail to recover populations. Southern Appalachia is a region of high biodiversity that has undergone dramatic change as a result of human activities such as historic logging, exotic invasions, and alteration of disturbance regimes—including reduction in application of fire. Contemporary efforts to restore fire-maintained ecosystems within southern Appalachian forests require tools to assess the effects of fire management practices on individual animal fitness and relate them to corresponding influences on species abundance. Using automated sensing equipment, we investigated the effects of burned forests on reptile habitat suitability within the western portion of Great Smoky Mountains National Park, Tennessee. Specifically, we used microclimate measurements to model northern fence lizard Sceloporus undulatus hyacinthinus diurnal activity budgets in unburned and variable burn age (3–27-y) forest stands. We estimated northern fence lizard occurrence and abundance along transects through burned and unburned forests. Burned forest stands had microclimates that resulted in longer modeled daily activity periods under most conditions during summer. S. undulatus abundance was 4.75 times greater on burned stands compared to paired unburned stands, although the relationship between burn age and abundance was not well determined. Results suggest the more open habitat structure of burned areas within these xeric pine–oak forests may benefit S. undulatus.

  16. 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

  17. Preliminary assessment of changes in a lizard assemblage at an ecotone in southeastern Arizona

    Science.gov (United States)

    Lawrence L. C. Jones

    2013-01-01

    The Madrean Archipelago and its associated valleys have the highest diversity of lizards in the United States. This is due to a convergence of ecoregions in an area that provides excellent environmental conditions for life history needs of terrestrial ectotherms. The study area, near Safford, Arizona, is known to have about 20 species of sympatric lizards, although...

  18. 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

  19. DNA Barcoding the Canadian Arctic Flora: Core Plastid Barcodes (rbcL + matK) for 490 Vascular Plant Species

    Science.gov (United States)

    Saarela, Jeffery M.; Sokoloff, Paul C.; Gillespie, Lynn J.; Consaul, Laurie L.; Bull, Roger D.

    2013-01-01

    Accurate identification of Arctic plant species is critical for understanding potential climate-induced changes in their diversity and distributions. To facilitate rapid identification we generated DNA barcodes for the core plastid barcode loci (rbcL and matK) for 490 vascular plant species, representing nearly half of the Canadian Arctic flora and 93% of the flora of the Canadian Arctic Archipelago. Sequence recovery was higher for rbcL than matK (93% and 81%), and rbcL was easier to recover than matK from herbarium specimens (92% and 77%). Distance-based and sequence-similarity analyses of combined rbcL + matK data discriminate 97% of genera, 56% of species, and 7% of infraspecific taxa. There is a significant negative correlation between the number of species sampled per genus and the percent species resolution per genus. We characterize barcode variation in detail in the ten largest genera sampled (Carex, Draba, Festuca, Pedicularis, Poa, Potentilla, Puccinellia, Ranunculus, Salix, and Saxifraga) in the context of their phylogenetic relationships and taxonomy. Discrimination with the core barcode loci in these genera ranges from 0% in Salix to 85% in Carex. Haplotype variation in multiple genera does not correspond to species boundaries, including Taraxacum, in which the distribution of plastid haplotypes among Arctic species is consistent with plastid variation documented in non-Arctic species. Introgression of Poa glauca plastid DNA into multiple individuals of P. hartzii is problematic for identification of these species with DNA barcodes. Of three supplementary barcode loci (psbA–trnH, psbK–psbI, atpF–atpH) collected for a subset of Poa and Puccinellia species, only atpF–atpH improved discrimination in Puccinellia, compared with rbcL and matK. Variation in matK in Vaccinium uliginosum and rbcL in Saxifraga oppositifolia corresponds to variation in other loci used to characterize the phylogeographic histories of these Arctic-alpine species. PMID

  20. 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

    2014-11-01

    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 (Bosc & 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. © 2014 Entomological Society of America.

  1. Intraspecific competition and high food availability are associated with insular gigantism in a lizard.

    Science.gov (United States)

    Pafilis, Panayiotis; Meiri, Shai; Foufopoulos, Johannes; Valakos, Efstratios

    2009-09-01

    Resource availability, competition, and predation commonly drive body size evolution. We assess the impact of high food availability and the consequent increased intraspecific competition, as expressed by tail injuries and cannibalism, on body size in Skyros wall lizards (Podarcis gaigeae). Lizard populations on islets surrounding Skyros (Aegean Sea) all have fewer predators and competitors than on Skyros but differ in the numbers of nesting seabirds. We predicted the following: (1) the presence of breeding seabirds (providing nutrients) will increase lizard population densities; (2) dense lizard populations will experience stronger intraspecific competition; and (3) such aggression, will be associated with larger average body size. We found a positive correlation between seabird and lizard densities. Cannibalism and tail injuries were considerably higher in dense populations. Increases in cannibalism and tail loss were associated with large body sizes. Adult cannibalism on juveniles may select for rapid growth, fuelled by high food abundance, setting thus the stage for the evolution of gigantism.

  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. 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 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.

  4. Delimiting the species Neosiphonia yendoi (Rhodomelaceae, Rhodophyta) based on COI and rbcL genetic variation in Korea and Japan

    Science.gov (United States)

    Kim, Byeongseok; Yang, Mi Yeon; Kim, Myung Sook

    2016-09-01

    Although the marine red algal genus Neosiphonia is well characterized, many species of Neosiphonia are poorly understood. To correctly define the species delimitation of Neosiphonia yendoi using genetic variation, owing to the confusion over identification with " N. sphaerocarpa" from Korea, we investigated intensively the haplotype network of the mitochondrial COI and the plastid rbcL genes of specimens collected from Korea and Japan. The molecular analyses indicated that specimens collected in different sites of Korea and Japan belong to the same species, Neosiphonia yendoi and " Neosiphonia sphaerocarpa" from Korea, which is distinguished from N. sphaerocarpa from Florida and is allied with N. yendoi collected from the type locality, Muroran of Japan. A total of 29 COI and 13 rbcL haplotypes were found and the COI haplotype network shows evidence of a clear break between specimens from Jeju Island and all other locations of Korea, suggesting the possibility of cryptic diversity within N. yendoi.

  5. 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......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...

  6. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. 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.

  8. RBC-/Cr-51/ half-life and albumin turnover in growing Beagle dogs during chronic radial acceleration

    Science.gov (United States)

    Beckman, D. A.; Evans, J. W.; Oyama, J.

    1979-01-01

    The effects of chronic centrifugation on growing Beagle dogs exposed to -2 or -2.6 Gx on albumin and RBC turnover rates, albumin concentration and space, and total blood volume were determined and compared with caged and run control of animals. Albumin-(I-125) and autologous RBC-(Cr-51) preparations were injected into all dogs at day 82 of the centrifugation periods, and the disappearance curves were determined by successive bleedings of the animals over the next 35 d, during which the centrifugation was continued. There were no differences in albumin turnover rates or space. Two populations of RBCs were found in both centrifugated groups, one with a normal half-life of 27 + or - 1 S.E.M. d, and one with a significantly (p less than 0.01) shorter half-life of 15 + or - 2 S.E.M. d. An absolute polycythemia was also observed in both centrifuged groups. The results suggest that chronic centrifugation acts through some as-yet unknown mechanism to affect RBC population kinetics.

  9. Epidemiology of RBC Transfusions in Patients With Severe Acute Kidney Injury: Analysis From the Randomized Evaluation of Normal Versus Augmented Level Study.

    Science.gov (United States)

    Bellomo, Rinaldo; Mårtensson, Johan; Kaukonen, Kirsi-Maija; Lo, Serigne; Gallagher, Martin; Cass, Alan; Myburgh, John; Finfer, Simon

    2016-05-01

    To assess the epidemiology and outcomes associated with RBC transfusion in patients with severe acute kidney injury requiring continuous renal replacement therapy. Post hoc analysis of data from a multicenter, randomized, controlled trial. Thirty-five ICUs in Australia and New Zealand. Cohort of 1,465 patients enrolled in the Randomized Evaluation of Normal versus Augmented Level replacement therapy study. Daily information on morning hemoglobin level and amount of RBC transfused were prospectively collected in the Randomized Evaluation of Normal versus Augmented Level study. We analyzed the epidemiology of such transfusions and their association with clinical outcomes. Overall, 977 patients(66.7%) received a total of 1,192 RBC units. By day 5, 785 of 977 transfused patients (80.4%) had received at least one RBC transfusion. Hemoglobin at randomization was lower in transfused than in nontransfused patients (94 vs 111 g/L; p regression analysis, RBC transfusion was independently associated with lower 90-day mortality (hazard ratio, 0.55; 95% CI, 0.38-0.79). However, we found no independent association between RBC transfusions and mortality when the analyses were restricted to patients surviving at least 5 days (hazard ratio, 1.29; 95% CI, 0.90-1.85). We found no independent association between RBC transfusion and renal replacement therapy-free days, mechanical ventilator-free days, or length of stay in ICU or hospital. In patients with severe acute kidney injury treated with continuous renal replacement therapy, we found no association of RBC transfusion with 90-day mortality or other patient-centered outcomes. The optimal hemoglobin threshold for RBC transfusion in such patients needs to be determined in future randomized controlled trials.

  10. Reconstructing a herbivore's diet using a novel rbcL DNA mini-barcode for plants.

    Science.gov (United States)

    Erickson, David L; Reed, Elizabeth; Ramachandran, Padmini; Bourg, Norman A; McShea, William J; Ottesen, Andrea

    2017-05-01

    Next Generation Sequencing and the application of metagenomic analyses can be used to answer questions about animal diet choice and study the consequences of selective foraging by herbivores. The quantification of herbivore diet choice with respect to native versus exotic plant species is particularly relevant given concerns of invasive species establishment and their effects on ecosystems. While increased abundance of white-tailed deer ( Odocoileus virginianus ) appears to correlate with increased incidence of invasive plant species, data supporting a causal link is scarce. We used a metabarcoding approach (PCR amplicons of the plant rbc L gene) to survey the diet of white-tailed deer (fecal samples), from a forested site in Warren County, Virginia with a comprehensive plant species inventory and corresponding reference collection of plant barcode and chloroplast sequences. We sampled fecal pellet piles and extracted DNA from 12 individual deer in October 2014. These samples were compared to a reference DNA library of plant species collected within the study area. For 72 % of the amplicons, we were able to assign taxonomy at the species level, which provides for the first time-sufficient taxonomic resolution to quantify the relative frequency at which native and exotic plant species are being consumed by white-tailed deer. For each of the 12 individual deer we collected three subsamples from the same fecal sample, resulting in sequencing 36 total samples. Using Qiime, we quantified the plant DNA found in all 36 samples, and found that variance within samples was less than variance between samples ( F  = 1.73, P  = 0.004), indicating additional subsamples may not be necessary. Species level diversity ranged from 60 to 93 OTUs per individual and nearly 70 % of all plant sequences recovered were from native plant species. The number of species detected did reduce significantly (range 4-12) when we excluded species whose OTU composed plants inventoried

  11. Circadian rhythm of temperature selection in a nocturnal lizard.

    Science.gov (United States)

    Refinetti, R; Susalka, S J

    1997-08-01

    We recorded body temperature and locomotor activity of Tokay geckos (Gekko gecko) with free access to a heat source under a 14:10 light-dark cycle and in constant darkness. Under the light-dark cycle, the lizards selected higher temperatures during the light phase, when locomotor activity was less intense. Rhythmicity in temperature selection was transiently disrupted but later resumed when the animals were placed in constant darkness. These results demonstrate the existence of a circadian rhythm of temperature selection in nocturnal ectotherms and extend previous findings of a temporal mismatch between the rhythms of locomotor activity and temperature selection in nocturnal rodents.

  12. The blue lizard spandrel and the island syndrome.

    Science.gov (United States)

    Raia, Pasquale; Guarino, Fabio M; Turano, Mimmo; Polese, Gianluca; Rippa, Daniela; Carotenuto, Francesco; Monti, Daria M; Cardi, Manuela; Fulgione, Domenico

    2010-09-20

    Many small vertebrates on islands grow larger, mature later, lay smaller clutches/litters, and are less sexually dimorphic and aggressive than their mainland relatives. This set of observations is referred to as the 'Island Syndrome'. The syndrome is linked to high population density on islands. We predicted that when population density is low and/or fluctuating insular vertebrates may evolve correlated trait shifts running opposite to the Island Syndrome, which we collectively refer to as the 'reversed island syndrome' (RIS) hypothesis. On the proximate level, we hypothesized that RIS is caused by increased activity levels in melanocortin receptors. Melanocortins are postranslational products of the proopiomelanocortin gene, which controls pleiotropically pigmentation, aggressiveness, sexual activity, and food intake in vertebrates. We tested the RIS hypothesis performing a number of behavioral, genetic, and ontogenetic tests on a blue colored insular variant of the Italian Wall lizard Podarcis sicula, living on a small island off the Southern Italian coast. The population density of this blue-colored variant was generally low and highly fluctuating from one year to the next.In keeping with our predictions, insular lizards were more aggressive and sexually dimorphic than their mainland relatives. Insular males had wide, peramorphic heads. The growth rate of insular females was slower than growth rates of mainland individuals of both sexes, and of insular males. Consequently, size and shape dimorphism are higher on the Island. As predicted, melanocortin receptors were much more active in individuals of the insular population. Insular lizards have a higher food intake rate than mainland individuals, which is consistent with the increased activity of melanocortin receptors. This may be adaptive in an unpredictable environment such as Licosa Island. Insular lizards of both sexes spent less time basking than their mainland relatives. We suspect this is a by

  13. The blue lizard spandrel and the island syndrome

    Directory of Open Access Journals (Sweden)

    Monti Daria M

    2010-09-01

    Full Text Available Abstract Background Many small vertebrates on islands grow larger, mature later, lay smaller clutches/litters, and are less sexually dimorphic and aggressive than their mainland relatives. This set of observations is referred to as the 'Island Syndrome'. The syndrome is linked to high population density on islands. We predicted that when population density is low and/or fluctuating insular vertebrates may evolve correlated trait shifts running opposite to the Island Syndrome, which we collectively refer to as the 'reversed island syndrome' (RIS hypothesis. On the proximate level, we hypothesized that RIS is caused by increased activity levels in melanocortin receptors. Melanocortins are postranslational products of the proopiomelanocortin gene, which controls pleiotropically pigmentation, aggressiveness, sexual activity, and food intake in vertebrates. Results We tested the RIS hypothesis performing a number of behavioral, genetic, and ontogenetic tests on a blue colored insular variant of the Italian Wall lizard Podarcis sicula, living on a small island off the Southern Italian coast. The population density of this blue-colored variant was generally low and highly fluctuating from one year to the next. In keeping with our predictions, insular lizards were more aggressive and sexually dimorphic than their mainland relatives. Insular males had wide, peramorphic heads. The growth rate of insular females was slower than growth rates of mainland individuals of both sexes, and of insular males. Consequently, size and shape dimorphism are higher on the Island. As predicted, melanocortin receptors were much more active in individuals of the insular population. Insular lizards have a higher food intake rate than mainland individuals, which is consistent with the increased activity of melanocortin receptors. This may be adaptive in an unpredictable environment such as Licosa Island. Insular lizards of both sexes spent less time basking than their

  14. Does the Morphology of the Forelimb Flexor Muscles Differ Between Lizards Using Different Habitats?

    Science.gov (United States)

    Lowie, Aurélien; Herrel, Anthony; Abdala, Virginia; Manzano, Adriana S; Fabre, Anne-Claire

    2018-03-01

    Lizards are an interesting group to study how habitat use impacts the morphology of the forelimb because they occupy a great diversity of ecological niches. In this study, we specifically investigated whether habitat use impacts the morphology of the forelimb flexor muscles in lizards. To do so, we performed dissections and quantified the physiological cross sectional area (PCSA), the fiber length, and the mass of four flexor muscles in 21 different species of lizards. Our results show that only the PCSA of the m. flexor carpi radialis is different among lizards with different ecologies (arboreal versus non-arboreal). This difference disappeared, however, when taking phylogeny into account. Arboreal species have a higher m. flexor carpi radialis cross sectional area likely allowing them to flex the wrist more forcefully which may allow them climb and hold on to branches better. In contrast, other muscles are not different between arboreal and non-arboreal species. Further studies focusing on additional anatomical features of the lizard forelimb as well as studies documenting how lizards use the arboreal niche are needed to fully understand how an arboreal life style may constrain limb morphology in lizards. Anat Rec, 301:424-433, 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

  15. 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.

  16. 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.

  17. Effects of asymmetry and learning on phonotaxis in a robot based on the lizard auditory system

    DEFF Research Database (Denmark)

    Zhang, L.; Hallam, J.; Christensen-Dalsgaard, J.

    2012-01-01

    Lizards have strong directional hearing across a broad band of frequencies. The directionality can be attributed to the acoustical properties of the ear, especially the strong acoustical coupling of the two eardrums. The peripheral auditory system of the lizard has previously been modeled...... and magnitude of their intrinsic bias. To attain effective directional hearing, the bias in the peripheral system should be compensated. In this article, with the peripheral models, we design a decision model and a behavior model, a virtual robot, to simulate the auditory system of the lizard in software...

  18. 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. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  19. Chemical communication, sexual selection, and introgression in wall lizards.

    Science.gov (United States)

    MacGregor, Hannah E A; Lewandowsky, Rachel A M; d'Ettorre, Patrizia; Leroy, Chloé; Davies, Noel W; While, Geoffrey M; Uller, Tobias

    2017-10-01

    Divergence in communication systems should influence the likelihood that individuals from different lineages interbreed, and consequently shape the direction and rate of hybridization. Here, we studied the role of chemical communication in hybridization, and its contribution to asymmetric and sexually selected introgression between two lineages of the common wall lizard (Podarcis muralis). Males of the two lineages differed in the chemical composition of their femoral secretions. Chemical profiles provided information regarding male secondary sexual characters, but the associations were variable and inconsistent between lineages. In experimental contact zones, chemical composition was weakly associated with male reproductive success, and did not predict the likelihood of hybridization. Consistent with these results, introgression of chemical profiles in a natural hybrid zone resembled that of neutral nuclear genetic markers overall, but one compound in particular (tocopherol methyl ether) matched closely the introgression of visual sexual characters. These results imply that associations among male chemical profiles, sexual characters, and reproductive success largely reflect transient and environmentally driven effects, and that genetic divergence in chemical composition is largely neutral. We therefore suggest that femoral secretions in wall lizards primarily provide information about residency and individual identity rather than function as sexual signals. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

  20. 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. Copyright © 2016 Elsevier Inc. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    I.G. Cordes

    1996-08-01

    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.

  2. Aggressive behavior and performance in the Tegu lizard Tupinambis merianae.

    Science.gov (United States)

    Herrel, Anthony; Andrade, Denis V; de Carvalho, José Eduardo; Brito, Ananda; Abe, Augusto; Navas, Carlos

    2009-01-01

    Aggression is an important component of behavior in many animals and may be crucial to providing individuals with a competitive advantage when resources are limited. Although much is known about the effects of catecholamines and hormones on aggression, relatively few studies have examined the effects of physical performance on aggression. Here we use a large, sexually dimorphic teiid lizard to test whether individuals that show high levels of physical performance (bite force) are also more aggressive toward a potential threat (i.e., a human approaching the lizard). Our results show that independent of their sex, larger individuals with higher bite forces were indeed more aggressive. Moreover, our data show that individuals with higher bite forces tend to show decreased escape responses and are slower, providing evidence for a trade-off between fight and flight abilities. As bite force increased dramatically with body size, we suggest that large body size and bite force may reduce the threshold for an individual to engage in an aggressive encounter, allowing it to potentially gain or maintain resources and fight off predators while minimizing the risk of injury.

  3. Incubation environment impacts the social cognition of adult lizards.

    Science.gov (United States)

    Siviter, Harry; Deeming, D Charles; van Giezen, M F T; Wilkinson, Anna

    2017-11-01

    Recent work exploring the relationship between early environmental conditions and cognition has shown that incubation environment can influence both brain anatomy and performance in simple operant tasks in young lizards. It is currently unknown how it impacts other, potentially more sophisticated, cognitive processes. Social-cognitive abilities, such as gaze following and social learning, are thought to be highly adaptive as they provide a short-cut to acquiring new information. Here, we investigated whether egg incubation temperature influenced two aspects of social cognition, gaze following and social learning in adult reptiles ( Pogona vitticeps ). Incubation temperature did not influence the gaze following ability of the bearded dragons; however, lizards incubated at colder temperatures were quicker at learning a social task and faster at completing that task. These results are the first to show that egg incubation temperature influences the social cognitive abilities of an oviparous reptile species and that it does so differentially depending on the task. Further, the results show that the effect of incubation environment was not ephemeral but lasted long into adulthood. It could thus have potential long-term effects on fitness.

  4. Arabidopsis Pol II-Dependent in Vitro Transcription System Reveals Role of Chromatin for Light-Inducible rbcS Gene Transcription1

    Science.gov (United States)

    Ido, Ayaka; Iwata, Shinya; Iwata, Yuka; Igarashi, Hisako; Hamada, Takahiro; Sonobe, Seiji; Sugiura, Masahiro; Yukawa, Yasushi

    2016-01-01

    In vitro transcription is an essential tool to study the molecular mechanisms of transcription. For over a decade, we have developed an in vitro transcription system from tobacco (Nicotiana tabacum)-cultured cells (BY-2), and this system supported the basic activities of the three RNA polymerases (Pol I, Pol II, and Pol III). However, it was not suitable to study photosynthetic genes, because BY-2 cells have lost their photosynthetic activity. Therefore, Arabidopsis (Arabidopsis thaliana) in vitro transcription systems were developed from green and etiolated suspension cells. Sufficient in vitro Pol II activity was detected after the minor modification of the nuclear soluble extracts preparation method; removal of vacuoles from protoplasts and L-ascorbic acid supplementation in the extraction buffer were particularly effective. Surprisingly, all four Arabidopsis Rubisco small subunit (rbcS-1A, rbcS-1B, rbcS-2B, and rbcS-3B) gene members were in vitro transcribed from the naked DNA templates without any light-dependent manner. However, clear light-inducible transcriptions were observed using chromatin template of rbcS-1A gene, which was prepared with a human nucleosome assembly protein 1 (hNAP1) and HeLa histones. This suggested that a key determinant of light-dependency through the rbcS gene transcription was a higher order of DNA structure (i.e. chromatin). PMID:26662274

  5. 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.

  6. 浮萍中一个新rbcS基因启动子的克隆及分析%Analysis of a Novel rbcS Promoter Cloned in Duckweed

    Institute of Scientific and Technical Information of China (English)

    王友如

    2010-01-01

    为了分离组织特异性、诱导性的启动子,本研究根据新克隆的浮萍rbcS基因序列设计引物,采用改进的5'walking技术从浮萍基因组中克隆了一个新的rbcS基因启动子,命名为SSU5C基因启动子.序列分析表明:SSU5C基因启动子长度为1 543 bp,含有保守性元件TATA和CAAT box,并且含有水杨酸、脱落酸、赤霉素、茉莉酸甲酯等植物激素和葡萄糖等的保守顺式作用元件.In silico分析初步推测SSU5C基因启动子受多种信号途径的协调调控.

  7. A model for the relation between stimulus frequency and spontaneous otoacoustic emissions in lizard papillae.

    Science.gov (United States)

    Wit, Hero P; van Dijk, Pim; Manley, Geoffrey A

    2012-11-01

    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 derived from hair cells as active oscillators. Data from the ears of two lizard species, one lacking a tectorial membrane and one with a chain of tectorial sallets, as described by Bergevin et al. ["Coupled, active oscillators and lizard otoacoustic emissions," AIP Conf. Proc. 1403, 453 (2008)], are modeled as an array of coupled self-sustained oscillators. The model, originally developed by Vilfan and Duke ["Frequency clustering in spontaneous otoacoustic emissions from a lizard's ear," Biophys. J. 95, 4622-4630 (2008)], well describes both the amplitude and phase characteristics of SFOAEs and the relation between SFOAEs and SOAEs.

  8. Rates of pulmonary infection by pentastomids in lizards species from a restinga habitat in northeastern Brazil.

    Science.gov (United States)

    Almeida, W O; Santana, G G; Vieira, W L S; Wanderley, I C; Ribeiro, S C

    2009-02-01

    Pulmonary parasitism by pentastomids was examined in two lizard species inhabiting an area of restinga vegetation (coastal sand dunes) situated in the municipality of Mataraca (6 degrees 29' S and 34 degrees 56' W), on the extreme northern coast of Paraíba State, Brazil. A total of 123 lizards were collected, being 75 specimens of Micrablepharus maximiliani (Gymnophtalmidae) and 48 specimens of Cnemidophorus ocellifer (Teiidae). Only a single species of Pentastomida (Raillietiella mottae) was found parasitizing three females M. maximiliani, with a prevalence of 4% and an average infection intensity of 2.3 +/- 1.3 (range 1-5). The infection rate by pentastomids encountered in the present study was similar to that seen with other species of restinga lizards. Raillietiella mottae is a generalist parasite species that is probably transmitted by common and widely distributed insects making up part of the diet of many insectivorous lizard species from northeastern Brazil.

  9. Chemical constituents of the femoral gland secretions of male tegu lizards (Tupinambis merianae) (Family teiidae).

    Science.gov (United States)

    Martín, José; Chamut, Silvia; Manes, Mario E; López, Pilar

    2011-01-01

    In spite of the importance of chemical signals (pheromones) in the reproductive behaviour of lizards, the chemical compounds secreted by their femoral glands, which may be used as sexual signals, are only known for a few lizard species. Based on mass spectra, obtained by GC-MS, we found 49 lipophilic compounds in femoral gland secretions of male tegu lizards (Tupinambis merianae) (fam. Teiidae), including a very high proportion of carboxylic acids and their esters ranging between n-C8 and n-C20 (mainly octadecanoic and 9,12-octadecadienoic acids), with much less proportions of steroids, tocopherol, aldehydes, and squalene. We discuss the potential function of these compounds in secretions, and compare the compounds found here with those documented for other lizard species.

  10. 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.

  11. Population demography of an endangered lizard, the Blue Mountains Water Skink

    OpenAIRE

    Dubey, Sylvain; Sinsch, Ulrich; Dehling, Maximilian J; Chevalley, Maya; Shine, Richard

    2013-01-01

    BACKGROUND: Information on the age structure within populations of an endangered species can facilitate effective management. The Blue Mountains Water Skink (Eulamprus leuraensis) is a viviparous scincid lizard that is restricted to < 40 isolated montane swamps in south-eastern Australia. We used skeletochronology of phalanges (corroborated by mark-recapture data) to estimate ages of 222 individuals from 13 populations. RESULTS: These lizards grow rapidly, from neonatal size (30 mm snou...

  12. Variation in the diet of the lizard Tropidurus torquatus along its coastal range in Brazil

    OpenAIRE

    Siqueira, Carla Costa; Kiefer, Mara Cíntia; Sluys, Monique Van; Rocha, Carlos Frederico Duarte

    2013-01-01

    The diet composition of lizards of a given species may vary among different populations. The feeding ecology of the tropidurid lizard Tropidurus torquatus was studied in 10 coastal areas in Brazil in order to detect to what extent the diet varies along its geographic range. A non-metric multidimensional scaling technique revealed three groups of localities according to the diet composition: one characterized by a relatively high consumption of Isoptera, one characterized by a relatively high ...

  13. Rates of pulmonary infection by pentastomids in lizards species from a restinga habitat in northeastern Brazil

    OpenAIRE

    Almeida, WO.; Santana, GG.; Vieira, WLS.; Wanderley, IC.; Ribeiro, SC.

    2009-01-01

    Pulmonary parasitism by pentastomids was examined in two lizard species inhabiting an area of restinga vegetation (coastal sand dunes) situated in the municipality of Mataraca (6° 29' S and 34° 56' W), on the extreme northern coast of Paraíba State, Brazil. A total of 123 lizards were collected, being 75 specimens of Micrablepharus maximiliani (Gymnophtalmidae) and 48 specimens of Cnemidophorus ocellifer (Teiidae). Only a single species of Pentastomida (Raillietiella mottae) was found parasit...

  14. Tegu (teiu) bite: report of human injury caused by a Teiidae lizard.

    Science.gov (United States)

    Haddad, Vidal; Duarte, Marcelo R; Neto, Domingos Garrone

    2008-01-01

    Lizards of the Teiidae family are large reptiles measuring up to 2 meters long. If threatened, they can demonstrate aggressive behavior by whipping their tail and occasionally biting. Here, we report a severe injury following a Teiidae lizard bite on the right index finger of a human. There was significant soft tissue damage and an avulsion fracture of the distal phalanx. He was treated with conservative wound care and prophylactic antibiotics. He developed no evidence of secondary infection and underwent delayed skin grafting.

  15. 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 ...

  16. 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...

  17. Can Camera Traps Monitor Komodo Dragons a Large Ectothermic Predator?

    OpenAIRE

    Ariefiandy, Achmad; Purwandana, Deni; Seno, Aganto; Ciofi, Claudio; Jessop, Tim S.

    2013-01-01

    Camera trapping has greatly enhanced population monitoring of often cryptic and low abundance apex carnivores. Effectiveness of passive infrared camera trapping, and ultimately population monitoring, relies on temperature mediated differences between the animal and its ambient environment to ensure good camera detection. In ectothermic predators such as large varanid lizards, this criterion is presumed less certain. Here we evaluated the effectiveness of camera trapping to potentially monitor...

  18. 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.

    2014-01-01

    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. PMID:25533521

  19. Validation of the HTO-18 method for determination of CO2 production of lizards (genus Sceloporus)

    International Nuclear Information System (INIS)

    Congdon, J.D.; King, W.W.; Nagy, K.A.

    1978-01-01

    The accuracy of doubly-labeled water measurements of CO 2 production in lizards of the genus Sceloporus was assessed by comparison of CO 2 production rates determined simultaneously by labeled water and gas chromatography. Five lizards were weighed and given intraperitoneal injections of 55 μl of water containing 10 microcuries of tritium as HTO and 50 atom % oxygen-18 as H 2 18 O. Initial blood samples were taken from the infraorbital sinus ten hours later, and the lizards were placed in sealed metabolism chambers kept at 28 C. After 179 h the lizards were weighed and blood samples taken. Blood samples were microdistilled, assayed for tritium activity and for oxygen-18 content. Isotope measurements were used to calculate rates of CO 2 production. Gas samples were withdrawn from each chamber after 18, 63, 109, and 179 h and measured against 0.5 and 1.0% CO 2 standards with a Beckman GC-55 gas chromatograph fitted with silica gel 42-60 mesh column. These results were used to calculate rates of CO 2 production. Results supported the conclusion that the doubly-labeled water method accurately measured rates of CO 2 production in Sceloporus lizards, and could therefore be a valuable technique in field studies of lizard energetics

  20. Leukocyte profiles for western fence lizards, Sceloporus occidentalis, naturally infected by the malaria parasite Plasmodium mexicanum.

    Science.gov (United States)

    Motz, Victoria L; Lewis, William D; Vardo-Zalik, Anne M

    2014-10-01

    Plasmodium mexicanum is a malaria parasite that naturally infects the western fence lizard, Sceloporus occidentalis , in northern California. We set out to determine whether lizards naturally infected with this malaria parasite have different leukocyte profiles, indicating an immune response to infection. We used 29 naturally infected western fence lizards paired with uninfected lizards based on sex, snout-to-vent length, tail status, and the presence-absence of ectoparasites such as ticks and mites, as well as the presence-absence of another hemoparasite, Schellackia occidentalis. Complete white blood cell (WBC) counts were conducted on blood smears stained with Giemsa, and the proportion of granulocytes per microliter of blood was estimated using the Avian Leukopet method. The abundance of each WBC class (lymphocytes, monocytes, heterophils, eosinophils, and basophils) in infected and uninfected lizards was compared to determine whether leukocyte densities varied with infection status. We found that the numbers of WBCs and lymphocytes per microliter of blood significantly differed (P lizard's immune response to increase the levels of circulating WBCs, but what effect this has on the biology of the parasite remains unclear.

  1. 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.

  2. HSF1 and HSF3 cooperatively regulate the heat shock response in lizards.

    Science.gov (United States)

    Takii, Ryosuke; Fujimoto, Mitsuaki; Matsuura, Yuki; Wu, Fangxu; Oshibe, Namiko; Takaki, Eiichi; Katiyar, Arpit; Akashi, Hiroshi; Makino, Takashi; Kawata, Masakado; Nakai, Akira

    2017-01-01

    Cells cope with temperature elevations, which cause protein misfolding, by expressing heat shock proteins (HSPs). This adaptive response is called the heat shock response (HSR), and it is regulated mainly by heat shock transcription factor (HSF). Among the four HSF family members in vertebrates, HSF1 is a master regulator of HSP expression during proteotoxic stress including heat shock in mammals, whereas HSF3 is required for the HSR in birds. To examine whether only one of the HSF family members possesses the potential to induce the HSR in vertebrate animals, we isolated cDNA clones encoding lizard and frog HSF genes. The reconstructed phylogenetic tree of vertebrate HSFs demonstrated that HSF3 in one species is unrelated with that in other species. We found that the DNA-binding activity of both HSF1 and HSF3 in lizard and frog cells was induced in response to heat shock. Unexpectedly, overexpression of lizard and frog HSF3 as well as HSF1 induced HSP70 expression in mouse cells during heat shock, indicating that the two factors have the potential to induce the HSR. Furthermore, knockdown of either HSF3 or HSF1 markedly reduced HSP70 induction in lizard cells and resistance to heat shock. These results demonstrated that HSF1 and HSF3 cooperatively regulate the HSR at least in lizards, and suggest complex mechanisms of the HSR in lizards as well as frogs.

  3. 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.

  4. Analysis of DNA damage in lizards D.raddei, from areas with different levels of soil contamination using comet assay

    International Nuclear Information System (INIS)

    Simonyan, A.E.; Gevorgyan, A.L.; Sargsyan, A.A.; Arakelyan, M.S.; Minasyan, S.H.

    2015-01-01

    The levels of DNA damage in erythrocytes of rock lizards Darevskia raddei from reserve Shikahogh and Kajaran (Republic of Armenia) and Zuar (Nagorno-Karabakh Republic), were assessed using the comet assay. Female lizards were more sensitive to environmental pollutants than males. Significant positive correlation was found between DNA damage in female lizards and content of Cu, Mo, Pb, Cd, V and As in soil

  5. Determination of degree of RBC agglutination for blood typing using a small quantity of blood sample in a microfluidic system.

    Science.gov (United States)

    Chang, Yaw-Jen; Ho, Ching-Yuan; Zhou, Xin-Miao; Yen, Hsiu-Rong

    2018-04-15

    Blood typing assay is a critical test to ensure the serological compatibility of a donor and an intended recipient prior to a blood transfusion. This paper presents a microfluidic blood typing system using a small quantity of blood sample to determine the degree of agglutination of red blood cell (RBC). Two measuring methods were proposed: impedimetric measurement and electroanalytical measurement. The charge transfer resistance in the impedimetric measurement and the power parameter in the electroanalytical measurement were used for the analysis of agglutination level. From the experimental results, both measuring methods provide quantitative results, and the parameters are linearly and monotonically related to the degree of RBC agglutination. However, the electroanalytical measurement is more reliable than the impedimetric technique because the impedimetric measurement may suffer from many influencing factors, such as chip conditions. Five levels from non-agglutination (level 0) to strong agglutination (level 4+) can be discriminated in this study, conforming to the clinical requirement to prevent any risks in transfusion. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Oral supplementation of vitamin E reduces osmotic fragility of RBC in hemolytic anemic patients with G6PD deficiency

    International Nuclear Information System (INIS)

    Sultana, N.; Begum, S.; Begum, N.; Ali, T.

    2009-01-01

    Vitamin E has role in maintaining the integrity of red cell member by preventing oxidation of polyunsaturated fatty acids, thus protects cells from oxidative stress-induced lysis in G6PD deficiency. Changes in osmotic fragility of RBC and some absolute values like MCV, MCH and MCHC may occur in haemolytic anaemic patients with G6PD deficiency. To observe the effects of vitamin E supplementation on these changes in order to evaluate the role of this anti-oxidant vitamin in reducing chronic haemolysis in G6PD deficient patients. A total number of 102 subjects with age ranged of 5 to 40 years of both sexes were included in the study. Among them 68 were G6PD enzyme deficient patients, of whom 34 were in supplemented group (experimental group) and 34 were in non-supplemented group (control group). The supplemented group received vitamin E supplementation for 60 consecutive days at a dose of 800 IU/day for adult and 400 IU/day for children ?12 years (in a divided dose, i.e., 4 times daily). Age and sex matched 34 apparently healthy subjects with normal blood G6PD level were taken to observe the base line data (healthy control) and also for comparison. All the G6PD deficient patients were selected from Out Patient Department (OPD) of Haematology, Banglabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from July 2005 to June 2006 and all healthy subjects were selected from personal contact. Blood G6PD level, osmotic fragility of RBC were measured by standard techniques and MCV, MCH, and MCHC were obtained by calculation. All the parameters were measured on day 1 of their first visit and also were on day 60 in deficient group. Data were compared among the deficient groups, also in supplemented group just before and after supplementation. Analysis of data was done by appropriate statistical method. Mean starting and completing points of osmotic fragility of RBC were significantly higher but MCV. MCH, MCHC were significantly lower in patients suffering from

  7. Genetic regulation of sex differences in songbirds and lizards

    Science.gov (United States)

    Wade, Juli

    2016-01-01

    Sex differences in the morphology of neural and peripheral structures related to reproduction often parallel the frequency of particular behaviours displayed by males and females. In a variety of model organisms, these sex differences are organized in development by gonadal steroids, which also act in adulthood to modulate behavioural expression and in some cases to generate parallel anatomical changes on a seasonal basis. Data collected from diverse species, however, suggest that changes in hormone availability are not sufficient to explain sex and seasonal differences in structure and function. This paper pulls together some of this literature from songbirds and lizards and considers the information in the broader context of taking a comparative approach to investigating genetic mechanisms associated with behavioural neuroendocrinology. PMID:26833833

  8. 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.

