Department of Integrative Biology, Oklahoma State University, 501 Life Science West, Stillwater, OK 74075, USA.
Department of Integrative Biology, Oklahoma State University, 501 Life Science West, Stillwater, OK 74075, USA.
J Insect Physiol. 2019 Jul;116:25-31. doi: 10.1016/j.jinsphys.2019.04.006. Epub 2019 Apr 19.
Predators feed on a diversity of prey that can vary widely in nutrient content. While prey nutrient content is known to have important consequences for life history traits, less is known about how it affects physiology and behavior. The purpose of this study was to test how diet affected the physiology and behavior of the wolf spider Hogna carolinensis. We hypothesized that higher protein intake would result in a lower metabolic rate due to less energy intake. Further, we also expected the high protein group to exhibit increased activity levels and aggression in an attempt to increase energy intake. Spiders were maintained on three different treatment diets in order to simulate prey with differing macronutrient composition: high protein, intermediate, and high lipid. Spider respiration was measured to quantify the baseline metabolic rate (SMR), digestive metabolic rate (SDA), and active metabolic rate (AMR). We found no significant effect of diet on metabolic rates. However, the SDA coefficient (i.e. digestive cost relative to prey content) was higher in the high protein group, meaning that this group metabolized a greater portion of their prey during digestion and had a lower net energy intake from prey. In our behavioral assays, spiders in the high protein group were significantly more active and attacked prey more quickly in their first trial. Our results demonstrate that diet had relatively little effect on predator metabolism but more of an effect on behavior. These findings suggest that diet regulation should be analyzed by studying multiple responses together, including metabolism and behavior, to gain a more comprehensive understanding of the effects of diet on organism performance and fitness.
掠食者以营养成分差异很大的各种猎物为食。虽然猎物的营养成分对生活史特征有重要影响，但人们对它如何影响生理和行为知之甚少。本研究旨在测试饮食如何影响狼蛛 Hogna carolinensis 的生理和行为。我们假设由于能量摄入减少，高蛋白摄入会导致较低的代谢率。此外，我们还预计高蛋白组会表现出更高的活动水平和攻击性，以增加能量摄入。为了模拟具有不同宏量营养素组成的猎物，蜘蛛被维持在三种不同的处理饮食中：高蛋白、中蛋白和高脂。通过测量蜘蛛的呼吸来量化基础代谢率（SMR）、消化代谢率（SDA）和主动代谢率（AMR）。我们没有发现饮食对代谢率有显著影响。然而，高蛋白组的 SDA 系数（即相对于猎物含量的消化成本）较高，这意味着该组在消化过程中代谢了更多的猎物，并且从猎物中获得的净能量摄入较低。在我们的行为测试中，高蛋白组的蜘蛛在第一次试验中明显更活跃，攻击猎物的速度也更快。我们的结果表明，饮食对捕食者代谢的影响相对较小，但对行为的影响更大。这些发现表明，应该通过研究代谢和行为等多种反应来分析饮食调节，以更全面地了解饮食对生物体表现和适应性的影响。
