The Experts below are selected from a list of 1119 Experts worldwide ranked by ideXlab platform

Kenneth B. Storey - One of the best experts on this subject based on the ideXlab platform.

  • nrf2 activates antioxidant enzymes in the anoxia tolerant red eared slider turtle Trachemys Scripta Elegans
    2021
    Co-Authors: Sarah A Breedon, Hanane Hadjmoussa, Kenneth B. Storey
    Abstract:

    The freshwater red-eared slider turtle, Trachemys Scripta Elegans, experiences weeks to months of anoxia at the bottom of ice-locked bodies of water in the winter. While this introduces anoxia-reoxygenation cycles similar to the ischemia-reperfusion events that mammals experience, T. s. Elegans does not suffer any apparent tissue damage. To survive prolonged anoxia and prevent cellular damage associated with reactive oxygen species, these turtles have developed numerous adaptions, including highly effective antioxidant defenses. Herein, we examined the subcellular localization and protein expression of nuclear factor erythroid-2-related factor 2 (Nrf2), a central transcription factor responsible for modulating cellular antioxidant responses, that was found to be upregulated and localized to the nucleus in anoxic turtles. Additionally, we examined protein levels of glutathione S-transferases (GSTs) and manganese superoxide dismutase (MnSOD) antioxidant enzymes in anoxic liver, kidney, heart, and skeletal muscle tissues. MnSOD levels were significantly higher in heart and muscle during anoxia, and the four GST isozymes (GSTK1, GSTT1, GSTP1, and GSTM3) were elevated in a tissue-specific manner during anoxia and/or aerobic recovery. Together, these results indicate that Nrf2 is likely involved in activating downstream antioxidant genes in response to anoxic stress. These results provide a possible Nrf2-mediated transcriptional mechanism that supports existing findings of enhanced antioxidant defenses that allow T. s. Elegans to cope with anoxia-reoxygenation cycles, and subsequent oxidative stress.

  • early life intestinal microbiome in Trachemys Scripta Elegans analyzed using 16s rrna sequencing
    2020
    Co-Authors: Qin Peng, Haitao Shi, Kenneth B. Storey, Yahui Chen, Li Ding, Zimiao Zhao, Peiyu Yan, Meiling Hong
    Abstract:

    During the early-life period, the hatchlings of red-eared slider turtles (Trachemys Scripta Elegans) rely on their own post-hatching internal yolk for several days before beginning to feed. The gut microbiome is critical for the adaptation of organisms to new environments, but, to date, how the microbiome taxa are assembled during early life of the turtle is unknown. In this study, the intestinal microbiome of red-eared slider hatchlings (fed on commercial particle food) was systematically analyzed at four different growth stages (0 d, 10 d, 20 d, 30 d) by a high-throughput sequencing approach. Results showed that the dominant phyla were Firmicutes (58.23%) and Proteobacteria (41.42%) at 0-day, Firmicutes (92.94%) at 10-day, Firmicutes (67.08%) and Bacteroidetes (27.17%) at 20-day, and Firmicutes (56.46%), Bacteroidetes (22.55%) and Proteobacteria (20.66%) at 30-day post-hatching. Members of the Bacteroidaceae family were absent in 0-day and 10-day turtles, but dominated in 20-day and 30-day turtles. The abundance of Clostridium also showed the highest value in 10-day turtles. The richness of the intestinal microbiomes was lower at 0-day and 30-day than that at 10-day and 20-day, while the diversity was higher at 10-day and 30-day than that at 0-day and 20-day. The results endowed the turtles with an ability to enhance their tolerance to the environment.

