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Gordon R. Ultsch - One of the best experts on this subject based on the ideXlab platform.

  • Emergence Season and Survival in the Nest of Hatchling Turtles in Southcentral New Hampshire
    Northeastern Naturalist, 2007
    Co-Authors: David M. Carroll, Gordon R. Ultsch
    Abstract:

    Abstract We report the season of emergence from the nest of hatchlings of five species of freshwater turtles from a wetlands/stream/lake complex in southcentral New Hampshire from 1988–1994. Only hatchling Chrysemys picta (Painted Turtle) overwintered in the nest and emerged the following spring, although there were some cases of autumn emergence, as well as some nests with hatchlings that emerged in both seasons. In nests monitored over the winter, mortality ranged from 26–100%. Hatchlings of the other four species—Chelydra serpentina (Snapping Turtle), Glyptemys insculpta (Wood Turtle), Clemmys guttata (Spotted Turtle), and Emydoidea blandingii (Blanding's Turtle)—emerged only in autumn.

  • Geographic variation of the physiological response to overwintering in the painted turtle (Chrysemys picta).
    Physiological and biochemical zoology : PBZ, 2004
    Co-Authors: Scott A. Reese, E. Ray Stewart, Carlos E. Crocker, Donald C. Jackson, Gordon R. Ultsch
    Abstract:

    Abstract We compared the physiological responses of latitudinal pairings of painted turtles submerged in normoxic and anoxic water at 3°C: western painted turtles (Chrysemys picta bellii) from Wisconsin (WI) versus southern painted turtles (Chrysemys picta dorsalis) from Louisiana (LA), Arkansas (AR), and Alabama (AL), and eastern painted turtles (Chrysemys picta picta) from Connecticut (CT) versus C. p. picta from Georgia (GA). Turtles in normoxic water accumulated lactate, with C. p. bellii accumulating less than (20 mmol/L) the other groups (44–47 mmol/L), but with relatively minor acid‐base and ionic disturbances. Chrysemys picta bellii had the lowest rate of lactate accumulation over the first 50 d in anoxic water (1.8 mmol/d vs. 2.1 for AR C. p. dorsalis, 2.4 mmol/d for GA C. p. picta, and 2.5 mmol/d for CT C. p. picta after 50 d and 2.6 mmol/d for AL C. p. dorsalis after 46 d). Northern turtles in both groups survive longer in anoxia than their southern counterparts. The diminished viability in C. ...

  • Molecular systematics, phylogeography, and the effects of Pleistocene glaciation in the painted turtle (Chrysemys picta) complex.
    Evolution; international journal of organic evolution, 2003
    Co-Authors: David E. Starkey, H. Bradley Shaffer, Russell L. Burke, Michael R. J. Forstner, John B. Iverson, Fredric J. Janzen, Anders G. J. Rhodin, Gordon R. Ultsch
    Abstract:

    The painted turtle, Chrysemys picta, is currently recognized as a continentally distributed polytypic species, ranging across North America from southern Canada to extreme northern Mexico. We analyzed variation in the rapidly evolving mitochondrial control region (CR) in 241 turtles from 117 localities across this range to examine whether the painted turtle represents a continentally distributed species based on molecular analysis. We found strong support for the novel hypothesis that C. p. dorsalis is the sister group to all remaining Chrysemys, with the remaining Chrysemys falling into a single, extremely wide-ranging and genetically undifferentiated species. Given our goal of an evolu- tionarily accurate taxonomy, we propose that two evolutionary lineages be recognized as species within Chrysemys: C. dorsalis (Agassiz 1857) in the southern Mississippi drainage region, and C. picta (Schneider 1783) from the rest of the range of the genus. Neither molecular nor recent morphological analyses argue for the hybrid origin of C. p. marginata as previously proposed. Within C. picta, we find evidence of at least two independent range expansions into previously glaciated regions of North America, one into New England and the other into the upper Midwest. We further find evidence of a massive extinction/recolonization event across the Great Plains/Rocky Mountain region encompassing over half the continental United States. The timing and extent of this colonization is consistent with a recently proposed regional aridification as the Laurentide ice sheets receded approximately 14,000 years ago, and we tentatively propose this paleoclimatological event as a major factor shaping genetic variation in Chrysemys.

