Warming up for cold water: influence of habitat type on thermoregulatory tactics in a semi-aquatic snake

2010 ◽  
Vol 31 (4) ◽  
pp. 525-531 ◽  
Author(s):  
Radika Michniewicz ◽  
Fabien Aubret

AbstractIn ectotherms, thermal acclimation and behavioural thermoregulation have evolved to match organismal performance with local or temporary thermal conditions. In semi-aquatic species, however, this matching encompasses a trade-off: organisms that thermoregulate close to optimal muscle function on land will inevitably depart from that optimum when entering water, a medium that may differ drastically in temperature. With regard to predator evasion and foraging success, how do semi-aquatic ectotherms deal with such a challenge? We experimentally raised young semi-aquatic Tiger snakes in either terrestrial or semi-aquatic environments over 11 months. When tested in a standardised enclosure, young snakes raised in a semi-aquatic environment selected slightly, but significantly higher mean body temperatures than their terrestrially raised siblings (respectively 30.3°C versus 29.5°C). The former allowed their body temperature to remain higher than 32°C for twice as long as the latter group (4.4 hours vs 2.1 hours). Locomotor performances (swimming speed) were, unsurprisingly, strongly linked to body temperature. Entering water with a higher body temperature (30°C versus 19°C) delayed a sharp drop in locomotor performances, and thus lengthened maximum performance time. We hypothesise that young snakes, by allowing their body temperature to reach above their usual optimum body temperature, may delay the drop in locomotor efficiency in case of foraging opportunity or in order to escape a predator.

2009 ◽  
Vol 27 (10) ◽  
pp. 987-993 ◽  
Author(s):  
Jeremiah J. Peiffer ◽  
Chris R. Abbiss ◽  
Greig Watson ◽  
Ken Nosaka ◽  
Paul B. Laursen

1998 ◽  
Vol 85 (1) ◽  
pp. 204-209 ◽  
Author(s):  
John W. Castellani ◽  
Andrew J. Young ◽  
Michael N. Sawka ◽  
Kent B. Pandolf

This study examined whether serial cold-water immersions over a 10-h period would lead to fatigue of shivering and vasoconstriction. Eight men were immersed (2 h) in 20°C water three times (0700, 1100, and 1500) in 1 day (Repeat). This trial was compared with single immersions (Control) conducted at the same times of day. Before Repeat exposures at 1100 and 1500, rewarming was employed to standardize initial rectal temperature. The following observations were made in the Repeat relative to the Control trial: 1) rectal temperature was lower and heat debt was higher ( P < 0.05) at 1100; 2) metabolic heat production was lower ( P < 0.05) at 1100 and 1500; 3) subjects perceived the Repeat trial as warmer at 1100. These data suggest that repeated cold exposures may impair the ability to maintain normal body temperature because of a blunting of metabolic heat production, perhaps reflecting a fatigue mechanism. An alternative explanation is that shivering habituation develops rapidly during serially repeated cold exposures.


1994 ◽  
Vol 44 (4) ◽  
pp. 583-587
Author(s):  
Minoru HIGASA ◽  
Iwao YAMAMOTO ◽  
Ichiro NARIKAWA
Keyword(s):  

2008 ◽  
Vol 88 (7) ◽  
pp. 1309-1317 ◽  
Author(s):  
Cristina Munari

Habitat fragmentation from natural or human-mediated causes is a common phenomenon in terrestrial and aquatic environments. In this study, the effects of varying the size of habitat patches on the abundance of benthic invertebrates inhabiting date mussel (Musculista senhousia) patches was studied at two different transition environments, the Goro Lagoon (Adriatic Sea) and the Padrongiano Delta (Tyrrhenian Sea). Benthic fauna responded to habitat patchiness in a complex manner that varied according to habitat type, taxon and animal body size (small: 0.5–2.0 mm; large >2 mm). Small invertebrates were mostly polychaetes, nemertea, amphipods and isopods. Large invertebrates were mostly large polychaetes, bivalves, gastropods and crabs. Invertebrate population size and diversity seemed to be maximized in landscapes that include both small and large patches of mussel beds ‘embedded’ in a continuous matrix. Musculista senhousia patches served as a critical refuge and foraging habitat for many species. Patchy and continuous areas may promote the persistence of organisms with different life histories, especially in environments like those studied where mussel patches represent the only structural refuge available.


