Overwintering behavior and physiology of eastern painted turtles (Chrysemys picta picta) in Rhode Island

Autor: Carlos E. Crocker, R A Feldman, Gordon R. Ultsch, Donald C. Jackson
Rok vydání: 2000
Předmět:
Zdroj: Canadian Journal of Zoology. 78:936-942
ISSN: 1480-3283
0008-4301
DOI: 10.1139/z00-032
Popis: We equipped 20 eastern painted turtles (Chrysemys picta picta) with radio transmitters and recovered them from a pond in Rhode Island during the winter of 1998-1999. Each month, three turtles were collected without permitting them to breathe. Blood was sampled by cardiac puncture and analyzed for pH, PCO2, PO2, and hematocrit; plasma was analyzed for [Na+], [K+], [Cl–], total [Ca], total [Mg], [lactate], and osmolality. In December 1998, mean values for pH, PO2, PCO2, [HCO3–], [lactate], total [Ca] and [Mg], hematocrit, and osmolality were 7.84 ± 0.02, 4.7 ± 1.9 mmHg (1 mmHg = 133.3 Pa), 10.2 ± 1.2 mmHg, 25.4 ± 2.6 mmol·L–1, 2.78 ± 1.16 mmol·L–1, 3.2 ± 0.4 mmol·L–1, 2.5 ± 0.1 mmol·L–1, 23% red blood cells, and 271 mosmol·kg–1H2O, respectively, values similar to those for turtles submerged in normoxic water for 10 days at the prevailing water temperature (2-3°C). Throughout the winter, ice intermittently covered approximately 80% of the pond, water PO2was greater than 75% of air saturation, and blood PO2was maintained between 0.8 ± 0.3 and 10.1 ± 1.1 mmHg. Between December and February, there were no changes in most of the measured blood variables but, in March 1999, although the pond was largely free of ice, plasma [lactate], total [Ca], and total [Mg] averaged nearly 30, 8.1 ± 1.7, and 4.5 ± 0.8 mmol·L–1, respectively, although with a large variation among individuals. The turtles did not bury in the substrate during the winter and, despite the increase in plasma lactate, there was no significant acidemia. However, the winter of 1998–1999 was relatively mild, and it is possible that more significant acid-base and ionic perturbations could occur during more severe winters, particularly in small ponds that cool sooner in late autumn and may have more prolonged ice cover than larger bodies of water.
Databáze: OpenAIRE
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