  9. Selection of GP. Mur antigen-negative RBC for blood recipients with anti-'Mia ' records decreases transfusion reaction rates in Taiwan.

    Science.gov (United States)

    Yang, C-A; Lin, J-A; Chang, C-W; Wu, K-H; Yeh, S-P; Ho, C-M; Chang, J-G

    2016-10-01

    To evaluate the clinical significance of GP. Mur antigen-negative blood selection for transfusion in patients with anti-'Mi a ' records. The GP. Mur RBC phenotype is prevalent (7·3%) in Taiwan. Antibodies against GP. Mur (anti-'Mi a ') are identified in 1·24% of our population, and anti-'Mi a ' screening using GP. Mur RBC has been routine for Taiwan's blood banks. However, due to the lack of commercial antibodies, only cross-matching was used to prevent transfusion of GP. Mur-positive blood to patients with anti-'Mi a ' in most hospitals. There is still a risk of GP. Mur-positive RBC exposure and subsequent anti-'Mi a '-related transfusion reactions. Since February 2014, GP. Mur antigen-negative RBCs identified by reaction with anti-'Mi a '-positive serum were selected for blood recipients with anti-'Mi a ' records. The transfusion reactions between January 2013 and January 2014 were compared with those that occurred between February 2014 and July 2015. The transfusion reaction rate was significantly higher in anti-'Mi a '-positive blood recipients compared to total subjects receiving an RBC transfusion before GP. Mur-negative donor RBC selection. After antigen-negative RBC selection, the transfusion reaction frequency in subjects with anti-'Mi a ' became similar to total blood recipients. IgG form anti-'Mi a ' antibodies were present in all cases of probable anti-'Mi a '-related transfusion reactions. The time required for anti-'Mi a ' boosting after transfusion was around 4-21 days. Selection of GP. Mur-negative RBC for transfusion to patients with anti-'Mi a ' records could decrease the rate of transfusion reaction and antibody boosting. This procedure should be incorporated into blood bank routines in areas where anti-'Mi a ' is prevalent. © 2016 British Blood Transfusion Society.

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

    Directory of Open Access Journals (Sweden)

    William E. COOPER, Jr., Wade C. SHERBROOKE

    2012-08-01

    Full Text Available 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 [Current Zoology 58 (4: 541–548, 2012].

  11. An ecophysiological background for biogeographic patterns of two island lizards?

    Science.gov (United States)

    Carretero, Miguel A.; Lopes, Evandro P.; Vasconcelos, Raquel

    2016-12-01

    Distributions of sedentary ectotherms are dependent on temperature and humidity due to their low homeostatic and dispersal abilities. Lizards are strongly conditioned by temperature, but hydric environment may be also important, at least in arid environments. Biotic interactions may also play a role in range patterns, but they are of minor importance in islands where native species monopolize well-delimited niche spaces. On the arid island of São Vicente (Cabo Verde), two endemic lizards display different spatial patterns. While the gecko Tarentola substituta is widely distributed across the island, the skink Chioninia stangeri is restricted to the NE, which is cooler, more humid, and vegetated. We hypothesized that this is due to differences in the fundamental niche, specifically in ecophysiology. We predict that C. stangeri should select for lower temperatures and lose more water by evaporation than T. substituta. We submitted adults of each species to standard experiments to assess preferred body temperatures (Tp) and evaporative water loss (EWL) rates, and examined the variation between species and through time using repeated-measures AN(C)OVAs. Results only partially supported our expectations. Contrary to the prediction, skinks attained higher Tp than geckos but in the long term showed a trend for higher EWL as predicted. Thus, while ecophysiology certainly contributes to functional interpretation of species distributions, it needs to be combined with other evidence such as habitat use and evolutionary history. These findings will be useful to perform mechanistic models to better understand the impact of climate change and habitat disturbance on these endemic species.

  12. 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

  13. Behavioral hypothermia of a domesticated lizard under treatment of the hypometabolic agent 3-iodothyronamine.

    Science.gov (United States)

    Ha, Kyoungbong; Shin, Haksup; Ju, Hyunwoo; Chung, Chan-Moon; Choi, Inho

    2017-05-03

    Ectothermic animals rely on behavioral thermoregulation due to low capacity of heat production and storage. Previously, lizards were shown to achieve 'fever' during microbial infection by increasing their preferred body temperature (PBT) behaviorally, thereby attaining a relatively high survival rate. The purpose of this study was to investigate whether domesticated lizards pursued 'behavioral hypothermia' induced by a hypometabolic agent 3-iodothyronamine (T1AM). We found that treatment with 8.0 mg/kg T1AM caused a lizard species, the leopard gecko (Eublepharis macularius), to decrease its ventilation and oxygen consumption rates 0.64- and 0.76-fold, respectively, compared to those of the control (P<0.05). The lizards, habituated at an ambient temperature of 30 ± 0.5°C, also showed a significant decrease in the PBT range over a freely accessible thermal gradient between 5°C and 45°C. The upper limit of the PBT in the treated lizards lowered from 31.9°C to 30.6°C, and the lower limit from 29.5°C to 26.3°C (P<0.001). These findings demonstrate that the treated lizards pursued behavioral hypothermia in conjunction with hypoventilation and hypometabolism. Because prior studies reported a similar hypometabolic response in T1AM-injected laboratory mice, the domesticated lizards, as a part of the vertebrate phylogeny, may be a useful laboratory model for biological and pharmacological researches such as drug potency test.

  14. 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. © 2014 American College of Veterinary Radiology.

  15. Analysis of RBC-microparticles in stored whole blood bags - a promising marker to detect blood doping in sports?

    Science.gov (United States)

    Voss, Sven Christian; Jaganjac, Morana; Al-Thani, Amna Mohamed; Grivel, Jean-Charles; Raynaud, Christophe Michel; Al-Jaber, Hind; Al-Menhali, Afnan Saleh; Merenkov, Zeyed Ahmad; Alsayrafi, Mohammed; Latiff, Aishah; Georgakopoulos, Costas

    2017-11-01

    Blood doping in sports is prohibited by the World Anti-Doping Agency (WADA). To find a possible biomarker for the detection of blood doping, we investigated the changes in blood stored in CPDA-1 blood bags of eight healthy subjects who donated one unit of blood. Aliquots were taken on days 0, 14, and 35. Platelet-free plasma was prepared and stored at -80°C until analysis on a flow cytometer dedicated for the analysis of microparticles (MPs). Changes in the number of red blood cell (RBC) -MPs were highly significant (p doping control but confirmation by a transfusion study is necessary. Copyright © 2017 John Wiley & Sons, Ltd.

  16. 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. © 2015 SETAC.

  17. Noninvasive evaluation of active lower gastrointestinal bleeding: comparison between contrast-enhanced MDCT and 99mTc-labeled RBC scintigraphy.

    Science.gov (United States)

    Zink, Stephen I; Ohki, Stephen K; Stein, Barry; Zambuto, Domenic A; Rosenberg, Ronald J; Choi, Jenny J; Tubbs, Daniel S

    2008-10-01

    The purpose of our study was to compare contrast-enhanced MDCT and (99m)Tc-labeled RBC scanning for the evaluation of active lower gastrointestinal bleeding. Over 17 months, 55 patients (32 men, 23 women; age range, 21-92 years) were evaluated prospectively with contrast-enhanced MDCT using 100 mL of iopromide 300 mg I/mL. Technetium-99m-labeled RBC scans were obtained on 41 of 55 patients and select patients underwent angiography for attempted embolization. Each imaging technique was reviewed in a blinded fashion for sensitivity for detection of active bleeding as well as the active lower gastrointestinal bleeding location. Findings were positive on both examinations in eight patients and negative on both examinations in 20 patients. Findings were positive on contrast-enhanced MDCT and negative on (99m)Tc-labeled RBC in two patients; findings were negative on contrast-enhanced MDCT and positive on (99m)Tc-labeled RBC in 11 patients. Statistics showed significant disagreement, with simple agreement = 68.3%, kappa = 0.341, and p = 0.014. Sixteen of 60 (26.7%) contrast-enhanced MDCT scans were positive prospectively, with all accurately localizing the site of bleeding and identification of the underlying lesion in eight of 16 (50%). Nineteen of 41 (46.3%) (99m)Tc-labeled RBC scans were positive. Eighteen of 41 matched patients went on to angiography. In four of these 18 (22.2%) patients, the site of bleeding was confirmed by angiography, but in 14 of 18 (77.8%), the findings were negative. Contrast-enhanced MDCT and (99m)Tc-labeled RBC scanning show significant disagreement for evaluation of active lower gastrointestinal bleeding. Contrast-enhanced MDCT appears effective for detection and localization in cases of active lower gastrointestinal bleeding in which hemorrhage is active at the time of CT.

  18. RBC acetyl cholinesterase: A poor man′s early diagnostic biomarker for familial alzheimer′s and Parkinson′s disease dementia

    Directory of Open Access Journals (Sweden)

    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.

  19. A Giant Hepatic Hemangioma Complicated by Kasabach-Merritt Syndrome: Findings of Tc-99m RBC Scintigraphy and SPECT Including a Total Body Blood Pool Imaging Study

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Myung Hee; Jeong, Hwan Jeong; Lim, Seok Tae; Kim, Dong Wook; Yim, Chang Yeol [Chonbuk National University Medical School, Jeonju (Korea, Republic of)

    2009-02-15

    Kasabach-Merritt syndrome (KMS) consists of thrombocytopenia, microangiopathic hemolytic anemia, and localized consumption coagulopathy that develops within vascular hemangioma. This syndrome may also be associated with occult hemangiomas located at various sites. Tc-99m RBC scintigraphy and SPECT have proven to be reliable for confirming or excluding hemangioma. Total body blood pool imaging study during the scintigraphy also provides a means of screening for occult lesions. The authors report the case of a 29-year-old man who presented with a giant hepatic hemangioma complicated by KMS, and underwent Tc-99m RBC scintigraphy and SPECT including a total body blood pool imaging study.

  20. 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.

  1. Response of lizards to high-severity wildfires in a southern United States mixed pine/hardwood forest

    Science.gov (United States)

    Adam ​Duarte; Donald J. Brown; Michael R. J. Forstner

    2017-01-01

    High-severity forest fires are increasing in large areas of the southern and western United States as the climate becomes warmer and drier. Natural resource managers need a better understanding of the short- and long-term effects of wildfires on lizard populations, but there is a paucity of studies focused on lizard-wildfire relationships. We used a before-after,...

  2. Legitimate seed dispersal by lizards in an alpine habitat: The case of Berberis empetrifolia (Berberidaceae) dispersed by Liolaemus belii (Tropiduridae)

    Science.gov (United States)

    Celedón-Neghme, Constanza; San Martin, Leonardo A.; Victoriano, Pedro F.; Cavieres, Lohengrin A.

    2008-05-01

    In this study we determined the effect of seed passage through Liolaemus bellii lizard digestive tracts on germination of fleshy-fruited Andean shrub species Berberis empetrifolia (Berberidaceae), and evaluated the effect of this passage on seed coat characteristics. In addition, we assessed the spatial patterns of fecal deposition by lizards onto various microhabitats available in the Andean environments of central Chile. The germination rate and the final percentage of lizard-ingested B. empetrifolia seeds was greater than control seeds. Comparing photographs and seed coat histological cuts, we suggest that the cutine wax present on seed coats from lizard-ingested seeds was probably removed by abrasion inside the lizards' digestive tract. Sixty-two percent of the lizard's feces was deposited on bare soil near rocks commonly inhabited by lizards. However, this microhabitat represents only 29% of the available ground cover at the study site. By enhancing seed germination and depositing seeds onto potential safe sites for recruitment, the lizard Liolaemus bellii is acting, at least qualitatively, as an effective disperser of Berberis empetrifolia.

  3. Historical colonization and dispersal limitation supplement climate and topography in shaping species richness of African lizards (Reptilia: Agaminae)

    NARCIS (Netherlands)

    Kissling, W.D.; Blach-Overgaard, A.; Zwaan, R.E.; Wagner, P.

    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

  4. 137Cs and 90Sr IN lizards of Semipalatinsk test site.

    Science.gov (United States)

    Panitskiy, А V; Lukashenko, S N; Kadyrova, N Zh

    2017-01-01

    The paper provides research results of 137 Cs and 90 Sr radionuclides concentrations in bodies of Lacertidae family lizards, inhabiting different parts of Semipalatinsk Test Site, and the parameters of these radionuclides' transfer into lizards' bodies. It shows that high activity concentration of radionuclides in lizards' bodies can be noticed if they live directly at locally contaminated areas. Since the distance from contaminated spots exceeds home range of the studied animals, no increased values of radionuclides' activity were found in the animal bodies. At some individual radioactively contaminated spots, very high activity concentrations of 90 Sr radionuclide up to 7.8 × 10 5  Bq kg -1 were found in lizards. So under certain conditions, lizards can significantly contribute to radionuclides redistribution in the natural environment. Mean concentration ratios (CR) of radionuclides were as follows: 137 Cs-6.2 × 10 -3 , 90 Sr-1.1 × 10 -2 . Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Variations upon a theme: Australian lizards provide insights into the endocrine control of vertebrate reproductive cycles.

    Science.gov (United States)

    Jones, Susan M

    2017-04-01

    Australian lizards exhibit a broad array of different reproductive strategies and provide an extraordinary diversity and range of models with which to address fundamental problems in reproductive biology. Studies on lizards have frequently led to new insights into hormonal regulatory pathways or mechanisms of control, but we have detailed knowledge of the reproductive cycle in only a small percentage of known species. This review provides an overview and synthesis of current knowledge of the hormonal control of reproductive cycles in Australian lizards. Agamid lizards have provided useful models with which to test hypotheses about the hormonal regulation of the expression of reproductive behaviors, while research on viviparous skinks is providing insights into the evolution of the endocrine control of gestation. However, in order to better understand the potential risks that environmental factors such as climate change and endocrine disrupting chemicals pose to our fauna, better knowledge is required of the fundamental characteristics of the reproductive cycle in a broader range of lizard species. Copyright © 2015 Elsevier Inc. All rights reserved.

  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.

    2012-01-01

    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. PMID:23075525

  7. Accumulation of transposable elements in Hox gene clusters during adaptive radiation of Anolis lizards.

    Science.gov (United States)

    Feiner, Nathalie

    2016-10-12

    Transposable elements (TEs) are DNA sequences that can insert elsewhere in the genome and modify genome structure and gene regulation. The role of TEs in evolution is contentious. One hypothesis posits that TE activity generates genomic incompatibilities that can cause reproductive isolation between incipient species. This predicts that TEs will accumulate during speciation events. Here, I tested the prediction that extant lineages with a relatively high rate of speciation have a high number of TEs in their genomes. I sequenced and analysed the TE content of a marker genomic region (Hox clusters) in Anolis lizards, a classic case of an adaptive radiation. Unlike other vertebrates, including closely related lizards, Anolis lizards have high numbers of TEs in their Hox clusters, genomic regions that regulate development of the morphological adaptations that characterize habitat specialists in these lizards. Following a burst of TE activity in the lineage leading to extant Anolis, TEs have continued to accumulate during or after speciation events, resulting in a positive relationship between TE density and lineage speciation rate. These results are consistent with the prediction that TE activity contributes to adaptive radiation by promoting speciation. Although there was no evidence that TE density per se is associated with ecological morphology, the activity of TEs in Hox clusters could have been a rich source for phenotypic variation that may have facilitated the rapid parallel morphological adaptation to microhabitats seen in extant Anolis lizards. © 2016 The Author(s).

  8. 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.

  9. 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. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

  10. Watch out where you sleep: nocturnal sleeping behaviour of Bay Island lizards

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    Nitya Prakash Mohanty

    2016-04-01

    Full Text Available Sleeping exposes lizards to predation. Therefore, sleeping strategies must be directed towards avoiding predation and might vary among syntopic species. We studied sleeping site characteristics of two syntopic, congeneric lizards—the Bay Island forest lizard, Coryphophylax subcristatus and the short-tailed Bay Island lizard, C. brevicaudus and evaluated inter-specific differences. We measured structural, microclimatic and potential predator avoidance at the sleeping perches of 386 C. subcristatus and 185 C. brevicaudus. Contrary to our expectation, we found similar perch use in both species. The lizards appeared to use narrow girth perch plants and accessed perches by moving both vertically and horizontally. Most lizards slept on leaves, with their heads directed towards the potential path of a predator approaching from the plant base. There was no inter-specific competition in the choices of sleeping perches. These choices indicate an anti-predator strategy involving both tactile and visual cues. This study provides insight into a rarely studied behaviour in reptiles and its adaptive significance.

  11. Microgeographic variation in locomotor traits among lizards in a human-built environment

    Directory of Open Access Journals (Sweden)

    Colin Donihue

    2016-03-01

    Full Text Available Microgeographic variation in fitness-relevant traits may be more common than previously appreciated. The fitness of many vertebrates is directly related to their locomotor capacity, a whole-organism trait integrating behavior, morphology, and physiology. Because locomotion is inextricably related to context, I hypothesized that it might vary with habitat structure in a wide-ranging lizard, Podarcis erhardii, found in the Greek Cyclade Islands. I compared lizard populations living on human-built rock walls, a novel habitat with complex vertical structure, with nearby lizard populations that are naive to human-built infrastructure and live in flat, loose-substrate habitat. I tested for differences in morphology, behavior, and performance. Lizards from built sites were larger and had significantly (and relatively longer forelimbs and hindlimbs. The differences in hindlimb morphology were especially pronounced for distal components—the foot and longest toe. These morphologies facilitated a significant behavioral shift in jumping propensity across a rocky experimental substrate. I found no difference in maximum velocity between these populations; however, females originating from wall sites potentially accelerated faster over the rocky experimental substrate. The variation between these closely neighboring populations suggests that the lizards inhabiting walls have experienced a suite of trait changes enabling them to take advantage of the novel habitat structure created by humans.

  12. Solubilization and purification of melatonin receptors from lizard brain

    International Nuclear Information System (INIS)

    Rivkees, S.A.; Conron, R.W. Jr.; Reppert, S.M.

    1990-01-01

    Melatonin receptors in lizard brain were identified and characterized using 125 I-labeled melatonin ([ 125 I]MEL) after solubilization with the detergent digitonin. Saturation studies of solubilized material revealed a high affinity binding site, with an apparent equilibrium dissociation constant of 181 +/- 45 pM. Binding was reversible and inhibited by melatonin and closely related analogs, but not by serotonin or norepinephrine. Treatment of solubilized material with the non-hydrolyzable GTP analog, guanosine 5'-(3-O-thiotriphosphate) (GTP-gamma-S), significantly reduced receptor affinity. Gel filtration chromatography of solubilized melatonin receptors revealed a high affinity, large (Mr 400,000) peak of specific binding. Pretreatment with GTP-gamma-S before solubilization resulted in elution of a lower affinity, smaller (Mr 150,000) peak of specific binding. To purify solubilized receptors, a novel affinity chromatography resin was developed by coupling 6-hydroxymelatonin with Epoxy-activated Sepharose 6B. Using this resin, melatonin receptors were purified approximately 10,000-fold. Purified material retained the pharmacologic specificity of melatonin receptors. These results show that melatonin receptors that bind ligand after detergent treatment can be solubilized and substantially purified by affinity chromatography

  13. Solubilization and purification of melatonin receptors from lizard brain.

    Science.gov (United States)

    Rivkees, S A; Conron, R W; Reppert, S M

    1990-09-01

    Melatonin receptors in lizard brain were identified and characterized using 125I-labeled melatonin ([125I]MEL) after solubilization with the detergent digitonin. Saturation studies of solubilized material revealed a high affinity binding site, with an apparent equilibrium dissociation constant of 181 +/- 45 pM. Binding was reversible and inhibited by melatonin and closely related analogs, but not by serotonin or norepinephrine. Treatment of solubilized material with the non-hydrolyzable GTP analog, guanosine 5'-(3-O-thiotriphosphate) (GTP-gamma-S), significantly reduced receptor affinity. Gel filtration chromatography of solubilized melatonin receptors revealed a high affinity, large (Mr 400,000) peak of specific binding. Pretreatment with GTP-gamma-S before solubilization resulted in elution of a lower affinity, smaller (Mr 150,000) peak of specific binding. To purify solubilized receptors, a novel affinity chromatography resin was developed by coupling 6-hydroxymelatonin with Epoxy-activated Sepharose 6B. Using this resin, melatonin receptors were purified approximately 10,000-fold. Purified material retained the pharmacologic specificity of melatonin receptors. These results show that melatonin receptors that bind ligand after detergent treatment can be solubilized and substantially purified by affinity chromatography.

  14. Speed and stamina trade-off in lacertid lizards.

    Science.gov (United States)

    Vanhooydonck, B; Van Damme, R; Aerts, P

    2001-05-01

    Morphological and physiological considerations suggest that sprinting ability and endurance capacity put conflicting demands on the design of an animal's locomotor apparatus and therefore cannot be maximized simultaneously. To test this hypothesis, we correlated size-corrected maximal sprint speed and stamina of 12 species of lacertid lizards. Phylogenetically independent contrasts of sprint speed and stamina showed a significant negative relationship, giving support to the idea of an evolutionary trade-off between the two performance measures. To test the hypothesis that the trade-off is mediated by a conflict in morphological requirements, we correlated both performance traits with snout-vent length, size-corrected estimates of body mass and limb length, and relative hindlimb length (the residuals of the relationship between hind- and forelimb length). Fast-running species had hindlimbs that were long compared to their forelimbs. None of the other size or shape variables showed a significant relationship with speed or endurance. We conclude that the evolution of sprint capacity may be constrained by the need for endurance capacity and vice versa, but the design conflict underlying this trade-off has yet to be identified.

  15. The effect of parity on morphological evolution among phrynosomatid lizards.

    Science.gov (United States)

    Oufiero, C E; Gartner, G E A

    2014-11-01

    The shift from egg laying to live-bearing is one of the most well-studied transitions in evolutionary biology. Few studies, however, have assessed the effect of this transition on morphological evolution. Here, we evaluated the effect of reproductive mode on the morphological evolution of 10 traits, among 108 species of phrynosomatid lizards. We assess whether the requirement for passing shelled eggs through the pelvic girdle has led to morphological constraints in oviparous species and whether long gestation times in viviparous species have led to constraints in locomotor morphology. We fit models to the data that vary both in their tempo (strength and rate of selection) and mode of evolution (Brownian or Ornstein-Uhlenbeck) and estimates of trait optima. We found that most traits are best fit by a generalized multipeak OU model, suggesting differing trait optima for viviparous vs. oviparous species. Additionally, rates (σ(2) ) of both pelvic girdle and forelimb trait evolution varied with parity; viviparous species had higher rates. Hindlimb traits, however, exhibited no difference in σ(2) between parity modes. In a functional context, our results suggest that the passage of shelled eggs constrains the morphology of the pelvic girdle, but we found no evidence of morphological constraint of the locomotor apparatus in viviparous species. Our results are consistent with recent lineage diversification analyses, leading to the conclusion that transitions to viviparity increase both lineage and morphological diversification. © 2014 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

  16. Developmental origin of limb size variation in lizards.

    Science.gov (United States)

    Andrews, Robin M; Skewes, Sable A

    2017-05-01

    In many respects, reptile hatchlings are fully functional, albeit miniature, adults. This means that the adult morphology must emerge during embryonic development. This insight emphasizes the connection between the mechanisms that generate phenotypic variation during embryonic development and the action of selection on post-hatching individuals. To determine when species-specific differences in limb and tail lengths emerge during embryonic development, we compared allometric patterns of early limb growth of four distantly related species of lizards. The major questions addressed were whether early embryonic limb and tail growth is characterized by the gradual (continuous allometry) or by the abrupt emergence (transpositional allometry) of size differences among species. Our observations supported transpositional allometry of both limbs and tails. Species-specific differences in limb and tail length were exhibited when limb and tail buds first protruded from the body wall. Genes known to be associated with early limb development of tetrapods are obvious targets for studies on the genetic mechanisms that determine interspecific differences in relative limb length. Broadly comparative studies of gene regulation would facilitate understanding of the mechanisms underlying adaptive variation in limb size, including limb reduction and loss, of squamate reptiles. © 2017 Wiley Periodicals, Inc.

  17. Visual motion detection and habitat preference in Anolis lizards.

    Science.gov (United States)

    Steinberg, David S; Leal, Manuel

    2016-11-01

    The perception of visual stimuli has been a major area of inquiry in sensory ecology, and much of this work has focused on coloration. However, for visually oriented organisms, the process of visual motion detection is often equally crucial to survival and reproduction. Despite the importance of motion detection to many organisms' daily activities, the degree of interspecific variation in the perception of visual motion remains largely unexplored. Furthermore, the factors driving this potential variation (e.g., ecology or evolutionary history) along with the effects of such variation on behavior are unknown. We used a behavioral assay under laboratory conditions to quantify the visual motion detection systems of three species of Puerto Rican Anolis lizard that prefer distinct structural habitat types. We then compared our results to data previously collected for anoles from Cuba, Puerto Rico, and Central America. Our findings indicate that general visual motion detection parameters are similar across species, regardless of habitat preference or evolutionary history. We argue that these conserved sensory properties may drive the evolution of visual communication behavior in this clade.

  18. Sister chromosome pairing maintains heterozygosity in parthenogenetic lizards.

    Science.gov (United States)

    Lutes, Aracely A; Neaves, William B; Baumann, Diana P; Wiegraebe, Winfried; Baumann, Peter

    2010-03-11

    Although bisexual reproduction has proven to be highly successful, parthenogenetic all-female populations occur frequently in certain taxa, including the whiptail lizards of the genus Aspidoscelis. Allozyme analysis revealed a high degree of fixed heterozygosity in these parthenogenetic species, supporting the view that they originated from hybridization events between related sexual species. It has remained unclear how the meiotic program is altered to produce diploid eggs while maintaining heterozygosity. Here we show that meiosis commences with twice the number of chromosomes in parthenogenetic versus sexual species, a mechanism that provides the basis for generating gametes with unreduced chromosome content without fundamental deviation from the classic meiotic program. Our observation of synaptonemal complexes and chiasmata demonstrate that a typical meiotic program occurs and that heterozygosity is not maintained by bypassing recombination. Instead, fluorescent in situ hybridization probes that distinguish between homologues reveal that bivalents form between sister chromosomes, the genetically identical products of the first of two premeiotic replication cycles. Sister chromosome pairing provides a mechanism for the maintenance of heterozygosity, which is critical for offsetting the reduced fitness associated with the lack of genetic diversity in parthenogenetic species.

  19. “Sexual” behavior in parthenogenetic lizards (Cnemidophorus)

    Science.gov (United States)

    Crews, David; Fitzgerald, Kevin T.

    1980-01-01

    All-female, parthenogenetic species afford a unique test of hypotheses regarding the nature and evolution of sexuality. Basic data on the behavior of parthenogens are lacking, however. We have discovered, from observations of captive Cnemidophorus uniparens, C. velox, and C. tesselatus, behavior patterns remarkably similar to the courtship and copulatory behavior of closely related sexual species. Briefly, in separately housed pairs, one lizard was repeatedly seen to mount and ride its cagemate and appose the cloacal regions. Dissection or palpation revealed that, in each instance, the courted animal was reproductively active, having ovaries containing large, preovulatory follicles, while the courting animal was either reproductively inactive or postovulatory, having ovaries containing only small, undeveloped follicles. These observations are significant for the questions they raise. For example, is this behavior a nonfunctional vestige of the species' ancestry, or is this behavior necessary for successful reproduction in the species (e.g., by priming reproductive neuroendocrine mechanisms as has been demonstrated in sexual species)? Images PMID:16592761

  20. Ascending connections to the forebrain in the Tegu lizard.

    Science.gov (United States)

    Lohman, A H; van Woerden-Verkley, I

    1978-12-01

    The ascending connections to the striatum and the cortex of the Tegu lizard, Tupinambis nigropunctatus, were studied by means of anterograde fiber degeneration and retrograde axonal transport. The striatum receives projections by way of the dorsal peduncle of the lateral forebrain bundle from four dorsal thalamic nuclei: nucleus rotundus, nucleus reuniens, the posterior part of the dorsal lateral geniculate nucleus and nucleus dorsomedialis. The former three nuclei project to circumscribed areas of the dorsal striatum, whereas nucleus dorsomedialis has a distribution to the whole dorsal striatum. Other sources of origin to the striatum are the mesencephalic reticular formation, substantia nigra and nucleus cerebelli lateralis. With the exception of the latter afferentation all these projections are ipsilateral. The ascending connections to the pallium originate for the major part from nucleus dorsolateralis anterior of the dorsal thalamus. The fibers course in both the medial forebrain bundle and the dorsal peduncle of the lateral forebrain bundle and terminate ipsilaterally in the middle of the molecular layer of the small-celled part of the mediodorsal cortex and bilaterally above the intermediate region of the dorsal cortex. The latter area is reached also by fibers from the septal area. The large-celled part of the mediodorsal cortex receives projections from nucleus raphes superior and the corpus mammillare.

  1. History of reptile placentology, part III: Giacomini's 1891 histological monograph on lizard placentation.

    Science.gov (United States)

    Blackburn, D G; Paulesu, L; Avanzati, A M; Roth, M

    2017-12-01

    By the 1890s, placental arrangements had been documented macroscopically in lizards and fishes, but placental studies on such species lagged far behind research on mammals. In 1891, the biologist Ercole Giacomini (at the University of Siena, Italy) published the first histological analysis of a reptile placenta. Focusing on a placentotrophic lizard (Chalcides chalcides) with a morphologically complex placenta, Giacomini documented the histological and cellular bases for placental nutrient transfer and gas exchange. In conjunction with a follow-up study in 1906, he demonstrated that placental structure is correlated with function and can vary dramatically between related species. Giacomini's work was highly influential in showing that placentation in lizards had converged evolutionarily on that of mammals, while establishing reptile placentology as a highly promising area for future research. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Lizards, ticks and contributions to Australian parasitology: C. Michael Bull (1947-2016).

    Science.gov (United States)

    Godfrey, Stephanie S; Gardner, Michael G

    2017-12-01

    Professor C. Michael Bull was a great scientist and mentor, and an Associate Editor of this journal. While his research career spanned the fields of behavioural ecology, conservation biology and herpetology, in this article, we pay tribute to his major contribution to Australian parasitology. Mike authored more than eighty articles on host-parasite ecology, and revealed major insights into the biology and ecology of ticks from his long term study of the parapatric boundary of two tick species ( Amblyomma limbatum and Bothriocroton hydrosauri ) on the sleepy lizard ( Tiliqua rugosa ). In this article, we provide an overview of how this research journey developed to become one of the longest-running studies of lizards and their ticks, totalling 35 years of continuous surveys of ticks on lizards, and the insights and knowledge that he generated along that journey.

  3. 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.

  4. The nematode community in the Atlantic rainforest lizard Enyalius perditus Jackson, from south-eastern Brazil.

    Science.gov (United States)

    Barreto-Lima, A F; Toledo, G M; Anjos, L A

    2012-12-01

    Studies focusing on communities of helminths from Brazilian lizards are increasing, but there are many blanks in the knowledge of parasitic fauna of wild fauna. This lack of knowledge hampers understanding of ecological and parasitological aspects of involved species. Moreover, the majority of research has focused on parasitic fauna of lizards from families Tropiduridae and Scincidae. Only a few studies have looked at lizards from the family Leiosauridae, including some species of Enyalius. This study presents data on the gastrointestinal parasite fauna of Enyalius perditus and their relationships with ecological aspects of hosts in a disturbed Atlantic rainforest area in the state of Minas Gerais, south-eastern Brazil. Two nematode species, Oswaldocruzia burseyi [(Molineidae) and Strongyluris oscari (Heterakidae) were found. Nematode species showed an aggregated distribution in this host population, with O. burseyi being more aggregated than S. oscari. The present study extends the range of occurrence of O. burseyi to the Brazilian continental area.

  5. Changes in developmental stages of the egyptian lizard chalcides ocellatus due to different radiation exposures

    International Nuclear Information System (INIS)

    Roushdy, H.M.; Mazhar, Fatma M.; Ashry, Madiha A.; Refaat, Sanaa M.

    1979-01-01

    Adult male and female Chalcides Ocellatus lizards of approximately the same age and size were irradiated at doses of 1000, 1500, 2000 and 4000 rads from a Cobalt-60 Gamma cell at a dose rate of 100 rads/sec. Examinations were carried out at 2 days, 1, 3 and 4 weeks post-irradiation and indicated the following: The LD 50 /30 was found to be 1250 rads. Radiation exposure had no significant effect on lizard's body length measurements along the whole experimentation period. Radiation exposure caused a progressive decrease in body weights of lizards which was often obscured by interfering fluctuations in body weights due to pregnancy development, embryo retention or abortion cases

  6. 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.

    2016-01-01

    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. PMID:26973870

  7. Relationships between hormones and aggressive behavior in green anole lizards: an analysis using structural equation modeling.

    Science.gov (United States)

    Yang, Eun-Jin; Wilczynski, Walter

    2002-09-01

    We investigated the relationship between aggressive behavior and circulating androgens in the context of agonistic social interaction and examined the effect of this interaction on the androgen-aggression relationship in response to a subsequent social challenge in male Anolis carolinensis lizards. Individuals comprising an aggressive encounter group were exposed to an aggressive conspecific male for 10 min per day during a 5-day encounter period, while controls were exposed to a neutral stimulus for the same period. On the sixth day, their responses to an intruder test were observed. At intervals, individuals were sacrificed to monitor plasma androgen levels. Structural equation modeling (SEM) was used to test three a priori interaction models of the relationship between social stimulus, aggressive behavior, and androgen. Model 1 posits that exposure to a social stimulus influences androgen and aggressive behavior independently. In Model 2, a social stimulus triggers aggressive behavior, which in turn increases circulating levels of androgen. In Model 3, exposure to a social stimulus influences circulating androgen levels, which in turn triggers aggressive behavior. During the 5 days of the encounter period, circulating testosterone (T) levels of the aggressive encounter group followed the same pattern as their aggressive behavioral responses, while the control group did not show significant changes in their aggressive behavior or T level. Our SEM results supported Model 2. A means analysis showed that during the intruder test, animals with 5 days of aggressive encounters showed more aggressive responses than did control animals, while their circulating androgen levels did not differ. This further supports Model 2, suggesting that an animal's own aggressive behavior may trigger increases in levels of plasma androgen. Copyright 2002 Elsevier Science (USA)

  8. Roadside verges as habitats for endangered lizard-orchids (Himantoglossum spp.): Ecological traps or refuges?

    Science.gov (United States)

    Fekete, Réka; Nagy, Timea; Bódis, Judit; Biró, Éva; Löki, Viktor; Süveges, Kristóf; Takács, Attila; Tökölyi, Jácint; Molnár V, Attila

    2017-12-31

    Alterations in traditional land use practices have led to severe declines in the area of semi-natural grasslands, thereby seriously threatening plant and animal species dependent on these habitats. Small anthropogenic managed habitats, like roadsides can act as refuges and might play an important role in conserving these species. Colonization of roadside verges by endangered lizard orchids (Himantoglossum spp.) has long been known, but few studies have systematically explored the suitability of roadside habitats for these orchids and the impact of roads on them. In this paper we present results of targeted surveys of three lizard orchid taxa on roadsides from eight European countries. During these surveys we searched for lizard orchids inhabiting roadside verges and recorded their distance from road, aspects of the roadside environment, as well as vegetative and reproductive characteristics of individual plants. We found large numbers of lizard orchids on roadside verges. Distance from roads was not uniformly distributed: orchids occurred more closely to roads than expected by chance. This suggests that regular management of roadsides (e.g. mowing) might enhance colonization and survival of lizard orchids. On the other hand, we also found that close proximity to roads negatively affects reproductive success, suggesting that the immediate vicinity of roads might act as an ecological trap (i.e. favorable in terms of colonization and survival but unfavorable in terms of reproduction). Nonetheless, the fact that significant and viable populations are maintained at roadsides suggests that traditionally managed roadside verges may allow long-term persistence of lizard orchid populations and may serve as refuges in a landscape context. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Reactions of green lizards (Lacerta viridis) to major repellent compounds secreted by Graphosoma lineatum (Heteroptera: Pentatomidae).

    Science.gov (United States)

    Gregorovičová, Martina; Černíková, Alena

    2015-06-01

    The chemical defence of Heteroptera is primarily based on repellent secretions which signal the potential toxicity of the bug to its predators. We tested the aversive reactions of green lizards (Lacerta viridis) towards the major compounds of the defensive secretion of Graphosoma lineatum, specifically: (i) a mixture of three aldehydes: (E)-hex-2-enal, (E)-oct-2-enal, (E)-dec-2-enal; (ii) a mixture of these three aldehydes and tridecane; (iii) oxoaldehyde: (E)-4-oxohex-2-enal; (iv) secretion extracted from metathoracic scent glands of G. lineatum adults and (v) hexane as a non-polar solvent. All chemicals were presented on a palatable food (Tenebrio molitor larvae). The aversive reactions of the green lizards towards the mealworms were evaluated by observing the approach latencies, attack latencies and approach-attack intervals. The green lizards exhibited a strong aversive reaction to the mixture of three aldehydes. Tridecane reduced the aversive reaction to the aldehyde mixture. Oxoaldehyde caused the weakest, but still significant, aversive reaction. The secretion from whole metathoracic scent glands also clearly had an aversive effect on the green lizards. Moreover, when a living specimen of G. lineatum or Pyrrhocoris apterus (another aposematic red-and-black prey) was presented to the green lizards before the trials with the aldehyde mixture, the aversive effect of the mixture was enhanced. In conclusion, the mixture of three aldehydes had the strong aversive effect and could signal the potential toxicity of G. lineatum to the green lizards. Copyright © 2015 Elsevier GmbH. All rights reserved.