  • regulation of p53 in the red eared slider Trachemys Scripta Elegans in response to salinity stress
    2019
    Co-Authors: Lingyue Liang, Haitao Shi, Kenneth B. Storey, Meiling Hong, Peng Ren, Li Ding
    Abstract:

    The freshwater red-eared slider (Trachemys Scripta Elegans) is found not only in freshwater but also in coastal saline habitats. Hyperosmotic salinity can induce cell damage. p53, regarded as the guardian of the genome, is very important and versatile in response to the change of environment. In this study, the role of p53 in T. s. Elegans under environmental salinity change will be explored. The results indicated that amino acid sequence of p53 showed high similarity to p53 of other species. In addition, the expression of p53 showed differences in various tissues under normal condition. Under salinity stress, the mRNA levels of p53 in the liver increased significantly at 48 h with 15‰ group (15 practical salinity units-exposed group). In the heart, p53 mRNA levels increased at 6 h in 5‰ (5 practical salinity units) and 15‰ groups. Furthermore, the changes of p21 mRNA expression levels in liver and heart were similar to p53, while cyclin D1, cyclin-dependent kinase4 (CDK4) and cyclin-dependent kinase6 (CDK6) showed opposite changes to p53. Moreover, Bax and caspase 3 mRNA expression levels were similar to p53, respectively, while Bcl-2 showed opposite changes. The positive cells of apoptosis were found in the liver of 15‰ at 48 h and 30 d of chronic stress. Taken together, these results indicated that the T. s. Elegans may protect itself by regulating cell cycle progression and apoptosis of damaged cells under salinity stress, which played an important role for T. s. Elegans in salinity adaptation.

  • Translational regulation in the anoxic turtle, Trachemys Scripta Elegans
    2018
    Co-Authors: Kama E. Szereszewski, Kenneth B. Storey
    Abstract:

    The red-eared slider turtle ( Trachemys Scripta Elegans ), has developed remarkable adaptive mechanisms for coping with decreased oxygen availability during winter when lakes and ponds become covered with ice. Strategies for enduring anoxia tolerance include an increase in fermentable fuel reserves to support anaerobic glycolysis, the buffering of end products to minimize acidosis, altered expression in crucial survival genes, and strong metabolic rate suppression to minimize ATP-expensive metabolic processes such as protein synthesis. The mammalian target of rapamycin (mTOR) is at the center of the insulin-signaling pathway that regulates protein translation. The present study analyzed the responses of the mTOR signaling pathway to 5 (5H) or 20 h (20H) of anoxic submergence in liver and skeletal muscle of T. Scripta Elegans with a particular focus on regulatory changes in the phosphorylation states of targets. The data showed that phosphorylation of multiple mTOR targets was suppressed in skeletal muscle, but activated in the liver. Phosphorylated mTOR^Ser2448 showed no change in skeletal muscle but had increased by approximately 4.5-fold in the liver after 20H of anoxia. The phosphorylation states of upstream positive regulators of mTOR (p-PDK-1^Ser241, p-AKT^Ser473, and protein levels of GβL), the relative levels of dephosphorylated active PTEN, as well as phosphorylation state of negative regulators (TSC2^Thr1462, p-PRAS40^Thr246) were generally found to be differentially regulated in skeletal muscle and in liver. Downstream targets of mTOR (p-p70 S6K^Thr389, p-S6^Ser235, PABP, p-4E-BP1^Thr37/46, and p-eIF4E^Ser209) were generally unchanged in skeletal muscle but upregulated in most targets in liver. These findings indicate that protein synthesis is enhanced in the liver and suggests an increase in the synthesis of crucial proteins required for anoxic survival.

  • exploration of low temperature microrna function in an anoxia tolerant vertebrate ectotherm the red eared slider turtle Trachemys Scripta Elegans
    2017
    Co-Authors: Kyle K. Biggar, Kenneth B. Storey
    Abstract:

    As a model for vertebrate long-term survival in oxygen-restricted environments, the red-eared slider turtle (Trachemys Scripta Elegans) can adapt at the biochemical level to survive in oxygen-free (anoxic) cold water (<10°C). This impressive ability is enabled through a coordinated suppression of energy-expensive, non-essential, cell processes. This study explored the anoxia-responsive expression of several microRNA species (miR-1a, -133, -17, -107, -148a, -21, -103, -210, -20a, -365 and -29b) in adult turtles exposed to 5h and 20h anoxia (at 5±1°C). Furthermore, since microRNA target binding is regularly defined only by microRNA-mRNA interactions at 37°C, the possibility of unique low temperature-selective microRNA targeting interactions with mRNA was explored in this ectotherm. Approximately twice as many microRNA-mRNA interactions were predicted at 5°C versus 37°C with particular enrichment of mRNA targets involved in biological processes known to be part of the stress response. Hence, the results suggest that the influence of temperature should be considered for the prediction of microRNA targets (and their follow-up) in poikilothermic animals and that interacting effects of low body temperature and anoxia on microRNA expression could potentially be important to achieve the profound metabolic rate depression that characterizes turtle hibernation underwater during the winter.

