In some turtle species, temperature selection may be influenced by environmental conditions, including acclimation temperature and substrate quality. These factors may be particularly important for softshell turtles that are highly aquatic and often thermoregulate by burying in the substrate in shallow water microhabitats. We tested for effects of acclimation temperature (22 °C or 27 °C) and substrate type (sand or gravel) on the selected temperature and movement patterns of 20 juvenile spiny softhshell turtles (Apalone spinifera; Reptilia: Trionychidae) in an aquatic thermal gradient of 14-34 °C. Among 7-11 month old juvenile softshell turtles, acclimation temperature and substrate type did not influence temperature selection, nor alter activity and movement patterns. During thermal gradient tests, both 22- and 27 °C-acclimated turtles selected the warmest temperature (34 °C) available most frequently, regardless of substrate type (sand or gravel). Similarly, acclimation temperature and substrate type did not influence movement patterns of turtles, nor the number of chambers used in the gradient tests. These results suggest that juvenile Apalone spinifera are capable of detecting small temperature increments and prefer warm temperatures that may positively influence growth and metabolism, and that thermal factors more significantly influence aquatic thermoregulation in this species than does substrate type.

中文翻译：

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驯化温度和基质类型对水生热梯度中多刺软壳龟（Apalone spinifera）幼鱼选择温度、运动和活动的影响

在一些龟类中，温度选择可能会受到环境条件的影响，包括驯化温度和基质质量。这些因素对于高度水生的软壳龟可能特别重要，并且通常通过埋在浅水微栖息地的基质中来调节体温。我们测试了适应温度（22°C 或 27°C）和基质类型（沙子或砾石）对 20 只幼年多刺软壳龟（Apalone spinifera；爬行动物：Trionychidae）在水生热梯度中的选定温度和运动模式的影响14-34°C。在 7-11 个月大的幼龟中，适应温度和基质类型不影响温度选择，也不改变活动和运动模式。在热梯度测试期间，无论基质类型（沙子或砾石）如何，适应 22°C 和 27°C 的海龟都选择最常可用的最热温度（34°C）。同样，驯化温度和基质类型不影响海龟的运动模式，也不影响梯度测试中使用的房间数量。这些结果表明，幼年的 Apalone spinifera 能够检测到小的温度增量，并且更喜欢可能对生长和代谢产生积极影响的温暖温度，并且热因素比底物类型更显着影响该物种的水生体温调节。也不是梯度测试中使用的腔室数量。这些结果表明，幼年的 Apalone spinifera 能够检测到小的温度增量，并且更喜欢可能对生长和代谢产生积极影响的温暖温度，并且热因素比底物类型更显着影响该物种的水生体温调节。也不是梯度测试中使用的腔室数量。这些结果表明，幼年的 Apalone spinifera 能够检测到小的温度增量，并且更喜欢可能对生长和代谢产生积极影响的温暖温度，并且热因素比底物类型更显着影响该物种的水生体温调节。