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oxygen consumption at different external temperaturesother rodents from different climatic regions.MATERIALS AND METHODSTen individuals from each species were collected, weighedanimals fed daily on wheat and crushed corn and a 250 WattThe resting metabolic rate (RMR) of the different sizerate (ccm/g/h) at different temperatures from 10 to 40ºC, using a a run can be calculated from the difference between the initial760 mmHg) by calculating it from the formula: 250 TEMPERATURE AND BODY SIZE VS. METABOLIC RATEHUSSEIN Table 1: Mean resting oxygen consumption values of the Mus musculus and rat Rattus rattus at different temperatures. Temperature No. ofanimals Body weight (g) Oxygen consumption(com/g/h)Mean No. ofanimals Body weight (g) Oxygen consumption(com/g/h)Mean 117.64 118.44 116.50 2.11 118.35 Mean body weight:15.47Mean oxygen consumption :Observed:1.94Estimated:1.71Observed/Estimated (%):113.45Metabolism (Kcal/g/h):9.31 120.04!3.611.70!1.161.9189.01 V= difference in the water level (ccm) in th

e burette at the where (B lism in terms of calories per gram per hour (kcal/g/h), it is suffi-different sized experimental species were made statistically byusing the analysis of variance (ANOVA). The rejection level ofRESULTSC was measured in two differentdata presented in Table 1 and Figure 2, it is clear that the The relationship of energy metabolism to size wasapplied according to Brody (7) as: QO2= a Wbis the oxygen uptake per hour per unit of bodyweight, W is the body mass, a and b are fitted constantsequals 3.8 and -0.27 respectively). From this equation,the estimated oxygen consumption for Mus musculuswas 1.71 when the mean body weight was 15.47 g 251 TEMPERATURE AND BODY SIZE VS. METABOLIC RATEHUSSEIN Figure 1: Diagram showing the structure of respirometer: a) glassabsorber (modified from Skvortsov, 1957). Figure 2: Effect of temperature on resting oxygen consumptionEach point represents the mean of 8 to 10 measure- difference between the experimental and estimatedconsumption was highly significant diffe

rence at different Moreover, the present data show that the mice affected oxygen consumption of some other rodentsinhabiting different Egyptian habitats (15) or the meandesert area of Kuwait (9), it is clear that the zone of ther-amount of food and water.also discussed by several other authors (8,11,17-19, 26, 28).2. Avery RA : Reptiles. In animal energetics. Ed by FJ Vern-iological ecology. Academic Press, New York, 13:155-199, 1982. 24. Skvortsov GN : Ulutsheneyi metodika opredeleniya inten-nych. (Improved method of determination of oxygen consumptionDept. of Zoology,Alexandria Univ, EGYPT. 252 TEMPERATURE AND BODY SIZE VS. METABOLIC RATEHUSSEIN H.K. HUSSEIN* SUMMARY: The metabolic rate of the different sized rodents in relation to external temperaturewas studied. These rodents are the house mice Mus musculus and the roof rat Rattus rattus inhabit-ing the houses and fields of Egypt. The results show that the mice Mus musculus of small size had ahigher rate of oxygen consumption and higher heat production than t

he large size one Rattus rattus.Also, the data indicate that increase of external temperature resulted in a significant decrease ofoxygen consumption in the two experimental species up to 30ºC, then a gradual increase in oxygenconsumption takes place as temperature increases. However, the zone of thermal neutrality and basalmetabolism lies around 30ºC. From the metabolic rates obtained at various ambient temperatures, atemperature- metabolism curve can be constructed in the two experimental species.Key words: Metabolic rate, mus musculus, rattus rattus. 249 the combined effects of the amount of active protoplasmicWhite ford and Victor (27), Gans and Pough (10) and basal rates of metabolism (11,18).inhabiting three different habitats. These rodents are the(zone of heat production), the oxygen consumption levelHowever, there is a little work was done on the Egypt- *From Department of Zoology, Faculty of Science, AlexandriaUniversity, Egypt. EFFECT OF TEMPERATURE AND BODYSIZE ON THE METABOLIC RATE OF THERAT RATTUSRATT