Natural freezing survival by painted turtles Chrysemys picta marginata and C. picta bellii

1992 ◽  
Vol 262 (3) ◽  
pp. R530-R537 ◽  
Author(s):  
T. A. Churchill ◽  
K. B. Storey

Hatchlings of both the Midland (Chrysemys picta marginata) and Western (C. picta bellii) subspecies of the painted turtle tolerate the freezing of extracellular body fluids while overwintering in terrestrial nests. Fall-collected hatchlings survived 3 days of continuous freezing at -2.5 degrees C, with ice contents of 43.5 +/- 1.0% of total body water (SE; n = 24) for C. picta marginata and 46.5 +/- 0.8% (n = 32) for C. picta bellii. Survival times dropped to 4-5 h when temperature was lowered to -4 degrees C, correlated with ice contents of greater than or equal to 50%. However, C. picta marginata tested immediately after excavation from nests in the spring showed greater freeze tolerance, with survival extending to 11 days at -2.5 degrees C and a higher mean ice content of 50.2 +/- 1.2% (n = 6). Spring hatchlings also had high supercooling points, -1.07 +/- 0.13 degrees C (n = 8), that dropped within 3 days to -4.83 +/- 0.83 degrees C (n = 4), suggesting a breakdown of endogenous ice-nucleating agents when hibernation ended. A search for possible cryoprotectants showed that both subspecies accumulated glucose and lactate in liver during freezing (net increase = 3-13 mumols/g wet wt); both also maintained large free amino acid pools in organs, with taurine making up 21-47% of the total.

1992 ◽  
Vol 167 (1) ◽  
pp. 221-233 ◽  
Author(s):  
T. A. Churchill ◽  
K. B. Storey

Hatchling red-eared turtles Trachemys (= Pseudemys) scripta elegans (Wied) from a Louisiana population display a significant ability to withstand the freezing of extracellular body fluids. All animals survived at least 2 h of freezing at −2.5 or −4 degrees C. At −2.5 degrees C, survival declined to 50% after 6 h of freezing and no animals recovered after 24 h or longer, when mean ice content reached 54.7 +/− 1.4% of total body water. At −4 degrees C, all turtles recovered from 4 h of freezing exposure with a mean ice content of 49.6 +/− 2.4%, but survival dropped sharply thereafter with no animals recovering after 8 h, when ice content had reached 64.5 +/− 0.7%. Survival times were substantially shorter and percentage ice values greater than comparable values for hatchling painted turtles (Chrysemys picta (Schneider)) from northern populations subjected to identical freezing exposures. The ability to synthesize cryoprotectants in response to freezing was poorly developed in T. s. elegans; maximal accumulation of glucose was only 3.2 mumol g-1 wet mass in liver. Lactate content increased two- to threefold in oxygen-sensitive organs (heart and brain) during freezing, but levels of lactate and other putative cryoprotectants were unchanged in other organs. Total free amino acid content rose significantly in liver, muscle and blood during freezing; increased taurine concentration was primarily responsible for the changes in liver and blood. The capacity for freezing survival by T. s. elegans hatchlings from southern populations would be of limited use for hibernation in a cold climate, but the metabolic responses to freezing displayed by these animals might be enhanced by northern populations to increase their freeze tolerance.


2001 ◽  
Vol 204 (9) ◽  
pp. 1667-1672 ◽  
Author(s):  
G.C. Packard ◽  
M.J. Packard ◽  
L.L. McDaniel