1994 ◽  
Vol 266 (4) ◽  
pp. R1319-R1326 ◽  
Author(s):  
E. Dumonteil ◽  
H. Barre ◽  
J. L. Rouanet ◽  
M. Diarra ◽  
J. Bouvier

Penguins are able to maintain a high and constant body temperature despite a thermally constraining environment. Evidence for progressive adaptation to cold and marine life was sought by comparing body and peripheral skin temperatures, metabolic rate, and thermal insulation in juvenile and adult Gentoo penguins exposed to various ambient temperatures in air (from -30 to +30 degrees C) and water (3-35 degrees C). Juvenile penguins in air showed metabolic and insulative capacities comparable with those displayed by adults. Both had a lower critical temperature (LCT) close to 0 degree C. In both adults and juveniles, the intercept of the metabolic curve with the abscissa at zero metabolic rate was far below body temperature. This was accompanied by a decrease in thermal insulation below LCT, allowing the preservation of a threshold temperature in the shell. However, this shell temperature maintenance was progressively abandoned in immersed penguins as adaptation to marine life developed, probably because of its prohibitive energy cost in water. Thus adaptation to cold air and to cold water does not rely on the same kind of reactions. Both of these strategies fail to follow the classical sequence linking metabolic and insulative reactions in the cold.


1963 ◽  
Vol 18 (6) ◽  
pp. 1234-1238 ◽  
Author(s):  
L. G. C. E. Pugh

Body temperature and respiratory experiments are reported on a Nepalese pilgrim who survived, uninjured, 4 days of exposure at 15,000–17,500 ft in midwinter, wearing only light clothing and no shoes or gloves. His resistance to cold depended on elevation of metabolism and, unlike tolerance of immersion in cold water, was not related to subcutaneous fat thickness. He slept soundly in spite of the cold and so did not become exhausted. In 3–4-hr experiments at o C (clothed), rectal temperature and skin temperature over the trunk showed only minor changes; hand and foot temperatures did not fall below 10–13 C. Maintenance of body temperature was accounted for by elevation of metabolism. survival in cold Submitted on February 19, 1963


1998 ◽  
Vol 118 (5) ◽  
pp. 571-575
Author(s):  
Patrick J. Antonelli ◽  
Robert M. Abrams ◽  
Kenneth J. Gerhardt ◽  
Matthias Schwab ◽  
Reinhard Bauer

Little is known about the functional development of the vestibular system before birth. The purpose of this study was to determine whether vestibular response to caloric stimulation could be elicited in the fetal sheep in utero. Late gestational fetal sheep ( n = 6) were instrumented through a midline hysterotomy. Copper caloric probes were inserted into the right bulla and beneath the left facial skin. Electrodes were placed in the skull for monitoring of electro-ocular activity. At least 3 days after surgery the probes were irrigated with water (100 ml/minute) at body temperature, 46° C, and 6° C. Cold water infusion of the bulla consistently produced well-recognized, slow-phase deviations followed by saccades directed contralaterally, findings consistent with vestibular nystagmus. The direction of the response reversed with warm water irrigation. The response was absent with irrigation at fetal body temperature. Only random eye movements were observed in response to caloric stimulation of the facial skin, regardless of water temperature. These results demonstrate that the sheep vestibular system is functioning prenatally. The importance of vestibular function for normal fetal brain maturation may be revealed in future studies using this animal model. (Otolaryngol Head Neck Surg 1998;118:571–5.)