  10. The Role of Diet in Shaping the Chemical Signal Design of Lacertid Lizards.

    Science.gov (United States)

    Baeckens, Simon; García-Roa, Roberto; Martín, José; Van Damme, Raoul

    2017-09-01

    Lizards communicate with others via chemical signals, the composition of which may vary among species. Although the selective pressures and constraints affecting chemical signal diversity at the species level remain poorly understood, the possible role of diet has been largely neglected. The chemical signals of many lizards originate from the femoral glands that exude a mixture of semiochemicals, and may be used in a variety of contexts. We analyzed the lipophilic fraction of the glandular secretions of 45 species of lacertid lizard species by gas chromatography/mass spectrometry. The proportions of nine major chemical classes (alcohols, aldehydes, fatty acids, furanones, ketones, steroids, terpenoids, tocopherols and waxy esters), the relative contributions of these different classes ('chemical diversity'), and the total number of different lipophilic compounds ('chemical richness') varied greatly among species. We examined whether interspecific differences in these chemical variables could be coupled to interspecific variation in diet using data from the literature. In addition, we compared chemical signal composition among species that almost never, occasionally, or often eat plant material. We found little support for the hypothesis that the chemical profile of a given species' secretion depends on the type of food consumed. Diet breadth did not correlate with chemical diversity or richness. The amount of plants or ants consumed did not affect the relative contribution of any of the nine major chemical classes to the secretion. Chemical diversity did not differ among lizards with different levels of plant consumption; however, chemical richness was low in species with an exclusive arthropod diet, suggesting that incorporating plants in the diet enables lizards to increase the number of compounds allocated to secretions, likely because a (partly) herbivorous diet allows them to include compounds of plant origin that are unavailable in animal prey. Still, overall

  11. Taxonomy, phylogenetics and biogeography of Chesneya (Fabaceae), evidenced from data of three sequences, ITS, trnS-trnG, and rbcL

    Science.gov (United States)

    Ming-Li Zhang; Zhi-Bin Wen; Xiao-Li Hao; Vyacheslav V. Byalt; Alexander P. Sukhorukov; Stewart C. Sanderson

    2015-01-01

    Plants of Central Asia have played a significant role in the origin of floras of Eurasia and the Northern Hemisphere. Chesneya, a small leguminous genus occurring in Central Asia, western Asia, and Tibet, is used to establish phylogenetic relationships and discuss the evolutionary and biogeographical history based on sequence data of ITS and trnS-trnG and rbcL.We...

  12. 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

  13. 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.

    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

  14. 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.

  15. Lizard assemblage from a sand dune habitat from southeastern Brazil: a niche overlap analysis.

    Science.gov (United States)

    Winck, Gisele R; Hatano, Fabio; Vrcibradic, Davor; VAN Sluys, Monique; Rocha, Carlos F D

    2016-01-01

    Communities are structured by interactions of historical and ecological factors, which influence the use of different resources in time and space. We acquired data on time of activity, microhabitat use and diet of a lizard assemblage from a sand dune habitat in a coastal area, southeastern Brazil (Restinga de Jurubatiba). We analyzed the data of niche overlap among species in these three axes (temporal, spatial and trophic) using null models. We found a significant overlap within the trophic niche, whereas the overlap for the other axes did not differ from the expected. Based on this result, we discuss the factors acting on the structure of the local lizard community.

  16. Intrapulmonary receptors in the Tegu lizard: I. Sensitivity to CO2.

    Science.gov (United States)

    Feede, M R; Kuhlmann, W D; Scheid, P

    1977-02-01

    Single unit vagal recordings from intrapulmonary receptors were obtained in decerebrate, paralyzed lizards both during pump ventilation and during unidirectional ventilation on the cannulated, sack-shaped lung. Two types of receptors were identified: (1) CO2-receptors, which increased their discharge frequency as intrapulmonary CO2 concentration decreased but were not sensitive to stretch of the lung. (2) Mechanoreceptors, which rapidly increased discharge frequency when the lung was stretched. These receptors' CO2 sensitivity varied. Lungs of lizards thus appeared to possess both CO2 receptors, which have functional characteristics similar to those in birds, and mechanoreceptors with properties similar to stretch receptors in mammals.

  17. Identification key to species of the flying lizard genus Draco Linnaeus, 1758 (Squamata: Agamidae in Thailand

    Directory of Open Access Journals (Sweden)

    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.

  18. Lizard assemblage from a sand dune habitat from southeastern Brazil: a niche overlap analysis

    Directory of Open Access Journals (Sweden)

    GISELE R. WINCK

    2016-01-01

    Full Text Available ABSTRACT Communities are structured by interactions of historical and ecological factors, which influence the use of different resources in time and space. We acquired data on time of activity, microhabitat use and diet of a lizard assemblage from a sand dune habitat in a coastal area, southeastern Brazil (Restinga de Jurubatiba. We analyzed the data of niche overlap among species in these three axes (temporal, spatial and trophic using null models. We found a significant overlap within the trophic niche, whereas the overlap for the other axes did not differ from the expected. Based on this result, we discuss the factors acting on the structure of the local lizard community.

  19. Locomotion, Energetics, Performance, and Behavior: A Mammalian Perspective on Lizards, and Vice Versa.

    Science.gov (United States)

    Garland, Theodore; Albuquerque, Ralph L

    2017-08-01

    Animals are constrained by their abilities and by interactions with environmental factors, such as low ambient temperatures. These constraints range from physical impossibilities to energetic inefficiencies, and may entail trade-offs. Some of the constraints related to locomotion and activity metabolism can be illustrated through allometric comparisons of mammals and lizards, as representative terrestrial vertebrate endotherms and ectotherms, respectively, because these lineages differ greatly in aerobic metabolic capacities, resting energetic costs, and thermoregulatory patterns. Allometric comparisons are both useful and unavoidable, but "outlier" species (unusual for their clade) can also inform evolutionary scenarios, as they help indicate extremes of possible adaptation within mammalian and saurian levels of organization. We compared mammals and lizards for standard metabolic rate (SMR), maximal oxygen consumption during forced exercise (VO2max), net (incremental) cost of transport (NCT), maximal aerobic speed (MAS), daily movement distance (DMD), daily energy expenditure (DEE) during the active season, and the ecological cost of transport (ECT = percentage of DEE attributable to locomotion). (Snakes were excluded because their limbless locomotion has no counterpart in terrestrial mammals.) We only considered lizard SMR, VO2max, NCT, MAS, and sprint speed data if measured at 35-40 °C. On average, MAS is ∼7.4-fold higher in mammals, whereas SMR and VO2max are ∼6-fold greater, but values for all three of these traits overlap (or almost overlap) between mammals and lizards, a fact that has not previously been appreciated. Previous studies show that sprint speeds are similar for smaller mammals and lizards, but at larger sizes lizards are not as fast as some mammals. Mammals move ∼6-fold further each day than lizards, and DMD is by far the most variable trait considered here, but their NCT is similar. Mammals exceed lizards by ∼11.4-fold for DEE. On

  20. Etiology of cardiogenic shock early after open-heart surgery: Assessment by Tc-99m RBC wall motion scintigraphy

    International Nuclear Information System (INIS)

    Bateman, T.; Gray, R.; Chaux, A.; Lee, M.; Matloff, J.; Raymond, M.; Berman, D.

    1984-01-01

    When life-threatening cardiogenic shock (CI 1.8 1/min/m/sup 2/, elevated right and left-side filling pressures) occurs early (0-48 hrs) after open-heart surgery, routine approaches frequently cannot distinguish between expected etiologies: (1) transient systolic failure of the LV, RV, or both, common early postoperatively (postop); (2) perioperative infarct of the LV or RV; (3) myocardial restriction due to active pericardial bleeding or to accumulated clots and fluid; (4) diminished LV reserve from aneurysmectomy; and (5) residual valvular regurgitation. Distinction is critical, because (1), (2), and (4) will be treated by optimizing preload and afterload; (3) with urgent (if active bleeding) or semi-urgent surgery; and (5) with repeat valvular surgery. In 22 pts with unexpected early postop cardiogenic shock, Tc-99m-RBC equilibrium radionuclide ventriculography revealed: global LV (3 pts) or RV (3 pts) dysfunction, new segmental LV dysfunction (2 pts), active bleeding (5 pts) and/or accumulated pericardial fluid ( 8 pts) with hyperdynamic LV and RV, and a small hyperdynamic LV without effusion (1 pt), providing a specific etiologic diagnosis in all cases. In the Cardiac Surgical ICU, therapeutic decisions frequently await and depend on the results of equilibrium radionuclide ventriculography, now routinely performed in postop pts with unexpected cardiogenic shock

  1. A fossil Diploglossus (Squamata, Anguidae) lizard from Basse-Terre and Grande-Terre Islands (Guadeloupe, French West Indies).

    Science.gov (United States)

    Bochaton, Corentin; Boistel, Renaud; Casagrande, Fabrice; Grouard, Sandrine; Bailon, Salvador

    2016-06-29

    Today, Diploglossine lizards (Anguidae) are common on the Greater Antillean Islands (West Indies), where they are represented by many endemic species. However these lizards are very rare on the Lesser Antillean Islands, where they are only represented by a single species, the Montserrat galliwasp (Diploglossus montisserrati). Here, we show that diploglossine lizards were present in the past on other Lesser Antillean islands, by reporting the discovery of Anguidae fossil remains in two Amerindian archaeological deposits and in a modern deposit. These remains are compared to skeletons of extant diploglossine lizards, including D. montisserrati, using X-ray microtomography of the type specimen of this critically endangered lizard. We also conducted a histological study of the osteoderms in order to estimate the putative age of the specimen. Our results show that the fossil specimens correspond to a member of the Diploglossus genus presenting strong similarities, but also minor morphological differences with D. montisserrati, although we postulate that these differences are not sufficient to warrant the description of a new species. These specimens, identified as Diploglossus sp., provide a new comparison point for the study of fossil diploglossine lizards and reflect the historical 17(th) century mentions of anguid lizards, which had not been observed since.

  2. 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.

  3. Polymorphic ROS scavenging revealed by CCCP in a lizard

    Science.gov (United States)

    Olsson, Mats; Wilson, Mark; Isaksson, Caroline; Uller, Tobias

    2009-07-01

    Ingestion of antioxidants has been argued to scavenge circulating reactive molecules (e.g., free radicals), play a part in mate choice (by mediating access to this important resource), and perhaps increase life span. However, recent work has come to question these relationships. We have shown elsewhere in the polychromatic lizard, Ctenophorus pictus, that diet supplementation of carotenoids as antioxidants does not depress circulating natural reactive oxygen species (ROS) levels and leads to no corresponding improvement of color traits. However, a much stronger test would be to experimentally manipulate the ROS levels themselves and assess carotenoid-induced ROS depression. Here, we achieve this by using carbonyl cyanide 3-chlorophenylhydrazone, which elevates superoxide (SO) formation approximately threefold at 10 μM in this model system. We then look for depressing effects on ROS of the carotenoids in order to assess whether ‘super-production’ of SO makes carotenoid effects on elevated ROS levels detectable. The rationale for this treatment was that if not even such elevated levels of SO are reduced by carotenoid supplementation, the putative link carotenoids, ROS depression, and mate quality (in terms of antioxidant capacity) is highly questionable. We conclude that there is no significant effect of carotenoids on mean SO levels even at the induced ROS levels. However, our results showed a significant interaction effect between carotenoid treatment and male color, with red males having higher ROS levels than yellow males. We suggest that this may be because different pigments are differently involved in the generation of the integumental colors in the two morphs with concomitant effects on ROS depletion depending on carotenoid uptake or allocation to coloration and antioxidation.

  4. 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.

  5. 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.

  6. Pentastomid, Raillietiella mottae Almeida, Freire and Lopes, 2008, infecting lizards in an area of caatinga, northeast, Brazil

    OpenAIRE

    Almeida, WO.; Santana, GG.; Vieira, WLS.; Wanderley, IC.; Freire, EMX.; Vasconcellos, A.

    2008-01-01

    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 (07º 25' S and 36º 30' W), located in the state ...

  7. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. 75 FR 77801 - Endangered and Threatened Wildlife and Plants; Endangered Status for Dunes Sagebrush Lizard

    Science.gov (United States)

    2010-12-14

    ... public lands in Texas. It is evident that the dunes sagebrush lizard is still present at the park, but... expected to contribute to habitat loss, modification, or fragmentation in the future include wind and solar... and Solar Energy Development Eastern New Mexico and western Texas are highly suitable areas for wind...

  9. Foraging mode of serpentiform, grass-living cordylid lizards: A case ...

    African Journals Online (AJOL)

    Nine C. anguina were habituated in glass terraria to accept mealworms offered to them. When all lizards accepted food without hesitation, they were tested for their ability to discriminate among three different odours presented to them in a randomized block design: prey odours consisting of mealworm surface odours, ...

  10. Acetaminophen and zinc phosphide for lethal management of invasive lizards Ctenosaura similis

    Directory of Open Access Journals (Sweden)

    Michael L. AVERY, John D. EISEMANN, Kandy L. KEACHER,Peter J. SAVARIE

    2011-10-01

    Full Text Available 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 commensal 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].

  11. Divergent calcium signaling in RBCs from Tropidurus torquatus (Squamata – Tropiduridae strengthen classification in lizard evolution

    Directory of Open Access Journals (Sweden)

    Garcia Célia RS

    2007-08-01

    Full Text Available Abstract Background We have previously reported that a Teiid lizard red blood cells (RBCs such as Ameiva ameiva and Tupinambis merianae controls intracellular calcium levels by displaying multiple mechanisms. In these cells, calcium stores could be discharged not only by: thapsigargin, but also by the Na+/H+ ionophore monensin, K+/H+ ionophore nigericin and the H+ pump inhibitor bafilomycin as well as ionomycin. Moreover, these lizards possess a P2Y-type purinoceptors that mobilize Ca2+ from intracellular stores upon ATP addition. Results Here we report, that RBCs from the tropidurid lizard Tropidurus torquatus store Ca2+ in endoplasmic reticulum (ER pool but unlike in the referred Teiidae, these cells do not store calcium in monensin-nigericin sensitive pools. Moreover, mitochondria from T. torquatus RBCs accumulate Ca2+. Addition of ATP to a calcium-free medium does not increase the [Ca2+]c levels, however in a calcium medium we observe an increase in cytosolic calcium. This is an indication that purinergic receptors in these cells are P2X-like. Conclusion T. torquatus RBCs present different mechanisms from Teiid lizard red blood cells (RBCs, for controlling its intracellular calcium levels. At T. torquatus the ion is only stored at endoplasmic reticulum and mitochondria. Moreover activation of purinergic receptor, P2X type, was able to induce an influx of calcium from extracelullar medium. These studies contribute to the understanding of the evolution of calcium homeostasis and signaling in nucleated RBCs.

  12. Behavioral implications of mechanistic ecology II: the African rainbow lizard, Agama agama

    Energy Technology Data Exchange (ETDEWEB)

    Porter, W.P.; James, F.C.

    1979-01-01

    The daily and seasonal activity of the African rainbow lizard, Agama agama is predicted in terms of heat transfer models for the microenvironment and the lizard. The models, originally developed for the temperate Mohave Desert and for the desert iguana, Dipsosaurus dorsalis, have been refined and are applicable to a tropical area and a tropical species. Field microclimate measurements and observations of lizard activity and food consumption by different sizes of lizards are consistent with these models. Environmental constraints on activity times, sun vs shade locations, height above the ground and postures are described. The sensitivity of the metabolic predictions to different maximum temperature preferences and behavioral options are discussed. The balance between maintenance energy savings via lower thermoregulatory temperatures and time available in different parts of the microenvironment are examined. A simple predator-prey interaction illustrates the substantial effect of climate in modifying amount of time both prey and predator would be expected to be active simultaneously in the tropics vs a temperate desert. Comparisons are made between A. agama and the desert iguana, D. dorsalis for daily and seasonal maintenance requirements and their implications for seasonal changes in growth and reproductive potential.

  13. Lizard community structure across a grassland - creosote bush ecotone in the Chihuahuan Desert

    OpenAIRE

    Menke, Sean B

    2003-01-01

    I investigated the distribution and abundance of lizard species (Aspidoscelis inornatus, Aspidoscelis tesselatus, Aspidoscelis tigris, Aspidoscelis uniparens, Cophosaurus texanus, Crotaphytus collaris, Eumeces obsoletus, Gambelia wislizenii, Holbrookia maculata, Phrynosoma cornutum, Sceloporus magister, and Uta stansburiana) across a desert grassland - creosote bush (Larrea tridentata) ecotone in Dona Ana County, New Mexico. The ecotonal area in the Jomada del Muerto basin has increased drama...

  14. An annotated checklist of the lizards of French Guiana, mainly based on two recent collections

    NARCIS (Netherlands)

    Hoogmoed, M.S.; Lescure, J.

    1975-01-01

    At the moment 36 species of lizards (6 Gekkonidae, 12 Iguanidae, 1 Scincidae and 17 Teiidae) are known for certain to occur in French Guiana. Of these 36 species, four are reported from that country for the first time (Anolis marmoratus speciosus Garman, Cercosaura o. ocellata Wagler, Prionodactylus

  15. Tissue distribution and toxicity effects of myclobutanil enantiomers in lizards (Eremias argus).

    Science.gov (United States)

    Chen, Li; Li, Ruiting; Diao, Jinling; Tian, Zhongnan; Di, Shanshan; Zhang, Wenjun; Cheng, Cheng; Zhou, Zhiqiang

    2017-11-01

    In recent years, serious environmental pollution has caused a decrease in the abundance of many species worldwide. Reptiles are the most diverse group of terrestrial vertebrates. There are large amounts of toxicological data available regarding myclobutanil, but the adverse effects of myclobutanil on lizards has not been widely reported. In this study, treatment groups were orally administered a single-dose of myclobutanil (20mg/kg body weight (bw)). Subsequently, it was found that there were differences in myclobutanil levels between the different tissues and concentrations also changed with degradation time. The tissue concentrations of myclobutanil decreased in the order of: stomach > liver > lung > blood > testis > kidney > heart > brain. Based on our results, the liver and testis were considered to be the main target organs in lizards, indicating that the myclobutanil could induce potential hepatic and reproductive toxicity on lizards. Meanwhile, it was also demonstrated that the toxic effects of myclobutanil was different in different species, and the distribution of different pesticides in lizards were different. Copyright © 2017. Published by Elsevier Inc.

  16. Thermoregulatory Behavior in Diurnal Lizards as a Vehicle for Teaching Scientific Process

    Science.gov (United States)

    Platz, James E.

    2009-01-01

    Field experiments offer the opportunity for hands on experience with the scientific process. While this is true of a wide variety of activities, many have pitfalls both experimental and logistical that reduce the overall rate of success, in turn, influencing student learning outcomes. Relying on small, territorial, diurnal lizards and an array of…

  17. An Adaptive Neural Mechanism with a Lizard Ear Model for Binaural Acoustic Tracking

    DEFF Research Database (Denmark)

    Shaikh, Danish; Manoonpong, Poramate

    2016-01-01

    expensive algorithms. We present a novel bioinspired solution to acoustic tracking that uses only two microphones. The system is based on a neural mechanism coupled with a model of the peripheral auditory system of lizards. The peripheral auditory model provides sound direction information which the neural...

  18. Making Olympic lizards: the effects of specialised exercise training on performance.

    Science.gov (United States)

    Husak, Jerry F; Keith, Allison R; Wittry, Beth N

    2015-03-01

    Exercise training is well known to affect a suite of physiological and performance traits in mammals, but effects of training in other vertebrate tetrapod groups have been inconsistent. We examined performance and physiological differences among green anole lizards (Anolis carolinensis) that were trained for sprinting or endurance, using an increasingly rigorous training regimen over 8 weeks. Lizards trained for endurance had significantly higher post-training endurance capacity compared with the other treatment groups, but groups did not show post-training differences in sprint speed. Although acclimation to the laboratory environment and training explain some of our results, mechanistic explanations for these results correspond with the observed performance differences. After training, endurance-trained lizards had higher haematocrit and larger fast glycolytic muscle fibres. Despite no detectable change in maximal performance of sprint-trained lizards, we detected that they had significantly larger slow oxidative muscle fibre areas compared with the other treatments. Treatment groups did not differ in the proportion of number of fibre types, nor in the mass of most limb muscles or the heart. Our results offer some caveats for investigators conducting training research on non-model organisms and they reveal that muscle plasticity in response to training may be widespread phylogenetically. © 2015. Published by The Company of Biologists Ltd.

  19. Vitamin E Supplementation Increases the Attractiveness of Males' Scent for Female European Green Lizards

    Science.gov (United States)

    Kopena, Renáta; Martín, José; López, Pilar; Herczeg, Gábor

    2011-01-01

    Background In spite that chemoreception is important in sexual selection for many animals, such as reptiles, the mechanisms that confer reliability to chemical signals are relatively unknown. European green lizards (Lacerta viridis) have substantial amounts of α-tocopherol ( = vitamin E) in their femoral secretions. Because vitamin E is metabolically important and can only be attained from the diet, its secretion is assumed to be costly. However, its role in intraspecific communication is unknown. Methodology/Principal Findings Here, we experimentally show that male European green lizards that received a dietary supplement of vitamin E increased proportions of vitamin E in their femoral secretions. Furthermore, our experiments revealed that females preferred to use areas scent marked by males with experimentally increased vitamin E levels in their secretions. Finally, female preferences were stronger when vitamin E differences between a pair of males' secretions were larger. Conclusions/Significance Our results demonstrate that female green lizards are able to discriminate between males based on the vitamin E content of the males' femoral secretions. We suggest that the possible cost of allocating vitamin E to secretions, which might be dependent on male quality, may be a mechanism that confers reliability to scent marks of green lizards and allows their evolution as sexual signals. PMID:21552540

  20. 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. Copyright © 2015 Elsevier GmbH. All rights reserved.

  1. The Effects of Air Pressure on Spontaneous Otoacoustic Emissions of Lizards

    NARCIS (Netherlands)

    van Dijk, Pim; Manley, Geoffrey A.

    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

  2. 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.

  3. 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. © 2015 Cambridge Philosophical Society.

  4. Phylogenomic analyses of more than 4000 nuclear loci resolve the origin of snakes among lizard families.

    Science.gov (United States)

    Streicher, Jeffrey W; Wiens, John J

    2017-09-01

    Squamate reptiles (lizards and snakes) are the most diverse group of terrestrial vertebrates, with more than 10 000 species. Despite considerable effort to resolve relationships among major squamates clades, some branches have remained difficult. Among the most vexing has been the placement of snakes among lizard families, with most studies yielding only weak support for the position of snakes. Furthermore, the placement of iguanian lizards has remained controversial. Here we used targeted sequence capture to obtain data from 4178 nuclear loci from ultraconserved elements from 32 squamate taxa (and five outgroups) including representatives of all major squamate groups. Using both concatenated and species-tree methods, we recover strong support for a sister relationship between iguanian and anguimorph lizards, with snakes strongly supported as the sister group of these two clades. These analyses strongly resolve the difficult placement of snakes within squamates and show overwhelming support for the contentious position of iguanians. More generally, we provide a strongly supported hypothesis of higher-level relationships in the most species-rich tetrapod clade using coalescent-based species-tree methods and approximately 100 times more loci than previous estimates. © 2017 The Author(s).

  5. 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

  6. 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 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.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.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.

  7. 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

  8. Effects of oxygen on responses to heating in two lizard species sampled along an elevational gradient.

    Science.gov (United States)

    DuBois, P Mason; Shea, Tanner K; Claunch, Natalie M; Taylor, Emily N

    2017-08-01

    Thermal tolerance is an important variable in predictive models about the effects of global climate change on species distributions, yet the physiological mechanisms responsible for reduced performance at high temperatures in air-breathing vertebrates are not clear. We conducted an experiment to examine how oxygen affects three variables exhibited by ectotherms as they heat-gaping threshold, panting threshold, and loss of righting response (the latter indicating the critical thermal maximum)-in two lizard species along an elevational (and therefore environmental oxygen partial pressure) gradient. Oxygen partial pressure did not impact these variables in either species. We also exposed lizards at each elevation to severely hypoxic gas to evaluate their responses to hypoxia. Severely low oxygen partial pressure treatments significantly reduced the gaping threshold, panting threshold, and critical thermal maximum. Further, under these extreme hypoxic conditions, these variables were strongly and positively related to partial pressure of oxygen. In an elevation where both species overlapped, the thermal tolerance of the high elevation species was less affected by hypoxia than that of the low elevation species, suggesting the high elevation species may be adapted to lower oxygen partial pressures. In the high elevation species, female lizards had higher thermal tolerance than males. Our data suggest that oxygen impacts the thermal tolerance of lizards, but only under severely hypoxic conditions, possibly as a result of hypoxia-induced anapyrexia. Copyright © 2017. Published by Elsevier Ltd.

  9. Immune responses of eastern fence lizards (Sceloporus undulatus) to repeated acute elevation of corticosterone.

    Science.gov (United States)

    McCormick, Gail L; Langkilde, Tracy

    2014-08-01

    Prolonged elevations of glucocorticoids due to long-duration (chronic) stress can suppress immune function. It is unclear, however, how natural stressors that result in repeated short-duration (acute) stress, such as frequent agonistic social encounters or predator attacks, fit into our current understanding of the immune consequences of stress. Since these types of stressors may activate the immune system due to increased risk of injury, immune suppression may be reduced at sites where individuals are repeatedly exposed to potentially damaging stressors. We tested whether repeated acute elevation of corticosterone (CORT, a glucocorticoid) suppresses immune function in eastern fence lizards (Sceloporus undulatus), and whether this effect varies between lizards from high-stress (high baseline CORT, invaded by predatory fire ants) and low-stress (low baseline CORT, uninvaded) sites. Lizards treated daily with exogenous CORT showed higher hemagglutination of novel proteins by their plasma (a test of constitutive humoral immunity) than control lizards, a pattern that was consistent across sites. There was no significant effect of CORT treatment on bacterial killing ability of plasma. These results suggest that repeated elevations of CORT, which are common in nature, produce immune effects more typical of those expected at the acute end of the acute-chronic spectrum and provide no evidence of modulated consequences of elevated CORT in animals from high-stress sites. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. 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.

  11. Himantoglossum jankae (Orchidaceae: Orchideae), a new name for a long-misnamed lizard orchid

    NARCIS (Netherlands)

    Molnar, A.; Kreutz, C.A.J.; Ovari, M.; Sennikov, A.N.; Bateman, R.M.; Takacs, A.; Somlyay, L.; Sramko, G.

    2012-01-01

    A new name, Himantoglossum jankae, is given to the widely recognised lizard orchid species that is distributed primarily in the Balkan Peninsula and the northwestern region of Asia Minor and has been erroneously named H. caprinum in most previous literature. The new species differs from its closest

  12. Positive Relationship between Abdominal Coloration and Dermal Melanin Density in Phrynosomatid Lizards

    Science.gov (United States)

    Vanessa S. Quinn; Diana K. Hews

    2003-01-01

    Phrynosomatid lizards show considerable variation among species in the occurrence of a secondary sexual trait, blue abdominal coloration. The production of blue skin may be controlled by at least two cellular components, melanin in melanophores, and guanine in iridophores. To examine the hypothesis that a mechanism producing variation in abdominal coloration is...

  13. Lizards of the genus Cnemidophorus from the Leeward Group and the adjacent mainland of South America

    NARCIS (Netherlands)

    Lammerée, Liesbeth

    1970-01-01

    When WAGENAAR HUMMELINCK (1940, p. 83—85) made a survey of the lizards of Curaçao, Aruba, Bonaire and the Venezuelan Islands, he could give no more than a short list of specimens collected, together with a few critical remarks, and a single table on “Variation in Cnemidophorus” based on 379

  14. RBC Antibody Screen

    Science.gov (United States)

    ... C Cystic Fibrosis (CF) Gene Mutations Testing Cytomegalovirus (CMV) Tests D-dimer Dengue Fever Testing Des-gamma- ... Index of Screening Recommendations Not Listed? Not Listed? Newborn Screening Screening Tests for Infants Screening Tests for ...

  15. RBC urine test

    Science.gov (United States)

    ... measurement for a result of this test. Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider ...

  16. 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. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Inhibition of plasma butyrylcholinesterase activity in the lizard Gallotia galloti palmae by pesticides: a field study

    International Nuclear Information System (INIS)

    Sanchez-Hernandez, Juan C.; Carbonell, R.; Henriquez Perez, A.; Montealegre, M.; Gomez, L.

    2004-01-01

    A field study was performed to evaluate the effect of exposure to organophosphorus (OP) and carbamate (CB) pesticides on the lizard Gallotia galloti palmae. Butyrylcholinesterase (BChE) activity was measured in the plasma of 420 lizards collected from agricultural and reference areas on the Island of La Palma (Canary Islands, Spain) in two sampling periods. Exposure to cholinesterase-inhibiting pesticides was evaluated by a statistical criterion based on a threshold value (two standard deviations below the mean enzyme activity) calculated for the reference group, and a chemical criterion based on the in vitro reactivation of BChE activity using pyridine-2-aldoxime methochloride (2-PAM) or after water dilution of the sample. Mean (±SD) BChE activity for lizards from agricultural areas was significantly lower (Fuencaliente site = 2.00 ± 0.98 μmol min -1 ml -1 , Tazacorte site = 2.88 ± 1.08) than that for lizards from the reference areas (Los Llanos site = 3.06 ± 1.17 μmol min -1 ml -1 , Tigalate site = 3.96 ± 1.62). According to the statistical criterion, the number of lizards with BChE depressed was higher at Fuencaliente (22% of males and 25.4% of females) than that sampled at Tazacorte (7.8% of males and 6.2% of females). According to the chemical criterion, Fuencaliente also yielded a higher number of individuals (112 males and 47 females) with BChE activity inhibited by both OP and CB pesticides. CBs appeared to be the pesticides most responsible for BChE inhibition because most of the samples showed reactivation of BChE activity after water treatment (63.3% from Fuencaliente and 29% from Tazacorte). We concluded that the use of reactivation techniques on plasma BChE activity is a better and more accurate method for assessing field exposure to OP/CB pesticides in this lizard species than making direct comparisons of enzyme activity levels between sampling areas. - Capsule: Chemical reactivation of lizard BChE activity is a suitable diagnostic method for

  18. Does ecophysiology mediate reptile responses to fire regimes? Evidence from Iberian lizards

    Directory of Open Access Journals (Sweden)

    Catarina C. Ferreira

    2016-06-01

    Full Text Available Background. Reptiles are sensitive to habitat disturbance induced by wildfires but species frequently show opposing responses. Functional causes of such variability have been scarcely explored. In the northernmost limit of the Mediterranean bioregion, lizard species of Mediterranean affinity (Psammodromus algirus and Podarcis guadarramae increase in abundance in burnt areas whereas Atlantic species (Lacerta schreiberi and Podarcis bocagei decrease. Timon lepidus, the largest Mediterranean lizard in the region, shows mixed responses depending on the locality and fire history. We tested whether such interspecific differences are of a functional nature, namely, if ecophysiological traits may determine lizard response to fire. Based on the variation in habitat structure between burnt and unburnt sites, we hypothesise that Mediterranean species, which increase density in open habitats promoted by frequent fire regimes, should be more thermophile and suffer lower water losses than Atlantic species. Methods. We submitted 6–10 adult males of the five species to standard experiments for assessing preferred body temperatures (Tp and evaporativewater loss rates (EWL, and examined the variation among species and along time by means of repeated-measures AN(COVAs. Results. Results only partially supported our initial expectations, since the medium-sized P. algirus clearly attained higher Tp and lower EWL. The two small wall lizards (P. bocagei and P. guadarramae displayed low Tp and high EWL while the two large green lizards (T. lepidus and L. schreiberi displayed intermediate values for both parameters. Discussion. The predicted differences according to the biogeographic affinities within each pair were not fully confirmed. We conclude that ecophysiology may help to understand functional reptile responses to fire but other biological traits are also to be considered.

  19. Reconstructing a herbivore’s diet using a novel rbcL DNA mini-barcode for plants

    Science.gov (United States)

    Erickson, David L.; Reed, Elizabeth; Ramachandran, Padmini; Bourg, Norman; McShea, William J.; Ottesen, Andrea

    2017-01-01

    Next Generation Sequencing and the application of metagenomic analyses can be used to answer questions about animal diet choice and study the consequences of selective foraging by herbivores. The quantification of herbivore diet choice with respect to native versus exotic plant species is particularly relevant given concerns of invasive species establishment and their effects on ecosystems. While increased abundance of white-tailed deer (Odocoileus virginianus) appears to correlate with increased incidence of invasive plant species, data supporting a causal link is scarce. We used a metabarcoding approach (PCR amplicons of the plant rbcL gene) to survey the diet of white-tailed deer (fecal samples), from a forested site in Warren County, Virginia with a comprehensive plant species inventory and corresponding reference collection of plant barcode and chloroplast sequences. We sampled fecal pellet piles and extracted DNA from 12 individual deer in October 2014. These samples were compared to a reference DNA library of plant species collected within the study area. For 72 % of the amplicons, we were able to assign taxonomy at the species level, which provides for the first time—sufficient taxonomic resolution to quantify the relative frequency at which native and exotic plant species are being consumed by white-tailed deer. For each of the 12 individual deer we collected three subsamples from the same fecal sample, resulting in sequencing 36 total samples. Using Qiime, we quantified the plant DNA found in all 36 samples, and found that variance within samples was less than variance between samples (F = 1.73, P = 0.004), indicating additional subsamples may not be necessary. Species level diversity ranged from 60 to 93 OTUs per individual and nearly 70 % of all plant sequences recovered were from native plant species. The number of species detected did reduce significantly (range 4–12) when we excluded species whose OTU composed behaviour may favour

  20. 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...... crossmatching and issuing practices. Respondents were asked to enumerate the number of RBCs crossmatched and issued at their institutions during the 2014 calendar year to calculate the C/I ratio. RESULTS: Fifty-two survey responses were received, mostly from North American transfusion services (28/52, 54......%). The electronic crossmatch was the most common technique (n = 29), and most respondents performed the crossmatch at the time that an order for RBCs was received in the transfusion service (even if an order to issue the RBCs was not received). Data to calculate the C/I ratio were supplied by 22 respondents...

  1. 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. Copyright © 2014 Wiley Periodicals, Inc.

  2. A study of secondary fabrics in rocks from the lizard Peninsula and adjacent areas in southwest cornwall, england

    Science.gov (United States)

    Rathore, Jaswant Singh

    1980-09-01

    Magnetic susceptibility anisotropy techniques were applied to samples taken in selected areas of the Lizard Peninsula in order to study secondary fabrics due to: (1) the intrusion of granites into sediments; (2) the compression in the sediments to the north of the Lizard thrust boundary; and (3) the intrusion of serpentine into hornblende schists of the Lizard metamorphic block. The magnetic fabric around the Carnmenellis and Godolphin granite masses shows a strong compressional fabric, tending to suggest that the Devonian sediments were compressed radially as the granites intruded them. The high degree of anisotropy observed at the Lizard boundary falls, with increasing distance from the thrust, systematically down to low values in the Devonian sediments. The distinct changes in the fabric parameters at the north end of Church Cove-Landewednack and the southern end of Cadgwith Cove appear to be the remnant secondary fabrics due to the intrusion of serpentine into hornblende schists.

  3. RBC deformability and amino acid concentrations after hypo-osmotic challenge may reflect chronic cell hydration status in healthy young men

    Science.gov (United States)

    Stookey, Jodi D; Klein, Alexis; Hamer, Janice; Chi, Christine; Higa, Annie; Ng, Vivian; Arieff, Allen; Kuypers, Frans A; Larkin, Sandra; Perrier, Erica; Lang, Florian

    2013-01-01

    Biomarkers of chronic cell hydration status are needed to determine whether chronic hyperosmotic stress increases chronic disease risk in population-representative samples. In vitro, cells adapt to chronic hyperosmotic stress by upregulating protein breakdown to counter the osmotic gradient with higher intracellular amino acid concentrations. If cells are subsequently exposed to hypo-osmotic conditions, the adaptation results in excess cell swelling and/or efflux of free amino acids. This study explored whether increased red blood cell (RBC) swelling and/or plasma or urine amino acid concentrations after hypo-osmotic challenge might be informative about relative chronic hyperosmotic stress in free-living men. Five healthy men (20–25 years) with baseline total water intake below 2 L/day participated in an 8-week clinical study: four 2-week periods in a U-shaped A-B-C-A design. Intake of drinking water was increased by +0.8 ± 0.3 L/day in period 2, and +1.5 ± 0.3 L/day in period 3, and returned to baseline intake (0.4 ± 0.2 L/day) in period 4. Each week, fasting blood and urine were collected after a 750 mL bolus of drinking water, following overnight water restriction. The periods of higher water intake were associated with significant decreases in RBC deformability (index of cell swelling), plasma histidine, urine arginine, and urine glutamic acid. After 4 weeks of higher water intake, four out of five participants had ½ maximal RBC deformability below 400 mmol/kg; plasma histidine below 100 μmol/L; and/or undetectable urine arginine and urine glutamic acid concentrations. Work is warranted to pursue RBC deformability and amino acid concentrations after hypo-osmotic challenge as possible biomarkers of chronic cell hydration. PMID:24303184

  4. Phylogeny of the Juncaceae based on rbcL sequences, with special emphasis on Luzula DC. and Juncus L

    DEFF Research Database (Denmark)

    Drábková, L.; Kirschner, J.; Seberg, Ole

    2003-01-01

    Cladistic analysis of rbcL nucleotide sequences was applied to 58 taxa representing most subgenera and sections of Luzula and Juncus, chosen to reflect morphological and geographical diversity of both genera. Additionally, representatives of all other genera of the Juncaceae and two taxa from the......-supported clade is represented by an assemblage of representatives of five genera and species distributed in the Southern Hemisphere: Juncus capensis and J. lomatophyllus (both from section Graminifolii), Rostkovia, Distichia, Marsippospermum, and Patosia....