Storey K. B.) - One of the best experts on this subject based on the ideXlab platform.

Haitao Shi - One of the best experts on this subject based on the ideXlab platform.

  • ontogenetic development of hearing sensitivity to airborne sound in the female red eared slider Trachemys Scripta Elegans
    2021
    Co-Authors: Jichao Wang, Tongliang Wang, Jianguo Cui, Bo Chen, Haitao Shi
    Abstract:

    Ontogenetic development of hearing sensitivity has been verified in many groups of vertebrates, but not turtles. Turtles exhibit sexual dimorphism in hearing. To examine the development of hearing in female turtles, auditory brainstem responses (ABR) were compared by assessing the hearing-sensitivity bandwidth, ABR threshold, and latency of female Trachemys Scripta Elegans aged 1 week, 1 month, 1 yr, and 5 yr. The hearing-sensitivity bandwidths were 0.2–1.1, 0.2–1.1, 0.2–1.3, and 0.2–1.4 kHz in each age group, respectively. Below 0.6 kHz, the ABR threshold decreased from the 1-week to 1-yr age group, with a significant difference between age groups. No significant difference was detected between the 1- and 5-yr age groups (within a stimulus frequency of 0.2–0.6 kHz). Above 0.6 kHz, ABR thresholds decreased significantly from the 1-yr to 5-yr age group (within a stimulus frequency of 0.7–1.0 kHz). There was no significant difference between the 1-month and 1-yr age groups (within a stimulus frequency of 0.7–1.0 kHz), or between the 1-week and 1-month age groups (within a stimulus frequency of 0.7–1.0 kHz, except 0.9 kHz). Thus, female turtle hearing shows frequency-segmented development.

  • early life intestinal microbiome in Trachemys Scripta Elegans analyzed using 16s rrna sequencing
    2020
    Co-Authors: Qin Peng, Haitao Shi, Kenneth B. Storey, Yahui Chen, Li Ding, Zimiao Zhao, Peiyu Yan, Meiling Hong
    Abstract:

    During the early-life period, the hatchlings of red-eared slider turtles (Trachemys Scripta Elegans) rely on their own post-hatching internal yolk for several days before beginning to feed. The gut microbiome is critical for the adaptation of organisms to new environments, but, to date, how the microbiome taxa are assembled during early life of the turtle is unknown. In this study, the intestinal microbiome of red-eared slider hatchlings (fed on commercial particle food) was systematically analyzed at four different growth stages (0 d, 10 d, 20 d, 30 d) by a high-throughput sequencing approach. Results showed that the dominant phyla were Firmicutes (58.23%) and Proteobacteria (41.42%) at 0-day, Firmicutes (92.94%) at 10-day, Firmicutes (67.08%) and Bacteroidetes (27.17%) at 20-day, and Firmicutes (56.46%), Bacteroidetes (22.55%) and Proteobacteria (20.66%) at 30-day post-hatching. Members of the Bacteroidaceae family were absent in 0-day and 10-day turtles, but dominated in 20-day and 30-day turtles. The abundance of Clostridium also showed the highest value in 10-day turtles. The richness of the intestinal microbiomes was lower at 0-day and 30-day than that at 10-day and 20-day, while the diversity was higher at 10-day and 30-day than that at 0-day and 20-day. The results endowed the turtles with an ability to enhance their tolerance to the environment.

