Water temperature is an important abiotic factor that impacts physiological processes in fish. Attempts to quantify thermal tolerance of fishes exposed to various temperatures have been performed since the 1800s. A common approach to test the thermal tolerance of fishes is the critical thermal method. Traditionally this method has required access to large and expensive lab equipment. However, many individuals may not have direct access to such equipment, making critical thermal studies difficult-to-impossible to conduct. We present a simple and cost-friendly alternative device to use for critical thermal minima trials. This device uses a cooler with a copper line and copper coil to chill water within an aquarium. A pump and valves control the water flow as it passes from the aquarium through the copper. This allows the user to lower the water temperature in the aquarium from 28^oC to 0^oC at a steady rate of 0.23^oC min⁻¹. The device allows those with limited funding or without access to traditional lab equipment the ability to perform critical thermal minima trials, expanding our collective understanding of life histories of fish and their potential vulnerabilities to increasingly altered thermal environments.

中文翻译：

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一种替代的、低成本的冷却水用于临界热最小值试验的方法

水温是影响鱼类生理过程的重要非生物因素。自 1800 年代以来，已经尝试量化暴露于各种温度的鱼类的耐热性。测试鱼类耐热性的常用方法是临界热法。传统上，这种方法需要使用大型且昂贵的实验室设备。然而，许多人可能无法直接使用此类设备，因此很难进行关键的热研究。我们提出了一种简单且成本友好的替代设备，用于临界热最小值试验。该设备使用带有铜线和铜线圈的冷却器来冷却水族箱内的水。当水从水族箱流过铜时，泵和阀门控制水流。^o C 到 0 ^o C 以 0.23 ^o C min ^-1的稳定速率。该设备使资金有限或无法使用传统实验室设备的人能够进行关键的最低热试验，扩大我们对鱼类生活史及其对日益变化的热环境的潜在脆弱性的集体理解。