  5. A segment of rbcL gene as a potential tool for forensic discrimination of Cannabis sativa seized at Rio de Janeiro, Brazil.

    Science.gov (United States)

    Mello, I C T; Ribeiro, A S D; Dias, V H G; Silva, R; Sabino, B D; Garrido, R G; Seldin, L; de Moura Neto, Rodrigo Soares

    2016-03-01

    Cannabis sativa, known by the common name marijuana, is the psychoactive drug most widely distributed in the world. Identification of Cannabis cultivars may be useful for association to illegal crops, which may reveal trafficking routes and related criminal groups. This study provides evidence for the performance of a segment of the rbcL gene, through genetic signature, as a tool for identification for C. sativa samples apprehended by the Rio de Janeiro Police, Brazil. The PCR amplified and further sequenced the fragment of approximately 561 bp of 24 samples of C. sativa rbcL gene and showed the same nucleotide sequences, suggesting a possible genetic similarity or identical varieties. Comparing with other Cannabaceae family sequences, we have found 99% of similarity between the Rio de Janeiro sequence and three other C. sativa rbcL genes. These findings suggest that the fragment utilized at this study is efficient in identifying C. sativa samples, therefore, useful in genetic discrimination of samples seized in forensic cases.

  6. Marked colour divergence in the gliding membranes of a tropical lizard mirrors population differences in the colour of falling leaves

    OpenAIRE

    Klomp, D. A.; Stuart-Fox, D.; Das, I.; Ord, T. J.

    2014-01-01

    Populations of the Bornean gliding lizard, Draco cornutus, differ markedly in the colour of their gliding membranes. They also differ in local vegetation type (mangrove forest versus lowland rainforest) and consequently, the colour of falling leaves (red and brown/black in mangrove versus green, brown and black in rainforest). We show that the gliding membranes of these lizards closely match the colours of freshly fallen leaves in the local habitat as they appear to the visual system of birds...

  7. 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.

  8. Daily and annual cycles in thermoregulatory behaviour and cardio-respiratory physiology of black and white tegu lizards.

    Science.gov (United States)

    Sanders, Colin E; Tattersall, Glenn J; Reichert, Michelle; Andrade, Denis V; Abe, Augusto S; Milsom, William K

    2015-12-01

    This study was designed to determine the manner in which metabolism is suppressed during dormancy in black and white tegu lizards (Tupinambis merianae). To this end, heart rate (fH), respiration rate (fR), and deep body temperature (Tb) were continuously monitored in outdoor enclosures by radio-telemetry for nine months. There was a continuous decline in nighttime breathing and heart rate, at constant Tb, throughout the late summer and fall suggestive of an active metabolic suppression that developed progressively at night preceding the entrance into dormancy. During the day, however, the tegus still emerged to bask. In May, when the tegus made a behavioural commitment to dormancy, Tb (day and night) fell to match burrow temperature, accompanied by a further reduction in fH and fR. Tegus, under the conditions of this study, did arouse periodically during dormancy. There was a complex interplay between changes in fH and Tb associated with the direct effects of temperature and the indirect effects of thermoregulation, activity, and changes in metabolism. This interplay gave rise to a daily hysteresis in the fH/Tb relationship reflective of the physiological changes associated with warming and cooling as preferred Tb alternated between daytime and nighttime levels. The shape of the hysteresis curve varied with season along with changes in metabolic state and daytime and nighttime body temperature preferences.

  9. Pentastomid, Raillietiella mottae Almeida, Freire and Lopes, 2008, infecting lizards in an area of caatinga, northeast, Brazil

    Directory of Open Access Journals (Sweden)

    WO. Almeida

    Full Text Available 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 (07º 25' S and 36º 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.

  10. Supplementation of male pheromone on rock substrates attracts female rock lizards to the territories of males: a field experiment.

    Directory of Open Access Journals (Sweden)

    José Martín

    Full Text Available 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.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.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.

  11. Supplementation of Male Pheromone on Rock Substrates Attracts Female Rock Lizards to the Territories of Males: A Field Experiment

    Science.gov (United States)

    Martín, José; López, Pilar

    2012-01-01

    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. PMID:22253895

  12. The importance of ultraviolet and near-infrared sensitivity for visual discrimination in two species of lacertid lizards.

    Science.gov (United States)

    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. © 2015. Published by The Company of Biologists Ltd.

  13. Thermal preference, thermal tolerance and the thermal de-pendence of digestive performance in two Phrynocephalus lizards (Agamidae), with a review of species studied

    OpenAIRE

    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 i...

  14. Reconstructing a herbivore’s diet using a novel rbcL DNA mini-barcode for plants

    Science.gov (United States)

    Erickson, David L.; Reed, Elizabeth; Ramachandran, Padmini; Bourg, Norman; McShea, William J.; Ottesen, Andrea

    2017-01-01

    Next Generation Sequencing and the application of metagenomic analyses can be used to answer questions about animal diet choice and study the consequences of selective foraging by herbivores. The quantification of herbivore diet choice with respect to native versus exotic plant species is particularly relevant given concerns of invasive species establishment and their effects on ecosystems. While increased abundance of white-tailed deer (Odocoileus virginianus) appears to correlate with increased incidence of invasive plant species, data supporting a causal link is scarce. We used a metabarcoding approach (PCR amplicons of the plant rbcL gene) to survey the diet of white-tailed deer (fecal samples), from a forested site in Warren County, Virginia with a comprehensive plant species inventory and corresponding reference collection of plant barcode and chloroplast sequences. We sampled fecal pellet piles and extracted DNA from 12 individual deer in October 2014. These samples were compared to a reference DNA library of plant species collected within the study area. For 72 % of the amplicons, we were able to assign taxonomy at the species level, which provides for the first time—sufficient taxonomic resolution to quantify the relative frequency at which native and exotic plant species are being consumed by white-tailed deer. For each of the 12 individual deer we collected three subsamples from the same fecal sample, resulting in sequencing 36 total samples. Using Qiime, we quantified the plant DNA found in all 36 samples, and found that variance within samples was less than variance between samples (F = 1.73, P = 0.004), indicating additional subsamples may not be necessary. Species level diversity ranged from 60 to 93 OTUs per individual and nearly 70 % of all plant sequences recovered were from native plant species. The number of species detected did reduce significantly (range 4–12) when we excluded species whose OTU composed <1 % of each

  15. 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

  16. Gliding lizards use the position of the sun to enhance social display.

    Science.gov (United States)

    Klomp, Danielle A; Stuart-Fox, Devi; Das, Indraneil; Ord, Terry J

    2017-02-01

    Effective communication requires animal signals to be readily detected by receivers in the environments in which they are typically given. Certain light conditions enhance the visibility of colour signals and these conditions can vary depending on the orientation of the sun and the position of the signaller. We tested whether Draco sumatranus gliding lizards modified their position relative to the sun to enhance the conspicuousness of their throat-fan (dewlap) during social display to conspecifics. The dewlap was translucent, and we found that lizards were significantly more likely to orient themselves perpendicular to the sun when displaying. This increases the dewlap's radiance, and likely, its conspicuousness, by increasing the amount of light transmitted through the ornament. This is a rare example of a behavioural adaptation for enhancing the visibility of an ornament to distant receivers. © 2017 The Author(s).

  17. Characterisation of major histocompatibility complex class I transcripts in an Australian dragon lizard.

    Science.gov (United States)

    Hacking, Jessica; Bertozzi, Terry; Moussalli, Adnan; Bradford, Tessa; Gardner, Michael

    2018-07-01

    Characterisation of squamate major histocompatibility complex (MHC) genes has lagged behind other taxonomic groups. MHC genes encode cell-surface glycoproteins that present self- and pathogen-derived peptides to T cells and play a critical role in pathogen recognition. Here we characterise MHC class I transcripts for an agamid lizard (Ctenophorus decresii) and investigate the evolution of MHC class I in Iguanian lizards. An iterative assembly strategy was used to identify six full-length C. decresii MHC class I transcripts, which were validated as likely to encode classical class I MHC molecules. Evidence for exon shuffling recombination was uncovered for C. decresii transcripts and Bayesian phylogenetic analysis of Iguanian MHC class I sequences revealed a pattern expected under a birth-and-death mode of evolution. This work provides a stepping stone towards further research on the agamid MHC class I region. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Erosion of lizard diversity by climate change and altered thermal niches.

    Science.gov (United States)

    Sinervo, Barry; Méndez-de-la-Cruz, Fausto; Miles, Donald B; Heulin, Benoit; Bastiaans, Elizabeth; Villagrán-Santa Cruz, Maricela; Lara-Resendiz, Rafael; Martínez-Méndez, Norberto; Calderón-Espinosa, Martha Lucía; Meza-Lázaro, Rubi Nelsi; Gadsden, Héctor; Avila, Luciano Javier; Morando, Mariana; De la Riva, Ignacio J; Victoriano Sepulveda, Pedro; Rocha, Carlos Frederico Duarte; Ibargüengoytía, Nora; Aguilar Puntriano, César; Massot, Manuel; Lepetz, Virginie; Oksanen, Tuula A; Chapple, David G; Bauer, Aaron M; Branch, William R; Clobert, Jean; Sites, Jack W

    2010-05-14

    It is predicted that climate change will cause species extinctions and distributional shifts in coming decades, but data to validate these predictions are relatively scarce. Here, we compare recent and historical surveys for 48 Mexican lizard species at 200 sites. Since 1975, 12% of local populations have gone extinct. We verified physiological models of extinction risk with observed local extinctions and extended projections worldwide. Since 1975, we estimate that 4% of local populations have gone extinct worldwide, but by 2080 local extinctions are projected to reach 39% worldwide, and species extinctions may reach 20%. Global extinction projections were validated with local extinctions observed from 1975 to 2009 for regional biotas on four other continents, suggesting that lizards have already crossed a threshold for extinctions caused by climate change.

  19. Methods and pitfalls of measuring thermal preference and tolerance in lizards.

    Science.gov (United States)

    Camacho, Agustín; Rusch, Travis W

    2017-08-01

    Understanding methodological and biological sources of bias during the measurement of thermal parameters is essential for the advancement of thermal biology. For more than a century, studies on lizards have deepened our understanding of thermal ecophysiology, employing multiple methods to measure thermal preferences and tolerances. We reviewed 129 articles concerned with measuring preferred body temperature (PBT), voluntary thermal tolerance, and critical temperatures of lizards to offer: a) an overview of the methods used to measure and report these parameters, b) a summary of the methodological and biological factors affecting thermal preference and tolerance, c) recommendations to avoid identified pitfalls, and d) directions for continued progress in our application and understanding of these thermal parameters. We emphasize the need for more methodological and comparative studies. Lastly, we urge researchers to provide more detailed methodological descriptions and suggest ways to make their raw data more informative to increase the utility of thermal biology studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Sterility among female lizards (Uta stansburiana) exposed to continuous γ irradiation

    International Nuclear Information System (INIS)

    Turner, F.B.; Medica, P.A.

    1977-01-01

    A natural population of the lizard Uta stansburiana occupying a fenced 9-ha area in southern Nevada was exposed to essentially continuous γ irradiation from an arificial source between February 1964 and September 1973. Tissue doses were estimated using implanted lithium fluoride microdosimeters. Females became sterile as early as 11 months of age, but many were still fertile at ages of 20 months and a very few may have reproduced at 32 months. Dosimetry showed some females to be sterile after accumulated doses of around 500 rad, while others may have required 1000 or more rad. One female estimated to have received over 1200 rad was still reproductive. Irradiated females may pass through a state of half sterility, during which time they possess one functional ovary. Female U. stansburiana are sterilized at lower doses than the sterilizing dose (1500 rad) previously suggested for the leopard lizard, Crotaphytus wislizenii

  1. 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.

  2. 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.

  3. 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.

  4. Prevalence and molecular identification of Cryptosporidium isolates from pet lizards and snakes in Italy

    Directory of Open Access Journals (Sweden)

    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.

  5. Immune activation affects chemical sexual ornaments of male Iberian wall lizards

    Science.gov (United States)

    López, Pilar; Gabirot, Marianne; Martín, José

    2009-01-01

    Many animals use chemical signals in sexual selection, but it is not clear how these sexual traits might have evolved to signal honestly male condition. It is possible that there is a trade-off between maintaining the immune system and the elaboration of ornaments. We experimentally challenged the immune system of male Iberian wall lizards, Podarcis hispanica, with a bacterial antigen (lipopolysaccharide), without pathogenic effects, to explore whether the immune activation affected chemical ornaments. Immune activation resulted in decreased proportions of a major chemical in femoral secretions (cholesta-5,7-dien-3-ol = provitamin D3) known to be selected in scent of males by females and which active form (vitamin D) has a variety of important effects on immune system function. This result suggests the existence of a potential trade-off between physiological regulation of the immune system and the allocation of essential nutrients (vitamins) to sexual chemical ornaments in male lizards.

  6. 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.

  7. Physiological Correlates of Multiple Parasitic Infections in Side-Blotched Lizards.

    Science.gov (United States)

    Spence, Austin R; Durso, Andrew M; Smith, Geoffrey D; Skinner, Heather M; French, Susannah S

    We investigated the presence of ectoparasites and hemoparasites in side-blotched lizards (Uta stansburiana) across a large part of their range and measured how parasitic infection related to several key physiological indicators of health. Blood samples were collected from 132 lizards from central Arizona, southern Utah, and eastern Oregon. Hemoparasites were found in 22 individuals (3.2% prevalence in Arizona, 19.1% in Utah, and 6.3% in Oregon), and ectoparasites were found on 51 individuals (56.3% prevalence in Arizona, 56.1% in Utah, and 6.7% in Oregon), with 11 individuals infected with both. Hemoparasites and ectoparasites were found in all three states. Immunocompetence was higher in individuals infected with both hemoparasites and ectoparasites. Body condition, glucocorticoid levels, and reproductive investment were not related to infection status. Our study provides evidence that parasitic infection is associated with an active immune system in wild reptiles but may not impose other costs usually associated with parasites.

  8. Checklist of helminths from lizards and amphisbaenians (Reptilia, Squamata of South America

    Directory of Open Access Journals (Sweden)

    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.

  9. 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.

  10. Dispersal and population state of an endangered island lizard following a conservation translocation.

    Science.gov (United States)

    Angeli, Nicole F; Lundgren, Ian F; Pollock, Clayton G; Hillis-Starr, Zandy M; Fitzgerald, Lee A

    2018-03-01

    Population size is widely used as a unit of ecological analysis, yet to estimate population size requires accounting for observed and latent heterogeneity influencing dispersion of individuals across landscapes. In newly established populations, such as when animals are translocated for conservation, dispersal and availability of resources influence patterns of abundance. We developed a process to estimate population size using N-mixture models and spatial models for newly established and dispersing populations. We used our approach to estimate the population size of critically endangered St. Croix ground lizards (Ameiva polops) five years after translocation of 57 individuals to Buck Island, an offshore island of St. Croix, United States Virgin Islands. Estimates of population size incorporated abiotic variables, dispersal limits, and operative environmental temperature available to the lizards to account for low species detection. Operative environmental temperature and distance from the translocation site were always important in fitting the N-mixture model indicating effects of dispersal and species biology on estimates of population size. We found that the population is increasing its range across the island by 5-10% every six months. We spatially interpolated site-specific abundance from the N-mixture model to the entire island, and we estimated 1,473 (95% CI, 940-1,802) St. Croix ground lizards on Buck Island in 2013 corresponding to survey results. This represents a 26-fold increase since the translocation. We predicted the future dispersal of the lizards to all habitats on Buck Island, with the potential for the population to increase by another five times in the future. Incorporating biologically relevant covariates as explicit parameters in population models can improve predictions of population size and the future spread of species introduced to new localities. © 2018 by the Ecological Society of America.

  11. 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...

  12. Moisture harvesting and water transport through specialized micro-structures on the integument of lizards.

    Science.gov (United States)

    Comanns, Philipp; Effertz, Christian; Hischen, Florian; Staudt, Konrad; Böhme, Wolfgang; Baumgartner, Werner

    2011-01-01

    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.

  13. 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.

  14. Correlated evolution of herbivory and food chemical discrimination in iguanian and ambush foraging lizards

    OpenAIRE

    William E. Cooper

    2003-01-01

    To efficiently locate and assess foods, animal sensory capacities and behavioral discriminations based on them must be appropriate for the diet and method of hunting. In lizards, actively foraging insectivores identify animal prey using lingually sampled chemical cues, but ambush foragers do not. Among plant eaters derived from active foragers, plant chemical discrimination is added to prey chemical discrimination, resulting in correlated evolution of plant diet and plant chemical discriminat...

  15. 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

  16. Moisture harvesting and water transport through specialized micro-structures on the integument of lizards

    Science.gov (United States)

    Comanns, Philipp; Effertz, Christian; Hischen, Florian; Staudt, Konrad; Böhme, Wolfgang

    2011-01-01

    Summary 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. PMID:21977432

  17. Little dragons prefer flowers to maidens: a lizard that laps nectar and pollinates trees

    OpenAIRE

    Sazima, Ivan; Sazima, Cristina; Sazima, Marlies

    2005-01-01

    Lizards rarely visit and pollinate flowers, the few recent records being mostly restricted to island habitats. We report here on the Noronha skink (Euprepis atlanticus) seeking nectar in the flowers of the leguminous mulungu tree (Erythrina velutina) at Fernando de Noronha Archipelago, off northeast Brazil. The mulungu tree blooms during the dry season, and each flower secretes copious and diluted nectar throughout the day. The Noronha skink climbs up to the inflorescences and laps the nectar...

  18. Long-term changes in abundances of Sonoran Desert lizards reveal complex responses to climatic variation.

    Science.gov (United States)

    Flesch, Aaron D; Rosen, Philip C; Holm, Peter

    2017-12-01

    Understanding how climatic variation affects animal populations and communities is essential for addressing threats posed by climate change, especially in systems where impacts are projected to be high. We evaluated abundance dynamics of five common species of diurnal lizards over 25 years in a Sonoran Desert transition zone where precipitation decreased and temperature increased across time, and assessed hypotheses for the influence of climatic flux on spatiotemporal variation in abundances. We repeatedly surveyed lizards in spring and summer of each year at up to 32 sites, and used hierarchical mixture models to estimate detection probabilities, abundances, and population growth rates. Among terrestrial species, abundances of a short-lived, winter-spring breeder increased markedly by an estimated 237%-285% across time, while two larger spring-summer breeders with higher thermal preferences declined by up to 64%. Abundances of two arboreal species that occupy shaded and thus sheltered microhabitats fluctuated but did not decline systematically. Abundances of all species increased with precipitation at short lag times (1-1.5 years) likely due to enhanced food availability, but often declined after periods of high precipitation at longer lag times (2-4 years) likely due to predation and other biotic pressures. Although rising maximum daily temperatures (T max ) are expected to drive global declines of lizards, associations with T max were variable and weak for most species. Instead, abundances of all species declined with rising daily minimum temperatures, suggesting degradation of cool refugia imposed widespread metabolic or other costs. Our results suggest climate warming and drying are having major impacts on lizard communities by driving declines in species with traits that augment exposure to abiotic extremes and by modifying species interactions. The complexity of patterns we report indicates that evaluating and responding to the influence of climate change

  19. Terminal distribution of retinal fibers in the tegu lizard (Tupinambis nigropunctatus).

    Science.gov (United States)

    Ebbesson, S O; Karten, H J

    1981-01-01

    The retinal projections in the tegu lizard were traced using degeneration-silver methods. Bilateral projections were found to the dorsolateral geniculate and the posterodorsal nuclei. Unilateral, crossed projections were traced to the suprachiasmatic nucleus, the ventrolateral geniculate nucleus, the mesencephalic lentiform nucleus, nucleus geniculatus praetectalis, the ectomammillary nucleus, and the optic tectum. Some of these connections are distinctly different from those reported in other reptiles and suggest that important interspecific variations occur among reptiles.

  20. Is the number and size of scales in Liolaemus lizards driven by climate?

    Science.gov (United States)

    José Tulli, María; Cruz, Félix B

    2018-05-03

    Ectothermic vertebrates are sensitive to thermal fluctuations in the environments where they occur. To buffer these fluctuations, ectotherms use different strategies, including the integument, which is a barrier that minimizes temperature exchange between the inner body and the surrounding air. In lizards, this barrier is constituted by keratinized scales of variable size, shape and texture, and its main function is protection, water loss avoidance and thermoregulation. The size of scales in lizards has been proposed to vary in relation to climatic gradients; however, it has also been observed that in some groups of Iguanian lizards could be related to phylogeny. Thus, here, we studied the area and number of scales (dorsal and ventral) of 61 species of Liolaemus lizards distributed in a broad latitudinal and altitudinal gradient to determine the nature of the variation of the scales with climate, and found that the number and size of scales are related to climatic variables, such as temperature and geographical variables as altitude. The evolutionary process that better explained how these morphological variables evolved was the Ornstein-Uhlenbeck model. The number of scales seemed to be related to common ancestry, whereas dorsal and ventral scale areas seemed to vary as a consequence of ecological traits. In fact, the ventral area is less exposed to climate conditions such as ultraviolet radiation or wind and is thus under less pressure to change in response to alterations in external conditions. It is possible that scale ornamentation such as keels and granulosity may bring some more information in this regard. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  1. 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.

  2. Pollution biomarkers in the spiny lizard (Sceloporus spp.) from two suburban populations of Monterrey, Mexico.

    Science.gov (United States)

    Aguilera, Carlos; del Pliego, Pamela González; Alfaro, Roberto Mendoza; Lazcano, David; Cruz, Julio

    2012-11-01

    Environmental pollution may severely impact reptile species in urbanized areas. The magnitude of the impact is analyzed in the present study using lizard tail tips for the quantitative evaluation of enzymatic biomarkers of pollution. Spiny lizards (Sceloporus serrifer and S. torquatus) were collected from two suburban localities in the Monterrey metropolitan area, Mexico: Chipinque Ecological Park, a natural protected area, and El Carmen Industrial Park (IP), a highly polluted site. Different enzymes were used as biomarkers including: acetylcholinesterase (AChE), butyrylcholinesterase (BChE), carboxylesterase (CaE), alkaline phosphatase (ALP), acid phosphatase (ACP), superoxide dismutase (SOD) and glutathione S-transferase (GST). The levels of AChE, BChE and ACP activity were not significantly different between localities. AChE and BChE, commonly used as biomarkers of neurotoxic polluting agents (e.g. organophosphate pesticides) do not appear to be affecting the populations from the study locations. In contrast, the levels of CaE, GST, ALP and SOD were significantly different between the localities. These biomarkers are regularly associated with oxidative stress and processes of detoxification, and generally indicate pollution caused by heavy metals or hydrocarbons, which are common in industrial sites. The data resulting from the analysis of these biomarkers indicate that these polluting agents are affecting the populations of Sceloporus in IP. The present work validates the possibility of conducting additional ecotoxicological studies using biomarkers in combination with a nondestructive sampling technique in species of spiny lizards that are abundant in many North America areas.

  3. 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.

  4. Life on the rocks: habitat use drives morphological and performance evolution in lizards.

    Science.gov (United States)

    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. 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.

  6. Tracing the developmental origin of a lizard skull: Chondrocranial architecture, heterochrony, and variation in lacertids.

    Science.gov (United States)

    Yaryhin, Oleksandr; Werneburg, Ingmar

    2018-06-08

    The sand lizard, Lacerta agilis, is a classical model species in herpetology. Its adult skull anatomy and its embryonic development are well known. The description of its fully formed primordial skull by Ernst Gaupp, in 1900, was a key publication in vertebrate morphology and influenced many comparative embryologists. Based on recent methodological considerations, we restudied the early cranial development of this species starting as early as the formation of mesenchymal condensations up to the fully formed chondrocranium. We traced the formation of the complex chondrocranial architecture in detail, clarified specific homologies for the first time, and uncovered major differences to old textbook descriptions. Comparison with other lacertid lizards revealed a very similar genesis of the primordial skull. However, we detected shifts in the developmental timing of particular cartilaginous elements, mainly in the nasal region, which may correlate to specific ecological adaptation in the adults. Late timing of nasal elements might be an important innovation for the successful wide range distribution of the well-known sand lizard. © 2018 Wiley Periodicals, Inc.

  7. Aridification driven diversification of fan-throated lizards from the Indian subcontinent.

    Science.gov (United States)

    Deepak, V; Karanth, Praveen

    2018-03-01

    The establishment of monsoon climate and the consequent aridification has been one of the most important climate change episodes in the Indian subcontinent. However, little is known about how these events might have shaped the diversification patterns among the widely distributed taxa. Fan-throated lizards (FTL) (Genus: Sitana, Sarada) are widespread, diurnal and restricted to the semi-arid zones of the Indian subcontinent. We sampled FTL in 107 localities across its range. We used molecular species delimitation method and delineated 15 species including six putative species. Thirteen of them were distinguishable based on morphology but two sister species were indistinguishable and have minor overlaps in distribution. Five fossils were used to calibrate and date the phylogeny. Diversification of fan-throated lizards lineage started ~18 mya and higher lineage diversification was observed after 11 my. The initial diversification corresponds to the time when monsoon climate was established and the latter was a period of intensification of monsoon and initiation of aridification. Thirteen out of the fifteen FTL species delimited are from Peninsular India; this is probably due to the landscape heterogeneity in this region. The species poor sister genus Otocryptis is paraphyletic and probably represents relict lineages which are now confined to forested areas. Thus, the seasonality led changes in habitat, from forests to open habitats appear to have driven diversification of fan-throated lizards. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Baseline values of immunologic parameters in the lizard Salvator merianae (Teiidae, Squamata)

    Science.gov (United States)

    Mestre, Ana Paula; Amavet, Patricia Susana; Siroski, Pablo Ariel

    2017-01-01

    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. PMID:28652981

  9. Refractoriness of the western fence lizard (Sceloporus occidentalis) to the Lyme disease group spirochete Borrelia bissettii.

    Science.gov (United States)

    Lane, R S; Mun, J; Eisen, L; Eisen, R J

    2006-08-01

    The western fence lizard, Sceloporus occidentalis, is refractory to experimental infection with Borrelia burgdorferi sensu stricto, one of several Lyme disease spirochetes pathogenic for humans. Another member of the Lyme disease spirochete complex, Borrelia bissettii, is distributed widely throughout North America and a similar, if not identical, spirochete has been implicated as a human pathogen in southern Europe. To determine the susceptibility of S. occidentalis to B. bissettii, 6 naïve lizards were exposed to the feeding activities of Ixodes pacificus nymphs experimentally infected with this spirochete. None of the lizards developed spirochetemias detectable by polymerase chain reaction for up to 8 wk post-tick feeding, infected nymphs apparently lost their B. bissettii infections within 1-2 wk after engorgement, and xenodiagnostic L. pacificus larvae that co-fed alongside infected nymphs did not acquire and maintain spirochetes. In contrast, 3 of 4 naïve deer mice (Peromyscus maniculatus) exposed similarly to feeding by 1 or more B. bissettii-infected nymphs developed patent infections within 4 wk. These and previous findings suggest that the complement system of S. occidentalis typically destroys B. burgdorferi sensu lato spirochetes present in tissues of attached and feeding I. pacificus nymphs, thereby potentially reducing the probability of transmission of these bacteria to humans or other animals by the resultant adult ticks.

  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. New insights into sex chromosome evolution in anole lizards (Reptilia, Dactyloidae).

    Science.gov (United States)

    Giovannotti, M; Trifonov, V A; Paoletti, A; Kichigin, I G; O'Brien, P C M; Kasai, F; Giovagnoli, G; Ng, B L; Ruggeri, P; Cerioni, P Nisi; Splendiani, A; Pereira, J C; Olmo, E; Rens, W; Caputo Barucchi, V; Ferguson-Smith, M A

    2017-03-01

    Anoles are a clade of iguanian lizards that underwent an extensive radiation between 125 and 65 million years ago. Their karyotypes show wide variation in diploid number spanning from 26 (Anolis evermanni) to 44 (A. insolitus). This chromosomal variation involves their sex chromosomes, ranging from simple systems (XX/XY), with heterochromosomes represented by either micro- or macrochromosomes, to multiple systems (X 1 X 1 X 2 X 2 /X 1 X 2 Y). Here, for the first time, the homology relationships of sex chromosomes have been investigated in nine anole lizards at the whole chromosome level. Cross-species chromosome painting using sex chromosome paints from A. carolinensis, Ctenonotus pogus and Norops sagrei and gene mapping of X-linked genes demonstrated that the anole ancestral sex chromosome system constituted by microchromosomes is retained in all the species with the ancestral karyotype (2n = 36, 12 macro- and 24 microchromosomes). On the contrary, species with a derived karyotype, namely those belonging to genera Ctenonotus and Norops, show a series of rearrangements (fusions/fissions) involving autosomes/microchromosomes that led to the formation of their current sex chromosome systems. These results demonstrate that different autosomes were involved in translocations with sex chromosomes in closely related lineages of anole lizards and that several sequential microautosome/sex chromosome fusions lead to a remarkable increase in size of Norops sagrei sex chromosomes.

  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. Catalogue of distribution of lizards (Reptilia: Squamata) from the Brazilian Amazonia. IV. Alopoglossidae, Gymnophthalmidae.

    Science.gov (United States)

    Ribeiro-Júnior, Marco A; Amaral, Silvana

    2017-05-22

    We present distribution data of all Alopoglossidae and Gymnophthalmidae lizards known from the Brazilian Amazonia, totaling 54 species-level taxa, belonging to 17 genera and two families. This represents 22 more species-level taxa than previously reported. Data were based on 17,431 specimens deposited in three North American and eight Brazilian museums, including the main collections harboring Amazonian material. Most species (~80%) are endemic to Amazonia; non-endemic species are mainly associated with open vegetation (savanna) enclaves or open dry (semideciduous) forest in Amazonia, with a few exceptions. As a whole, seven taxa (including one species complex) are widespread in Amazonia, six are restricted to eastern Amazonia, seven to western Amazonia, two to southwestern Amazonia, 11 to southern Amazonia, 11 to northern Amazonia (either in part of it or widespread in the Guiana region), and six to the southern peripheral portion of Amazonia. Besides, four species present unique distributions. Considering this study and the other three catalogues of distribution of lizards already published, the total number of lizard species from Brazilian Amazonia increased from 97 to 142 species-level tava. It represents an increase of 45 species from the region since the last revision.

  14. When Field Experiments Yield Unexpected Results: Lessons Learned from Measuring Selection in White Sands Lizards

    Science.gov (United States)

    Hardwick, Kayla M.; Harmon, Luke J.; Hardwick, Scott D.; Rosenblum, Erica Bree

    2015-01-01

    Determining the adaptive significance of phenotypic traits is key for understanding evolution and diversification in natural populations. However, evolutionary biologists have an incomplete understanding of how specific traits affect fitness in most populations. The White Sands system provides an opportunity to study the adaptive significance of traits in an experimental context. Blanched color evolved recently in three species of lizards inhabiting the gypsum dunes of White Sands and is likely an adaptation to avoid predation. To determine whether there is a relationship between color and susceptibility to predation in White Sands lizards, we conducted enclosure experiments, quantifying survivorship of Holbrookia maculate exhibiting substrate-matched and substrate-mismatched phenotypes. Lizards in our study experienced strong predation. Color did not have a significant effect on survival, but we found several unexpected relationships including variation in predation over small spatial and temporal scales. In addition, we detected a marginally significant interaction between sex and color, suggesting selection for substrate matching may be stronger for males than females. We use our results as a case study to examine six major challenges frequently encountered in field-based studies of natural selection, and suggest that insight into the complexities of selection often results when experiments turn out differently than expected. PMID:25714838

  15. Mimicking lizard-like surface structures upon ultrashort laser pulse irradiation of inorganic materials

    Science.gov (United States)

    Hermens, U.; Kirner, S. V.; Emonts, C.; Comanns, P.; Skoulas, E.; Mimidis, A.; Mescheder, H.; Winands, K.; Krüger, J.; Stratakis, E.; Bonse, J.

    2017-10-01

    Inorganic materials, such as steel, were functionalized by ultrashort laser pulse irradiation (fs- to ps-range) to modify the surface's wetting behavior. The laser processing was performed by scanning the laser beam across the surface of initially polished flat sample material. A systematic experimental study of the laser processing parameters (peak fluence, scan velocity, line overlap) allowed the identification of different regimes associated with characteristic surface morphologies (laser-induced periodic surface structures, grooves, spikes, etc.). Analyses of the surface using optical as well as scanning electron microscopy revealed morphologies providing the optimum similarity to the natural skin of lizards. For mimicking skin structures of moisture-harvesting lizards towards an optimization of the surface wetting behavior, additionally a two-step laser processing strategy was established for realizing hierarchical microstructures. In this approach, micrometer-scaled capillaries (step 1) were superimposed by a laser-generated regular array of small dimples (step 2). Optical focus variation imaging measurements finally disclosed the three dimensional topography of the laser processed surfaces derived from lizard skin structures. The functionality of these surfaces was analyzed in view of wetting properties.

  16. Sexual Dimorphisms of Appendicular Musculoskeletal Morphology Related to Social Display in Cuban Anolis Lizards.

    Science.gov (United States)

    Anzai, Wataru; Cádiz, Antonio; Endo, Hideki

    2015-10-01

    In Anolis lizards, sexual dimorphism has been reported in morphological and ecological traits. Males show larger body size and longer limbs related to territorial combat and courtship display with the dewlap. Although functional-anatomical traits are closely related to locomotor behaviors, differences between sexes in musculoskeletal traits on limbs remain unclear. We explored the relationships among sexual dimorphisms in musculoskeletal morphology, habitat, and locomotor traits in Anolis lizards. Specifically, we examined appendicular musculoskeletal morphology in three species of Cuban Anolis by measuring muscle mass and lengths of moment arms. Through comparisons of crossing locomotion, we found that the runner species possessed larger extensors in hindlimbs, which are advantageous for running, whereas the masses of the humeral and femoral retractors were larger in climber species, allowing these lizards to hold up their bodies and occupy tree substrates. Comparisons between the sexes showed different trends among the three species. Males of A. porcatus, which inhabit narrow branches or leaves, had stronger elbow extensors that maintain the display posture. In contrast, males of A. sagrei, which occupy broad surfaces, did not show sexual differences that affected social display. Moreover, A. bartschi indicated sexual differences despite the absence of dewlapping behavior. Our findings suggest that both sexes show fundamentally similar relationships between muscular morphology and locomotor habits to adapt arboreal or terrestrial substrates, and yet sexual dimorphism in forelimb muscles may additionally affected by male specific display with the dewlap.

  17. Living in sympatry: The effect of habitat partitioning on the thermoregulation of three Mediterranean lizards.

    Science.gov (United States)

    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 (T b ), operative (T e ) and preferred (T pref ) 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 T b 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.

  18. Wall lizards display conspicuous signals to conspecifics and reduce detection by avian predators

    Science.gov (United States)

    Stevens, Martin

    2014-01-01

    Visual signals are often under conflicting selection to be hidden from predators while being conspicuous to mates and rivals. Here, we investigated whether 3 different island populations of Aegean wall lizards (Podarcis erhardii) with variable coloration among diverse island habitats exhibit simultaneous camouflage and sexual signals. We examined whether signals appear better tuned to conspecific vision as opposed to that of avian predators, and whether background-matching camouflage and sexual signals are partitioned to specific body regions. This could facilitate both covert sexual signaling and camouflage according to the viewing perspectives of predators and conspecifics. We found that lizards typically appeared twice as conspicuous to conspecifics than to avian predators against the same visual background, largely due to lizards’ enhanced sensitivity to ultraviolet, suggesting that P. erhardii signals are tuned to conspecific vision to reduce detection by predators. Males were more conspicuous than females to both predators and conspecifics. In 2 populations, male backs were relatively more camouflaged to predators compared to signaling flanks, whereas in females, exposed and concealed surfaces were camouflaged to predators and generally did not differ in background matching. These findings indicate that lizard coloration evolves under the competing demands of natural and sexual selection to promote signals that are visible to conspecifics while being less perceptible to avian predators. They also elucidate how interactions between natural and sexual selection influence signal detectability and partitioning to different body regions, highlighting the importance of considering receiver vision, viewing perspectives, and signaling environments in studies of signal evolution. PMID:25419083

  19. Low rate of interchromosomal rearrangements during old radiation of gekkotan lizards (Squamata: Gekkota).

    Science.gov (United States)

    Johnson Pokorná, Martina; Trifonov, Vladimir A; Rens, Willem; Ferguson-Smith, Malcolm A; Kratochvíl, Lukáš

    2015-06-01

    Gekkotan lizards are a highly specious (∼1600 described species) clade of squamate lizards with nearly cosmopolitan distribution in warmer areas. The clade is primarily nocturnal and forms an ecologically dominant part of the world nocturnal herpetofauna. However, molecular cytogenetic methods to study the evolution of karyotypes have not been widely applied in geckos. Our aim here was to uncover the extent of chromosomal rearrangements across the whole group Gekkota and to search for putative synapomorphies supporting the newly proposed phylogenetic relationships within this clade. We applied cross-species chromosome painting with the recently derived whole-chromosomal probes from the gekkonid species Gekko japonicus to members of the major gekkotan lineages. We included members of the families Diplodactylidae, Carphodactylidae, Pygopodidae, Eublepharidae, Phyllodactylidae and Gekkonidae. Our study demonstrates relatively high chromosome conservatism across the ancient group of gekkotan lizards. We documented that many changes in chromosomal shape across geckos can be attributed to intrachromosomal rearrangements. The documented rearrangements are not totally in agreement with the recently newly erected family Phyllodactylidae. The results also pointed to homoplasy, particularly in the reuse of chromosome breakpoints, in the evolution of gecko karyotypes.

  20. A gravid lizard from the Cretaceous of China and the early history of squamate viviparity

    Science.gov (United States)

    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.

  1. Ontogenic development of spermatids during spermiogenesis in the high altitude bunchgrass lizard (Sceloporus bicanthalis).

