Ratio Representations of Specific Dynamic Action (Mass‐Specific SDA and SDA Coefficient) Do Not Standardize for Body Mass and Meal Size

2005 ◽  
Vol 78 (1) ◽  
pp. 126-131 ◽  
Author(s):  
Steven J. Beaupre
Keyword(s):  
Body Mass ◽  
Specific Dynamic Action ◽  
Meal Size ◽  
Dynamic Action

Determinants and modeling of specific dynamic action for the Common Garter Snake (Thamnophis sirtalis)

2010 ◽  
Vol 88 (8) ◽  
pp. 808-820 ◽  
Author(s):  
Scott M. Bessler ◽  
Mary C. Stubblefield ◽  
G. R. Ultsch ◽  
Stephen M. Secor
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Body Mass ◽  
Metabolic Response ◽  
Specific Dynamic Action ◽  
Meal Size ◽  
Garter Snake ◽  
Thamnophis Sirtalis ◽  
Dynamic Action ◽  
The Common

Specific dynamic action (SDA), the cumulative energy expended on digestion and assimilation, can contribute significantly to individual daily energy expenditure (DEE). The Common Garter Snake (Thamnophis sirtalis (L., 1758)) is a widely distributed generalist predator that could experience considerable variation in SDA and hence the contribution of SDA to DEE. We examined the effects of meal size, meal type, and body temperature on the postprandial metabolic response and SDA of the Eastern Garter Snake ( Thamnophis sirtalis sirtalis (L., 1758)) and generated predictive models of SDA based on meal size, body mass, and body temperature, and separately based on meal energy. Postprandial peak in oxygen consumption, duration of significantly elevated oxygen consumption, and SDA increased with increasing meal size (5%–45% of body mass). Postprandial metabolic response digesting six different equal-size prey items varied significantly; vertebrate prey generated larger SDA responses than soft-bodied invertebrates. Increases in experimental temperature (15–35 °C) yielded a matched increase in postprandial peak in oxygen consumption and decrease in digestive duration. For a 1-month hypothetical feeding history for an adult T. sirtalis, the cumulative predicted SDA varied by 4.5% among the three models (minimal, intermediate, and maximal intake of prey) and averaged 8%, 22%, and 38% of DEE, respectively.

scholarly journals Specific dynamic action, apparent assimilation efficiency, and digestive rate in an arboreal pitviper, Trimeresurus stejnegeri stejnegeri

2008 ◽  
Vol 86 (10) ◽  
pp. 1139-1151 ◽  
Author(s):  
Tein-Shun Tsai ◽  
How-Jing Lee ◽  
Ming-Chung Tu
Keyword(s):  
Assimilation Efficiency ◽  
Specific Dynamic Action ◽  
Meal Size ◽  
Digestive Physiology ◽  
Postprandial Metabolism ◽  
Preferred Temperature ◽  
Time To Peak ◽  
Dynamic Action ◽  
Effects Of Temperature ◽  
Arboreal Snakes

The major aims of this study were to assess the effects of temperature (15–35 °C) and meal size (less than 30% snake mass) on the metabolism and digestive physiology of Trimeresurus stejnegeri stejnegeri Schmidt, 1925 and to compare the results with those of terrestrial snakes. Specific dynamic action (SDA), peak Vo2, and scope of peak Vo2 increased with meal size. Temperature had little effect on SDA. With regression analysis, we found that baseline metabolic rates of T. s. stejnegeri were generally smaller than that for frequent feeders and larger than that for infrequent feeders. We generalized three types of SDA profiles among T. s. stejnegeri and terrestrial snakes (including frequent and infrequent feeders). Trimeresurus stejnegeri stejnegeri had a more shallow and extended profile of postprandial metabolism, which did not support our hypothesis that the pace of digestive metabolism of arboreal snakes is faster than that of terrestrial snakes. The apparent assimilation efficiency (range 0.698–0.884) was significantly lower at 15 °C. At the preferred temperature (26.5–28.8 °C) for a postprandial 50 g snake, the simulated ratios of four parameters (time to peak Vo2, first defecation time, gastric digestion time, and final defecation time) to SDA duration approximated 0.2, 0.5–0.7, 0.7, and 1.1, respectively.