2001 ◽  
Vol 49 (3) ◽  
pp. 223 ◽  
Author(s):  
Detlef H. Rohr ◽  
Brian S. Malone

Local climatic conditions influence the way in which ectotherms regulate their body temperature and activity. We examined correlations between local climatic conditions, body temperature and activity in adult, basking lowland copperheads (Austrelaps superbus) from two localities (warm-temperate versus cool-temperate) in south-eastern Australia. We also collected data from highland copperheads (Austrelaps ramsayi) at a locality with cold-temperate climate. We found that across the active season, mean body temperatures were similar among localities (approximately 27˚C) irrespective of species. In contrast, activity times differed. Cool-temperate A. superbus emerged earlier in spring and in the morning and retreated earlier in the evening and in autumn than their conspecifics from the warm-temperate locality. Spring emergence was correlated with yearly fluctuations in thermal conditions, suggesting that activity times depend on environmental temperatures. Predator–prey interactions influenced body temperature and activity to some extent in spring when warm-temperate A. superbus with relatively low body temperatures (as low as 18.5˚C) were captured around ponds in which they had been foraging for frogs. Austrelaps ramsayi from the cold-temperate locality not only displayed a later emergence in spring and reduced daily activity times compared with warm and cool-temperate A. superbus but also compared with A. ramsayi, as reported from a warmer locality in eastern Australia. These data indicate that activity times vary on a geographic basis while snake body temperatures largely remain inflexible. The surprising exception was that cold-temperate A. ramsayi retreated later in autumn than cool-temperate A. superbus, and at that time they showed body temperatures as low as 12.5˚C, well below those we had recorded for A. superbus. We suggest that A. ramsayi retreat later in autumn because they need to extend their reproductive season and that this is mediated via adaptive changes in the critical minimum body temperature, as has been reported for other snakes.


1965 ◽  
Vol 20 (1) ◽  
pp. 61-64 ◽  
Author(s):  
A. C. L. Hsieh ◽  
T. Nagasaka ◽  
L. D. Carlson

The temperatures of the tip of the middle fingers ( Ts) of nine comfortably warm subjects have been recorded during immersion of all the fingers of one hand in a 27–liter bath containing slowly stirred water at temperatures ranging from 4.6 to 40 C ( Tw). Blood flow ( F = ml/cm2 per min) was estimated from the average Ts for the last 15 min of a 20-min period, Tw and body temperature ( Tb) by using the equation: F = 1,087 x K( Ts – Tw)/ ( Tb – Ts). (K = 0.0134 kcal/cm2 per min per °C.) The increase in F per °C reduction in Tw below 10 C was 0.16 ± 0.077 (P < .05). This value gives a measure of the vasodilatation occasioned by immersion in water below 10 C. The sample regression equation of F on Tw was: F = 4.1 – .16 Tw ± 0.17 (n = 27; range of Tw = 4.6 to 10 C). This method of estimating blood flow at several levels of Tw describes more fully the peripheral circulatory response to cold than methods in which only one level of Tw is used. cold-induced vasodilatation; temperature and finger blood flow Submitted on August 28, 1963


1963 ◽  
Vol 18 (3) ◽  
pp. 483-488 ◽  
Author(s):  
B. S. Kang ◽  
S. H. Song ◽  
C. S. Suh ◽  
S. K. Hong

Oral temperatures of Korean diving women (ama) were measured before and after diving work in four seasons of the year. Their basal metabolic rate, measured in four seasons, was compared to that of nondiving women who lived in the same community and ate the same diet as the ama. Average oral temperatures declined to 35 C after 70 min of work in summer (water temp., 27 C) and to 33 C after 15 min of work in the winter (water temp., 10 C). Average body temperature, computed from weighted oral and average skin temperatures, declined to 34.6 C in summer and to 30 C in winter. Duration of work periods was determined principally by water temperature, since oral temperature declined at a rate inversely proportional to water temperature. The lower deep body temperatures which the ama endure in winter do, however, prolong their winter work period. The BMR of nondiving women was the same as the Dubois standard throughout the year. However, the BMR of ama varied with the season, ranging from +5 of the Dubois standard in summer to +35 in winter. We conclude that the elevated BMR of ama during the winter is cold adaptation, induced by repeated immersion in cold water. Submitted on November 23, 1962


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