    Science.gov (United States)

    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.

  2. Energetic costs of performance in trained and untrained Anolis carolinensis lizards.

    Science.gov (United States)

    Lailvaux, Simon P; Wang, Andrew Z; Husak, Jerry F

    2018-03-12

    The energetic costs of performance constitute a non-trivial component of animals' daily energetic budgets. However, we currently lack an understanding of how those costs are partitioned among the various stages of performance development, maintenance, and production. We manipulated individual investment in performance by training Anolis carolinensis lizards for endurance or sprinting ability. We then measured energetic expenditure both at rest and immediately following exercise to test whether such training alters the maintenance and production costs of performance. Trained lizards had lower resting metabolic rates than controls, suggestive of a maintenance saving associated with enhanced performance as opposed to a cost. Production costs also differed, with sprint-trained lizards incurring the largest energetic performance cost and experiencing the longest recovery times compared to endurance trained and control animals. Although performance training modifies metabolism, production costs are probably the key drivers of trade-offs between performance and other life-history traits in this species. © 2018. Published by The Company of Biologists Ltd.

  3. Pre- and Postcopulatory Traits of Salvator Male Lizards in Allopatry and Sympatry

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    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.

  4. Purification and characterization of liver lectins from a lizard, Sceloporus spinosus.

    Science.gov (United States)

    Fenton, N Bertha; Arreguín, L Barbarin; Méndez, C Fausto; Arreguín, E Roberto

    2004-05-01

    This study discusses the purification of soluble beta-galactose lectins obtained from the lizard liver of Sceloporus spinosus. The first lectin named lizard hepatic lectin-1 (LHL-1) presented a molecular weight of 31,750, with an isoelectric point of 4.25. The highest specific hemagglutinating activity was achieved using human blood type A1: N-acetylgalactosamine (GalNAc)-galactose (Gal)-fucose (Fuc). Carbohydrate inhibition assays indicated a higher lectin specificity for GalNAc. For LHL-2 the molecular weight obtained was 23,850 with an isoelectric point of 3.25. The highest carbohydrate specificity was observed for Gal. These lizard hepatic lectins are similar to the mammal hepatic lectins previously reported. However, it is different from the alligator hepatic lectin (AHL). The homology analyses of LHL-1 resulted in 100% identity with the Steroidogenic acute regulatory protein (StAR), while LHL-2 was similar to adenylate kinase (75% identity). We suggest that these liver lectins are related to the inherent functions of liver previously reported.

  5. Baseline values of immunologic parameters in the lizard Salvator merianae (Teiidae, Squamata).

    Science.gov (United States)

    Mestre, Ana Paula; Amavet, Patricia Susana; Siroski, Pablo Ariel

    2017-01-01

    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.

  6. Spontaneous genetic damage in the tegu lizard (Tupinambis merianae): the effect of age.

    Science.gov (United States)

    Schaumburg, Laura G; Poletta, Gisela L; Siroski, Pablo A; Mudry, Marta D

    2014-05-15

    Several studies indicate that certain factors such as age, sex or nutritional status among others, may affect the level of DNA damage, both induced and spontaneous, so it is very important to consider them for a more accurate interpretation of the findings. The aim of this study was to analyze the influence of age, sex, and nest of origin on spontaneous genetic damage of Tupinambis merianae determined by the comet assay (CA) and the micronucleus (MN) test, in order to improve reference data for future in vivo studies of xenobiotics exposure in this species. Sixty-five tegu lizards of three different ages: newborns (NB), juveniles (JUV) and adults (AD), both sexes and from different nests of origin were used. Blood samples were collected from the caudal vein of all animals and the MN test and CA were applied on peripheral blood erythrocytes to determine basal frequency of MN (BFMN) and basal damage index (BDI). The comparison between age groups showed statistically significant differences in the BFMN and BDI (p0.05). A weak negative relationship was found only between BFMN and weight of NB tegu lizard (p=0.014; R(2)=0.245). Basal values of genetic damage obtained with both biomarkers in the tegu lizard evidenced that age is an intrinsic factor that should be taken into account to avoid misunderstanding of the results in future biomonitoring studies. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Baseline values of immunologic parameters in the lizard Salvator merianae (Teiidae, Squamata

    Directory of Open Access Journals (Sweden)

    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.

  8. Natural history of the lizard Enyalius iheringii (Squamata, Leiosauridae in southern Brazilian Atlantic forest

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    Ricardo Rautenberg

    2010-12-01

    Full Text Available Studies on the natural history of the lizard Enyalius iheringii Boulenger, 1885, as well as other tropical lizards, are rare. In this study, some aspects of the natural history of this endemic species from the Atlantic forest are reported in areas of Vale do Itajaí, state of Santa Catarina, Brazil. Twenty individuals were found, of which 18 were collected. Most of them were found over the vegetation (n=17 and on the ground (n=3. The main defensive strategy displayed was camouflage (n=16. Jumping (n=1, jumping and running (n=1 and running (n=2 were also observed in some individuals. When handled, lizards exhibited mouth wide open, hissing, and occasionally biting, as well as color change in males. Regarding its diet, the numerically most important prey was beetles (Coleoptera, followed by Lepidoptera larvae. Beetles, lepidopteran larvae and spiders were the most frequent food items. Males and females did not differ in size. Three sexually mature females (100-113 mm SVL were found in December and January.

  9. Prey availability affects territory size, but not territorial display behavior, in green anole lizards

    Science.gov (United States)

    Stehle, Chelsea M.; Battles, Andrew C.; Sparks, Michelle N.; Johnson, Michele A.

    2017-10-01

    The availability of food resources can affect the size and shape of territories, as well as the behaviors used to defend territories, in a variety of animal taxa. However, individuals within a population may respond differently to variation in food availability if the benefits of territoriality vary among those individuals. For example, benefits to territoriality may differ for animals of differing sizes, because larger individuals may require greater territory size to acquire required resources, or territorial behavior may differ between the sexes if males and females defend different resources in their territories. In this study, we tested whether arthropod abundance and biomass were associated with natural variation in territory size and defense in insectivorous green anole lizards, Anolis carolinensis. Our results showed that both male and female lizards had smaller territories in a habitat with greater prey biomass than lizards in habitats with less available prey, but the rates of aggressive behaviors used to defend territories did not differ among these habitats. Further, we did not find a relationship between body size and territory size, and the sexes did not differ in their relationships between food availability and territory size or behavioral defense. Together, these results suggest that differences in food availability influenced male and female territorial strategies similarly, and that territory size may be more strongly associated with variation in food resources than social display behavior. Thus, anole investment in the behavioral defense of a territory may not vary with territory quality.

  10. 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.

  11. 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.

  12. A two-locus global DNA barcode for land plants: the coding rbcL gene complements the non-coding trnH-psbA spacer region.

    Science.gov (United States)

    Kress, W John; Erickson, David L

    2007-06-06

    A useful DNA barcode requires sufficient sequence variation to distinguish between species and ease of application across a broad range of taxa. Discovery of a DNA barcode for land plants has been limited by intrinsically lower rates of sequence evolution in plant genomes than that observed in animals. This low rate has complicated the trade-off in finding a locus that is universal and readily sequenced and has sufficiently high sequence divergence at the species-level. Here, a global plant DNA barcode system is evaluated by comparing universal application and degree of sequence divergence for nine putative barcode loci, including coding and non-coding regions, singly and in pairs across a phylogenetically diverse set of 48 genera (two species per genus). No single locus could discriminate among species in a pair in more than 79% of genera, whereas discrimination increased to nearly 88% when the non-coding trnH-psbA spacer was paired with one of three coding loci, including rbcL. In silico trials were conducted in which DNA sequences from GenBank were used to further evaluate the discriminatory power of a subset of these loci. These trials supported the earlier observation that trnH-psbA coupled with rbcL can correctly identify and discriminate among related species. A combination of the non-coding trnH-psbA spacer region and a portion of the coding rbcL gene is recommended as a two-locus global land plant barcode that provides the necessary universality and species discrimination.

  13. Diagnosis of hemodynamic compromise in patients with chronic cerebral ischemia; Measurement of cerebral blood volume (CBV) with sup 99m Tc-RBC SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Kuroda, Satoshi; Sakuragi, Mitsugi; Motomiya, Mineo; Nakagawa, Tango; Mitsumori, Kenji; Tsuru, Mitsuo (Hokkaido Neurosurgical Memorial Hospital (Japan)); Takigawa, Shugo; Kamiyama, Hiroyasu; Abe, Hiroshi

    1990-03-01

    To evaluate the efficacy of tests for selecting patients with hemodynamic compromise, measurement of cerebral blood volume (CBV) with {sup 99m}Tc-RBC single photon emission computed tomography (SPECT) was performed in thirteen patients with occlusive cerebrovascular disease, and was compared with results obtained by {sup 133}Xe SPECT and acetazolamide (Diamox) test. All patients in our study suffered TIA, RIND, or minor completed stroke. Cerebral angiography demonstrated severe stenosis or occlusion in the ipsilateral internal carotid artery or middle cerebral artery, although plain CT scan or MRI revealed no or, if any, only localized infarcted lesions. Regional cerebral blood volume (rCBV) was measured with {sup 99m}Tc-RBC SPECT and regional cerebral blood flow (rCBF) was measured with {sup 133}Xe SPECT before and after intravenous injection of 10 - 12 mg/kg acetazolamide (Diamox). Our results suggest that the ipsilateral rCBV/rCBF (mean transit time) is a more sensitive index of the cerebral perfusion reserve than the use of only rCBV or rCBF of the ipsilateral hemisphere. Also, the ipsilateral rCBV/rCBF is significantly correlated (r= -0.72) with the Diamox reactivity of rCBF, which is considered to represent the cerebral vasodilatory capacity in patients with chronic cerebral ischemia. Postoperative SPECT study revealed remarkable improvement of ipsilateral rCBV/rCBF and Diamox reactivity in four patients who underwent EC/IC bypass surgery to improve the hemodynamic compromise. In conclusion, our results suggest that the measurement of rCBV/rCBF with {sup 133}Xe SPECT and {sup 99m}Tc-RBC SPECT is useful for detecting the hemodynamic compromise in patients with occlusive cerebrovascular disease. (author).

  14. Celestial orientation with the sun not in view: lizards use a time-compensated sky polarization compass.

    Science.gov (United States)

    Maoret, Francesco; Beltrami, Giulia; Bertolucci, Cristiano; Foà, Augusto

    2014-04-01

    The present investigation was aimed at testing whether the lizard sky polarization compass is time compensated. For this purpose, ruin lizards, Podarcis sicula, were both trained and tested for orientation inside a Morris water maze under clear skies with the sun not in view. During training, lizards showed a striking bimodal orientation along the training axis, demonstrating their capability of determining the symmetry plane of the sky polarization pattern and thus the use of polarization information in orientation. After reaching criteria, lizards were kept 7 days in a 6-h fast clock-shift treatment and then released with the sun not in view. Six-hour clock-shifted lizards showed a bimodal distribution of directional choices, which was oriented perpendicularly to the training axis, as it was expected on the basis of the clock-shift. The results show that the only celestial diurnal compass mechanism that does not need a direct vision of the sun disk (i.e., the sky polarization compass) is a time-compensated compass.

  15. Effects of repeated exposure to malathion on growth, food consumption, and locomotor performance of the western fence lizard (Sceloporus occidentalis)

    Energy Technology Data Exchange (ETDEWEB)

    Holem, Ryan R. [University of Georgia, Savannah River Ecology Laboratory, Aiken, SC 29801 (United States); ENTRIX, Inc., Okemos, MI 48864 (United States); Hopkins, William A. [University of Georgia, Savannah River Ecology Laboratory, Aiken, SC 29801 (United States); Department of Fisheries and Wildlife Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States)], E-mail: hopkinsw@vt.edu; Talent, Larry G. [Natural Resource Ecology and Management, Oklahoma State University, Stillwater, OK 74078 (United States)

    2008-03-15

    Effects of repeated pollutant exposure on growth, locomotor performance, and behavior have rarely been evaluated in reptiles. We administered three doses of malathion (2.0, 20, or 100 mg/kg body weight) to western fence lizards (Sceloporus occidentalis) over an 81 day period. Eight and 23% mortality occurred at 20 and 100 mg/kg (p = 0.079) and 85% of lizards in the 100 mg/kg group exhibited clinical symptoms of poisoning. Growth, food consumption, body condition index, and terrestrial locomotor performance were not significantly influenced by malathion. However, arboreal sprint velocity was significantly reduced in lizards receiving 100 mg/kg. Fifty percent of lizards in the 100 mg/kg group also refused to sprint in the arboreal setting (p = 0.085). Based on these results, arboreal locomotor performance was the most sensitive metric of exposure we evaluated. Further study of compounds such as malathion is warranted due to highly variable application rates and exposure scenarios. - Repeated exposure of western fence lizards to malathion caused reduced arboreal performance and some mortality but growth, food consumption, and terrestrial performance were not affected.

  16. Patterns of infestation by chigger mites in four diurnal lizard species from a restinga habitat (Jurubatiba of Southeastern Brazil

    Directory of Open Access Journals (Sweden)

    M. Cunha-Barros

    Full Text Available We studied the parasitism by larvae of the chigger mite Eutrombicula alfreddugesi on the lizard community of Restinga de Jurubatiba, Rio de Janeiro State, Southeastern Brazil. We investigated the patterns of infestation (prevalence and intensity of chigger mites in four sympatric lizards: Tropidurus torquatus, Mabuya agilis, M. macrorhyncha and Cnemidophorus littoralis. All lizards collected were checked for the presence of mites, which were counted under stereomicroscope. We tested the relationship between intensity of infestation and lizard body size for each species using regression analysis. The prevalences and mean intensities (+ one standard deviation of infestation on each host species were, respectively: 100%; 86.4 + 94.6 in T. torquatus (n = 62; 100%; 20.9 + 9.3 in M. agilis (n = 7; 100%; 11.1 + 13.1 in M. macrorhyncha (n = 12; and 95.2%; 19.1 + 16.8 in C. littoralis (n = 21. Only for C. littoralis did body size significantly affect the intensity of infestation (r = 0.27, p = 0.02. For all lizard species, the body parts where chiggers occurred with the highest intensity were those of skin folds and joint regions.

  17. When the going gets tough: behavioural type-dependent space use in the sleepy lizard changes as the season dries.

    Science.gov (United States)

    Spiegel, Orr; Leu, Stephan T; Sih, Andrew; Godfrey, Stephanie S; Bull, C Michael

    2015-11-22

    Understanding space use remains a major challenge for animal ecology, with implications for species interactions, disease spread, and conservation. Behavioural type (BT) may shape the space use of individuals within animal populations. Bolder or more aggressive individuals tend to be more exploratory and disperse further. Yet, to date we have limited knowledge on how space use other than dispersal depends on BT. To address this question we studied BT-dependent space-use patterns of sleepy lizards (Tiliqua rugosa) in southern Australia. We combined high-resolution global positioning system (GPS) tracking of 72 free-ranging lizards with repeated behavioural assays, and with a survey of the spatial distributions of their food and refuge resources. Bayesian generalized linear mixed models (GLMM) showed that lizards responded to the spatial distribution of resources at the neighbourhood scale and to the intensity of space use by other conspecifics (showing apparent conspecific avoidance). BT (especially aggressiveness) affected space use by lizards and their response to ecological and social factors, in a seasonally dependent manner. Many of these effects and interactions were stronger later in the season when food became scarce and environmental conditions got tougher. For example, refuge and food availability became more important later in the season and unaggressive lizards were more responsive to these predictors. These findings highlight a commonly overlooked source of heterogeneity in animal space use and improve our mechanistic understanding of processes leading to behaviourally driven disease dynamics and social structure. © 2015 The Author(s).

  18. Effects of repeated exposure to malathion on growth, food consumption, and locomotor performance of the western fence lizard (Sceloporus occidentalis)

    International Nuclear Information System (INIS)

    Holem, Ryan R.; Hopkins, William A.; Talent, Larry G.

    2008-01-01

    Effects of repeated pollutant exposure on growth, locomotor performance, and behavior have rarely been evaluated in reptiles. We administered three doses of malathion (2.0, 20, or 100 mg/kg body weight) to western fence lizards (Sceloporus occidentalis) over an 81 day period. Eight and 23% mortality occurred at 20 and 100 mg/kg (p = 0.079) and 85% of lizards in the 100 mg/kg group exhibited clinical symptoms of poisoning. Growth, food consumption, body condition index, and terrestrial locomotor performance were not significantly influenced by malathion. However, arboreal sprint velocity was significantly reduced in lizards receiving 100 mg/kg. Fifty percent of lizards in the 100 mg/kg group also refused to sprint in the arboreal setting (p = 0.085). Based on these results, arboreal locomotor performance was the most sensitive metric of exposure we evaluated. Further study of compounds such as malathion is warranted due to highly variable application rates and exposure scenarios. - Repeated exposure of western fence lizards to malathion caused reduced arboreal performance and some mortality but growth, food consumption, and terrestrial performance were not affected

  19. Patterns of infestation by chigger mites in four diurnal lizard species from a Restinga habitat (Jurubatiba) of southeastern Brazil.

    Science.gov (United States)

    Cunha-Barros, M; Van Sluys, M; Vrcibradic, D; Galdino, C A; Hatano, F H; Rocha, C F

    2003-08-01

    We studied the parasitism by larvae of the chigger mite Eutrombicula alfreddugesi on the lizard community of Restinga de Jurubatiba, Rio de Janeiro State, Southeastern Brazil. We investigated the patterns of infestation (prevalence and intensity) of chigger mites in four sympatric lizards: Tropidurus torquatus, Mabuya agilis, M. macrorhyncha and Cnemidophorus littoralis. All lizards collected were checked for the presence of mites, which were counted under stereomicroscope. We tested the relationship between intensity of infestation and lizard body size for each species using regression analysis. The prevalences and mean intensities (+ one standard deviation) of infestation on each host species were, respectively: 100%; 86.4 + 94.6 in T. torquatus (n = 62); 100%; 20.9 + 9.3 in M. agilis (n = 7); 100%; 11.1 + 13.1 in M. macrorhyncha (n = 12); and 95.2%; 19.1 + 16.8 in C. littoralis (n = 21). Only for C. littoralis did body size significantly affect the intensity of infestation (r = 0.27, p = 0.02). For all lizard species, the body parts where chiggers occurred with the highest intensity were those of skin folds and joint regions.

  20. Toxic effects of oral 2-amino-4,6-dinitrotoluene in the Western fence lizard (Sceloporus occidentalis)

    Energy Technology Data Exchange (ETDEWEB)

    McFarland, Craig A., E-mail: craig.a.mcfarland@us.army.mi [US Army Public Health Command (Prov), Aberdeen Proving Ground, MD 21010 (United States); Quinn, Michael J [US Army Public Health Command (Prov), Aberdeen Proving Ground, MD 21010 (United States); Boyce, John [Biotechnics, LLC, Hillsborough, NC 27278 (United States); LaFiandra, Emily M; Bazar, Matthew A [US Army Public Health Command (Prov), Aberdeen Proving Ground, MD 21010 (United States); Talent, Larry G [Oklahoma State University, Department of Natural Resource Ecology and Management, Stillwater, OK 74078 (United States); Johnson, Mark S [US Army Public Health Command (Prov), Aberdeen Proving Ground, MD 21010 (United States)

    2011-02-15

    The compound 2-amino-4,6-dinitrotoluene (2A-DNT) was evaluated under laboratory conditions in the Western fence lizard (Sceloporus occidentalis) to assess the potential for reptile toxicity. Oral LD{sub 50} values were 1406 and 1867 mg/kg for male and female lizards, respectively. Based on responses from a 14-day subacute study, a 60-day subchronic experiment followed where lizards were orally dosed at 0, 5, 15, 20, 25, 30 mg/kg-d. At day 60, number of days and survivors, food consumption, and change in body weight were inversely related to dose. Signs of toxicity were characterized by anorexia and generalized cachexia. Significant adverse histopathology was observed in hepatic tissue at {>=}15 mg/kg-d, consistent with hepatocellular transdifferentiation. Based on survival, loss of body weight, diminished food intake, changes in liver, kidney, and testes, and increased blood urea nitrogen, these data suggest a LOAEL of 15 mg/kg-d and a NOAEL of 5 mg/kg-d in S. occidentalis. - Research highlights: Oral LD{sub 50} (mg/kg) values were 1406 for male and 1867 for female lizards. Dose-dependent hepatocellular transdifferentiation was observed at {>=}5 mg/kg-d. Chromaturia in 2A-DNT and the parent TNT suggest biomarkers of exposure and effect. Health effects of metabolites support comprehensive ecological risk assessments. - The Western fence lizard (Sceloporus occidentalis) is a suitable reptile model for assessing the toxicity of energetic compounds and their metabolites.

  1. Toxic effects of oral 2-amino-4,6-dinitrotoluene in the Western fence lizard (Sceloporus occidentalis)

    International Nuclear Information System (INIS)

    McFarland, Craig A.; Quinn, Michael J.; Boyce, John; LaFiandra, Emily M.; Bazar, Matthew A.; Talent, Larry G.; Johnson, Mark S.

    2011-01-01

    The compound 2-amino-4,6-dinitrotoluene (2A-DNT) was evaluated under laboratory conditions in the Western fence lizard (Sceloporus occidentalis) to assess the potential for reptile toxicity. Oral LD 50 values were 1406 and 1867 mg/kg for male and female lizards, respectively. Based on responses from a 14-day subacute study, a 60-day subchronic experiment followed where lizards were orally dosed at 0, 5, 15, 20, 25, 30 mg/kg-d. At day 60, number of days and survivors, food consumption, and change in body weight were inversely related to dose. Signs of toxicity were characterized by anorexia and generalized cachexia. Significant adverse histopathology was observed in hepatic tissue at ≥15 mg/kg-d, consistent with hepatocellular transdifferentiation. Based on survival, loss of body weight, diminished food intake, changes in liver, kidney, and testes, and increased blood urea nitrogen, these data suggest a LOAEL of 15 mg/kg-d and a NOAEL of 5 mg/kg-d in S. occidentalis. - Research highlights: → Oral LD 50 (mg/kg) values were 1406 for male and 1867 for female lizards. → Dose-dependent hepatocellular transdifferentiation was observed at ≥5 mg/kg-d. → Chromaturia in 2A-DNT and the parent TNT suggest biomarkers of exposure and effect. → Health effects of metabolites support comprehensive ecological risk assessments. - The Western fence lizard (Sceloporus occidentalis) is a suitable reptile model for assessing the toxicity of energetic compounds and their metabolites.

  2. Influence of iron deficiency in the radiopharmaceutical behavior of red blood cells labeled with 99mTc(99mTC-RBC)

    International Nuclear Information System (INIS)

    Calmanovici, G.; Salgueiro, M.J.; Pernas, L.; Collia, N.; Leonardi, N.; Zubillaga, M.

    2005-01-01

    Full text: Red blood cells (RBCs) labeled with 99m Tc are commonly used in the evaluation of cardiac function, gastrointestinal tract bleeding, red blood cell volume or splenic sequestration. Generally stannous ion is used as reducing agent. A proposed mechanism is that once the stannous ion (Sn) and the pertechnetate ( 99m Tc) reach the interior of the RBC, the radionuclide is mainly house in the β-chain of hemoglobin. The aim of this study was to determine if hemoglobin content reduction, an indicator of iron deficiency anemia, could affect the efficiency of RBC labeling and the biological distribution of this radiopharmaceutical. We studied 30 rats fed for 3 weeks after weaning with diets with iron contents of 6.5 ppm (group A), 18 ppm (group B) and 100 ppm (control). For all groups, the labeling yields were always higher than 97%; the percentage of radioactivity was mostly founded in blood with almost negligible radioactivity the rest of the studied organs. We can conclude that the decrease in hemoglobin content, an indicator of iron deficiency anemia, does not interfere neither in the labeling nor in the biodistribution of red blood cells labeled with 99m Tc. (author)

  3. Implications of resin-based composite (RBC) restoration on cuspal deflection and microleakage score in molar teeth: Placement protocol and restorative material.

    Science.gov (United States)

    McHugh, Lauren E J; Politi, Ioanna; Al-Fodeh, Rami S; Fleming, Garry J P

    2017-09-01

    To assess the cuspal deflection of standardised large mesio-occluso-distal (MOD) cavities in third molar teeth restored using conventional resin-based composite (RBC) or their bulk fill restorative counterparts compared with the unbound condition using a twin channel deflection measuring gauge. Following thermocycling, the cervical microleakage of the restored teeth was assessed to determine marginal integrity. Standardised MOD cavities were prepared in forty-eight sound third molar teeth and randomly allocated to six groups. Restorations were placed in conjunction with (and without) a universal bonding system and resin restorative materials were irradiated with a light-emitting-diode light-curing-unit. The dependent variable was the restoration protocol, eight oblique increments for conventional RBCs or two horizontal increments for the bulk fill resin restoratives. The cumulative buccal and palatal cuspal deflections from a twin channel deflection measuring gauge were summed, the restored teeth thermally fatigued, immersed in 0.2% basic fuchsin dye for 24h, sectioned and examined for cervical microleakage score. The one-way analysis of variance (ANOVA) identified third molar teeth restored using conventional RBC materials had significantly higher mean total cuspal deflection values compared with bulk fill resin restorative restoration (all pmaterial selection is vital in the absence of clinical data. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  4. Ulva and Enteromorpha (Ulvaceae, Chlorophyta) from two sides of the Yellow Sea: analysis of nuclear rDNA ITS and plastid rbcL sequence data

    Science.gov (United States)

    Wang, Jinfeng; Li, Nan; Jiang, Peng; Boo, Sung Min; Lee, Wook Jae; Cui, Yulin; Lin, Hanzhi; Zhao, Jin; Liu, Zhengyi; Qin, Song

    2010-07-01

    Ulvacean green seaweeds are common worldwide; they formed massive green tides in the Yellow Sea in recent years, which caused marine ecological problems as well as a social issue. We investigated two major genera of the Ulvaceae, Ulva and Enteromorpha, and collected the plastid rbcL and nuclear ITS sequences of specimens of the genera in two sides of the Yellow Sea and analyzed them. Phylogenetic trees of rbcL data show the occurrence of five species of Enteromorpha ( E. compressa, E. flexuosa, E. intestinalis, E. linza and E. prolifera) and three species of Ulva ( U. pertusa, U. rigida and U. ohnoi). However, we found U. ohnoi, which is known as a subtropical to tropical species, at two sites on Jeju Island, Korea. Four ribotypes in partial sequences of 5.8S rDNA and ITS2 from E. compressa were also found. Ribotype network analysis revealed that the common ribotype, occurring in China, Korea and Europe, is connected with ribotypes from Europe and China/Japan. Although samples of the same species were collected from both sides of the Yellow Sea, intraspecific genetic polymorphism of each species was low among samples collected worldwide.

  5. Survey of the reptilian fauna of the Kingdom of Saudi Arabia. V. The lizard fauna of Turaif region

    Directory of Open Access Journals (Sweden)

    Mohammed K. Al-Sadoon

    2016-09-01

    Full Text Available 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.

  6. The Ecological Associations of Surface-Dwelling Lizards in Qom Province in the Northwest of Central Plateau of Iran

    Science.gov (United States)

    Ebrahimi, Mehregan; Ahmadzadeh, Faraham; Mostafavi, Hossein; Mehrabian, Aahmad Reza; Abdoli, Asghar; Mahini, Abdolrasoul Salman

    2013-01-01

    We used pitfall trapping to investigate the effects of elevation, plant density and soil structure on species diversity and the impact of these habitat factors on lizard habitat selectivity in the Qom Province in the Central Plateau of Iran. From a total of 12 1-ha plots, we captured 363 individuals of 15 species of lizards (six species of Lacertidae, five species of Agamidae, two species of Gekkonidae, one species of Varanidae and one species of Scincidae). A generalized linear model (GLM) determined that elevation was the most important factor impacting species diversity. The highest species diversity was at the intermediate elevation (1289 m). Abundance of 6 out of 15 species showed strong relationships with some habitat factors. These relationships were demonstrated by habitat selectivity index (Ivlev's index). Our result supports other surveys that showed that elevation plays an important role in determining lizard species diversity. PMID:24349557

  7. Diet and foraging of the endemic lizard Cnemidophorus littoralis (Squamata, Teiidae) in the restinga de Jurubatiba, Macaé, RJ.

    Science.gov (United States)

    Menezes, V A; Amaral, V C; Sluys, M V; Rocha, C F D

    2006-08-01

    We investigated the diet and foraging of the endemic teiid lizard Cnemidophorus littoralis in a restinga habitat in Jurubatiba, Macaé - RJ. The stomach contents were removed, analyzed and identified to the Order level. There was no relationship between C. littoralis morphological variables and number, length or volume of preys. Termites (48.7%) and larvae (35.5%) were the most important prey items which occurred in the examined lizards' stomachs. The diet did not differ between males and females. Cnemidophorus littoralis is an active forager and predominantly consumes relatively sedentary prey or prey that is aggregated in the environment. We also found an intact and undigested hatchling of the crepuscular/nocturnal gekkonid lizard Hemidactylus mabouia in the stomach of an adult male of C. littoralis, which indicates that C. littoralis is a potential source of mortality for individuals of H. mabouia in the restinga de Jurubatiba.

  8. Plasma esterases in the tegu lizard Tupinambis merianae (Reptilia, Teiidae): impact of developmental stage, sex, and organophosphorus in vitro exposure.

    Science.gov (United States)

    Basso, Agustín; Attademo, Andrés M; Lajmanovich, Rafael C; Peltzer, Paola M; Junges, Celina; Cabagna, Mariana C; Fiorenza, Gabriela S; Sanchez-Hernandez, Juan Carlos

    2012-01-01

    In this study, we determined normal serum butyrylcholinesterase (BChE) and carboxylesterase (CbE) activities in Tupinambis merianae in order to obtain reference values for organophosphorus pesticide monitoring. Forty-two T. merianae individuals were grouped by sex and size to identify potential differences in their enzyme levels to allow for proper representation of normal values for females, males, juveniles, and hatchlings. Mean CbE was determined using two model substrates: alpha-naphtylacetate (α-NA) and p-nitrophenyl valerate (4-NPV). BChE and CbE sensitivity to malaoxon (Mx) was also evaluated as well as the possibility of BChE reactivation with pyridine-2-aldoxime methochloride (2-PAM). Mean adult females' BChE was significantly higher than adult males, juveniles, and hatchlings. No significant differences were found between groups regarding CbE. CbE (4-NPV) activity showed slightly negative correlation with lizard snout-vent length, while BChE and CbE (α-NA) showed no correlation with body size. Apparent IC(50) values for BChE and CbE (α-NA) suggested different sensitivities among groups. CbE (4-NPV) could not be inhibited. All Mx-inhibited groups treated with 2-PAM in a final concentration of 2.8 mM showed clear signs of reactivation. In conclusion, the results demonstrate that (1) plasma esterase activity did not vary with age and sex, except for BChE activity, and (2) because biological and environmental variables could be confounding factors in the response of plasma cholinesterases, complementary biomarkers like CbE inhibition and oxime-induced reactivation of esterases are strongly recommended.

  9. Effects of Diet Restriction and Diet Complexity on Life History Strategies in Side-Blotched Lizards (Uta stansburiana).

    Science.gov (United States)

    Skinner, Heather M; Durso, Andrew M; Neuman-Lee, Lorin A; Durham, Susan L; Mueller, Sarah D; French, Susannah S

    2016-11-01

    Organisms must balance energy invested into self-maintenance, reproduction, and somatic growth over their lifetime. In this study, the effects of diet restriction and diet complexity on side-blotched lizards (Uta stansburiana) were analyzed. Thirty male lizards, housed in the laboratory, were fed either an ad libitum or a restricted diet for 18 days (phase 1). Individuals from both treatments were then assigned to a diet of the same quantity of food that was either simple (only crickets) or complex (crickets, cockroaches, waxworms, and mealworms) for 35 days (phase 2). We evaluated (1) how diet restriction affected life history strategies and (2) how diet complexity affected recovery from diet restriction as measured at the end of phase 2 by body mass, snout-vent length, calculated body condition score, wound healing, tail regrowth, bacterial killing ability, oxidative stress, and plasma testosterone and corticosterone concentrations. Lizards without diet restriction allocated more energy to self-maintenance (i.e., maintaining higher body condition scores, healing wounds more quickly) than lizards with diet restriction. Lizards with diet restriction had higher plasma testosterone concentrations and larger increases in snout-vent lengths than those fed ad libitum, which may reflect allocations toward reproduction and somatic growth. A complex diet resulted in better body condition and faster tail regrowth than a simple diet, suggesting that a complex diet enhanced recovery from diet restriction, although long-term life history choices remained unaltered. Finally, lizards on a complex diet consumed substantially less food while maintaining higher body condition, suggesting that key nutrients may be lacking from a simple diet. © 2017 Wiley Periodicals, Inc.

  10. A novel varanic acid epimer--(24R,25S)-3α,7α,12α,24-tetrahydroxy-5β-cholestan-27-oic acid--is a major biliary bile acid in two varanid lizards and the Gila monster.

    Science.gov (United States)

    Hagey, Lee R; Ogawa, Shoujiro; Kato, Narimi; Satoh née Okihara, Rika; Une, Mizuho; Mitamura, Kuniko; Ikegawa, Shigeo; Hofmann, Alan F; Iida, Takashi

    2012-11-01

    A key intermediate in the biosynthetic pathway by which C(24) bile acids are formed from cholesterol has long been considered to be varanic acid, (24ξ,25ξ)-3α,7α,12α-24-tetrahydroxy-5β-cholestan-27-oic acid. The (24R,25R)-epimer of this tetrahydroxy bile acid, in the form of its taurine N-acyl amidate, was thought to be the major biliary bile acid in lizards of the family Varanidae. We report here that a major biliary bile acid of three lizard species - the Komodo dragon (Varanus komodoensis), Gray's monitor (Varanus olivaceus), and the Gila monster (Heloderma suspectum) - is a novel epimer of varanic acid. The epimer was shown to be (24R,25S)-3α,7α,12α,24-tetrahydroxy-5β-cholestan-27-oic acid (present in bile as its taurine conjugate). The structure was established by mass spectroscopy and by (1)H and (13)C nuclear magnetic spectroscopy, as well as by synthesis of the compound. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. The role of vicariance vs. dispersal in shaping genetic patterns in ocellated lizard species in the western Mediterranean

    DEFF Research Database (Denmark)

    Paulo, O. S.; Pinheiro, J.; Miraldo, A.

    2008-01-01

    in the western Mediterranean as exemplified by the distribution of species and subspecies and genetic variation within the ocellated lizard group. To reassess the role of the MSC, partial sequences of three mitochondrial DNA genes (cytochrome b, 12S and 16S ribosomal RNA) and two nuclear genes (beta......-fibrinogen and C-mos) from species of the ocellated lizard group were analysed. Three alternative hypotheses were tested: that divergence was initiated (i) by post-MSC vicariance as the basin filled, (ii) when separate populations established either side of the strait by pre-MSC overseas dispersal, and (iii...

  12. Density of the tegu lizard (Tupinambis merianae) and its role as nest predator at Anchieta Island, Brazil

    OpenAIRE

    Bovendorp, Ricardo S.; Alvarez, Ariane D.; Gialetti, Mauro

    2008-01-01

    Mammals has been pointed out to be the main nest predators in islands, but recent studies has shown that tree snakes are also important nest predator in tropical forests. Here we present information on the density tegu lizards Tupinambis merianae and its role as nest predator at Anchieta Island, Ubatuba, in southeastern Brazil. The mean density of tegu lizards wets estimated to be 83 individuals/km2, which is 1.83 times lower than other well-known population (Fernando de Noronha Archipelago)....

  13. The ultrastructure of the spermatozoon of the lizard Iguana iguana (Reptilia, Squamata, Iguanidae) and the variability of sperm morphology among iguanian lizards

    Science.gov (United States)

    Vieira, Gustavo H C; Colli, Guarino R; Báo, Sônia N

    2004-01-01

    The spermatozoon of Iguana iguana is filiform and resembles that of other iguanian lizards, being most similar to Tropidurus. All sperm synapomorphies of Tetrapoda, Amniota and Squamata are present in the sperm of Iguana iguana. By reconstructing the evolution of 30 sperm characters we identified a novel synapomorphy of Iguania: the presence of a well-developed acrosomal ridge at the level of the epinuclear lucent zone. Because of the poor topological resolution among iguanian clades we could not discount the possibility of convergence or neutral selection as determinant of the variability in characteristics of the sperm cell. In agreement with previous studies, we identified heterogeneous rates of evolution among the three main regions of the sperm cell, namely the head, midpiece and tail. PMID:15198687

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

    Science.gov (United States)

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

    2011-04-01

    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 differentiation. Nevertheless, the mechanism that actually transduces temperature into a biological signal for ovary versus testis development is not known in any species. Classical genetics could be used to identify the loci underlying TSD, but only if there is segregating variation for TSD. Here, we use the 'animal model' to analyze inheritance of sexual phenotype in a 13-generation pedigree of captive leopard geckos, Eublepharis macularius, a TSD reptile. We directly show genetic variance and genotype-by-temperature interactions for sex determination. Additive genetic variation was significant at a temperature that produces a female-biased sex ratio (30°C), but not at a temperature that produces a male-biased sex ratio (32.5°C). Conversely, dominance variance was significant at the male-biased temperature (32.5°C), but not at the female-biased temperature (30°C). Non-genetic maternal effects on sex determination were negligible in comparison with additive genetic variance, dominance variance and the primary effect of temperature. These data show for the first time that there is segregating variation for TSD in a reptile and consequently that a quantitative trait locus analysis would be practicable for identifying the genes underlying TSD.

  15. Sequencing, de novo assembling, and annotating the genome of the endangered Chinese crocodile lizard Shinisaurus crocodilurus.