Maria Marques - One of the best experts on this subject based on the ideXlab platform.

  • Effects of fasting and seasonal variations in brain glycogen disposition in the turtle (Chrysemys dorbigni)
    Comparative Biochemistry and Physiology Part A: Physiology, 1994
    Co-Authors: Wania Aparecida Partata, Maria Marques
    Abstract:

    Abstract The effects of fasting and seasonal variations on tissue glycogen content were studied in the turtle Chrysemys dorbigni . The brain, hepatic and muscle glycogen content did not change significantly after 1,15 and 30 days without food, but showed a tendency to decrease. A significant rise in brain glycogen was observed during winter. In contrast, the liver glycogen showed the highest concentrations in the summer. In both tissues the lowest glycogen content was found in the spring. In muscle, this metabolic reserve reached the lowest level in the autumn. It is concluded that the seasonal influence affects differently the glycogen reserves in the brain and in the peripheral tissues of Chrysemys dorbigni .

  • Isolation, purification and primary structure of insulin from the turtle Chrysemys dorbigni.
    General and comparative endocrinology, 1991
    Co-Authors: O. Cascone, Maria Marques, Daniel Turyn, J.m. Dellacha, Vera Lúcia Andrade Machado, N. Vita, C. Cassan, P. Ferrara, Jean-claude Guillemot
    Abstract:

    Insulin A and B chains from pancreas of the turtle Chrysemys dorbigni have been purified to homogeneity, and their primary structures have been determined. The sequence of the A chain is G-I-V-E-Q-C-C-H-N-T-C-S-L-Y-Q-L-E-N-Y-C-N, and that of the B chain is A-A-N-Q-H-L-C-G-S-H-L-V-E-A-L-Y-L-V-C-G-E-R-G-F-F-Y-S-P-K-A. The amino acid sequence of Chrysemys insulin is identical to that of another turtle (Pseudemys scripta), the chicken, and turkey. When compared with alligator insulin, it has three conservative substitutions in the B chain. However, there are seven substitutions when compared with the insulin of the rattlesnake.

Jacqueline D. Litzgus - One of the best experts on this subject based on the ideXlab platform.

  • Sex-biased seasonal capture rates in Painted Turtle ( Chrysemys picta )
    The Canadian Field-Naturalist, 2018
    Co-Authors: Patrick D. Moldowan, Ronald J. Brooks, Jacqueline D. Litzgus
    Abstract:

    We examined captures of Painted Turtle ( Chrysemys picta ) in Algonquin Provincial Park, Ontario, Canada, during the understudied summer–autumn transition period (August–September). The proportion of captured male turtles increased relative to the proportion of females during the late summer and early autumn sampling period, leading to male-biased capture rates in a population with a strongly female-biased sex ratio. We consider explanations for the capture bias in relation to sex-specific activity patterns and briefly discuss the implications of sampling period on the outcome of population structure studies.

  • Diet and Feeding Behaviour of Snapping Turtles ( Chelydra serpentina ) and Midland Painted Turtles ( Chrysemys picta marginata ) in Algonquin Provincial Park, Ontario
    The Canadian Field-Naturalist, 2016
    Co-Authors: Patrick D. Moldowan, Matthew G. Keevil, Peter B. Mills, Ronald J. Brooks, Jacqueline D. Litzgus
    Abstract:

    We compare diet and feeding behaviour of Snapping Turtles ( Chelydra serpentina ) and Midland Painted Turtles ( Chrysemys picta marginata ) in Algonquin Provincial Park, Ontario, Canada. We observed young Chelydra and Chrysemys turtles feeding on insect and amphibian larvae in ephemeral ponds, adult  Chrysemys terrestrially foraging on odonate larvae, and adult Chelydra consuming aquatic vegetation and seeds. These and other observations highlight the importance of seasonally available habitat and food for juvenile turtles. We also discuss the evidence for, and importance of, turtles as seed-dispersal agents for aquatic vegetation. Illustrative video recordings accompany our dietary observations.