  • Auditory brainstem responses in the red-eared slider Trachemys Scripta Elegans (Testudoformes: Emydidae) reveal sexually dimorphic hearing sensitivity
    2019
    Co-Authors: Tongliang Wang, Xiaofei Zhai, Handong Li, Haitao Shi, Jianguo Cui, Jichao Wang
    Abstract:

    Hearing sensitivity is of general interest from the perspective of understanding the functionality and evolution of vertebrate auditory systems. Sexual dimorphism of auditory systems has been reported in several species of vertebrates, but little is known about this phenomenon in turtles. Some morphological characteristics, such as middle ear and tympanic membrane that influence the hearing sensitivity of animals can result in hearing sexual dimorphism. To examine whether sexual dimorphism in hearing sensitivity occurs in turtles and to compare hearing characteristics with respect to the shape of the tympanic membrane, we measured the hearing sensitivity and tympanum diameter in both sexes of Trachemys Scripta Elegans . The results showed that, with the exception of 0.9 kHz, auditory brainstem response thresholds were significantly lower in females than in males for frequencies in the 0.2–1.1 kHz range, indicating that the hearing of females shows greater sensitivity. No significant differences were detected in the tympanum diameter of both sexes. These results showed that sexually dimorphic hearing sensitivity has evolved in turtles; however, this difference does not appear to be related to differences in the size of the tympanic membrane. The possible origin and function of the sexual differences in auditory characteristic are discussed.

  • developmental plasticity of hearing sensitivity in red eared slider Trachemys Scripta Elegans
    2019
    Co-Authors: Jichao Wang, Tongliang Wang, Haitao Shi, Jianguo Cui, Bo Chen
    Abstract:

    Abstract Developmental plasticity of hearing sensitivity (DPHS) has been verified in some groups of vertebrates. Turtles face a trade-off between terrestrial and aquatic hearing in different acoustic environments throughout ontogeny. However, how chelonian hearing sensitivity changes throughout ontogeny is still unclear. To verify DPHS in turtles, auditory brainstem responses (ABR) were compared using hearing thresholds and latencies in female red-eared slider (Trachemys Scripta Elegans) aged 1 week, 1 month, 1 year, and 5 years, and the results showed hearing sensitivity bandwidths of approximately 200–1100, 200–1100, 200–1300, and 200–1400 Hz, respectively. The lowest threshold sensitivity was approximately 600□Hz. Below 600 Hz, ABR threshold decreased rapidly with increasing age (1 week to 1 year), with significant differences between age groups, but no significant difference between the 1- and 5-year age groups (stimulus frequency, 200–600 Hz). Above 600 Hz, ABR threshold was the lowest in the 5-year age group. These findings show that aging was accompanied by hearing sensitivity changes, suggesting rapid, frequency-segmented development during ontogeny. This variability in hearing sensitivity differs from that reported in other vertebrates, and allows adaptation to acoustically distinct environments throughout ontogeny. Our findings further elucidate the developmental patterns of the vertebrate auditory system.

  • regulation of p53 in the red eared slider Trachemys Scripta Elegans in response to salinity stress
    2019
    Co-Authors: Lingyue Liang, Haitao Shi, Kenneth B. Storey, Meiling Hong, Peng Ren, Li Ding
    Abstract:

    The freshwater red-eared slider (Trachemys Scripta Elegans) is found not only in freshwater but also in coastal saline habitats. Hyperosmotic salinity can induce cell damage. p53, regarded as the guardian of the genome, is very important and versatile in response to the change of environment. In this study, the role of p53 in T. s. Elegans under environmental salinity change will be explored. The results indicated that amino acid sequence of p53 showed high similarity to p53 of other species. In addition, the expression of p53 showed differences in various tissues under normal condition. Under salinity stress, the mRNA levels of p53 in the liver increased significantly at 48 h with 15‰ group (15 practical salinity units-exposed group). In the heart, p53 mRNA levels increased at 6 h in 5‰ (5 practical salinity units) and 15‰ groups. Furthermore, the changes of p21 mRNA expression levels in liver and heart were similar to p53, while cyclin D1, cyclin-dependent kinase4 (CDK4) and cyclin-dependent kinase6 (CDK6) showed opposite changes to p53. Moreover, Bax and caspase 3 mRNA expression levels were similar to p53, respectively, while Bcl-2 showed opposite changes. The positive cells of apoptosis were found in the liver of 15‰ at 48 h and 30 d of chronic stress. Taken together, these results indicated that the T. s. Elegans may protect itself by regulating cell cycle progression and apoptosis of damaged cells under salinity stress, which played an important role for T. s. Elegans in salinity adaptation.