    Science.gov (United States)

    Gao, Jian; Li, Qiye; Wang, Zongji; Zhou, Yang; Martelli, Paolo; Li, Fang; Xiong, Zijun; Wang, Jian; Yang, Huanming; Zhang, Guojie

    2017-07-01

    The Chinese crocodile lizard, Shinisaurus crocodilurus, is the only living representative of the monotypic family Shinisauridae under the order Squamata. It is an obligate semi-aquatic, viviparous, diurnal species restricted to specific portions of mountainous locations in southwestern China and northeastern Vietnam. However, in the past several decades, this species has undergone a rapid decrease in population size due to illegal poaching and habitat disruption, making this unique reptile species endangered and listed in the Convention on International Trade in Endangered Species of Wild Fauna and Flora Appendix II since 1990. A proposal to uplist it to Appendix I was passed at the Convention on International Trade in Endangered Species of Wild Fauna and Flora Seventeenth meeting of the Conference of the Parties in 2016. To promote the conservation of this species, we sequenced the genome of a male Chinese crocodile lizard using a whole-genome shotgun strategy on the Illumina HiSeq 2000 platform. In total, we generated ∼291 Gb of raw sequencing data (×149 depth) from 13 libraries with insert sizes ranging from 250 bp to 40 kb. After filtering for polymerase chain reaction-duplicated and low-quality reads, ∼137 Gb of clean data (×70 depth) were obtained for genome assembly. We yielded a draft genome assembly with a total length of 2.24 Gb and an N50 scaffold size of 1.47 Mb. The assembled genome was predicted to contain 20 150 protein-coding genes and up to 1114 Mb (49.6%) of repetitive elements. The genomic resource of the Chinese crocodile lizard will contribute to deciphering the biology of this organism and provides an essential tool for conservation efforts. It also provides a valuable resource for future study of squamate evolution. © The Authors 2017. Published by Oxford University Press.

  16. Zebrin II Is Expressed in Sagittal Stripes in the Cerebellum of Dragon Lizards (Ctenophorus sp.).

    Science.gov (United States)

    Wylie, Douglas R; Hoops, Daniel; Aspden, Joel W; Iwaniuk, Andrew N

    2016-01-01

    Aldolase C, also known as zebrin II (ZII), is a glycolytic enzyme that is expressed in cerebellar Purkinje cells of the vertebrate cerebellum. In both mammals and birds, ZII is expressed heterogeneously, such that there are sagittal stripes of Purkinje cells with high ZII expression (ZII+) alternating with stripes of Purkinje cells with little or no expression (ZII-). In contrast, in snakes and turtles, ZII is not expressed heterogeneously; rather all Purkinje cells are ZII+. Here, we examined the expression of ZII in the cerebellum of lizards to elucidate the evolutionary origins of ZII stripes in Sauropsida. We focused on the central netted dragon (Ctenophorus nuchalis) but also examined cerebellar ZII expression in 5 other dragon species (Ctenophorus spp.). In contrast to what has been observed in snakes and turtles, we found that in these lizards, ZII is heterogeneously expressed. In the posterior part of the cerebellum, on each side of the midline, there were 3 sagittal stripes consisting of Purkinje cells with high ZII expression (ZII+) alternating with 2 sagittal stripes with weaker ZII expression (ZIIw). More anteriorly, most of the Purkinje cells were ZII+, except laterally, where the Purkinje cells did not express ZII (ZII-). Finally, all Purkinje cells in the auricle (flocculus) were ZII-. Overall, the parasagittal heterogeneous expression of ZII in the cerebellum of lizards is similar to that in mammals and birds, and contrasts with the homogenous ZII+ expression seen in snakes and turtles. We suggest that a sagittal heterogeneous expression of ZII represents the ancestral condition in stem reptiles which was lost in snakes and turtles. © 2017 S. Karger AG, Basel.

  17. Phylogenomic analysis of the Chilean clade of Liolaemus lizards (Squamata: Liolaemidae based on sequence capture data

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    Alejandra Panzera

    2017-10-01

    Full Text Available The genus Liolaemus is one of the most ecologically diverse and species-rich genera of lizards worldwide. It currently includes more than 250 recognized species, which have been subject to many ecological and evolutionary studies. Nevertheless, Liolaemus lizards have a complex taxonomic history, mainly due to the incongruence between morphological and genetic data, incomplete taxon sampling, incomplete lineage sorting and hybridization. In addition, as many species have restricted and remote distributions, this has hampered their examination and inclusion in molecular systematic studies. The aims of this study are to infer a robust phylogeny for a subsample of lizards representing the Chilean clade (subgenus Liolaemus sensu stricto, and to test the monophyly of several of the major species groups. We use a phylogenomic approach, targeting 541 ultra-conserved elements (UCEs and 44 protein-coding genes for 16 taxa. We conduct a comparison of phylogenetic analyses using maximum-likelihood and several species tree inference methods. The UCEs provide stronger support for phylogenetic relationships compared to the protein-coding genes; however, the UCEs outnumber the protein-coding genes by 10-fold. On average, the protein-coding genes contain over twice the number of informative sites. Based on our phylogenomic analyses, all the groups sampled are polyphyletic. Liolaemus tenuis tenuis is difficult to place in the phylogeny, because only a few loci (nine were recovered for this species. Topologies or support values did not change dramatically upon exclusion of L. t. tenuis from analyses, suggesting that missing data did not had a significant impact on phylogenetic inference in this data set. The phylogenomic analyses provide strong support for sister group relationships between L. fuscus, L. monticola, L. nigroviridis and L. nitidus, and L. platei and L. velosoi. Despite our limited taxon sampling, we have provided a reliable starting hypothesis for

  18. Would behavioral thermoregulation enable pregnant viviparous tropical lizards to cope with a warmer world?

    Science.gov (United States)

    López-Alcaide, Saúl; Nakamura, Miguel; Smith, Eric N; Martínez-Meyer, Enrique

    2017-09-01

    Sceloporus lizards depend on external heat to achieve their preferred temperature (T sel ) for performing physiological processes. Evidence both in the field and laboratory indicates that pregnant females of this Genus select body temperatures (T b ) lower than 34 °C as higher temperatures may be lethal to embryos. Therefore, thermoregulation is crucial for successful embryo development. Given the increase in global air temperature, it is expected that the first compensatory response of species that inhabit tropical climates will be behavioral thermoregulation. We tested whether viviparous Sceloporus formosus group lizards in the wild exhibited differences in thermoregulatory behavior to achieve the known T sel for developing embryos regardless of local thermal conditions. We quantified field active body temperature, thermoregulatory behavior mechanisms (time of sighting, microhabitat used and basking time) and available microhabitat thermal conditions (i.e. operative temperature) for 10 lizard species during gestation, distributed along an altitudinal gradient. We applied both conventional and phylogenic analyses to explore whether T b or behavioral thermoregulation could be regulated in response to different thermal conditions. These species showed no significant differences in field T b during gestation regardless of local thermal conditions. In contrast, they exhibited significant differences in their behavioral thermoregulation associated with local environmental conditions. Based on these observations, the differences in thermoregulatory behavior identified are interpreted as compensatory adjustments to local thermal conditions. We conclude that these species may deal with higher temperatures predicted for the tropics by modulating their thermoregulatory behavior. © 2017 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

  19. How to tackle chemical communication? Relative proportions versus semiquantitative determination of compounds in lizard chemical secretions.

    Science.gov (United States)

    García-Roa, Roberto; Sáiz, Jorge; Gómara, Belén; López, Pilar; Martín, José

    2018-02-01

    Knowledge about chemical communication in some vertebrates is still relatively limited. Squamates are a glaring example of this, even when recent evidences indicate that scents are involved in social and sexual interactions. In lizards, where our understanding of chemical communication has considerably progressed in the last few years, many questions about chemical interactions remain unanswered. A potential reason for this is the inherent complexity and technical limitations that some methodologies embody when analyzing the compounds used to convey information. We provide here a straightforward procedure to analyze lizard chemical secretions based on gas chromatography coupled to mass spectrometry that uses an internal standard for the semiquantification of compounds. We compare the results of this method with those obtained by the traditional procedure of calculating relative proportions of compounds. For such purpose, we designed two experiments to investigate if these procedures allowed revealing changes in chemical secretions 1) when lizards received previously a vitamin dietary supplementation or 2) when the chemical secretions were exposed to high temperatures. Our results show that the procedure based on relative proportions is useful to describe the overall chemical profile, or changes in it, at population or species levels. On the other hand, the use of the procedure based on semiquantitative determination can be applied when the target of study is the variation in one or more particular compounds of the sample, as it has proved more accurate detecting quantitative variations in the secretions. This method would reveal new aspects produced by, for example, the effects of different physiological and climatic factors that the traditional method does not show.

  20. Evidence for a carotid body homolog in the lizard Tupinambis merianae.

    Science.gov (United States)

    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. © 2015. Published by The Company of Biologists Ltd.

  1. A decrease in nasal CO2 stimulates breathing in the tegu lizard.

    Science.gov (United States)

    Coates, E L; Furilla, R A; Ballam, G O; Bartlett, D

    1991-10-01

    Tegu lizards decrease ventilatory frequency (f) when constant CO2, as low as 0.4%, is delivered to the nasal cavities. In contrast, CO2, as high as 6%, pulsed into the nasal cavities during the expiratory phase of the breathing cycle does not alter f. The purpose of the present study was to investigate further the effect of nasal CO2 pattern on f in tegu lizards. Specifically, we tested: (1) whether f was affected by CO2 delivered to the nasal cavities during the inspiratory phase of the breathing cycle, and (2) whether pulsed decreases in nasal CO2 from 4% to 2% and from 4% to 0% would remove the f inhibition caused by constant nasal CO2. Ventilation was measured using a pneumotachograph and pressure transducer in-line with an endotracheal T-tube inserted through the glottis. CO2 was delivered to the nasal cavities through small tubes inserted into the external nares. Ventilatory frequency was not significantly altered when 4% CO2 was pulsed into the nasal cavities during inspiration. Dropping the CO2 in the nasal cavities from 4% to 0% at either 15 cycles/min (0.25 Hz) or for one cycle stimulated breathing. There was no significant difference between the f response to a drop in CO2 from 4% to 0% and that to a drop in CO2 from 4% to 2%. The failure to link the phasic CO2 ventilatory response to a phase in the respiratory cycle indicates that the nasal CO2 receptors do not participate in the breath-by-breath regulation of breathing in these lizards. The observation that small decreases in nasal CO2 abolished the f inhibition caused by constant nasal CO2 provides further evidence for the ability of the nasal CO2 receptors to distinguish between pulsed and constant CO2.

  2. The VIP/VPACR system in the reproductive cycle of male lizard Podarcis sicula.

    Science.gov (United States)

    Agnese, Marisa; Rosati, Luigi; Prisco, Marina; Coraggio, Francesca; Valiante, Salvatore; Scudiero, Rosaria; Laforgia, Vincenza; Andreuccetti, Piero

    2014-09-01

    Starting from the knowledge that in the reproductive period the Vasoactive Intestinal Peptide (VIP) is widely distributed in Podarcis sicula testis, we studied VIP expression and the localization of the neuropeptide and its receptors in the testis of the Italian wall lizard P. sicula in the other phases of its reproductive cycle (summer stasis, autumnal resumption, winter stasis, spring resumption). By Real Time-PCR, we demonstrated that testicular VIP mRNA levels change during the reproductive cycle, showing a cyclic trend with two peaks, one in the mid-autumnal resumption and the other in the reproductive period. By in situ hybridization and immunohistochemistry, we demonstrated that both VIP mRNA and protein were widely distributed in the testis in almost all the phases of the cycle, except in the early autumnal resumption. As regards the receptors, the VPAC1R was localized mainly in Leydig cells, while the VPAC2R showed the same distribution of VIP. Our results demonstrate that, differently from mammals, where VIP is present only in nerve fibres innerving the testis, an endotesticular synthesis takes place in the lizard and the VIP synthesis changes throughout the reproductive cycle. Moreover, the VIP/VPAC receptor system distribution observed in germ and somatic cells in various phases of the cycle, and particularly in the autumnal resumption and the reproductive period, strongly suggests its involvement in both spermatogenesis and steroidogenesis. Finally, the wider distribution of VIP in lizards with respect to mammals leads us to hypothesize that during the evolution the synthesis sites have been transferred from the testis to other districts, such as the brain. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Nutritional modulation of IGF-1 in relation to growth and body condition in Sceloporus lizards.

    Science.gov (United States)

    Duncan, Christine A; Jetzt, Amanda E; Cohick, Wendie S; John-Alder, Henry B

    2015-05-15

    Nutrition and energy balance are important regulators of growth and the growth hormone/insulin-like growth factor (GH/IGF) axis. However, our understanding of these functions does not extend uniformly to all classes of vertebrates and is mainly limited to controlled laboratory conditions. Lizards can be useful models to improve our understanding of the nutritional regulation of the GH/IGF-1 axis because many species are relatively easy to observe and manipulate both in the laboratory and in the field. In the present study, the effects of variation in food intake on growth, body condition, and hepatic IGF-1 mRNA levels were measured in (1) juveniles of Sceloporus jarrovii maintained on a full or 1/3 ration and (2) hatchlings of Sceloporus undulatus subjected to full or zero ration with or without re-feeding. These parameters plus plasma IGF-1 were measured in a third experiment using adults of S. undulatus subjected to full or zero ration with or without re-feeding. In all experiments, plasma corticosterone was measured as an anticipated indicator of nutritional stress. In S. jarrovii, growth and body condition were reduced but lizards remained in positive energy balance on 1/3 ration, and hepatic IGF-1 mRNA and plasma corticosterone were not affected in comparison to full ration. In S. undulatus, growth, body condition, hepatic IGF-1 mRNA, and plasma IGF-1 were all reduced by zero ration and restored by refeeding. Plasma corticosterone was increased in response to zero ration and restored by full ration in hatchlings but not adults of S. undulatus. These data indicate that lizards conform to the broader vertebrate model in which severe food deprivation and negative energy balance is required to attenuate systemic IGF-1 expression. However, when animals remain in positive energy balance, reduced food intake does not appear to affect systemic IGF-1. Consistent with other studies on lizards, the corticosterone response to reduced food intake is an unreliable indicator

  4. Effect of gamma-rays on the life-shortening of the lizard uromastyx hardwickii

    International Nuclear Information System (INIS)

    Ahmed, M.; Taqawi, I.H.

    1978-01-01

    Three groups of starved lizards, Uromastyx hardwickii, in 3 groups were exposed to 60 Co gamma radiation of 3000 R, 3500 R, and 4000 R, resp., maintained at 30 0 +- 1 0 C, and observed for 4 weeks. Increase of irradiation decreased the survival time. The LD 50 /30 days was about 4000 R. This appears to be the highest dose so far obtained for any vertebrate, and indicates poikilotherms to respond differently from homoiotherms. The higher radioresistance of cold-blooded animals appears to be due to the low metabolic activity. (author)

  5. Yolk sac development in lizards (Lacertilia: Scincidae): New perspectives on the egg of amniotes.

    Science.gov (United States)

    Stewart, James R; Thompson, Michael B

    2017-04-01

    Embryos of oviparous reptiles develop on the surface of a large mass of yolk, which they metabolize to become relatively large hatchlings. Access to the yolk is provided by tissues growing outward from the embryo to cover the surface of the yolk. A key feature of yolk sac development is a dedicated blood vascular system to communicate with the embryo. The best known model for yolk sac development and function of oviparous amniotes is based on numerous studies of birds, primarily domestic chickens. In this model, the vascular yolk sac forms the perimeter of the large yolk mass and is lined by a specialized epithelium, which takes up, processes and transports yolk nutrients to the yolk sac blood vessels. Studies of lizard yolk sac development, dating to more than 100 years ago, report characteristics inconsistent with this model. We compared development of the yolk sac from oviposition to near hatching in embryonic series of three species of oviparous scincid lizards to consider congruence with the pattern described for birds. Our findings reinforce results of prior studies indicating that squamate reptiles mobilize and metabolize the large yolk reserves in their eggs through a process unknown in other amniotes. Development of the yolk sac of lizards differs from birds in four primary characteristics, migration of mesoderm, proliferation of endoderm, vascular development and cellular diversity within the yolk sac cavity. Notably, all of the yolk is incorporated into cells relatively early in development and endodermal cells within the yolk sac cavity align along blood vessels which course throughout the yolk sac cavity. The pattern of uptake of yolk by endodermal cells indicates that the mechanism of yolk metabolism differs between lizards and birds and that the evolution of a fundamental characteristic of embryonic nutrition diverged in these two lineages. Attributes of the yolk sac of squamates reveal the existence of phylogenetic diversity among amniote lineages

  6. Lizards and Amphisbaenians, municipality of Viçosa, state of Minas Gerais, southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Rodrigues, A. C.

    2009-01-01

    Full Text Available We performed a survey of lizards and amphisbaenians from municipality of Viçosa, in Atlantic Forest from state ofMinas Gerais, southeastern Brazil, based on data of the herpetological collections of Museu de Zoologia João Moojen,Universidade Federal de Viçosa, and Museu de Zoologia, Universidade de São Paulo. One hundred and forty sixspecimens of 14 species were analyzed, belonging to the following families: Amphisbaenidae, Anguidae, Gekkonidae,Gymnophthalmidae, Leiosauridae, Polychrotidae, Scincidae, Teiidae and Tropiduridae. We hope to supply basicinformation that helps to understand species distribution of this group in the Atlantic Forest of Minas Gerais andsoutheastern Brazil.

  7. Resurrection of Bronchocela burmana Blanford, 1878 for the Green Crested Lizard (Squamata, Agamidae of southern Myanmar

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    George R. Zug

    2017-02-01

    Full Text Available Recent fieldwork in southern Tanintharyi revealed the presence of a small Green Crested Lizard in the wet evergreen forest. We generated mtDNA sequence data (ND2 that demonstrates that this population’s nearest relative is Bronchocela rayaensis Grismer et al., 2015 of Pulau Langkawi, northwestern Peninsular Malaysia and Phuket Island. Morphologically the Burmese Bronchocela shares many features with B. rayaensis, which potentially would make this recently described Thai-Malay species a synonym of Bronchocela burmana Blanford, 1878; however, we interpret the genetic and morphological differences to reflect evolutionary divergence and recommend the recognition of both species.

  8. Baseline values of micronuclei and comet assay in the lizard Tupinambis merianae (Teiidae, Squamata).

    Science.gov (United States)

    Schaumburg, Laura G; Poletta, Gisela L; Siroski, Pablo A; Mudry, Marta D

    2012-10-01

    The Micronucleus test (MN) and Comet assay (CA) are currently the most widely used methods that allow the characterization of DNA damage induced by physical and chemical agents in wild species. The continuous expansion of the cultivated areas in Argentina, since the introduction of transgenic crops, mainly soy, in association with the increased use of pesticides, transformed deeply the natural environments where the lizard Tupinambis merianae (tegu lizard) occurs. Despite the fact that reptiles have shown to be excellent bioindicators of environmental contaminants, there is no record of genotoxicity studies in T. merianae. The aim of the present study was to adjust the MN test and CA protocols to be applied in erythrocytes of T. merianae, and determine the baseline values of DNA damage in this species. We used 20 adult lizards (10 males: 10 females) from Estación Zoológica Experimental "Granja La Esmeralda" (Santa Fe, Argentina). Peripheral blood samples were collected from all animals and the MN test and CA applied according to the protocols established for other reptilian species. We test critical parameters of CA protocol (cell density, unwinding and electrophoresis times) using increasing concentrations of H2O2 (10, 25 and 50 μM) as a known genotoxic agent to induce DNA damage. Based on this, we determined the most suitable conditions for the CA in this species: a cell density of 4×10(3) erythrocytes per slide, 10 min of unwinding and 15 min of electrophoresis at 0.90 V/cm approximately. The baseline frequency of micronuclei (BFMN=MN/1000 erythrocytes counted) determined for this species was 0.95±0.27 and the basal damage index (BDI: calculated from 100 comet images classified in arbitrary units)=103.85±0.97. No differences were observed between sexes in the BFMN or BDI (p>0.05), and no relation was found between baseline values and length or weight of the analyzed animals (p>0.05). These results demonstrated the sensitivity of both biomarkers of

  9. Efferent projections of the septum in the Tegu lizard, Tupinambis nigropunctatus.

    Science.gov (United States)

    Sligar, C M; Voneida, T J

    1981-09-01

    A H3 proline or H3 leucine mixture was injected into the septal region of the Tegu lizard in order to determine its efferent projections. The brains were processed according to standard autoradiographic technique and counterstained with cresyl violet. Septal projections were limited to either telencephalic or diencephalic areas. Intratelencephalic projections consisted of efferents to medial pallium, nucleus accumbens, bed nucleus of the anterior commissure, preoptic area and septum itself. Fibers entering the diencephalon projected to medial habenular nucleus, dorsomedial thalamic nucleus, dorsolateral thalamic area, periventricular nucleus of the hypothalamus, lateral hypothalamic area and mammillary nucleus. The results are discussed in relation to the efferent projections of the septum in other vertebrates.

  10. Bearded dragons (Pogona vitticeps) asymptomatically infected with Devriesea agamarum are a source of persistent clinical infection in captive colonies of dab lizards (Uromastyx sp.).

    Science.gov (United States)

    Devloo, R; Martel, A; Hellebuyck, T; Vranckx, K; Haesebrouck, F; Pasmans, F

    2011-06-02

    Devriesea agamarum causes dermatitis and septicaemia in a variety of lizards, notably those belonging to the genus Uromastyx, whereas other species such as bearded dragons (Pogona vitticeps) seem to be asymptomatic carriers. Using amplified fragment length polymorphism (AFLP), the relatedness between 69 D. agamarum isolates was examined. The isolates derived from 44 diseased lizards, of which 31 belonged to the genus Uromastyx, and from 25 healthy lizards, of which 21 were bearded dragons. Eight AFLP genotypes were obtained, four of which comprised 93% of the isolates. These four genotypes were each present in 2, 2, 8 and 13 different captive colonies. Up to three genotypes were isolated from a single infected colony simultaneously. On two occasions, the same genotype was found in healthy bearded dragons and diseased Uromastyx lizards from the same colony, confirming the role of the former as an asymptomatic source of infection for the latter. Two genotypes, comprising 12 isolates, were exclusively associated with diseased Uromastyx lizards, suggesting strain dependent host adaptation. Finally, D. agamarum was shown to be able to persist for at least seven years in a lizard colony, persistently causing severe disease in several lizard species. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. Analysis of a herpetofaunal community from an altered marshy area in Sicily; with special remarks on habitat use (niche breadth and overlap), relative abundance of lizards and snakes, and the correlation between predator abundance and tail loss in lizards

    NARCIS (Netherlands)

    Luiselli, L.; Angelici, F.M.; Di Vittorio, M.; Spinnato, A.; Politano, E.

    2005-01-01

    A field survey was conducted in a highly degraded barren environment in Sicily in order to investigate herpetofaunal community composition and structure, habitat use (niche breadth and overlap) and relative abundance of a snake predator and two species of lizard prey. The site was chosen because it

  12. Bamboo tea: reduction of taxonomic complexity and application of DNA diagnostics based on rbcL and matK sequence data

    Science.gov (United States)

    Häser, Annette

    2016-01-01

    Background Names used in ingredient lists of food products are trivial and in their nature rarely precise. The most recent scientific interpretation of the term bamboo (Bambusoideae, Poaceae) comprises over 1,600 distinct species. In the European Union only few of these exotic species are well known sources for food ingredients (i.e., bamboo sprouts) and are thus not considered novel foods, which would require safety assessments before marketing of corresponding products. In contrast, the use of bamboo leaves and their taxonomic origin is mostly unclear. However, products containing bamboo leaves are currently marketed. Methods We analysed bamboo species and tea products containing bamboo leaves using anatomical leaf characters and DNA sequence data. To reduce taxonomic complexity associated with the term bamboo, we used a phylogenetic framework to trace the origin of DNA from commercially available bamboo leaves within the bambusoid subfamily. For authentication purposes, we introduced a simple PCR based test distinguishing genuine bamboo from other leaf components and assessed the diagnostic potential of rbcL and matK to resolve taxonomic entities within the bamboo subfamily and tribes. Results Based on anatomical and DNA data we were able to trace the taxonomic origin of bamboo leaves used in products to the genera Phyllostachys and Pseudosasa from the temperate “woody” bamboo tribe (Arundinarieae). Currently available rbcL and matK sequence data allow the character based diagnosis of 80% of represented bamboo genera. We detected adulteration by carnation in four of eight tea products and, after adapting our objectives, could trace the taxonomic origin of the adulterant to Dianthus chinensis (Caryophyllaceae), a well known traditional Chinese medicine with counter indications for pregnant women. PMID:27957401

  13. New host and distributional records for Cryptosporidium sp. (Apicomplexa: Cryptosporidiidae) from lizards (Sauria: Gekkonidae, Scincidae) from the Cook Islands and Vanuatu, South Pacific

    Science.gov (United States)

    McAllister, Chris T.; Duszynski, Donald W.; Fisher, Robert N.

    2013-01-01

    Between 1991 and 1993, 295 lizards, comprising 21 species in 2 families (Gekkonidae, Scincidae) from the Cook Islands, Fiji, Palau, Takapoto, and Vanuatu in the South Pacific, were examined for Cryptosporidium oocysts. Only 6 lizards (2%) were found to be passing Cryptosporidium oocysts in their feces, including 2 of 30 (7%) Oceania geckos, Gehyra oceanica, from Rarotonga, Cook Islands, and 4 of 26 (15%) Pacific blue-tailed skinks, Emoia caeruleocauda, from Efate Island, Vanuatu. This represents the largest survey for Cryptosporidium in Pacific island lizards, and we document 2 new host and 2 new locality records for this parasite genus.

  14. Molecular survey and microscopic examination of Hepatozoon Miller, 1908 (Apicomplexa: Adeleorina) in lacertid lizards from the western Mediterranean.

    Science.gov (United States)

    Maia, João P M C; Perera, Ana; Harris, D James

    2012-12-01

    The genus Hepatozoon Miller, 1908 (Apicomplexa: Adeleorina) is composed of intracellular haemogregarine parasites that are widely distributed among all tetrapod groups. The present study combines microscopic and molecular data on haemogregarine parasites from lizards in the western Mediterranean. We screened tissue samples and examined blood smears for the presence of species of Hepatozoon from four lizards, namely Algyroides marchi Valverde, endemic to Southeast Spain, Podarcis bocagei Seoane from Spain and Portugal, P hispanica Steindachner from Spain, and P lilfordi Günther from Cabrera, Balearic Islands (Spain). Our results show that prevalence and intensity of Hepatozoon parasites vary between and within lizard species from different regions. Algyroides marchi and P bocagei from Spain had the lowest values, whereas P hispanica had the highest. Phylogeny based on 18S rRNA gene sequences indicates that most of the new Hepatozoon sequences are part of a clade exclusive from North African and Iberian lizards, except for a single P bocagei isolate that is found related to another clade including isolates from other reptile host species and rodents. Interestingly, isolates from Algyroides form a distinct monophyletic subgroup, which could be a signal of strict host-specificity within this host genus.

  15. Patterns of infestation by the trombiculid mite Eutrombicula alfreddugesi in four sympatric lizard species (genus Tropidurus) in northeastern Brazil.

    Science.gov (United States)

    Rocha, C F D; Cunha-Barros, M; Menezes, V A; Fontes, A f; Vrcibradic, D; Van Sluys, M

    2008-06-01

    We studied the parasitism by the chigger mite Eutrombicula alfreddugesi on four sympatric lizard species of the genus Tropidurus in Morro do Chapéu, Bahia state, Brazil: T. hispidus, T. cocorobensis, T. semitaeniatus and T. erythrocephalus. For each species, we investigated the patterns of infestation and analyzed to which extent they varied among the hosts. We calculated the spatial niche breadth of the chigger mite on the body of each host species and the distribution of mites along the hosts' bodies for each Tropidurus species. All four species of Tropidurus at Morro do Chapéu were parasited by the chigger mite, with high (97-100%) prevalences. Host body size significantly explained the intensity of mite infestation for all species, except T. erythrocephalus. The body regions with highest intensity of infestation in the four lizard species were the mite pockets. The spacial niche width of the chigger varied consistently among the four lizards species studied being highest for T. erytrocephalus and lowest for T. cocorobensis. We conclude that the distribution and intensity with which lizards of the genus Tropidurus are infested by Eutrombicula alfreddugesi larvae results from the interaction between aspects of host morphology (such as body size and the occurrence and distribution of mite pockets) and ecology (especially microhabitat use).

  16. Patterns of infestation by the trombiculid mite Eutrombicula alfreddugesi in four sympatric lizard species (genus Tropidurus in northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Rocha C.F.D.

    2008-06-01

    Full Text Available We studied the parasitism by the chigger mite Eutrombicula alfreddugesi on four sympatric lizard species of the genus Tropidurus in Morro do Chapéu, Bahia state, Brazil: T. hispidus, T. cocorobensis, T. semitaeniatus and T. erythrocephalus. For each species, we investigated the patterns of infestation and analyzed to which extent they varied among the hosts. We calculated the spatial niche breadth of the chigger mite on the body of each host species and the distribution of mites along the hosts’ bodies for each Tropidurus species. All four species of Tropidurus at Morro do Chapéu were parasited by the chigger mite, with high (97-100% prevalences. Host body size significantly explained the intensity of mite infestation for all species, except T. erythrocephalus. The body regions with highest intensity of infestation in the four lizard species were the mite pockets. The spacial niche width of the chigger varied consistently among the four lizards species studied being highest for T. erytrocephalus and lowest for T. cocorobensis. We conclude that the distribution and intensity with which lizards of the genus Tropidurus are infested by Eutrombicula alfreddugesi larvae results from the interaction between aspects of host morphology (such as body size and the occurrence and distribution of mite pockets and ecology (especially microhabitat use.

  17. Contrasting effects of landscape features on genetic structure in different geographic regions in the ornate dragon lizard, Ctenophorus ornatus.

    Science.gov (United States)

    Levy, Esther; Tomkins, Joseph L; Lebas, Natasha R; Kennington, W Jason

    2013-08-01

    Habitat fragmentation can have profound effects on the distribution of genetic variation within and between populations. Previously, we showed that in the ornate dragon lizard, Ctenophorus ornatus, lizards residing on outcrops that are separated by cleared agricultural land are significantly more isolated and hold less genetic variation than lizards residing on neighbouring outcrops connected by undisturbed native vegetation. Here, we extend the fine-scale study to examine the pattern of genetic variation and population structure across the species' range. Using a landscape genetics approach, we test whether land clearing for agricultural purposes has affected the population structure of the ornate dragon lizard. We found significant genetic differentiation between outcrop populations (FST  = 0.12), as well as isolation by distance within each geographic region. In support of our previous study, land clearing was associated with higher genetic divergences between outcrops and lower genetic variation within outcrops, but only in the region that had been exposed to intense agriculture for the longest period of time. No other landscape features influenced population structure in any geographic region. These results show that the effects of landscape features can vary across species' ranges and suggest there may be a temporal lag in response to contemporary changes in land use. These findings therefore highlight the need for caution when assessing the impact of contemporary land use practices on genetic variation and population structure. © 2013 John Wiley & Sons Ltd.

  18. There's more than one way to climb a tree: Limb length and microhabitat use in lizards with toe pads.

    Directory of Open Access Journals (Sweden)

    Travis J Hagey

    Full Text Available Ecomorphology links microhabitat and morphology. By comparing ecomorphological associations across clades, we can investigate the extent to which evolution can produce similar solutions in response to similar challenges. While Anolis lizards represent a well-studied example of repeated convergent evolution, very few studies have investigated the ecomorphology of geckos. Similar to anoles, gekkonid lizards have independently evolved adhesive toe pads and many species are scansorial. We quantified gecko and anole limb length and microhabitat use, finding that geckos tend to have shorter limbs than anoles. Combining these measurements with microhabitat observations of geckos in Queensland, Australia, we observed geckos using similar microhabitats as reported for anoles, but geckos with relatively longer limbs were using narrower perches, differing from patterns observed in anoles and other lizards. We also observed arboreal geckos with relatively shorter proximal limb segments as compared to rock-dwelling and terrestrial geckos, similar to patterns observed for other lizards. We conclude that although both geckos and anoles have adhesive pads and use similar microhabitats, their locomotor systems likely complement their adhesive pads in unique ways and result in different ecomorphological patterns, reinforcing the idea that species with convergent morphologies still have idiosyncratic characteristics due to their own separate evolutionary histories.

  19. Transcriptomic analysis of tail regeneration in the lizard Anolis carolinensis reveals activation of conserved vertebrate developmental and repair mechanisms.

    Directory of Open Access Journals (Sweden)

    Elizabeth D Hutchins

    Full Text Available Lizards, which are amniote vertebrates like humans, are able to lose and regenerate a functional tail. Understanding the molecular basis of this process would advance regenerative approaches in amniotes, including humans. We have carried out the first transcriptomic analysis of tail regeneration in a lizard, the green anole Anolis carolinensis, which revealed 326 differentially expressed genes activating multiple developmental and repair mechanisms. Specifically, genes involved in wound response, hormonal regulation, musculoskeletal development, and the Wnt and MAPK/FGF pathways were differentially expressed along the regenerating tail axis. Furthermore, we identified 2 microRNA precursor families, 22 unclassified non-coding RNAs, and 3 novel protein-coding genes significantly enriched in the regenerating tail. However, high levels of progenitor/stem cell markers were not observed in any region of the regenerating tail. Furthermore, we observed multiple tissue-type specific clusters of proliferating cells along the regenerating tail, not localized to the tail tip. These findings predict a different mechanism of regeneration in the lizard than the blastema model described in the salamander and the zebrafish, which are anamniote vertebrates. Thus, lizard tail regrowth involves the activation of conserved developmental and wound response pathways, which are potential targets for regenerative medical therapies.

  20. Lizard Microhabitat and Microclimate Relationships in Southeastern Pine-Hardwood Forests Managed With Prescribed Burning and Thinning

    Science.gov (United States)

    W.B. Sutton; Y. Wang; C.J. Schweitzer; D.A. Steen

    2014-01-01

    Understanding the impacts of disturbances in forest ecosystems is essential for long-term biodiversity conservation. Many studies have evaluated wildlife responses to various disturbances but most generally do not use changes in microclimate features or crohabitat structure to explain these responses. We examined lizard responses to two common forest management...

  1. Minimal role of eastern fence lizards in Borrelia burgdorferi transmission in central New Jersey oak/pine woodlands

    Science.gov (United States)

    Rulison, Eric L.; Kerr, Kaetlyn T; Dyer, Megan C; Han, Seungeun; Burke, Russell L.; Tsao, Jean I.; Ginsberg, Howard S.

    2014-01-01

    The Eastern fence lizard, Sceloporus undulatus, is widely distributed in eastern and central North America, ranging through areas with high levels of Lyme disease, as well as areas where Lyme disease is rare or absent. We studied the potential role of S. undulatus in transmission dynamics of Lyme spirochetes by sampling ticks from a variety of natural hosts at field sites in central New Jersey, and by testing the reservoir competence of S. undulatus for Borrelia burgdorferi in the laboratory. The infestation rate of ticks on fence lizards was extremely low (proportion infested = 0.087, n = 23) compared to that on white footed mice and other small mammals (proportion infested = 0.53, n = 140). Of 159 nymphs that had fed as larvae on lizards that had previously been exposed to infected nymphs, none was infected with B. burgdorferi, compared with 79.9% of 209 nymphs that had fed as larvae on infected control mice. Simulations suggest that changes in the numbers of fence lizards in a natural habitat would have little effect on the infection rate of nymphal ticks with Lyme spirochetes. We conclude that in central New Jersey S. undulatus plays a minimal role in the enzootic transmission cycle of Lyme spirochetes.

  2. There's more than one way to climb a tree: Limb length and microhabitat use in lizards with toe pads.

    Science.gov (United States)

    Hagey, Travis J; Harte, Scott; Vickers, Mathew; Harmon, Luke J; Schwarzkopf, Lin

    2017-01-01

    Ecomorphology links microhabitat and morphology. By comparing ecomorphological associations across clades, we can investigate the extent to which evolution can produce similar solutions in response to similar challenges. While Anolis lizards represent a well-studied example of repeated convergent evolution, very few studies have investigated the ecomorphology of geckos. Similar to anoles, gekkonid lizards have independently evolved adhesive toe pads and many species are scansorial. We quantified gecko and anole limb length and microhabitat use, finding that geckos tend to have shorter limbs than anoles. Combining these measurements with microhabitat observations of geckos in Queensland, Australia, we observed geckos using similar microhabitats as reported for anoles, but geckos with relatively longer limbs were using narrower perches, differing from patterns observed in anoles and other lizards. We also observed arboreal geckos with relatively shorter proximal limb segments as compared to rock-dwelling and terrestrial geckos, similar to patterns observed for other lizards. We conclude that although both geckos and anoles have adhesive pads and use similar microhabitats, their locomotor systems likely complement their adhesive pads in unique ways and result in different ecomorphological patterns, reinforcing the idea that species with convergent morphologies still have idiosyncratic characteristics due to their own separate evolutionary histories.

  3. Detection of zoonotic and livestock-specific assemblages of Giardia duodenalis in free-living wild lizards

    Directory of Open Access Journals (Sweden)

    Aurora Reboredo-Fernández

    Full Text Available Abstract Giardia duodenalis is a zoonotic parasite that infects the gut of a wide range of vertebrates, including numerous wildlife species. However, little is known about this protozoan parasite in reptiles. Fecal samples from 31 wild lizards were collected in Galicia (northwest Spain and screened for the presence of Giardia by PCR amplification and sequencing of the ITS1-5.8S-ITS2 region in the ribosomal unit. This allowed detection of the parasite in 5 samples (16.1%, and enabled identification of G. duodenalis assemblage A2 in two samples of Iberian rock lizard (Iberolacerta monticola, G. duodenalis assemblage B in other two samples of I. monticola, and G. duodenalis assemblage E in one sample of Bocage’s wall lizard (Podarcis bocagei. The results obtained after PCR amplification and sequencing of the SSU-rDNA gene confirmed the presence of G. duodenalis assemblage A in two samples of I. monticola. This is the first report of G. duodenalis in free-living lizards, although further studies are needed to distinguish between actual infection and mechanical dissemination of cysts. The detection of zoonotic and livestock-specific assemblages of G. duodenalis demonstrates the wide environmental contamination by this parasite, possibly due to human activities.

