Virginia Institute of Marine Science, William & Mary, 1370 Greate Rd, Gloucester Point, VA 23062, USA; Department of Biological Sciences, Western Illinois University, 1 University Circle, Macomb, IL 61455, USA.
Virginia Institute of Marine Science, William & Mary, 1370 Greate Rd, Gloucester Point, VA 23062, USA.
J Therm Biol. 2024 Aug;124:103951. doi: 10.1016/j.jtherbio.2024.103951. Epub 2024 Aug 15.
Blue catfish Ictalurus furcatus has been widely introduced throughout the United States to enhance recreational fisheries. Its success in both its native and non-native range, especially in the context of climate change, will be influenced by its thermal performance. We conducted a laboratory experiment to investigate the responses of wild-captured, subadult blue catfish to temperatures ranging from 7 °C to 38 °C. Blue catfish had relatively low standard metabolic rates, indicating low energetic demands, and hence an ability to survive well even during low-food conditions. Metabolic scope and food consumption rate increased with temperature, with metabolic scope peaking at 29.1 °C, and consumption rate peaking at 32 °C. Body condition remained high up to 32 °C, but decreased drastically thereafter, suggesting limitations in maintaining metabolism through food consumption at temperatures >32 °C; blue catfish cannot survive in such habitats indefinitely. Yet, many fish were able to survive temperatures as high as 38 °C for 5 days, suggesting that acute and occasionally chronic heat waves will not limit this species. Using these results, we also predicted the performance of blue catfish under prevailing conditions and under climate warming at seven locations throughout their current range in the U.S. We found that some blue catfish populations in southern and southeastern areas will likely experience temperatures above the optimal temperature for extended periods due to climate change, thus limiting potential habitat availability for this species. But, many non-native populations, especially those in northern areas such as Idaho, North Dakota, and northern California, may benefit from the expected warmer temperatures during spring and fall.
蓝鲶 Ictalurus furcatus 已被广泛引入美国各地，以增强娱乐性渔业。它在其原生和非原生范围内的成功，特别是在气候变化的背景下，将受到其热性能的影响。我们进行了一项实验室实验，以研究野生捕获的亚成体蓝鲶对 7°C 至 38°C 温度范围的反应。蓝鲶的标准代谢率相对较低，表明其能量需求较低，因此即使在食物匮乏的情况下也能很好地生存。代谢范围和食物消耗率随温度升高而增加，代谢范围在 29.1°C 时达到峰值，消耗率在 32°C 时达到峰值。身体状况在 32°C 时仍保持较高水平，但此后急剧下降，表明在温度高于 32°C 时，通过食物消耗来维持代谢存在限制；蓝鲶不能无限期地在这样的栖息地生存。然而，许多鱼能够在 38°C 的高温下存活 5 天，这表明急性和偶尔的热浪不会限制该物种。利用这些结果，我们还预测了蓝鲶在其当前分布范围内的七个地点的现行条件和气候变暖下的表现。我们发现，由于气候变化，南部和东南部的一些蓝鲶种群可能会经历长时间的温度高于最佳温度，从而限制了该物种的潜在栖息地可用性。但是，许多非本地种群，特别是爱达荷州、北达科他州和加利福尼亚州北部等北部地区的种群，可能会受益于春季和秋季预期的温暖气温。
