The Physiology of Hibernation among Painted Turtles: The Eastern Painted TurtleChrysemys picta picta

Abstract

Eastern painted turtles (Chrysemys picta picta) from Connecticut were submerged at 3 degrees C in normoxic and anoxic water to simulate potential respiratory environments within their hibernacula. Those in normoxic water could survive submergence for at least 150 d, while those in anoxic water could survive for a maximum of about 125 d. Turtles in normoxic water developed a slight metabolic acidosis as plasma lactate accumulated to about 50 mM in 150 d, while anoxic turtles developed a severe lactic acidosis as plasma lactate reached about 200 mM in 125 d; there was no respiratory acidosis in either group. Plasma [Na+] changed little in either group, [Cl-] fell by about one-third in both, and [K+] increased by about fourfold in anoxic turtles but only slightly in those in normoxic water. Total plasma magnesium and calcium increased profoundly in anoxic turtles but moderately in those in normoxic water. Consideration of charge balance indicates that all major ions were measured in both groups. Plasma glucose remained unchanged in anoxic turtles until after about 75 d of submergence, when it increased and continued to increase with the duration of anoxia, with much variation among individuals; glucose remained unchanged throughout in turtles in normoxic water. Hematocrit doubled in 150 d in turtles in normoxic water; in anoxic turtles, an initial increase was no longer significant by day 100. Plasma osmolality increased markedly in anoxic turtles, largely because of accumulation of lactate, but anoxic turtles only gained about half the mass of turtles in normoxic water, who showed no increase in osmolality. The higher weight gain in the latter group is attributed to selective perfusion and ventilation of extrapulmonary gas exchange surfaces, resulting in a greater osmotic influx of water. The physiologic responses to simulated hibernation of C. picta picta are intermediate between those of Chrysemys picta bellii and Chrysemys picta dorsalis, which correlates with the severity of the winter each subspecies would be expected to encounter.

Tribute to P. L. Lutz: cardiac performance and cardiovascular regulation during anoxia/hypoxia in freshwater turtles

“…Indeed, several species of freshwater turtles can survive for months in cold anoxic water (e.g. Ultsch and Jackson, 1982;Ultsch, 1985;Ultsch et al, 1999;Jackson, 2000;Reese et al, 2002;Ultsch, 2006). Thus, together with the Crucian carp, which survives prolonged anoxia during the winter in Scandinavian lakes, freshwater turtles exhibit the highest known anoxia tolerance among vertebrates (Lutz and Nilsson, 1997).…”

“…Of all the parameters examined, it seems that hyperkalemia is most detrimental in terms of cardiac performance. During long-term anoxic submergence, [K + ] o actually increases above 10·mmol·l -1 in painted turtles Ultsch et al, 1999), and it is possible that the progressive hyperkalemia and the ensuing depolarisation are ultimately important for determining the limit for anoxic survival.…”

Molecular Systematics, Phylogeography, and the Effects of Pleistocene Glaciation in the Painted Turtle (Chrysemys Picta) Complex

“…The broad, red middorsal stripe of dorsalis provides one striking morphological apomorphy for this species (Carr 1952), and dorsalis is instantly recognizable morphologically. In a series of comparative studies on hibernation physiology of painted turtles, Ultsch and colleagues have shown that dorsalis uniquely perishes from anoxia after about 50 days, whereas the remaining subspecies of Chrysemys generally live over 120 days under identical experimental conditions (Ultsch et al 1985(Ultsch et al , 1999. Although these morphological and physiological differences do not confirm species status, they do indicate that dorsalis is divergent across several data types.…”

Physiological disturbances and behavioural impairment associated with the incidental capture of freshwater turtles in a commercial fyke-net fishery

“…Despite having the ability to tolerate true anoxia in cold water, when submerged in elevated normoxic conditions (such as in this study), painted turtles were unable to acquire sufficient oxygen through secondary gas exchange mechanisms to remain aerobic (Ultsch & Jackson 1982, Jackson et al 2000, Reese et al 2001 as indicated in our study by elevated blood lactate and reduced blood pH. Therefore, painted turtles must metabolize energy anaerobically, resulting in blood acidosis (Ultsch & Jackson 1982, Ultsch et al 1999, Jackson et al 2000, Reese et al 2001. Another mechanism of tolerating submergence is the use of gas exchange via extrapulmonary oxygen uptake or bimodal respiration, which is typified by musk and map turtles (Ultsch et al 1984, Reese et al 2001.…”