  4. Seasonal changes in blood oxygen transport and acid-base status in the tegu lizard, Tupinambis merianae.

    Science.gov (United States)

    Andrade, Denis V; Brito, Simone P; Toledo, Luís Felipe; Abe, Augusto S

    2004-05-20

    Oxygen-binding properties, blood gases, and acid-base parameters were studied in tegu lizards, Tupinambis merianae, at different seasons and temperatures. Independent of temperature and pH, blood oxygen affinity was higher in dormant lizards than in those active during the summer. Haematocrit (Hct) and hemoglobin content ([Hb]) were greater in active lizards resulting in a higher oxygen-carrying capacity. Nucleoside triphosphate content ([NTP]) was reduced during dormancy, but the ratio between [NTP] and [Hb] remained unchanged. Dormancy was accompanied by an increase in plasma bicarbonate ([HCO-(3)]pl) and an elevation of arterial CO2 partial pressure (PaCO2) and CO2 content in the plasma (CplCO2). These changes in acid-base parameters persist over a broad range of body temperatures. In vivo, arterial O2 partial pressure (PaO2) and O2 content (CaO2) were not affected by season and tended to increase with temperature. Arterial pH (pHa) of dormant animals is reduced compared to active lizards at body temperatures below 15 degrees C, while no significant difference was noticed at higher temperatures. Copyright 2003 Elsevier B.V.

  5. 75 FR 9377 - Endangered and Threatened Wildlife and Plants; Listing the Flat-Tailed Horned Lizard as Threatened

    Science.gov (United States)

    2010-03-02

    ... available scientific and commercial information, we request information on the flat-tailed horned lizard... commercial, recreational, scientific, or educational purposes; (c) Disease or predation; (d) The inadequacy....S. District Court for the Southern District of California challenging our 1997 withdrawal of the...

  6. Geographical variation in body size and sexual size dimorphism in an Australian lizard, Boulenger's Skink (Morethia boulengeri).

    Science.gov (United States)

    Michael, Damian R; Banks, Sam C; Piggott, Maxine P; Cunningham, Ross B; Crane, Mason; MacGregor, Christopher; McBurney, Lachlan; Lindenmayer, David B

    2014-01-01

    Ecogeographical rules help explain spatial and temporal patterns in intraspecific body size. However, many of these rules, when applied to ectothermic organisms such as reptiles, are controversial and require further investigation. To explore factors that influence body size in reptiles, we performed a heuristic study to examine body size variation in an Australian lizard, Boulenger's Skink Morethia boulengeri from agricultural landscapes in southern New South Wales, south-eastern Australia. We collected tissue and morphological data on 337 adult lizards across a broad elevation and climate gradient. We used a model-selection procedure to determine if environmental or ecological variables best explained body size variation. We explored the relationship between morphology and phylogenetic structure before modeling candidate variables from four broad domains: (1) geography (latitude, longitude and elevation), (2) climate (temperature and rainfall), (3) habitat (vegetation type, number of logs and ground cover attributes), and (4) management (land use and grazing history). Broad phylogenetic structure was evident, but on a scale larger than our study area. Lizards were sexually dimorphic, whereby females had longer snout-vent length than males, providing support for the fecundity selection hypothesis. Body size variation in M. boulengeri was correlated with temperature and rainfall, a pattern consistent with larger individuals occupying cooler and more productive parts of the landscape. Climate change forecasts, which predict warmer temperature and increased aridity, may result in reduced lizard biomass and decoupling of trophic interactions with potential implications for community organization and ecosystem function.

  7. 78 FR 7907 - Endangered and Threatened Wildlife and Plants; Removing the Island Night Lizard From the Federal...

    Science.gov (United States)

    2013-02-04

    ... establishing population and habitat baselines, or for detecting variations from those baselines over the course... snout to vent (Goldberg and Bezy 1974, p. 356; Fellers and Drost 1991, p. 28; Mautz 1993, p. 422... slow-growing, late-maturing, and long- lived lizard (Goldberg and Bezy 1974, pp. 355-358; Fellers and...

  8. Endocrine function and reproductive impairment in an irradiated population of the lizard Uta stansburiana

    International Nuclear Information System (INIS)

    Pearson, A.K.; Licht, P.; Nagy, K.A.; Medica, P.A.

    1978-01-01

    Gonadal changes in lizards (Uta stansburiana) exposed to chronic low levels of γ radiation (1.5 to 10 R/day) under field conditions are described, and attempts to evaluate endocrine involvement in these changes are made. Reproductive impairment in irradiated males was demonstrated during the breeding season by reduced testes weights and by seminiferous tubules devoid of germ cells. Ultrastructural morphology of Leydig cells, plasma testosterone levels, and developed accessory sex structures indicatedd normal steroidogenesis in such males; cytology of the pituitary gonadotropes and pituitary gonadotropin content indicated normal gonadotropin levels. These findings suggest that low levels of radiation affect the spermatogenic process directly, rather than through damage to the pituitary. Comparable irradiation caused complete resorption of ovarian tissue in some female Uta. The oviducts were atrophic and the pituitary gonadotropes hyperactive. Resemblance of gonadotropes to those of castrated animals and reduced pituitary hormone content suggests elevated levels of gonadotropin production, probably due to the absence of ovarian steroid feedback in affected animals. The continued mitotic activity of oogonia in adult reptiles and their limited number contributed to the vulnerability of germinal tissue in irradiated female lizards. Destruction of the germ cells was accompanied by resorption of all ovarian tissue including steroidogenic elements. Thus, in females as in males, radiation appears to damage gametogenesis rather than pituitary function

  9. Expression of Recombinant Human Coagulation Factor VII by the Lizard Leishmania Expression System

    Directory of Open Access Journals (Sweden)

    Sina Mirzaahmadi

    2011-01-01

    Full Text Available The variety of recombinant protein expression systems have been developed as a resource of FVII gene expression. In the current study, the authors used a novel protein expression system based on the Iranian Lizard Leishmania, a trypanosomatid protozoan as a host for expression of FVII. Plasmid containing cDNA encoding full-length human FVII was introduced into Lizard Leishmania and positive transfectants were analyzed by SDS-PAGE and Western blot analysis. Furthermore, biological activity of purified protein was detected by PT assay. The recombinant strain harboring a construct was analyzed for expression of FVII at the mRNA and protein level. Purified rFVII was obtained and in order to confirm the purified compound was in fact rFVII. Western blot analysis was carried out. Clotting time in PT assay was reduced about 30 seconds with the purified rFVII. In Conclusion, this study has demonstrated, for the first time, that Leishmania cells can be used as an expression system for producing recombinant FVII.

  10. Convergence across a continent: adaptive diversification in a recent radiation of Australian lizards.

    Science.gov (United States)

    Blom, Mozes P K; Horner, Paul; Moritz, Craig

    2016-06-15

    Recent radiations are important to evolutionary biologists, because they provide an opportunity to study the mechanisms that link micro- and macroevolution. The role of ecological speciation during adaptive radiation has been intensively studied, but radiations can arise from a diversity of evolutionary processes; in particular, on large continental landmasses where allopatric speciation might frequently precede ecological differentiation. It is therefore important to establish a phylogenetic and ecological framework for recent continental-scale radiations that are species-rich and ecologically diverse. Here, we use a genomic (approx. 1 200 loci, exon capture) approach to fit branch lengths on a summary-coalescent species tree and generate a time-calibrated phylogeny for a recent and ecologically diverse radiation of Australian scincid lizards; the genus Cryptoblepharus We then combine the phylogeny with a comprehensive phenotypic dataset for over 800 individuals across the 26 species, and use comparative methods to test whether habitat specialization can explain current patterns of phenotypic variation in ecologically relevant traits. We find significant differences in morphology between species that occur in distinct environments and convergence in ecomorphology with repeated habitat shifts across the continent. These results suggest that isolated analogous habitats have provided parallel ecological opportunity and have repeatedly promoted adaptive diversification. By contrast, speciation processes within the same habitat have resulted in distinct lineages with relatively limited morphological variation. Overall, our study illustrates how alternative diversification processes might have jointly stimulated species proliferation across the continent and generated a remarkably diverse group of Australian lizards. © 2016 The Author(s).

  11. The role of habitat shift in the evolution of lizard morphology: evidence from tropical Tropidurus

    Science.gov (United States)

    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 along an axis representing primarily three components of shape: body width, body height, and hind-leg length. Morphological divergence was supported by a principal components analysis of size-free morphological variables. Mitochondrial DNA sequences of ATPase 6 indicate that these populations are closely related relative to other T. hispidus, the rock outcrop morphology and ecology are derived within T. hispidus, and morphological and ecological divergence has occurred more rapidly than genetic divergence. This suggests that natural selection can rapidly adjust morphology and ecology in response to a recent history of exposure to habitats differing in structure, a result heretofore implied from comparative studies among lizard species. PMID:9108063

  12. The role of habitat shift in the evolution of lizard morphology: evidence from tropical Tropidurus.

    Science.gov (United States)

    Vitt, L J; Caldwell, J P; Zani, P A; Titus, T A

    1997-04-15

    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 along an axis representing primarily three components of shape: body width, body height, and hind-leg length. Morphological divergence was supported by a principal components analysis of size-free morphological variables. Mitochondrial DNA sequences of ATPase 6 indicate that these populations are closely related relative to other T. hispidus, the rock outcrop morphology and ecology are derived within T. hispidus, and morphological and ecological divergence has occurred more rapidly than genetic divergence. This suggests that natural selection can rapidly adjust morphology and ecology in response to a recent history of exposure to habitats differing in structure, a result heretofore implied from comparative studies among lizard species.

  13. Factors affecting helminths community structure of the Egyptian lizard Chalcides ocellatus (Forskal, 1775

    Directory of Open Access Journals (Sweden)

    Ibrahim M.M.

    2005-12-01

    Full Text Available The variation in the component community structure of intestinal helminths in the lizard Chalcides ocellatus (Forskal, 1775 was studied in relation to the seasonal variation and host weight and sex. 120 lizards were collected seasonally during year 2004, from Al Firdan, Ismailia governorate, Egypt. The helminths community consisted of six species (five nematodes and one cestode. The various helminths differed according to host sex. The prevalence of total helminths infection was 67.6 % while the prevalences of Thelandros schusteri, Pharyngodon mamillatus, Parapharyngodon bulbosus, Cosmocerca vrcibradici, Spauligodon petersi and Oochoristica maccoyi were 43.4 %, 3.9 %, 13.2 %, 5.3 %, 6.6 %, and 14.3 %, respectively. The results showed that the season was the main factor affecting infracommunity species richness and parasite abundance. Moreover, there was interaction between season and host sex on abundance of P. bulbosus. The prevalence of intestinal helminths varied significantly in relation to host weight classes and sex in some species. Helminths abundance and intensity were independent from host sex. In addition, correlations were found between total helminths abundance and host weight. In conclusion, the helminths community of C. ocellatus was depauperate and the influence of the studied factors varied from species to another one. We cannot say if the low species richness and infection rates observed in the present study are typical of the host species or if they are due to characteristics of the study area, since no available data on parasite assemblages exist for other C. ocellatus populations.

  14. Behavioral and physiological polymorphism in males of the austral lizard Liolaemus sarmientoi.

    Science.gov (United States)

    Fernández, Jimena B; Bastiaans, Elizabeth; Medina, Marlin; Méndez De la Cruz, Fausto R; Sinervo, Barry R; Ibargüengoytía, Nora R

    2018-02-01

    Integrative behavioral studies show that the interplay between individual physiology and social behavior influences the ecology of the species, ultimately affecting individual fitness. Particularly in lizards, color polymorphism is associated with differential behaviors and reproductive strategies, which are evident in mature males during the mating season. Dominant males generally have greater endurance, higher body temperature, and larger bodies than submissive males, so they can acquire and defend larger territories and have greater access to females for mating. We studied whether the color morphs observed in males of one of the world's southernmost reptiles, Liolaemus sarmientoi, are related to behavioral variation during agonistic interactions, thermal physiology, morphology, and/or locomotor stamina. Liolaemus sarmientoi males exhibit three color morphs: red (RR), red-yellow (RY), and yellow (YY). These lizards exhibit subtle behavioral displays and we did not observe stamina differences among morphs. However, we found that RR males are more aggressive than YY males during agonistic encounters. In addition, greater body temperature change during trials, higher field body temperatures, and greater head sizes of RR males compared to RY or YY indicate that RR is a dominant morph, which may influence their ability to acquire and defend territory and tactics for achieving reproductive success.

  15. Convergent evolution and divergent selection: lizards at the White Sands ecotone.

    Science.gov (United States)

    Rosenblum, Erica Bree

    2006-01-01

    Ecological transition zones, where organismal phenotypes result from a delicate balance between selection and migration, highlight the interplay of local adaptation and gene flow. Here, I study the response of an entire species assemblage to natural selection across a common ecotone. Three lizard species, distributed along a dramatic environmental gradient in substrate color, display convergent adaptation of blanched coloration on the gypsum dunes of White Sands National Monument. I investigate the role of gene flow in modulating phenotypic response to selection by quantifying color variation and genetic variation across the ecotone. I find species differences in degree of background matching and in genetic connectivity of populations across the ecotone. Differences among species in phenotypic response to selection scale precisely to levels of genetic isolation. Species with higher levels of gene flow across the ecotone exhibit less dramatic responses to selection. Results also reveal a strong signal of ecologically mediated divergence for White Sands lizards. For all species, phenotypic variation is better explained by habitat similarity than genetic similarity. Convergent evolution of blanched coloration at White Sands clearly reflects the action of strong divergent selection; however, adaptive response appears to be modulated by gene flow and demographic history and can be predicted by divergence-with-gene-flow models.

  16. Basking behavior predicts the evolution of heat tolerance in Australian rainforest lizards.

    Science.gov (United States)

    Muñoz, Martha M; Langham, Gary M; Brandley, Matthew C; Rosauer, Dan F; Williams, Stephen E; Moritz, Craig

    2016-11-01

    There is pressing urgency to understand how tropical ectotherms can behaviorally and physiologically respond to climate warming. We examine how basking behavior and thermal environment interact to influence evolutionary variation in thermal physiology of multiple species of lygosomine rainforest skinks from the Wet Tropics of northeastern Queensland, Australia (AWT). These tropical lizards are behaviorally specialized to exploit canopy or sun, and are distributed across marked thermal clines in the AWT. Using phylogenetic analyses, we demonstrate that physiological parameters are either associated with changes in local thermal habitat or to basking behavior, but not both. Cold tolerance, the optimal sprint speed, and performance breadth are primarily influenced by local thermal environment. Specifically, montane lizards are more cool tolerant, have broader performance breadths, and higher optimum sprinting temperatures than their lowland counterparts. Heat tolerance, in contrast, is strongly affected by basking behavior: there are two evolutionary optima, with basking species having considerably higher heat tolerance than shade skinks, with no effect of elevation. These distinct responses among traits indicate the multiple selective pressures and constraints that shape the evolution of thermal performance. We discuss how behavior and physiology interact to shape organisms' vulnerability and potential resilience to climate change. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  17. Distribution, Metabolism and Toxic Effects of Beta-Cypermethrin in Lizards (Eremias argus) Following Oral Administration.

    Science.gov (United States)

    Chen, Li; Xu, Peng; Diao, Jinling; Di, Shanshan; Li, Ruiting; Zhou, Zhiqiang

    2016-04-05

    Beta-cypermethrin (BCYP), a synthetic pyrethriod (PYR) pesticide which is a mixture of the alpha- and theta- cypermethrin, have been reported various toxicological profiles to non-target organisms. But little is known about assimilation, accumulation and toxic effects of BCYP in reptiles. The present study firstly elucidated absorption, tissue distribution, excretion of BCYP in Eremias argus . Treated group were administered orally with BCYP 20mg/kg body weight (bw) dissolved in corn oil. Neurotoxicity was observed at 24h after gavage, and the poisoning symptom ameliorated at 72h. The changes of BCYP concentration depended on degradation time and tissues. Lizards had a strong capacity to eliminate BCYP with different tissue distribution. The tissues concentration of BCYP from high to low were intestine, stomach, heart, kidney, blood, lung, liver and brain. Bimodal phenomena were observed in lung, liver and kidney. These results may be due to the activities of enzymes, circadian rhythm, and enterohepatic circulation in lizards. Based on the results of organ coefficient and histopathology analysis in liver, the liver was confirmed as the main target organ. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Comparative ecophysiology of two sympatric lizards. Laying the groundwork for mechanistic distribution models

    Directory of Open Access Journals (Sweden)

    Enrique García-Muñoz

    2013-12-01

    Full Text Available Distribution modelling usually makes inferences correlating species presence and environmental variables but does not take biotic relations into account. Alternative approaches based on a mechanistic understanding of biological processes are now being applied. Regarding lacertid lizards, physiological traits such as preferred body temperature (Tp are well known to correlate with several physiological optima. Much less is known about their water ecology although body temperature and evaporative water loss (Wl may trade-off. Two saxicolous lacertids, Algyroides marchi and Podarcis hispanica ss are sympatric in the Subbetic Mountains (SE Spain were they can be found in syntopy. Previous distribution modelling indicates the first species is associated with mountains, low temperatures; high precipitation and forest cover whereas the second one is more generalistic. Here, we perform two ecophysiological tests with both species: a Tp experiment in thermal gradient and a Wl experiment in sealed chambers. Although both species attained similar body temperatures, A. marchi lost more water and more uniformly in time than P. hispanica ss that displayed an apparent response to dehydration. These results suggest that water loss rather temperature is crucial to explain the distribution patterns of A. marchi in relation to P. hispanica ss, the former risking dehydration in dry areas no matter what temperature is. Ecophysiological traits represent a promising tool to build future mechanistic models for (lacertid lizards. Additionally, the implications for their biogeography and conservation are discussed.

  19. The relevance of morphology for habitat use and locomotion in two species of wall lizards

    Science.gov (United States)

    Gomes, Verónica; Carretero, Miguel A.; Kaliontzopoulou, Antigoni

    2016-01-01

    Understanding if morphological differences between organisms that occupy different environments are associated to differences in functional performance can suggest a functional link between environmental and morphological variation. In this study we examined three components of the ecomorphological paradigm - morphology, locomotor performance and habitat use - using two syntopic wall lizards endemic to the Iberian Peninsula as a case study to establish whether morphological variation is associated with habitat use and determine the potential relevance of locomotor performance for such an association. Differences in habitat use between both lizards matched patterns of morphological variation. Indeed, individuals of Podarcis guadarramae lusitanicus, which are more flattened, used more rocky environments, whereas Podarcis bocagei, which have higher heads, used more vegetation than rocks. These patterns translated into a significant association between morphology and habitat use. Nevertheless, the two species were only differentiated in some of the functional traits quantified, and locomotor performance did not exhibit an association with morphological traits. Our results suggest that the link between morphology and habitat use is mediated by refuge use, rather than locomotor performance, in this system, and advise caution when extrapolating morphology-performance-environment associations across organisms.

  20. Parallel behavioral and morphological divergence in fence lizards on two college campuses

    Science.gov (United States)

    Howe, Stephen; Hynes, Stephanie; Hobbs, Brooke; Handal, Karina

    2018-01-01

    The spread of urban development has dramatically altered natural habitats, modifying community relationships, abiotic factors, and structural features. Animal populations living in these areas must perish, emigrate, or find ways to adjust to a suite of new selective pressures. Those that successfully inhabit the urban environment may make behavioral, physiological, and/or morphological adjustments that represent either evolutionary change and/or phenotypic plasticity. We tested for effects of urbanization on antipredator behavior and associated morphology across an urban-wild gradient in the western fence lizard (Sceloporus occidentalis) in two California counties, Santa Barbara and San Luis Obispo. We compared college campuses in both counties with adjacent rural habitats, conducting field trials that allowed us to characterize antipredator behavior in response to the acute stress of capture. We found notable divergence between campus and rural behavior, with campus lizards more frequently exhibiting diminished escape behavior, including tonic immobility, and lower sprint speeds. Furthermore, campus females had significantly shorter limbs, and while this did not explain variation in sprint speed, those with shorter limbs were more likely to show tonic immobility. We hypothesize that these parallel behavioral and morphological changes on both campuses reflect adjustment to a novel environment involving changes in predation and human presence. PMID:29444102

  1. Clutch frequency affects the offspring size-number trade-off in lizards.

    Directory of Open Access Journals (Sweden)

    Zheng Wang

    2011-01-01

    Full Text Available Studies of lizards have shown that offspring size cannot be altered by manipulating clutch size in species with a high clutch frequency. This raises a question of whether clutch frequency has a key role in influencing the offspring size-number trade-off in lizards.To test the hypothesis that females reproducing more frequently are less likely to tradeoff offspring size against offspring number, we applied the follicle ablation technique to female Eremias argus (Lacertidae from Handan (HD and Gonghe (GH, the two populations that differ in clutch frequency. Follicle ablation resulted in enlargement of egg size in GH females, but not in HD females. GH females switched from producing a larger number of smaller eggs in the first clutch to a smaller number of larger eggs in the second clutch; HD females showed a similar pattern of seasonal shifts in egg size, but kept clutch size constant between the first two clutches. Thus, the egg size-number trade-off was evident in GH females, but not in HD females.As HD females (mean  = 3.1 clutches per year reproduce more frequently than do GH females (mean  = 1.6 clutches per year, our data therefore validate the hypothesis tested. Our data also provide an inference that maximization of maternal fitness could be achieved in females by diverting a large enough, rather than a higher-than-usual, fraction of the available energy to individual offspring in a given reproductive episode.

  2. Phylogenomics of Phrynosomatid Lizards: Conflicting Signals from Sequence Capture versus Restriction Site Associated DNA Sequencing

    Science.gov (United States)

    Leaché, Adam D.; Chavez, Andreas S.; Jones, Leonard N.; Grummer, Jared A.; Gottscho, Andrew D.; Linkem, Charles W.

    2015-01-01

    Sequence capture and restriction site associated DNA sequencing (RADseq) are popular methods for obtaining large numbers of loci for phylogenetic analysis. These methods are typically used to collect data at different evolutionary timescales; sequence capture is primarily used for obtaining conserved loci, whereas RADseq is designed for discovering single nucleotide polymorphisms (SNPs) suitable for population genetic or phylogeographic analyses. Phylogenetic questions that span both “recent” and “deep” timescales could benefit from either type of data, but studies that directly compare the two approaches are lacking. We compared phylogenies estimated from sequence capture and double digest RADseq (ddRADseq) data for North American phrynosomatid lizards, a species-rich and diverse group containing nine genera that began diversifying approximately 55 Ma. Sequence capture resulted in 584 loci that provided a consistent and strong phylogeny using concatenation and species tree inference. However, the phylogeny estimated from the ddRADseq data was sensitive to the bioinformatics steps used for determining homology, detecting paralogs, and filtering missing data. The topological conflicts among the SNP trees were not restricted to any particular timescale, but instead were associated with short internal branches. Species tree analysis of the largest SNP assembly, which also included the most missing data, supported a topology that matched the sequence capture tree. This preferred phylogeny provides strong support for the paraphyly of the earless lizard genera Holbrookia and Cophosaurus, suggesting that the earless morphology either evolved twice or evolved once and was subsequently lost in Callisaurus. PMID:25663487

  3. Biogeography of worm lizards (Amphisbaenia) driven by end-Cretaceous mass extinction.

    Science.gov (United States)

    Longrich, Nicholas R; Vinther, Jakob; Pyron, R Alexander; Pisani, Davide; Gauthier, Jacques A

    2015-05-07

    Worm lizards (Amphisbaenia) are burrowing squamates that live as subterranean predators. Their underground existence should limit dispersal, yet they are widespread throughout the Americas, Europe and Africa. This pattern was traditionally explained by continental drift, but molecular clocks suggest a Cenozoic diversification, long after the break-up of Pangaea, implying dispersal. Here, we describe primitive amphisbaenians from the North American Palaeocene, including the oldest known amphisbaenian, and provide new and older molecular divergence estimates for the clade, showing that worm lizards originated in North America, then radiated and dispersed in the Palaeogene following the Cretaceous-Palaeogene (K-Pg) extinction. This scenario implies at least three trans-oceanic dispersals: from North America to Europe, from North America to Africa and from Africa to South America. Amphisbaenians provide a striking case study in biogeography, suggesting that the role of continental drift in biogeography may be overstated. Instead, these patterns support Darwin and Wallace's hypothesis that the geographical ranges of modern clades result from dispersal, including oceanic rafting. Mass extinctions may facilitate dispersal events by eliminating competitors and predators that would otherwise hinder establishment of dispersing populations, removing biotic barriers to dispersal. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  4. Colour change on different body regions provides thermal and signalling advantages in bearded dragon lizards

    Science.gov (United States)

    Cadena, Viviana; Porter, Warren P.; Kearney, Michael R.

    2016-01-01

    Many terrestrial ectotherms are capable of rapid colour change, yet it is unclear how these animals accommodate the multiple functions of colour, particularly camouflage, communication and thermoregulation, especially when functions require very different colours. Thermal benefits of colour change depend on an animal's absorptance of solar energy in both UV–visible (300–700 nm) and near-infrared (NIR; 700–2600 nm) wavelengths, yet colour research has focused almost exclusively on the former. Here, we show that wild-caught bearded dragon lizards (Pogona vitticeps) exhibit substantial UV–visible and NIR skin reflectance change in response to temperature for dorsal but not ventral (throat and upper chest) body regions. By contrast, lizards showed the greatest temperature-independent colour change on the beard and upper chest during social interactions and as a result of circadian colour change. Biophysical simulations of heat transfer predicted that the maximum temperature-dependent change in dorsal reflectivity could reduce the time taken to reach active body temperature by an average of 22 min per active day, saving 85 h of basking time throughout the activity season. Our results confirm that colour change may serve a thermoregulatory function, and competing thermoregulation and signalling requirements may be met by partitioning colour change to different body regions in different circumstances.

  5. The effects of sex steroid treatments on sexual differentiation in a unisexual lizard, Cnemidophorus uniparens (Teiidae).

    Science.gov (United States)

    Billy, A J; Crews, D

    1986-02-01

    Cnemidophorus uniparens is a parthenogenetic unisexual species of lizard in which each individual develops as a female, making it a unique animal model for the study of sexual differentiation. In one study, administration of exogenous testosterone before and/or after hatching influenced the development of the gonads, the accessory reproductive ducts, the renal sex segment of the mesonephric kidney, and the femoral glands, a secondary sex character. Testosterone treatment also affected the cross-sectional area of the gonad and the proportions of cortical and medullary tissues present in the developing gonad. The oviducts and femoral glands of testosterone-treated individuals were hypertrophied; the collecting tubules of the kidney of these animals contained granules, an androgen-dependent, sexually dimorphic character in squamate reptiles. In another study, testosterone, dihydrotestosterone, or estradiol were administered to C. uniparens embryos. No treatment effects on gonadal development were detected on the day of hatching. However, estradiol, but not testosterone and dihydrotestosterone, stimulated development of the oviducts. Taken together these studies suggest that androgen aromatization may play a role in sexual differentiation in lizards.

  6. Rickettsia Detected in the Reptile Tick Bothriocroton hydrosauri from the Lizard Tiliqua rugosa in South Australia

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    Harriet Whiley

    2016-06-01

    Full Text Available Rickettsiosis is a potentially fatal tick borne disease. It is caused by the obligate intracellular bacteria Rickettsia, which is transferred to humans through salivary excretions of ticks during the biting process. Globally, the incidence of tick-borne diseases is increasing; as such, there is a need for a greater understanding of tick–host interactions to create more informed risk management strategies. Flinders Island spotted fever rickettsioses has been identified throughout Australia (Tasmania, South Australia, Queensland and Torres Strait Islands with possible identifications in Thailand, Sri Lanka and Italy. Flinders Island spotted fever is thought to be spread through tick bites and the reptile tick Bothriocroton hydrosauri has been implicated as a vector in this transmission. This study used qPCR to assay Bothriocroton hydrosauri ticks collected from Tiliqua rugosa (sleepy lizard hosts on mainland South Australia near where spotted fever cases have been identified. We report that, although we discovered Rickettsia in all tick samples, it was not Rickettsia honei. This study is the first to use PCR to positively identify Rickettsia from South Australian Bothriocroton hydrosauri ticks collected from Tiliqua rugosa (sleepy lizard hosts. These findings suggest that B. hydrosauri may be a vector of multiple Rickettsia spp. Also as all 41 tested B. hydrosauri ticks were positive for Rickettsia this indicates an extremely high prevalence within the studied area in South Australia.

  7. Direct fitness correlates and thermal consequences of facultative aggregation in a desert lizard.

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    Alison R Davis Rabosky

    Full Text Available Social aggregation is a common behavioral phenomenon thought to evolve through adaptive benefits to group living. Comparing fitness differences between aggregated and solitary individuals in nature--necessary to infer an evolutionary benefit to living in groups--has proven difficult because communally-living species tend to be obligately social and behaviorally complex. However, these differences and the mechanisms driving them are critical to understanding how solitary individuals transition to group living, as well as how and why nascent social systems change over time. Here we demonstrate that facultative aggregation in a reptile (the Desert Night Lizard, Xantusia vigilis confers direct reproductive success and survival advantages and that thermal benefits of winter huddling disproportionately benefit small juveniles, which can favor delayed dispersal of offspring and the formation of kin groups. Using climate projection models, however, we estimate that future aggregation in night lizards could decline more than 50% due to warmer temperatures. Our results support the theory that transitions to group living arise from direct benefits to social individuals and offer a clear mechanism for the origin of kin groups through juvenile philopatry. The temperature dependence of aggregation in this and other taxa suggests that environmental variation may be a powerful but underappreciated force in the rapid transition between social and solitary behavior.

  8. Toward a Periodic Table of Niches, or Exploring the Lizard Niche Hypervolume.

    Science.gov (United States)

    Pianka, Eric R; Vitt, Laurie J; Pelegrin, Nicolás; Fitzgerald, Daniel B; Winemiller, Kirk O

    2017-11-01

    Widespread niche convergence suggests that species can be organized according to functional trait combinations to create a framework analogous to a periodic table. We compiled ecological data for lizards to examine patterns of global and regional niche diversification, and we used multivariate statistical approaches to develop the beginnings for a periodic table of niches. Data (50+ variables) for five major niche dimensions (habitat, diet, life history, metabolism, defense) were compiled for 134 species of lizards representing 24 of the 38 extant families. Principal coordinates analyses were performed on niche dimensional data sets, and species scores for the first three axes were used as input for a principal components analysis to ordinate species in continuous niche space and for a regression tree analysis to separate species into discrete niche categories. Three-dimensional models facilitate exploration of species positions in relation to major gradients within the niche hypervolume. The first gradient loads on body size, foraging mode, and clutch size. The second was influenced by metabolism and terrestrial versus arboreal microhabitat. The third was influenced by activity time, life history, and diet. Natural dichotomies are activity time, foraging mode, parity mode, and habitat. Regression tree analysis identified 103 cases of extreme niche conservatism within clades and 100 convergences between clades. Extending this approach to other taxa should lead to a wider understanding of niche evolution.

  9. High prevalence of Salmonella in tegu lizards (Tupinambis merianae), and susceptibility of the serotypes to antibiotics.

    Science.gov (United States)

    Maciel, B M; Argôlo Filho, R C; Nogueira, S S C; Dias, J C T; Rezende, R P

    2010-12-01

    Species of tegu (Tupinambis) are the largest lizards in South America. Large numbers of these lizards are hunted; there is a vigorous trade in their skins and the meat is consumed by rural and native peoples. The animals are also bred in captivity, an economic activity for rural populations which can help in the animals' conservation. Faecal samples from 30 captive-born tegus were analysed for the presence of Salmonella in two separate samplings. In the first analysis, samples from 26 animals (87%) yielded Salmonella enterica of which 23% were of Rubislaw serotype; 20% Carrau and Agona serotypes; 7% Infantis and Saint-Paul serotypes; 3% Panama and Brandenburg serotypes; 10% were S. enterica subsp. enterica and 7% were rough form. In the second analysis, four tegus (13%) which had been negative in the first sampling were positive, thus, 100% of the animals studied carried the bacterium. Antibiotic susceptibility showed resistance to sulfonamide in 82% of the isolates, streptomycin in 64%, tetracycline in 6% and Chloramphenicol in 20%. Two animals carried strains of the same serotype with different patterns of antibiotic susceptibility. Although it is well known that reptiles are a significant source of Salmonella, to our knowledge, its prevalence in tegu has not been studied previously.

  10. Upper airway CO2 receptors in tegu lizards: localization and ventilatory sensitivity.

    Science.gov (United States)

    Coates, E L; Ballam, G O

    1987-01-01

    1. Tidal volume, end-tidal CO2, and ventilatory frequency in Tupinambis nigropunctatus were measured in response to CO2 (1-4%) delivered to either the mouth or nares. Additionally, the sensitivity of the ventilatory response to nasal CO2 was evaluated at CO2 concentrations less than 1%. The ventilatory parameters were also measured in response to CO2 (1-4%) delivered to the nares after the olfactory peduncle was transected. 2. It was found that (0.4-4%) nasal CO2 depressed ventilatory frequency by 9% to 83% respectively, while tidal volume was not significantly altered. CO2 (1-4%) delivered to the mouth produced no apparent changes in any of the ventilatory parameters. Following transection of the olfactory peduncle, nasal CO2 was ineffective in producing any change in ventilatory frequency or depth. 3. These findings indicate that CO2-sensitive receptors are located in either the nasal or vomeronasal membranes of tegu lizards and that the olfactory peduncle must be intact for these receptors to affect ventilatory changes in response to elevated CO2 concentrations. The receptors are capable of mediating a ventilatory response to CO2 concentrations lower than those found in either expired air or in confined spaces such as occupied burrows. 4. The discrepancies in the ventilatory responses of lizards and snakes to inspired CO2 reported in past experiments may be partially explained by the presence of nasal or vomeronasal CO2-sensitive receptors.

  11. Conservatism of lizard thermal tolerances and body temperatures across evolutionary history and geography.

    Science.gov (United States)

    Grigg, Joseph W; Buckley, Lauren B

    2013-04-23

    Species may exhibit similar thermal tolerances via either common ancestry or environmental filtering and local adaptation, if the species inhabit similar environments. We ask whether upper and lower thermal limits (critical thermal maxima and minima) and body temperatures are more strongly conserved across evolutionary history or geography for lizard populations distributed globally. We find that critical thermal maxima are highly conserved with location accounting for a higher proportion of the variation than phylogeny. Notably, thermal tolerance breadth is conserved across the phylogeny despite critical thermal minima showing little niche conservatism. Body temperatures observed during activity in the field show the greatest degree of conservatism, with phylogeny accounting for most of the variation. This suggests that propensities for thermoregulatory behaviour, which can buffer body temperatures from environmental variation, are similar within lineages. Phylogeny and geography constrain thermal tolerances similarly within continents, but variably within clades. Conservatism of thermal tolerances across lineages suggests that the potential for local adaptation to alleviate the impacts of climate change on lizards may be limited.

  12. Developmental and adult-specific processes contribute to de novo neuromuscular regeneration in the lizard tail.

    Science.gov (United States)

    Tokuyama, Minami A; Xu, Cindy; Fisher, Rebecca E; Wilson-Rawls, Jeanne; Kusumi, Kenro; Newbern, Jason M

    2018-01-15

    Peripheral nerves exhibit robust regenerative capabilities in response to selective injury among amniotes, but the regeneration of entire muscle groups following volumetric muscle loss is limited in birds and mammals. In contrast, lizards possess the remarkable ability to regenerate extensive de novo muscle after tail loss. However, the mechanisms underlying reformation of the entire neuromuscular system in the regenerating lizard tail are not completely understood. We have tested whether the regeneration of the peripheral nerve and neuromuscular junctions (NMJs) recapitulate processes observed during normal neuromuscular development in the green anole, Anolis carolinensis. Our data confirm robust axonal outgrowth during early stages of tail regeneration and subsequent NMJ formation within weeks of autotomy. Interestingly, NMJs are overproduced as evidenced by a persistent increase in NMJ density 120 and 250 days post autotomy (DPA). Substantial Myelin Basic Protein (MBP) expression could also be detected along regenerating nerves indicating that the ability of Schwann cells to myelinate newly formed axons remained intact. Overall, our data suggest that the mechanism of de novo nerve and NMJ reformation parallel, in part, those observed during neuromuscular development. However, the prolonged increase in NMJ number and aberrant muscle differentiation hint at processes specific to the adult response. An examination of the coordinated exchange between peripheral nerves, Schwann cells, and newly synthesized muscle of the regenerating neuromuscular system may assist in the identification of candidate molecules that promote neuromuscular recovery in organisms incapable of a robust regenerative response. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Color Change for Thermoregulation versus Camouflage in Free-Ranging Lizards.

    Science.gov (United States)

    Smith, Kathleen R; Cadena, Viviana; Endler, John A; Kearney, Michael R; Porter, Warren P; Stuart-Fox, Devi

    2016-12-01

    Animal coloration has multiple functions including thermoregulation, camouflage, and social signaling, and the requirements of each function may sometimes conflict. Many terrestrial ectotherms accommodate the multiple functions of color through color change. However, the relative importance of these functions and how color-changing species accommodate them when they do conflict are poorly understood because we lack data on color change in the wild. Here, we show that the color of individual radio-tracked bearded dragon lizards, Pogona vitticeps, correlates strongly with background color and less strongly, but significantly, with temperature. We found no evidence that individuals simultaneously optimize camouflage and thermoregulation by choosing light backgrounds when hot or dark backgrounds when cold. In laboratory experiments, lizards showed both UV-visible (300-700 nm) and near-infrared (700-2,100 nm) reflectance changes in response to different background and temperature treatments, consistent with camouflage and thermoregulatory functions, respectively, but with no interaction between the two. Overall, our results suggest that wild bearded dragons change color to improve both thermoregulation and camouflage but predominantly adjust for camouflage, suggesting that compromising camouflage may entail a greater potential immediate survival cost.