Effects of meal size, meal type, and body temperature on the specific dynamic action of anurans

2006 ◽  
Vol 177 (2) ◽  
pp. 165-182 ◽  
Author(s):  
Stephen M. Secor ◽  
Jessica A. Wooten ◽  
Christian L. Cox
Keyword(s):  
Body Temperature ◽  
Specific Dynamic Action ◽  
Meal Size ◽  
Dynamic Action

Metabolic physiology of the freshwater planaria Girardia dorotocephela and Schmidtea mediterranea: reproductive mode, specific dynamic action, and temperature

2020 ◽  
Vol 319 (4) ◽  
pp. R428-R438
Author(s):  
Melissa Lewallen ◽  
Warren Burggren
Keyword(s):  
Animal Model ◽  
Body Mass ◽  
Circulatory System ◽  
Metabolic Cost ◽  
Reproductive Mode ◽  
Fold Increase ◽  
Specific Dynamic Action ◽  
Schmidtea Mediterranea ◽  
Simple Diffusion ◽  
Dynamic Action

Planarians are widely used animal models for studies in regeneration, developmental biology, neurobiology, and behavior. However, surprisingly little is known about other aspects of their basic biology, even though such information might help validate these flatworms as a general animal model. We hypothesized that planaria, although dependent on simple diffusion of O2 across the integument for O2 uptake, would nonetheless show changes in oxygen consumption (V̇o2) associated with reproductive mode (sexual or asexual), feeding (specific dynamic action; SDA), temperature (Q10 values), and photoperiod typical of those responses of more complex invertebrates. In the current experiments, routine V̇o2 was measured over the range of 13-28°C in Schmidtea mediterranea and Girardia dorotocephala. At the long-term maintenance temperature of 18°C, routine V̇o2 was ~13 µL O2·g−1·h−1 in the two asexual strains, but approximately twice as high (27 µL O2·g−1·h−1) in the sexual strain of S. mediterranea, suggesting a metabolic cost for sexual reproduction. Metabolic temperature sensitivity, measured by Q10, was about one to three for all three groups. All three groups showed a large (~2- to 3-fold) increase in V̇o2 within a day following feeding, suggesting a large SDA effect. Starvation, causing “degrowth” in some planaria, resulted in a loss of one-third of body mass in sexual S. mediterranea but no body mass loss in either asexual strains. Collectively, these data indicate that, while being a relatively simple flatworm with no dedicated respiratory or circulatory system, their metabolic physiological responses are quite similar to those shown by more complex invertebrates and vertebrates, contributing to their validation as an animal model.

Effects of meal size on postprandial responses in juvenile Burmese pythons (Python molurus)

1997 ◽  
Vol 272 (3) ◽  
pp. R902-R912 ◽  
Author(s):  
S. M. Secor ◽  
J. Diamond
Keyword(s):  
Body Mass ◽  
Specific Dynamic Action ◽  
Meal Size ◽  
O2 Consumption ◽  
Adaptive Responses ◽  
Uptake Rates ◽  
Consumption Rates ◽  
Python Molurus ◽  
Pass Through ◽  
Mucosal Mass

Pythons were reported previously to exhibit large changes in intestinal mass and transporter activities on consuming meals equal to 25% of the snake's body mass. This paper examines how those and other adaptive responses to feeding vary with meal size (5, 25, or 65% of body mass). Larger meals took longer to pass through the stomach and small intestine. After ingestion of a meal, O2 consumption rates rose to up to 32 times fasting levels and remained significantly elevated for up to 13 days. This specific dynamic action equaled 29-36% of ingested energy. After 25 and 65% size meals, plasma Cl- significantly dropped, whereas plasma CO2, glucose, creatinine, and urea nitrogen increased as much as a factor of 2.3-4.2. Within 1 day the intestinal mucosal mass more than doubled, and masses of the intestinal serosa, liver, stomach, pancreas, and kidneys also increased. Intestinal uptake rates of amino acids and of D-glucose increased by up to 43 times fasting levels, whereas uptake capacities increased by up to 59 times fasting levels. Magnitudes of many of these responses (O2 consumption rate, kidney hypertrophy, and D-glucose and L-lysine uptake) increased with meal size up to the largest meals studied; other responses (Na+-independent L-leucine uptake, plasma Cl-, and organ masses) plateaued at meals equal to 25% of the snake's body mass; and still other responses (nutrient uptake at day 1, passive glucose uptake, and plasma protein and alkaline phosphatase) were all-or-nothing, being independent of meal size between 5 and 65% of body mass. Pythons undergo a wide array of postprandial responses, many of which differ in their sensitivity to meal size.

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