Anastasia Krivoruchko - One of the best experts on this subject based on the ideXlab platform.

  • Response of the JAK-STAT signaling pathway to oxygen deprivation in the red eared slider turtle, Trachemys Scripta Elegans
    2016
    Co-Authors: Saumya Bansal, Kyle K. Biggar, Anastasia Krivoruchko, Kenneth B. Storey
    Abstract:

    The red-eared slider turtle, Trachemys Scripta Elegans, is a model organism commonly used to study the environmental stress of anoxia. It exhibits multiple biochemical adaptations to ensure its survival during the winter months where quantities of oxygen are largely depleted. We proposed that JAK-STAT signaling would display stress responsive regulation to mediate the survival of the red-eared slider turtle, Trachemys Scripta Elegans, during anoxic stress. Importantly, the JAK-STAT signaling pathway is involved in transmitting extracellular signals to the nucleus resulting in the expression of select genes that aid cell survival and growth. Immunoblotting was used to compare the relative phosphorylation levels of JAK proteins, STAT proteins, and two of its inhibitors, SOCS and PIAS, in response to anoxia. A clear activation of the JAK-STAT pathway was observed in the liver tissue while no significant changes were found in the skeletal muscle. To further support our findings we also found an increase in mRNA transcripts of downstream targets of STATs, namely bcl-xL and bcl-2, using PCR analysis in the liver tissues. These findings suggest an important role for the JAK-STAT pathway in exhibiting natural anoxia tolerance by the red-eared slider turtle.

  • anoxia responsive regulation of the foxo transcription factors in freshwater turtles Trachemys Scripta Elegans
    2013
    Co-Authors: Anastasia Krivoruchko, Kenneth B. Storey
    Abstract:

    Abstract Background The forkhead class O (FoxO) transcription factors are important regulators of multiple aspects of cellular metabolism. We hypothesized that activation of these transcription factors could play crucial roles in low oxygen survival in the anoxia-tolerant turtle, Trachemys Scripta Elegans . Methods Two FoxOs, FoxO1 and FoxO3, were examined in turtle tissues in response to 5 and 20 h of anoxic submergence using techniques of RT-PCR, western immunoblotting and DNA-binding assays to assess activation. Transcript levels of FoxO-responsive genes were also quantified using RT-PCR. Results FoxO1 was anoxia-responsive in the liver, with increases in transcript levels, protein levels, nuclear levels and DNA-binding of 1.7–4.8 fold in response to anoxia. Levels of phosphorylated FoxO1 also decreased to 57% of control values in response to 5 h of anoxia, indicating activation. FoxO3 was activated in the heart, kidney and liver in response to anoxia, with nuclear levels increasing by 1.5–3.7 fold and DNA-binding activity increasing by 1.3–2.9 fold. Transcript levels of two FoxO-target genes, p27kip1 and catalase , also rose by 2.4–2.5 fold in the turtle liver under anoxia. Conclusions The results suggest that the FoxO transcription factors are activated in response to anoxia in T. Scripta Elegans , potentially contributing to the regulation of stress resistance and metabolic depression. General significance This study provides the first demonstration of activation of FoxOs in a natural model for vertebrate anoxia tolerance, further improving understanding of how tissues can survive without oxygen.