  • cold hardiness and evaporative water loss in hatchling turtles
    Physiological and Biochemical Zoology, 2001
    Co-Authors: Jon P. Costanzo, Jacqueline D. Litzgus, John B. Iverson
    Abstract:

    Abstract North American turtles hatch in late summer and spend their first winter either on land or underwater. Adaptations for terrestrial overwintering of hatchlings in northern regions, where winter thermal and hydric regimes are harsh, have not been systematically investigated in many species. We measured intrinsic supercooling capacity, resistance to inoculative freezing, and desiccation resistance in hatchlings of terrestrial and aquatic turtles collected from northern (Terrapene ornata, Chrysemys picta bellii, Kinosternon flavescens, Chelydra serpentina) and southern (Chrysemys picta dorsalis, Trachemys scripta, Sternotherus odoratus, Sternotherus carinatus) locales. Supercooling capacity was estimated from the crystallization temperature of turtles cooled in the absence of external ice nuclei. Mean values ranged from −8.1° to −15.5°C and tended to be lower in terrestrial hibernators. Inoculation resistance was estimated from the crystallization temperature of turtles cooled in a matrix of frozen s...

  • Seasonal changes in physiology and development of cold hardiness in the hatchling painted turtle Chrysemys picta.
    The Journal of Experimental Biology, 2000
    Co-Authors: Jon P. Costanzo, Jacqueline D. Litzgus, John B. Iverson, Richard E. Lee
    Abstract:

    Hatchling painted turtles (Chrysemys picta) commonly hibernate in shallow, natal nests where winter temperatures may fall below -10 degrees C. Although hatchlings are moderately freeze-tolerant, they apparently rely on supercooling to survive exposure to severe cold. We investigated seasonal changes in physiology and in the development of supercooling capacity and resistance to inoculative freezing in hatchling Chrysemys picta exposed in the laboratory to temperatures that decreased from 22 to 4 degrees C over a 5.5 month period. For comparison, we also studied hatchling snapping turtles (Chelydra serpentina), a less cold-hardy species that usually overwinters under water. Although Chrysemys picta and Chelydra serpentina differed in some physiological responses, both species lost dry mass, catabolized lipid and tended to gain body water during the acclimation regimen. Recently hatched, 22 degrees C-acclimated Chrysemys picta supercooled only modestly (mean temperature of crystallization -6.3+/-0.2 degrees C; N=6) and were susceptible to inoculation by ice nuclei in a frozen substratum (mean temperature of crystallization -1.1+/-0.1 degrees C; N=6) (means +/- s.e.m.). In contrast, cold-acclimated turtles exhibited pronounced capacities for supercooling and resistance to inoculative freezing. The development of cold hardiness reflected the elimination or deactivation of potent endogenous ice nuclei and an elevation of blood osmolality that was due primarily to the retention of urea, but was not associated with accumulation of the polyols, sugars or amino acids commonly found in the cryoprotection systems of other animals. Also, Chrysemys picta (and Chelydra serpentina) lacked both antifreeze proteins and ice-nucleating proteins, which are used by some animals to promote supercooling and to initiate freezing at the high temperatures conducive to freezing survival, respectively.

John B. Iverson - One of the best experts on this subject based on the ideXlab platform.

  • Molecular systematics, phylogeography, and the effects of Pleistocene glaciation in the painted turtle (Chrysemys picta) complex.
    Evolution; international journal of organic evolution, 2003
    Co-Authors: David E. Starkey, H. Bradley Shaffer, Russell L. Burke, Michael R. J. Forstner, John B. Iverson, Fredric J. Janzen, Anders G. J. Rhodin, Gordon R. Ultsch
    Abstract:

