U.S. Geological Survey, Fort Collins Science Center - South Florida Field Station, 40001 SR 9336, Homestead, FL 33034, USA.
Conservancy of Southwest Florida, Naples, FL 34102, USA.
Biol Open. 2021 Nov 15;10(11). doi: 10.1242/bio.058739. Epub 2021 Nov 19.
Identifying which environmental and genetic factors affect growth pattern phenotypes can help biologists predict how organisms distribute finite energy resources in response to varying environmental conditions and physiological states. This information may be useful for monitoring and managing populations of cryptic, endangered, and invasive species. Consequently, we assessed the effects of food availability, clutch, and sex on the growth of invasive Burmese pythons (Python bivittatus Kuhl) from the Greater Everglades Ecosystem in Florida, USA. Though little is known from the wild, Burmese pythons have been physiological model organisms for decades, with most experimental research sourcing individuals from the pet trade. Here, we used 60 hatchlings collected as eggs from the nests of two wild pythons, assigned them to High or Low feeding treatments, and monitored growth and meal consumption for 12 weeks, a period when pythons are thought to grow very rapidly. None of the 30 hatchlings that were offered food prior to their fourth week post-hatching consumed it, presumably because they were relying on internal yolk stores. Although only two clutches were used in the experiment, we found that nearly all phenotypic variation was explained by clutch rather than feeding treatment or sex. Hatchlings from clutch 1 (C1) grew faster and were longer, heavier, in better body condition, ate more frequently, and were bolder than hatchlings from clutch 2 (C2), regardless of food availability. On average, C1 and C2 hatchling snout-vent length (SVL) and weight grew 0.15 cm d-1 and 0.10 cm d-1, and 0.20 g d-1 and 0.03 g d-1, respectively. Additional research may be warranted to determine whether these effects remain with larger clutch sample sizes and to identify the underlying mechanisms and fitness implications of this variation to help inform risk assessments and management. This article has an associated First Person interview with the first author of the paper.
确定哪些环境和遗传因素会影响生长模式表型，可以帮助生物学家预测生物体如何根据不同的环境条件和生理状态分配有限的能量资源。这些信息对于监测和管理隐密、濒危和入侵物种的种群可能是有用的。因此，我们评估了食物供应、卵窝和性别的影响，以评估来自美国佛罗里达州大沼泽地生态系统的入侵缅甸蟒蛇（Python bivittatus Kuhl）的生长情况。尽管野外对缅甸蟒蛇知之甚少，但几十年来，缅甸蟒蛇一直是生理模式生物，大多数实验研究都从宠物贸易中获取个体。在这里，我们使用从两条野生蟒蛇的巢穴中收集的 60 个卵孵化的幼体，将它们分配到高或低喂养处理中，并监测了 12 周的生长和摄食情况，这是蟒蛇被认为生长非常迅速的时期。在孵化后的第四周之前提供食物的 30 只幼体中，没有一只幼体进食，大概是因为它们依赖于内部蛋黄储备。尽管实验只使用了两个卵窝，但我们发现几乎所有的表型变异都可以用卵窝来解释，而不是喂养处理或性别。来自卵窝 1（C1）的幼体生长更快，体型更大，体重更重，身体状况更好，进食更频繁，并且比来自卵窝 2（C2）的幼体更大胆，而不管食物供应情况如何。平均而言，C1 和 C2 幼体的吻肛长度（SVL）和体重分别以 0.15cm/d 和 0.10cm/d 以及 0.20g/d 和 0.03g/d 的速度增长。可能需要进一步的研究来确定这些影响是否会随着更大的卵窝样本大小而保持，并确定这种变异的潜在机制和对适应度的影响，以帮助为风险评估和管理提供信息。本文有一篇与论文第一作者的第一人称访谈。