  • activation of the unfolded protein response during anoxia exposure in the turtle Trachemys Scripta Elegans
    2013
    Co-Authors: Anastasia Krivoruchko, Kenneth B. Storey
    Abstract:

    Red-eared slider turtles, Trachemys Scripta Elegans, can survive for several weeks without oxygen when submerged in cold water. We hypothesized that anaerobiosis is aided by adaptive up-regulation of the unfolded protein response (UPR), a stress-responsive pathway that is activated by accumulation of unfolded proteins in the endoplasmic reticulum (ER) and functions to restore ER homeostasis. RT-PCR, western immunoblotting and DNA-binding assays were used to quantify the responses and/or activation status of UPR-responsive genes and proteins in turtle tissues after animal exposure to 5 or 20 h of anoxic submergence at 4 C. The phosphorylation state of protein kinase-like ER kinase (PERK) (a UPR-regulated kinase) and eukaryotic initiation factor 2 (eIF2α) increased by 1.43-2.50 fold in response to anoxia in turtle heart, kidney, and liver. Activation of the PERK-regulated transcription factor, activating transcription factor 4 (ATF4), during anoxia was documented by elevated atf4 transcripts and total ATF4 protein (1.60-2.43 fold), increased nuclear ATF4 content, and increased DNA-binding activity (1.44-2.32 fold). ATF3 and GADD34 (downstream targets of ATF4) also increased by 1.38-3.32 fold in heart and liver under anoxia, and atf3 transcripts were also elevated in heart. Two characteristic chaperones of the UPR, GRP78, and GRP94, also responded positively to anoxia with strong increases in both the transcript and protein levels. The data demonstrate that the UPR is activated in turtle heart, kidney, and liver in response to anoxia, suggesting that this pathway mediates an integrated stress response to protect tissues during oxygen deprivation. © 2012 Springer Science+Business Media New York.

  • regulation of the heat shock response under anoxia in the turtle Trachemys Scripta Elegans
    2010
    Co-Authors: Anastasia Krivoruchko, Kenneth B. Storey
    Abstract:

    The effects of 20 h of anoxic submergence in cold water and 5 h of aerobic recovery on the heat shock response were analyzed in four organs of the anoxia-tolerant turtle Trachemys Scripta Elegans. Immunoblotting was used to analyze levels of active and inactive forms of the heat shock transcription factor 1 (HSF1), nuclear translocation of HSF1, and the levels of six heat shock proteins (HSPs). PCR was also used to retrieve the turtle HSF1 nucleotide sequence; its deduced amino acid sequence showed 97% identity with chicken HSF1. White skeletal muscle showed a strong fivefold increase in the amount of active HSF1 under anoxic conditions as well as an 80% increase in nuclear localization. This was accompanied by upregulation of five HSPs by 1.8- to 2.9-fold: Hsp25, Hsp40, Hsp70, Hsc70, and Hsp90, the latter two remained elevated after 5 h of aerobic recovery. Kidney and liver showed little change in active HSF1 content during anoxia and recovery, but a significant increase in the nuclear localization of HSF1 during anoxia. This supported enhanced expression of three HSPs in kidney (Hsp40, Hsc70, and Hsp90) and four in liver (Hsp40, Hsp60, Hsp70, Hsc70). Heart displayed a strong increase in active HSF1 during anoxia and recovery (6.6- to 6.8-fold higher than control) and increased nuclear localization but heart HSP levels did not rise. The data demonstrate organ-specific regulation of HSPs during anoxia exposure and aerobic recovery in T. s. Elegans and suggest that the heat shock response is an important aspect of cytoprotection during facultative anaerobiosis, particularly with regard to underwater hibernation of turtles in cold water.

Pierre Joly - One of the best experts on this subject based on the ideXlab platform.

  • impact of the introduction of the red eared slider Trachemys Scripta Elegans on survival rates of the european pond turtle emys orbicularis
    2004
    Co-Authors: Antoine Cadi, Pierre Joly
    Abstract:

    Recent massive imports of slider turtles, (Trachemys Scripta Elegans) into Europe as pets have induced frequent release of these exotic turtles in natural habitats. As a consequence, T. s. Elegans is now widely distributed in most wetlands. Moreover, reproduction of this species has been repeatedly observed in Europe under Mediterranean climatic conditions. In this context, we studied competition between this introduced species and the European pond turtle (Emys orbicularis) under experimental conditions. We compared weight variation and survival between control groups and mixed groups during three years of monitoring. We found both weight loss and high mortality in E. orbicularis of the mixed groups. This study argues for applying a precaution principle and stopping slider turtle introductions in all wetlands in Europe.