Hatchlings of the North American painted turtle (Chrysemys picta) typically spend their first winter of life inside the shallow, subterranean nest where they completed incubation the preceding summer. This facet of their natural history commonly causes neonates in northerly populations to be exposed in mid-winter to ice and cold, which many animals survive by remaining unfrozen and supercooled. We measured the limit of supercooling in samples of turtles taken shortly after hatching and in other samples after 2 months of acclimation (or acclimatization) to a reduced temperature in the laboratory or field. Animals initially had only a limited capacity for supercooling, but they acquired an ability to undergo deeper supercooling during the course of acclimation. The gut of most turtles was packed with particles of soil and eggshell shortly after hatching, but not after acclimation. Thus, the relatively high limit of supercooling for turtles in the days immediately after hatching may have resulted from the ingestion of soil (and associated nucleating agents) by the animals as they were freeing themselves from their eggshell, whereas the relatively low limit of supercooling attained by acclimated turtles may have resulted from their purging their gut of its contents. Parallels may, therefore, exist between the natural-history strategy expressed by hatchling painted turtles and that expressed by numerous terrestrial arthropods that withstand the cold of winter by sustaining a state of supercooling.


1989 ◽  
Vol 67 (4) ◽  
pp. 1082-1084 ◽  
Author(s):  
Gary L. Paukstis ◽  
Robert D. Shuman ◽  
Fredric J. Janzen

Hatchling painted turtles, (Chrysemys picta) in north central Nebraska overwinter terrestrially within the nest cavity. Nest temperatures as low as −2.1 °C were recorded during January 1982 within nests from which hatchlings survived. Under laboratory conditions, nine turtles survived a cooling cycle (0 to −8.0 to 0 °C) over a 29-h period. Four of these turtles exhibited the ability to supercool to temperatures as low as −8.9 °C at which point freezing occurred. Partial freeze tolerance was exhibited by one individual. The ability of hatchling painted turtles to supercool and to survive subfreezing temperatures may be an important factor in the northern distribution of this species.


2000 ◽  
Vol 124 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Scott A. Reese ◽  
Carlos E. Crocker ◽  
Donald C. Jackson ◽  
Gordon R. Ultsch

Author(s):  
Clare I. M. Adams ◽  
Luke A. Hoekstra ◽  
Morgan R. Muell ◽  
Fredric J. Janzen

Environmental DNA (eDNA) is an increasingly used non-invasive molecular tool for detecting species presence and monitoring populations. In this article, we review the current state of non-avian reptile eDNA work in aquatic systems, as well as present a field experiment on detecting the presence of painted turtle (Chrysemys picta) eDNA. Thus far, turtle and snake eDNA studies have been successful mostly in detecting the presence of these animals in field conditions. However, some instances of low detection rates and non-detection occur for these non-avian reptiles, especially for squamates. We explored this matter by sampling lentic ponds with different densities (0 kg/ha, 6 kg/ha, 9 kg/ha, and 13 kg/ha) of painted turtles over three months, attempting to detect differences in eDNA accumulation using a qPCR assay. Only one sample of the highest density pond readily amplified eDNA. Yet, estimates of eDNA concentration from pond eDNA were rank-order correlated with turtle density. We present a “shedding hypothesis”–the possibility that animals with hard, keratinized integument do not shed as much DNA as mucus-covered organisms–as a potential challenge for turtle eDNA studies. Despite challenges with eDNA inhibition and availability in water samples, we remain hopeful that eDNA can be used to detect freshwater turtles in the field. We provide key recommendations for biologists wishing to use eDNA methods for detecting non-avian reptiles.


1994 ◽  
Vol 72 (8) ◽  
pp. 1436-1443 ◽  
Author(s):  
Robert St. Clair ◽  
Patrick T. Gregory ◽  
J. Malcolm Macartney

Widely distributed animals often show considerable differences in growth and maturation both between sexes and among populations. We compared growth and maturation between the sexes in the painted turtle (Chrysemys picta) at the northern limit of its range and related these differences to patterns observed in southern populations. In British Columbia, females grow faster and mature later than males, and as a consequence, are both larger and older than males at maturity. Northern individuals of both sexes show greater annual growth than populations farther south, despite a shorter growing season. Northern males may mature at a similar age to those in the south but northern females mature later than those in the south and this, coupled with faster growth, results in larger size at maturity. Because of constraints on the number of clutches that may be successfully incubated per year at a higher latitude, northern females reproduce at most once per year, whereas southern females can produce several clutches over a summer. Therefore, delayed maturity and faster growth may be favoured in northern females so that they may produce larger clutches at a necessarily lower annual frequency.