  14. A new miniaturized lizard from the late Eocene of France and Spain.

    Science.gov (United States)

    Bolet, Arnau; Augé, Marc

    2014-03-01

    We report here a new lizard genus and species shared by two late Eocene localities situated at both versants of the present Pyrenees (South-Western Europe), one located in France (Escamps, MP19), and the other in Catalonia, Spain (Sossís, MP17a). The recovered specimens are remarkable because of their small size and peculiar morphology. Features of the dentary are interpreted as adaptations to a fossorial or semi-fossorial lifestyle, although such modifications obscure the exact phylogenetic relationships of the new taxon. We suggest that it might represent a further example of scincoid lizard that independently achieved adaptations for burrowing or surface-dwelling. This taxon reinforces the hypotheses that link the Southern Pyrenean assemblages to those from France rather than to those of the rest of the Iberian Peninsula, which are supposed to be somehow isolated and endemic to a certain degree during the middle and late Eocene, forming part of the so-called Western Iberian Bioprovince. Copyright © 2014 Wiley Periodicals, Inc.

  15. Genetic restoration in the eastern collared lizard under prescribed woodland burning.

    Science.gov (United States)

    Neuwald, Jennifer L; Templeton, Alan R

    2013-07-01

    Eastern collared lizards of the Ozarks live in glades--open, rocky habitats embedded in a woodland matrix. Past fire suppression had made the woodlands a barrier to dispersal, leading to habitat destruction, fragmentation and local extinction. Reintroduced populations of lizards were subjected to 10 years of habitat fragmentation under continued fire suppression followed by twelve years of landscape restoration with prescribed burns. Prior to prescribed burning, genetic diversity decreased within glades and differentiation increased among glades. With woodland burning, genetic diversity within glades first decreased during an expanding colonization phase, but then increased as a dynamically stable metapopulation was established. Population differentiation among glades also stabilized in the metapopulation under weak isolation-by-distance. This study is one of the first to examine the genetic changes in a species of conservation concern throughout all the stages of decline and recovery and shows the importance of landscape-level restoration for maintaining the genetic integrity of populations. This study also demonstrates how mark-recapture and genetic data together can yield detailed insight into metapopulation dynamics that would be impossible from just one type of data alone. © 2013 John Wiley & Sons Ltd.

  16. Two new Liolaemus lizards from the Andean highlands of Southern Chile (Squamata, Iguania, Liolaemidae)

    Science.gov (United States)

    Troncoso-Palacios, Jaime; Diaz, Hugo A.; Puas, German I.; Riveros-Riffo, Edvin; Elorza, Alvaro A.

    2016-01-01

    Abstract Liolaemus is a diverse genus of lizards, subdivided into two subgenera: Liolaemus (sensu stricto) and Eulaemus, distributed mainly in Chile and Argentina. The Liolaemus elongatus-kriegi complex is the most diverse group within Liolaemus (sensu stricto), especially the species closely related to Liolaemus elongatus, which form a clade currently comprising nine species. Several Chilean species of this group have been recently described, mainly from volcanoes and poorly explored mountains. Here molecular and morphological evidence are provided for a new species of the Liolaemus elongatus clade, which is characterized by its small size and lack of dorsal pattern, unusual features for the species of this group of lizards. Additionally, the lack of precloacal pores in males of Liolaemus (sensu stricto) is a trait found in few species, which do not constitute a monophyletic group. A second new southern Chilean species is also described, without precloacal pores and supported by molecular phylogenetics to be related to Liolaemus villaricensis. Both new species were found in the same locality, near a lake located in a pre-Andean zone with Araucaria and Nothofagus forest. The two species are dedicated to prominent Lonkos (tribal chiefs) of the Mapuche and Pehuenche people: Janequeo and Leftraru. Additionally, the phylogenetic results suggest that Liolaemus lonquimayensis is a synonym of Liolaemus elongatus. PMID:27920609

  17. Evaluation of palatability, protein and energi consumtion of adult lizard (Mabouya multifasciata by feed them of with many diet variations

    Directory of Open Access Journals (Sweden)

    RONI RIDWAN

    2001-01-01

    Full Text Available Lizard (Mabouya multifasciata, one of natural resources that spreads almost all Indonesian islands. The animals can potentially be used as a source of protein and medicine as well as a pet. The objectives of the research were therefore to investigate the preference of certain kind of diet, measure the protein and energy consumption, and also to observe the weight gain of the lizard. Seventy two lizards consisting of 36 females that each having weight of 29.7 + 2.6 grams and 36 male that having weight of 30.0 + 2.9 grams were used in this study. These lizards were captured from their wild nature around Bogor, Ciamis, Sumedang and Cianjur of West Java. Block experimental design was used, with 4 diet treatments and two grouping based on sex, (male and female. The diets were crickets, mealworm, red ant larva and artificial diet. Each tree lizards was put on 0.30m x 0.30m x 0.50m nets made from glass. Diets were given 3% dry matter of lizard body weight and water has given ad libitum. Parameter measured was dry matter consumption, protein consumption, energy consumption and body weight gain. ANOVA used for the data analysis, followed with Duncan range-test. The result showed that dry matter consumption of crickets, red ant larva and artificial diet was significantly (P<0.01 higher than mealworms. Consumption of crickets crude-protein was significantly (P<0.01 higher than mealworms, red ant larva and artificial diet. Mealworm crude-protein consumption was significantly (P<0.01 lower compared with both red ant larva and artificial diet. Crickets and red ant larva showed higher affect (P<0.01 on body weight gain than artificial diet. However, there were no significant effect of all diet on consumption, brute energy and relatively metabolic energy. Grouping based on sex also did not show any significant affect to all parameters observed. It can be concluded that lizards prefer eating crickets, red ant larva and diet than mealworms.

  18. Spatial Variation and Survival of Salmonella enterica Subspecies in a Population of Australian Sleepy Lizards (Tiliqua rugosa).

    Science.gov (United States)

    Parsons, Sandra K; Bull, C Michael; Gordon, David M

    2015-09-01

    The life cycles of many enteric bacterial species require a transition between two very distinct environments. Their primary habitat is the gastrointestinal tract of the host, while their secondary habitat, during transmission from one host to another, consists of environments external to the host, such as soil, water, and sediments. Consequently, both host and environmental factors shape the genetic structure of enteric bacterial populations. This study examined the distribution of four Salmonella enterica subspecies in a population of sleepy lizards, Tiliqua rugosa, in a semiarid region of South Australia. The lizards living within the 1,920-m by 720-m study site were radio tracked, and their enteric bacteria were sampled at regular intervals throughout their active seasons in the years 2001, 2002, and 2006. Four of the six subspecies of S. enterica were present in this population and were nonrandomly distributed among the lizards. In particular, S. enterica subsp. diarizonae was restricted to lizards living in the most shaded parts of the study site with an overstorey of Casuarina trees. Experiments undertaken to investigate the survival of S. enterica cells under seminatural conditions revealed that cell survival decreased with increased exposure to elevated temperatures and UV light. Among the three S. enterica subspecies tested, S. enterica subsp. diarizonae consistently had an average expected life span that was shorter than that observed for the other two subspecies. There was no indication in the data that there was any competitive dominance hierarchy among the S. enterica subspecies within individual hosts. Thus, the nonrandom distribution of S. enterica subspecies in this population of lizards appears to be driven by their different survival characteristics in the external environment. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  19. Interpopulational Variations in Sexual Chemical Signals of Iberian Wall Lizards May Allow Maximizing Signal Efficiency under Different Climatic Conditions.

    Science.gov (United States)

    Martín, José; Ortega, Jesús; López, Pilar

    2015-01-01

    Sexual signals used in intraspecific communication are expected to evolve to maximize efficacy under a given climatic condition. Thus, chemical secretions of lizards might evolve in the evolutionary time to ensure that signals are perfectly tuned to local humidity and temperature conditions affecting their volatility and therefore their persistence and transmission through the environment. We tested experimentally whether interpopulational altitudinal differences in chemical composition of femoral gland secretions of male Iberian wall lizards (Podarcis hispanicus) have evolved to maximize efficacy of chemical signals in different environmental conditions. Chemical analyses first showed that the characteristics of chemical signals of male lizards differed between two populations inhabiting environments with different climatic conditions in spite of the fact that these two populations are closely related genetically. We also examined experimentally whether the temporal attenuation of the chemical stimuli depended on simulated climatic conditions. Thus, we used tongue-flick essays to test whether female lizards were able to detect male scent marks maintained under different conditions of temperature and humidity by chemosensory cues alone. Chemosensory tests showed that chemical signals of males had a lower efficacy (i.e. detectability and persistence) when temperature and dryness increase, but that these effects were more detrimental for signals of the highest elevation population, which occupies naturally colder and more humid environments. We suggest that the abiotic environment may cause a selective pressure on the form and expression of sexual chemical signals. Therefore, interpopulational differences in chemical profiles of femoral secretions of male P. hispanicus lizards may reflect adaptation to maximize the efficacy of the chemical signal in different climates.

  20. Pollination and seed dispersal of Melocactus ernestii Vaupel subsp. ernestii (Cactaceae) by lizards: an example of double mutualism.

    Science.gov (United States)

    Gomes, V G N; Quirino, Z G M; Machado, I C

    2014-03-01

    Recent studies show that the mutualistic role of lizards as pollinators and seed dispersers has been underestimated, with several ecological factors promoting such plant-animal interactions, especially on oceanic islands. Our aim is to provide a quantitative assessment of pollination and seed dispersal mutualisms with lizards in continental xeric habitats. We carried out focal observations of natural populations of Melocactus ernestii (Cactaceae) in the Caatinga, a Brazilian semiarid ecosystem, in order to record the frequency of visits, kind of resource searched and behaviour of visiting animals towards flowers and/or fruits. We made a new record of the lizard Tropidurus semitaeniatus foraging on flowers and fruits of M. ernestii. During the search for nectar, T. semitaeniatus contacted the reproductive structures of the flowers and transported pollen attached to its snout. Nectar production started at 14:00 h, with an average volume of 24.4 μl and an average concentration of solutes of 33%. Approximately 80% of the seeds of M. ernestii found in the faeces of T. semitaeniatus germinated under natural conditions. The roles of T. semitaeniatus as pollinator and seed disperser for M. ernestii show a clear relationship of double mutualism between two endemic species, which may result from the environmental conditions to which both species are subject. Seasonality, low water availability and arthropod supply in the environment, high local lizard densities, continuous nectar production by the flower and fruits with juicy pulp may be influencing the visits and, consequently, pollination and seed dispersal by lizards in this cactus. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

  1. Detection and Analysis of Six Lizard Adenoviruses by Consensus Primer PCR Provides Further Evidence of a Reptilian Origin for the Atadenoviruses

    OpenAIRE

    Wellehan, James F. X.; Johnson, April J.; Harrach, Balázs; Benkö, Mária; Pessier, Allan P.; Johnson, Calvin M.; Garner, Michael M.; Childress, April; Jacobson, Elliott R.

    2004-01-01

    A consensus nested-PCR method was designed for investigation of the DNA polymerase gene of adenoviruses. Gene fragments were amplified and sequenced from six novel adenoviruses from seven lizard species, including four species from which adenoviruses had not previously been reported. Host species included Gila monster, leopard gecko, fat-tail gecko, blue-tongued skink, Tokay gecko, bearded dragon, and mountain chameleon. This is the first sequence information from lizard adenoviruses. Phyloge...

  2. Oxidant trade-offs in immunity: an experimental test in a lizard.

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    Michael Tobler

    Full Text Available Immune system functioning and maintenance entails costs which may limit investment into other processes such as reproduction. Yet, the proximate mechanisms and 'currencies' mediating the costs of immune responses remain elusive. In vertebrates, up-regulation of the innate immune system is associated with rapid phagocytic production of pro-oxidant molecules (so-called 'oxidative burst' responses. Oxidative burst responses are intended to eliminate pathogens but may also constitute an immunopathological risk as they may induce oxidative damage to self cells. To minimize the risk of infection and, at the same time, damage to self, oxidative burst activity must be carefully balanced. The current levels of pro- and antioxidants (i.e. the individual oxidative state is likely to be a critical factor affecting this balance, but this has not yet been evaluated. Here, we perform an experiment on wild-caught painted dragon lizards (Ctenophorus pictus to examine how the strength of immune-stimulated oxidative burst responses of phagocytes in whole blood relates to individual oxidative status under control conditions and during an in vivo immune challenge with Escherichia coli lipopolysaccharide (LPS. Under control conditions, oxidative burst responses were not predicted by the oxidative status of the lizards. LPS-injected individuals showed a strong increase in pro-oxidant levels and a strong decrease in antioxidant levels compared to control individuals demonstrating a shift in the pro-/antioxidant balance. Oxidative burst responses in LPS-injected lizards were positively related to post-challenge extracellular pro-oxidants (reflecting the level of cell activation and negatively related to pre-challenge levels of mitochondrial superoxide (suggesting an immunoregulatory effect of this pro-oxidant. LPS-challenged males had higher oxidative burst responses than females, and in females oxidative burst responses seemed to depend more strongly on antioxidant

  3. Which came first: The lizard or the egg? Robustness in phylogenetic reconstruction of ancestral states.

    Science.gov (United States)

    Wright, April M; Lyons, Kathleen M; Brandley, Matthew C; Hillis, David M

    2015-09-01

    Changes in parity mode between egg-laying (oviparity) and live-bearing (viviparity) have occurred repeatedly throughout vertebrate evolution. Oviparity is the ancestral amniote state, and viviparity has evolved many times independently within amniotes (especially in lizards and snakes), with possibly a few reversions to oviparity. In amniotes, the shelled egg is considered a complex structure that is unlikely to re-evolve if lost (i.e., it is an example of Dollo's Principle). However, a recent ancestral state reconstruction analysis concluded that viviparity was the ancestral state of squamate reptiles (lizards and snakes), and that oviparity re-evolved from viviparity many times throughout the evolutionary history of squamates. Here, we re-evaluate support for this provocative conclusion by testing the sensitivity of the analysis to model assumptions and estimates of squamate phylogeny. We found that the models and methods used for parity mode reconstruction are highly sensitive to the specific estimate of phylogeny used, and that the point estimate of phylogeny used to suggest that viviparity is the root state of the squamate tree is far from an optimal phylogenetic solution. The ancestral state reconstructions are also highly sensitive to model choice and specific values of model parameters. A method that is designed to account for biases in taxon sampling actually accentuates, rather than lessens, those biases with respect to ancestral state reconstructions. In contrast to recent conclusions from the same data set, we find that ancestral state reconstruction analyses provide highly equivocal support for the number and direction of transitions between oviparity and viviparity in squamates. Moreover, the reconstructions of ancestral parity state are highly dependent on the assumptions of each model. We conclude that the common ancestor of squamates was oviparous, and subsequent evolutionary transitions to viviparity were common, but reversals to oviparity were

  4. Redescription of Tijubina pontei, an Early Cretaceous lizard (Reptilia; Squamata from the Crato Formation of Brazil

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    Tiago R. Simões

    2012-03-01

    Full Text Available The record of Gondwanan Mesozoic lizards is very poor. Among the few species described for this region there is Tijubina pontei, an Early Cretaceous lizard from the Crato Formation (late Aptian of northeast Brazil. Its description is very brief and lacks most of its diagnostic characters and clear delimitation from other lizard species. Here, a full redescription of the holotype is provided. T. pontei is demonstrated to be a valid species and a new diagnosis is provided with reference to Olindalacerta brasiliensis, a contemporary species of the Crato Formation. It lacks the posteroventral and posterodorsal processes of the dentary; the tibial/fibular length equals the femoral length and its posterior dentary teeth are robust, cylindrically based, unsculptured and bear no cuspids. The systematic position of T. pontei still needs further clarification, but preliminary analyses indicate that it lies in a rather basal position among the Squamata, similarly to O. brasiliensis.O registro de lagartos do Mesozóico de Gondwana é extremamente limitado. Dentre as poucas espécies descritas para esta região está Tijubina pontei, um lagarto do Cretáceo Inferior da Formação Crato (Aptiano superior do nordeste do Brasil. A sua descrição é muito breve e não contém a maioria dos seus caracteres diagnósticos ou uma clara delimitação das outras espécies de lagartos. Neste trabalho, uma redescrição completa do holótipo, é provida. É demonstrado que T. pontei é espécie válida, e uma nova diagnose é provida com referência à Olindalacerta brasiliensis, uma espécie contemporânea da Formação Crato. Ele não possui os processos posteroventral e posterodorsal do dentário; o comprimento tibilar/fibular é relativamente igual ao comprimento do fêmur e os seus dentes posteriores no dentário são robustos, de base cilindrica, sem ornamentações e sem cúspides. Embora a posição sistemática de T. pontei ainda necessite de maiores

  5. Use of Laser Assisted Optical Rotational Cell Analyzer (LoRRca MaxSis in the Diagnosis of RBC Membrane Disorders, Enzyme Defects, and Congenital Dyserythropoietic Anemias: A Monocentric Study on 202 Patients

    Directory of Open Access Journals (Sweden)

    Anna Zaninoni

    2018-04-01

    Full Text Available Chronic hemolytic anemias are a group of heterogeneous diseases mainly due to abnormalities of red cell (RBC membrane and metabolism. The more common RBC membrane disorders, classified on the basis of blood smear morphology, are hereditary spherocytosis (HS, elliptocytosis, and hereditary stomatocytoses (HSt. Among RBC enzymopathies, the most frequent is pyruvate kinase (PK deficiency, followed by glucose-6-phosphate isomerase, pyrimidine 5′ nucleotidase P5′N, and other rare enzymes defects. Because of the rarity and heterogeneity of these diseases, diagnosis may be often challenging despite the availability of a variety of laboratory tests. The ektacytometer laser-assisted optical rotational cell analyser (LoRRca MaxSis, able to assess the RBC deformability in osmotic gradient conditions (Osmoscan analysis, is a useful diagnostic tool for RBC membrane disorders and in particular for the identification of hereditary stomatocytosis. Few data are so far available in other hemolytic anemias. We evaluated the diagnostic power of LoRRca MaxSis in a large series of 140 patients affected by RBC membrane disorders, 37 by enzymopathies, and 16 by congenital diserythropoietic anemia type II. Moreover, nine patients with paroxysmal nocturnal hemoglobinuria (PNH were also investigated. All the hereditary spherocytoses, regardless the biochemical defect, showed altered Osmoscan curves, with a decreased Elongation Index (EI max and right shifted Omin; hereditary elliptocytosis (HE displayed a trapezoidal curve and decreased EImax. Dehydrated hereditary stomatocytosis (DHSt caused by PIEZO1 mutations was characterized by left-shifted curve, whereas KCNN4 mutations were associated with a normal curve. Congenital diserythropoietic anemia type II and RBC enzymopathies had Osmoscan curve within the normal range except for glucosephosphate isomerase (GPI deficient cases who displayed an enlarged curve associated with significantly increased Ohyper, offering a

  6. Metabolic characteristics and response to high altitude in Phrynocephalus erythrurus (Lacertilia: Agamidae, a lizard dwell at altitudes higher than any other living lizards in the world.

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    Xiaolong Tang

    Full Text Available Metabolic response to high altitude remains poorly explored in reptiles. In the present study, the metabolic characteristics of Phrynocephaluserythrurus (Lacertilia: Agamidae, which inhabits high altitudes (4500 m and Phrynocephalusprzewalskii (Lacertilia: Agamidae, which inhabits low altitudes, were analysed to explore the metabolic regulatory strategies for lizards living at high-altitude environments. The results indicated that the mitochondrial respiratory rates of P. erythrurus were significantly lower than those of P. przewalskii, and that proton leak accounts for 74~79% of state 4 and 7~8% of state3 in P. erythrurus vs. 43~48% of state 4 and 24~26% of state3 in P. przewalskii. Lactate dehydrogenase (LDH activity in P. erythrurus was lower than in P. przewalskii, indicating that at high altitude the former does not, relatively, have a greater reliance on anaerobic metabolism. A higher activity related to β-hydroxyacyl coenzyme A dehydrogenase (HOAD and the HOAD/citrate synthase (CS ratio suggested there was a possible higher utilization of fat in P. erythrurus. The lower expression of PGC-1α and PPAR-γ in P. erythrurus suggested their expression was not influenced by cold and low PO2 at high altitude. These distinct characteristics of P. erythrurus are considered to be necessary strategies in metabolic regulation for living at high altitude and may effectively compensate for the negative influence of cold and low PO2.

  7. Identification of the linkage group of the Z sex chromosomes of the sand lizard (Lacerta agilis, Lacertidae) and elucidation of karyotype evolution in lacertid lizards.

    Science.gov (United States)

    Srikulnath, Kornsorn; Matsubara, Kazumi; Uno, Yoshinobu; Nishida, Chizuko; Olsson, Mats; Matsuda, Yoichi

    2014-12-01

    The sand lizard (Lacerta agilis, Lacertidae) has a chromosome number of 2n = 38, with 17 pairs of acrocentric chromosomes, one pair of microchromosomes, a large acrocentric Z chromosome, and a micro-W chromosome. To investigate the process of karyotype evolution in L. agilis, we performed chromosome banding and fluorescent in situ hybridization for gene mapping and constructed a cytogenetic map with 86 functional genes. Chromosome banding revealed that the Z chromosome is the fifth largest chromosome. The cytogenetic map revealed homology of the L. agilis Z chromosome with chicken chromosomes 6 and 9. Comparison of the L. agilis cytogenetic map with those of four Toxicofera species with many microchromosomes (Elaphe quadrivirgata, Varanus salvator macromaculatus, Leiolepis reevesii rubritaeniata, and Anolis carolinensis) showed highly conserved linkage homology of L. agilis chromosomes (LAG) 1, 2, 3, 4, 5(Z), 7, 8, 9, and 10 with macrochromosomes and/or macrochromosome segments of the four Toxicofera species. Most of the genes located on the microchromosomes of Toxicofera were localized to LAG6, small acrocentric chromosomes (LAG11-18), and a microchromosome (LAG19) in L. agilis. These results suggest that the L. agilis karyotype resulted from frequent fusions of microchromosomes, which occurred in the ancestral karyotype of Toxicofera and led to the disappearance of microchromosomes and the appearance of many small macrochromosomes.

  8. Escape by the Balearic Lizard (Podarcis lilfordi is affected by elevation of an approaching predator, but not by some other potential predation risk factors

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    William E. Cooper

    2011-12-01

    Full Text Available Many predation risk factors to affect escape behavior by lizards, but effects of some potential risk factors are unknown or are variable among species. We studied effects of several risk factors on escape responses by the Balearic lizard (Podarcis lilfordi, Lacertidae on escape responses. Escape was elicited by an approaching experimenter who recorded flight initiation distance (predator-prey distance when escape begins and distance fled. When an experimenter approached from above (upslope, flight initiation distance and distance fled were longer than when the experimenter approached from below. This novel effect suggests that lizards exposed to aerial predation might have been naturally selected to respond rapidly to predators approaching from above or that effects of path inclination of escape ability may differ between predators and prey in a manner requiring a larger margin of safety during approaches from above than below. Although sex differences in aspects of escape occur in some lizards, including lacertids, no sex difference was observed in P. lilfordi. Because vigilance and some other aspects of antipredatory behavior exhibit cortical lateralization, we tested effects of approach from the left and right sides of lizards. As predicted by optimal escape theory, side of approach did not affect flight initiation distance. Because many lizards have color vision and respond to pigmentation of conspecifics in social settings, researchers have often worn only drably colored clothing when simulating predators. This precaution may be unnecessary because flight initiation distance did not differ among investigator shirt colors (red, orange, olive.

  9. Communal nesting under climate change: fitness consequences of higher incubation temperatures for a nocturnal lizard.

    Science.gov (United States)

    Dayananda, Buddhi; Gray, Sarah; Pike, David; Webb, Jonathan K

    2016-07-01

    Communal nesting lizards may be vulnerable to climate warming, particularly if air temperatures regulate nest temperatures. In southeastern Australia, velvet geckos Oedura lesueurii lay eggs communally inside rock crevices. We investigated whether increases in air temperatures could elevate nest temperatures, and if so, how this could influence hatching phenotypes, survival, and population dynamics. In natural nests, maximum daily air temperature influenced mean and maximum daily nest temperatures, implying that nest temperatures will increase under climate warming. To determine whether hotter nests influence hatchling phenotypes, we incubated eggs under two fluctuating temperature regimes to mimic current 'cold' nests (mean = 23.2 °C, range 10-33 °C) and future 'hot' nests (27.0 °C, 14-37 °C). 'Hot' incubation temperatures produced smaller hatchlings than did cold temperature incubation. We released individually marked hatchlings into the wild in 2014 and 2015, and monitored their survival over 10 months. In 2014 and 2015, hot-incubated hatchlings had higher annual mortality (99%, 97%) than cold-incubated (11%, 58%) or wild-born hatchlings (78%, 22%). To determine future trajectories of velvet gecko populations under climate warming, we ran population viability analyses in Vortex and varied annual rates of hatchling mortality within the range 78- 96%. Hatchling mortality strongly influenced the probability of extinction and the mean time to extinction. When hatchling mortality was >86%, populations had a higher probability of extinction (PE: range 0.52- 1.0) with mean times to extinction of 18-44 years. Whether future changes in hatchling survival translate into reduced population viability will depend on the ability of females to modify their nest-site choices. Over the period 1992-2015, females used the same communal nests annually, suggesting that there may be little plasticity in maternal nest-site selection. The impacts of climate change may

  10. Evaluación de la estrategia de rehabilitación de base comunitaria (RBC desde la perspectiva de la comunidad y los equipos locales de rehabilitación

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    Alejandro Guajardo Córdoba

    2015-09-01

    Full Text Available A través de este proyecto de investigación se evalúo, desde la perspectiva de la comunidad y los equipos locales de rehabilitación en Chile, los distintos niveles de intervención de la RBC. Así, el objetivo que guío esta investigación fue evaluar el impacto social percibido y la aceptabilidad social de la estrategia de Rehabilitación de Base Comunitaria (RBC desde la perspectiva de la comunidad y los equipos locales de rehabilitación. El marco metodológico fue definido bajo los parámetros de una investigación cualitativa de carácter descriptivo y transversal. El universo de estudio correspondió a las comunas que contaban con programas de RBC que se desarrollan a nivel nacional como parte de la política nacional de discapacidad y rehabilitación en salud. Los criterios que guiaron el proceso de muestreo fueron los de pertinencia y suficiencia de la información, por lo que  se optó  por un muestreo estructural. El procesamiento de los datos se realizó mediante análisis de contenido semánticamente orientado, siguiendo una estratega intensiva, es decir, se analizó toda la información producida durante la fase de terreno. Los resultados dan cuenta de la RBC como una estrategia  con variadas formas de implementación y desarrollo que se relaciona con la historia local, el perfil de la comunidad, perfil del centro,  perfil de usuarias/ios y las características de vinculación municipal con el programa de rehabilitación. El estudio identifica en la estrategia de RBC tres modelos de acción: biomédico, biopsicosocial y comunitario.

  11. Functional trade-off between strength and thermal capacity of dermal armor: Insights from girdled lizards.

    Science.gov (United States)

    Broeckhoven, Chris; du Plessis, Anton; Hui, Cang

    2017-10-01

    The presence of dermal armor is often unambiguously considered the result of an evolutionary predator-prey arms-race. Recent studies focusing predominantly on osteoderms - mineralized elements embedded in the dermis layer of various extant and extinct vertebrates - have instead proposed that dermal armor might exhibit additional functionalities besides protection. Multiple divergent functionalities could impose conflicting demands on a phenotype, yet, functional trade-offs in dermal armor have rarely been investigated. Here, we use high-resolution micro-computed tomography and voxel-based simulations to test for a trade-off between the strength and thermal capacity of osteoderms using two armored cordylid lizards as model organisms. We demonstrate that high vascularization, associated with improved thermal capacity might limit the strength of osteoderms. These results call for a holistic, cautionary future approach to studies investigating dermal armor, especially those aiming to inspire artificial protective materials. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Oral microbiota of Patagonian lizards of genus Diplolaemus (Leiosauridae: fable to facts

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    Ibargüengoytía, Nora R.

    2004-11-01

    Full Text Available Existe la creencia popular de que los lagartos del género Diplolaemus (Leiosauridae de Patagonia, Argentina, son capaces de conferir mordeduras venenosas que pueden causar inflamación e incluso la muerte de animales de granja o salvajes. No obstante, no existe evidencia de la existencia de glándulas de veneno en estos lagartos. La inflamación y absceso provocado como resultado de las heridas de mordedura podría ser causado por agentes infecciosos. Este es el primer estudio acerca de la microbiota oral de los lagartos del género Diplolaemus de Argentina. Para este trabajo se analizó un espécimen de D. darwini y tres individuos de Diplolaemus "forma alto patagonica". Las muestras de hisopados de boca de los lagartos fueron incubados aeróbica y anaeróbicamente, algunos de ellos fueron subcultivados en agar de sangre ovina al 5% e incubados nuevamente. Todas las colonias representativas observadas fueron subcultivadas para su purificación y sujetas a tests bioquímicos. La bacteria Clostridium perfigrens fue determinada por medio de la técnica de reacción en cadena de la Polimerasa. Se identificaron cuatro especies de bacterias: Staphylococus warneri, Clostridium bifermentans, Clostridium perfringens y Stomatococcus muscilaginosus. Estas especies son conocidas como agentes etiológicos de numerosas infecciones de humanos y animales. Si bien estas bacterias representan sólo un pequeño número de las posibles bacterias aisladas de la cavidad oral de Diplolaemus, están indicando la presencia de patógenos humanos y animales. Lizards of genus Diplolaemus (Leiosauridae from Patagonia, Argentina are believed to have "poisonous" bites that can cause inflammation and death of farm and wild animals. However there is no evidence of poisonous glands in these lizards. It is proposed that the inflammation and abscesses resulting from these bite wounds are caused by infectious agent(s. This is the first study of the oral microbiota of Diplolaemus

  13. Parthenogenesis through the ice ages: A biogeographic analysis of Caucasian rock lizards (genus Darevskia).

    Science.gov (United States)

    Freitas, Susana; Rocha, Sara; Campos, João; Ahmadzadeh, Faraham; Corti, Claudia; Sillero, Neftali; Ilgaz, Çetin; Kumlutaş, Yusuf; Arakelyan, Marine; Harris, D James; Carretero, Miguel A

    2016-09-01

    Darevskia rock lizards include both sexual and parthenogenetic species, mostly distributed in the heterogeneous and ecologically diverse Caucasus. The parthenogenetic species originated via directional hybridogenesis, with only some of the sexual species known to serve as parentals. However, it remains unclear when and where these events happened and how many parental lineages were involved. A multilocus phylogeographic analysis was performed on the parthenogens D. unisexualis, D. bendimahiensis and D. uzzeli, and their putative maternal species D. raddei. Results show the parthenogenetic species all have relatively recent origins, approximately 200-70kyr ago, and at least three hybridization events were involved in their formation. Ecological niche models identify the region where hybridization events leading to the formation of D. unisexualis took place, namely in the northeast of the current distribution. Models also suggest that the sexual D. raddei might have undergone a habitat shift between the Last Interglacial and the Last Glacial Maximum. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Effects of experimental seaweed deposition on lizard and ant predation in an island food web.

    Science.gov (United States)

    Piovia-Scott, Jonah; Spiller, David A; Schoener, Thomas W

    2011-01-28

    The effect of environmental change on ecosystems is mediated by species interactions. Environmental change may remove or add species and shift life-history events, altering which species interact at a given time. However, environmental change may also reconfigure multispecies interactions when both species composition and phenology remain intact. In a Caribbean island system, a major manifestation of environmental change is seaweed deposition, which has been linked to eutrophication, overfishing, and hurricanes. Here, we show in a whole-island field experiment that without seaweed two predators--lizards and ants--had a substantially greater-than-additive effect on herbivory. When seaweed was added to mimic deposition by hurricanes, no interactive predator effect occurred. Thus environmental change can substantially restructure food-web interactions, complicating efforts to predict anthropogenic changes in ecosystem processes.

  15. Lizard karyotype tropidurus hispidus (sauria: tropiduridae) in the east of Venezuela

    International Nuclear Information System (INIS)

    Gonzalez S, Luis Alejandro; Bonilla, Ana; Velasquez, Jenniffer

    2011-01-01

    A cytogenetic study by Giemsa staining in three xerophytic regions (continental, peninsular and insular) in eastern Venezuela, showed a diploid number 2n=36, consisting of 6 pairs of metacentric and submetacentric macrochromosomes and 12 pairs of acrocentric microchromosomes maintained, this feature in males and females in the three populations studied. it was determined that the first pair of macrochromosomes is metacentric and the continental region represents 13% of total relative length (TRL) as the larger chromosome, with respect to the peninsular population with 9.4% and the insular population 7.1%, the latter population containing the smallest chromosomes. Whereas chromosomal differences and geographic isolation exists, these lizards have a process of vicariant allopatric speciation.

  16. A contibution to the knowledge of the trophic spectrum of three lacertid lizards from Bulgaria

    Directory of Open Access Journals (Sweden)

    Ivelin Mollov

    2013-01-01

    Full Text Available A study on the trophic spectrum of three species of lacertid lizards (Lacerta agilis, Lacerta trilineata and Podarcis muralis was carried out, based on 20 specimens collected in the period 1967-1973 in various localities in Bulgaria. The analyzed data showed that the insects (Insecta are the most numerous and the most frequently met among the alimentary components of the total amount of food of the studied stomachs (except for Lacerta agilis, where spiders are slightly predominating. The non-insect components consisted spiders and isopods. The largest niche breadth was recorded in Lacerta trilineata (8.25, followed by Podarcis muralis (5.20 and Lacerta agilis (3.44. The niche overlap between the three species (pair-wise comparison showed medium values and in our opinion there should not be any serious competition for food resources at the places withsympatric distribution.

  17. How Ecology Could Affect Cerebral Lateralization for Explorative Behaviour in Lizards

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    Beatrice Bonati

    2017-08-01

    Full Text Available As recent studies have shown a left-eye preference during exploration in Podarcis muralis, which could be strictly related to its territoriality, we tested the same behaviour in a similar species, but one living in different habitats and showing a different ecology. In particular, we assessed the preferential turning direction in adults of a non-territorial lizard, Zootoca vivipara, during the exploration of an unknown maze. At the population level, no significant preference emerged, possibly for the lack of the territorial habit and the characteristics of the natural environment. Nevertheless, females turned to the left more frequently than males did. We hypothesize this as a motor bias, possibly due to a necessity for females to be coordinated and fast in moving in the environment, because of their viviparous condition and the resultant reduction of physical performance during pregnant periods, which are likely to increase vulnerability to predators.

  18. Cost of ventilation and effect of digestive state on the ventilatory response of the tegu lizard.

    Science.gov (United States)

    Skovgaard, Nini; Wang, Tobias

    2004-07-12

    We performed simultaneous measurements of ventilation, oxygen uptake and carbon dioxide production in the South American lizard, Tupinambis merianae, equipped with a mask and maintained at 25 degrees C. Ventilation of resting animals was stimulated by progressive exposure to hypercapnia (2, 4 and 6%) or hypoxia (15, 10, 8 and 6%) in inspired gas mixture. This was carried out in both fasting and digesting animals. The ventilatory response to hypercapnia and hypoxia were affected by digestive state, with a more vigorous ventilatory response in digesting animals compared to fasting animals. Hypoxia doubled total ventilation while hypercapnia led to a four-fold increase in total ventilation both accomplished through an increase in tidal volume. Oxygen uptake remained constant during all hypercapnic exposures while there was an increase during hypoxia. Cost of ventilation was estimated to be 17% during hypoxia but less than 1% during hypercapnia. Our data indicate that ventilation can be greatly elevated at a small energetic cost.

  19. Altered energy metabolism in an irradiated population of lizards at the Nevada Test Site

    International Nuclear Information System (INIS)

    Nagy, K.A.; Medica, P.A.

    1985-01-01

    Field metabolic rates (via doubly labeled water), body compartmentalization of energy stores, and energy assimilation efficiencies were measured to assess all avenues of energy utilization in Uta stansburiana living in a low-level γ-irradiated plot in Rock Valley, Nevada. Comparison of energy budgets for radiation-sterilized females with those of nonirradiated control lizards revealed several substantial differences. Sterile females were heavier, mainly because they had extraordinarily large energy (fat) storage depots. Sterile females had much lower rates of energy expenditure via respiration and lower rates of energy intake by feeding. These differences are interpreted as indirect responses to radiation-induced sterility. There is little evidence of direct radiation effects on physiological functions other than reproduction

  20. Three-dimensional sound localisation with a lizard peripheral auditory model

    DEFF Research Database (Denmark)

    Kjær Schmidt, Michael; Shaikh, Danish

    the networks learned a transfer function that translated the three-dimensional non-linear mapping into estimated azimuth and elevation values for the acoustic target. The neural network with two hidden layers as expected performed better than that with only one hidden layer. Our approach assumes that for any...... location of an acoustic target in three dimensions. Our approach utilises a model of the peripheral auditory system of lizards [Christensen-Dalsgaard and Manley 2005] coupled with a multi-layer perceptron neural network. The peripheral auditory model’s response to sound input encodes sound direction...... information in a single plane which by itself is insufficient to localise the acoustic target in three dimensions. A multi-layer perceptron neural network is used to combine two independent responses of the model, corresponding to two rotational movements, into an estimate of the sound direction in terms...