  • Successful reproduction of the introduced slider turtle (Trachemys Scripta Elegans) in the South of France
    2004
    Co-Authors: Antoine Cadi, Pierre Joly, Virginie Delmas, Anne-caroline Prévot-julliard, Claude Pieau, Marc Girondot
    Abstract:

    1. Massive importation of slider turtles (Trachemys Scripta Elegans) as a pet in France over the past few decades has been followed by the release of many of these turtles into natural environments. T. Scripta Elegans is now widely distributed in France. 2. This paper reports on the successful reproduction of this species in France, with confirmed production of both sexes from nests incubated in the wild. These results indicate that the turtle T. Scripta Elegans can reproduce in the wild and that its long-term persistence is possible in France. 3. The potential impact of this invasive species in natural ecosystems warrants future study. Meanwhile, authorities are strongly encouraged to educate the public to the potential danger of exotic species introduction for local ecosystems and to capture and remove this species from wetlands in southern Europe. Copyright © 2004 John Wiley & Sons, Ltd.

  • competition for basking places between the endangered european pond turtle emys orbicularis galloitalica and the introduced red eared slider Trachemys Scripta Elegans
    2003
    Co-Authors: Antoine Cadi, Pierre Joly
    Abstract:

    Large numbers of red-eared sliders (Trachemys Scripta Elegans) have been imported into Europe for several years as part of the pet trade. These alien turtles have entered habitats where they intera...

  • competition for basking places between the endangered european pond turtle emys orbicularis galloitalica and the introduced red eared slider Trachemys Scripta Elegans
    2003
    Co-Authors: Antoine Cadi, Pierre Joly
    Abstract:

    Large numbers of red-eared sliders (Trachemys Scripta Elegans) have been imported into Europe for several years as part of the pet trade. These alien turtles have entered habitats where they interact with native pond turtles (Emys orbicularis). We investigated competition for basking sites, because optimal basking sites may be a restricted re - source in the wild. We used experimental ponds to compare basking-place selection between single-species groups and mixed-species groups. Both species preferred basking places in open deep water. In mixed groups the sliders outcompeted the European turtles for preferred basking places. Although competition for basking places is only one component of resource partitioning between these two species, it provided an insight into the relationships between an introduced and a native species. Behavioural asymmetries like those detected in our experiments argue for the caution principle in the animal trade. Resume : La tortue a tempes rouges (Trachemys Scripta Elegans) a ete importee en Europe en grands nombres pendant plusieurs annees. Vendue comme animal de compagnie, elle a ete relâchee massivement dans la nature, en particulier dans des habitats occupes par la cistude d'Europe (Emys orbicularis), espece en danger d'extinction. Dans ce contexte, nous nous interessons a l'eventuelle competition entre les deux especes au moment du bain de soleil, considerant que la disponibilite de cette ressource peut etre limitee en conditions naturelles et que ce comportement revet une impor- tance particuliere pour la thermoregulation de ces ectothermes. Notre etude s'est deroulee en conditions experimentales afin de comparer simultanement les comportements de groupes monospecifiques et de groupes mixtes. Lorsqu'elles sont elevees separement, les deux especes selectionnent le meme type de site de bain de soleil, en eau profonde et a decouvert. Lorsqu'elles sont elevees ensemble, la tortue a tempes rouges domine nettement la cistude d'Europe pour l'utilisation de ces sites preferes de bain de soleil, cette derniere occupant alors des sites moins bien exposes. Meme si les sites de bain de soleil ne sont qu'une composante des niches des deux especes, notre etude illustre les relations de competition que l'on peut craindre entre une espece introduite et une espece indigene. Dans le contexte de la conserva - tion de la biodiversite, les resultats de notre travail plaident pour l'application du principe de precaution et de l'arret des importations de tortues vers l'Europe et d'autres pays. Cadi and Joly 1398