1985 ◽  
Vol 63 (1) ◽  
pp. 49-54 ◽  
Author(s):  
Janet M. Storey ◽  
Kenneth B. Storey

Biochemical adaptations allowing the natural survival of extracellular freezing were examined in the gray tree frog, Hyla versicolor. Laboratory-reared immature adults froze between −1 and −1.5 °C and survived 5 days of freezing at −2 °C as well as repeated rapid bouts of freeze–thaw. Measurements of ice content showed 41.5% of total body water frozen. Glycerol accumulated as the cryoprotectant in sexually mature adult H. versicolor (423 μmol/mL in blood) while both glycerol and glucose accumulated in immature adults (16.3 ± 6.8 and 25.9 ± 11.6 μmol/mL in blood, respectively). Cryoprotectant synthesis was freezing stimulated only and did not occur over long-term cold acclimation at 0 to 1 °C. Cryoprotectant synthesis was correlated with a 203% increase in liver total phosphorylase activity and an increase in phosphorylase a content from 40 to 60%. Activities of 15 other enzymes of intermediary metabolism were determined in liver and leg muscle; activities of most enzymes increased with freezing exposure as did soluble protein content. Survival of freezing depends upon anaerobic mechanisms of energy production in tissues. Frogs frozen at −2 °C accumulated lactate in liver and muscle. Energy charge dropped in both tissues and the creatine phosphate reserves of muscle were depleted.


1997 ◽  
Vol 75 (3) ◽  
pp. 401-406 ◽  
Author(s):  
Gary C. Packard ◽  
Sarah L. Fasano ◽  
Marcus B. Attaway ◽  
Leslie D. Lohmiller ◽  
Trina L. Lynch

We monitored temperatures during the winter of 1995–1996 inside 18 nests containing hatchling painted turtles (Chrysemys picta). The study was performed at the Valentine National Wildlife Refuge in north-central Nebraska to assess survival of neonatal turtles in relation to the thermal environment inside their hibernacula. Minimum temperatures in the nests varied from −3 to −21 °C, and were better predictors of survival of hatchlings than other measures of the thermal environment. All hatchlings survived in nests where the temperature never went below −7 °C, some animals survived in nests where the minimum was between −7 and −13 °C, but no turtle survived in a nest where the minimum was below −14 °C. Hatchlings probably survived the cold by sustaining a state of supercooling, because the duration of exposure to low temperatures was far too long for animals in most nests to have survived in a frozen state.


1982 ◽  
Vol 60 (12) ◽  
pp. 3290-3292 ◽  
Author(s):  
Jonathan E. Snow

This study examined the relationship between nest age and predation rate in painted turtles (Chrysemys picta). Eighty-one intact nests were found; 33 were eventually preyed upon during the study. New nests (less than 72 h old) do not appear to have a greater risk of predation than older nests. The majority (55%) of nests preyed upon were older than 72 h. Nests were divided into two groups: the first 41 of the season's nestings and the remaining 40 nestings. The proportion of nests preyed upon did not differ significantly between the two groups. Predators appeared to have made more frequent daily visits during the time the latter group of nests were being constructed. The average age of nests preyed upon in each group was 13.7 and 2.7 d, respectively; these averages are significantly different. Identifiable predators included skunks (Mephitis mephitis), raccoons (Procyon lotor), foxes (Vulpes fulva), and chipmunks (Tamias striatus) that accounted for 23, 4, 4, and 5, respectively, of the nests preyed upon.


1999 ◽  
Vol 72 (4) ◽  
pp. 493-501 ◽  
Author(s):  
Gordon R. Ultsch ◽  
Mary E. Carwile ◽  
Carlos E. Crocker ◽  
Donald C. Jackson

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