Ecological energetics of three species of ectothermic vertebrates. [Snakes, toads]
Ecological energetics of three species of ectothermic vertebrates. [Snakes, toads]
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三种变温脊椎动物的生态能量学。
DOI：
10.2307/1934814
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发表时间：
1976
期刊：
影响因子：
--
通讯作者：
I. Smith
中科院分区：
文献类型：
--
作者：
I. Smith
一个bstract。对在美国东南部发现的三种温带脊椎动物的能量收支进行了比较。研究的三个物种是ELAP/ie guttata(玉米蛇)、Heterodon platyr/iinos(东部猪鼻蛇)和Bufo terrestris(南部蟾蜍)。同化效率、摄取、排泄、生长、脱落、新陈代谢和繁殖的值被转换为热量单位，并整合到每个物种的能量流模型中。在所有体重等级中，ELAP/e滴虫每周的摄食率都高于其他两个物种。三种鱼的同化效率(摄食-摄食/摄食×100)分别为滴状棘豆88.92%、扁尾轮虫83.92%和白对虾73.70%。这些值与其他食肉动物的报告值相似。在152C、202C、252C和300C温度下，三种鱼每小时代谢的回归方程分别为：lnO2=-4.19+0.68(W+Olot+0.24)，n02=-3.60+0.76 lnW+0.14T？0.36。=-5.78+1.04ln W+O.Lot+0.28。这三个物种脂肪体中的脂肪储量在春季最低，恰逢繁殖力最强的时期，这表明很大比例的能量储备被用于这一目的。在实验室中，Elaphe guttata的生长速度比其他两个物种要快得多。生长的差异与摄食量直接相关，因为同化效率和新陈代谢在所有摄食水平下保持不变。在252C温度下，两种蛇的蜕皮间隔平均为40.5天(滴虫)和38.3天(白纹蛇)。猪鼻蛇的干重/体重比随着体型的增大而增加，而玉米蛇的干重/体重比则随着体型的增大而减小。卵的离合器占所有三种雌性的总热量的42%。这表明，繁殖所需的能源成本将需要大量的脂肪储备，这些脂肪将在一年或多年的时间内积累。生产-同化率(生产/同化X100)玉米蛇为86%，猪鼻蛇为81%，南方蟾蜍为49%。对三种研究物种能量流的比较表明，对于所有三种研究物种，摄取方法(A=I-E)的结果显著高于生产-呼吸方法(A=P+R)，而变化较小。
A bstract. Comparisons were made of the energy budgets of three ectothermic vertebrates found in the Southeastern United States. The three species studied were Elap/ie guttata (corn snakes), Heterodon platyr/iinos (eastern hognose snakes), and Bufo terrestris (southern toads). Values for assimilation efficiency, ingestion, excretion, growth, shedding, metabolism, and reproduction were converted to caloric units and integrated into energy flow models for each species. Elap/e guttata had a greater weekly ingestion rate than did the other two species in all weight classes. Assimilation efficiencies (ingestion-egestion/ingestion x 100) for the three species were 88.92% for E. guttata, 83.92% for H. platyr/iinos, and 73.70% for B. terrestris. These values are similar to those reported for other carnivores. Regression equations of metabolism per animal hour at 152C, 202C, 252C, and 300C for the three species were ln O2 = -4.19 + 0.68 In W + OlOT + 0.24 for E. guttata, n 02 = -3.60 + 0.76 ln W + 0.14T ? 0.36 for B. terrestris, and ln 0. = -5.78 + 1.04 ln W + O. lOT + 0.28 for H. platyrhinos. Reserves of fat in the fat bodies of the three species were lowest in the spring and coincided with periods of maximal reproduction suggesting that a large percentage of the energy reserves were utilized for this purpose. Elaphe guttata showed a much greater rate of growth than the other two species in the laboratory. Differences in growth were directly related to amount of food ingested, since assimilation efficiency and metabolism remained constant at all feeding levels. Shedding intervals for the two snake species at 252C averaged 40.5 days for E. guttata and 38.3 days for H. platyr/iinos. The dry shed weight:body weight ratio increased with increasing size for hognose snakes but decreased for corn snakes. Egg clutches comprised 42% of the total caloric values of the females of all three species. This suggests that the energy cost of reproduction would require large reserves of fat which would accumulate over a period of one or more years. Production-assimilation ratios (production/assimilation X 100) were 86% for corn snakes, 81% for hognose snakes, and 49% for southern toads. Comparisons of energy flow in the three study species revealed that ingestion methods (A = I - E) gave significantly higher and less variable results than production-respiration methods (A = P + R) for all three study species.