    The painted turtle, Chrysemys picta, is currently recognized as a continentally distributed polytypic species, ranging across North America from southern Canada to extreme northern Mexico. We analyzed variation in the rapidly evolving mitochondrial control region (CR) in 241 turtles from 117 localities across this range to examine whether the painted turtle represents a continentally distributed species based on molecular analysis. We found strong support for the novel hypothesis that C. p. dorsalis is the sister group to all remaining Chrysemys, with the remaining Chrysemys falling into a single, extremely wide-ranging and genetically undifferentiated species. Given our goal of an evolu- tionarily accurate taxonomy, we propose that two evolutionary lineages be recognized as species within Chrysemys: C. dorsalis (Agassiz 1857) in the southern Mississippi drainage region, and C. picta (Schneider 1783) from the rest of the range of the genus. Neither molecular nor recent morphological analyses argue for the hybrid origin of C. p. marginata as previously proposed. Within C. picta, we find evidence of at least two independent range expansions into previously glaciated regions of North America, one into New England and the other into the upper Midwest. We further find evidence of a massive extinction/recolonization event across the Great Plains/Rocky Mountain region encompassing over half the continental United States. The timing and extent of this colonization is consistent with a recently proposed regional aridification as the Laurentide ice sheets receded approximately 14,000 years ago, and we tentatively propose this paleoclimatological event as a major factor shaping genetic variation in Chrysemys.

  • cold hardiness and evaporative water loss in hatchling turtles
    Physiological and Biochemical Zoology, 2001
    Co-Authors: Jon P. Costanzo, Jacqueline D. Litzgus, John B. Iverson
    Abstract:

    Abstract North American turtles hatch in late summer and spend their first winter either on land or underwater. Adaptations for terrestrial overwintering of hatchlings in northern regions, where winter thermal and hydric regimes are harsh, have not been systematically investigated in many species. We measured intrinsic supercooling capacity, resistance to inoculative freezing, and desiccation resistance in hatchlings of terrestrial and aquatic turtles collected from northern (Terrapene ornata, Chrysemys picta bellii, Kinosternon flavescens, Chelydra serpentina) and southern (Chrysemys picta dorsalis, Trachemys scripta, Sternotherus odoratus, Sternotherus carinatus) locales. Supercooling capacity was estimated from the crystallization temperature of turtles cooled in the absence of external ice nuclei. Mean values ranged from −8.1° to −15.5°C and tended to be lower in terrestrial hibernators. Inoculation resistance was estimated from the crystallization temperature of turtles cooled in a matrix of frozen s...

  • Seasonal changes in physiology and development of cold hardiness in the hatchling painted turtle Chrysemys picta.
    The Journal of Experimental Biology, 2000
    Co-Authors: Jon P. Costanzo, Jacqueline D. Litzgus, John B. Iverson, Richard E. Lee
    Abstract:

    Hatchling painted turtles (Chrysemys picta) commonly hibernate in shallow, natal nests where winter temperatures may fall below -10 degrees C. Although hatchlings are moderately freeze-tolerant, they apparently rely on supercooling to survive exposure to severe cold. We investigated seasonal changes in physiology and in the development of supercooling capacity and resistance to inoculative freezing in hatchling Chrysemys picta exposed in the laboratory to temperatures that decreased from 22 to 4 degrees C over a 5.5 month period. For comparison, we also studied hatchling snapping turtles (Chelydra serpentina), a less cold-hardy species that usually overwinters under water. Although Chrysemys picta and Chelydra serpentina differed in some physiological responses, both species lost dry mass, catabolized lipid and tended to gain body water during the acclimation regimen. Recently hatched, 22 degrees C-acclimated Chrysemys picta supercooled only modestly (mean temperature of crystallization -6.3+/-0.2 degrees C; N=6) and were susceptible to inoculation by ice nuclei in a frozen substratum (mean temperature of crystallization -1.1+/-0.1 degrees C; N=6) (means +/- s.e.m.). In contrast, cold-acclimated turtles exhibited pronounced capacities for supercooling and resistance to inoculative freezing. The development of cold hardiness reflected the elimination or deactivation of potent endogenous ice nuclei and an elevation of blood osmolality that was due primarily to the retention of urea, but was not associated with accumulation of the polyols, sugars or amino acids commonly found in the cryoprotection systems of other animals. Also, Chrysemys picta (and Chelydra serpentina) lacked both antifreeze proteins and ice-nucleating proteins, which are used by some animals to promote supercooling and to initiate freezing at the high temperatures conducive to freezing survival, respectively.

Barbour, Roger W. - One of the best experts on this subject based on the ideXlab platform.