Department of Ocean Sciences, Memorial University of Newfoundland and Labrador, St. John's, Newfoundland and Labrador, Canada.
J Fish Biol. 2024 Jun;104(6):1813-1823. doi: 10.1111/jfb.15716. Epub 2024 Mar 14.
Lumpfish (Cyclopterus lumpus) mortalities have been reported during the summer at some North Atlantic salmon cage-sites where they serve as "cleaner fish." To better understand this species' physiology and whether limitations in their metabolic capacity and thermal tolerance can explain this phenomenon, we compared the aerobic scope (AS) of 6°C-acclimated lumpfish (~50 g and 8.8 cm in length at the beginning of experiments) when all individuals (N = 12) were given a chase to exhaustion, a critical swim speed (U) test, and a critical thermal maximum (CT) test (rate of warming 2°C h). The U and CT of the lumpfish were 2.36 ± 0.08 body lengths per second and 20.6 ± 0.3°C. The AS of lumpfish was higher during the U test (206.4 ± 8.5 mg O kg h) versus that measured in either the CT test or after the chase to exhaustion (141.0 ± 15.0 and 124.7 ± 15.5 mg O kg h, respectively). Maximum metabolic rate (MMR), AS, and "realistic" AS (AS) measured using the three different protocols were not significantly correlated, indicating that measurements of metabolic capacity using one of these methods cannot be used to estimate values that would be obtained using another method. Additional findings include that (1) the lumpfish's metabolic capacity is comparable to that of Atlantic cod, suggesting that they are not as "sluggish" as previously suggested in the literature, and (2) their CT (20.6°C when acclimated to 6°C), in combination with their recently determined IT (20.6°C when acclimated to 10°C), indicates that high sea-cage temperatures are unlikely to be the primary cause of lumpfish mortalities at salmon sea-cages during the summer.
在一些北大西洋三文鱼网箱养殖区，毛鳞鱼（Cyclopterus lumpus）在夏季的死亡率有所上升，它们在这些养殖区中充当着“清洁鱼”的角色。为了更好地了解该物种的生理学特性，以及其代谢能力和热耐受极限是否可以解释这一现象，我们比较了 6°C 驯化的毛鳞鱼（实验开始时体长约 50 克，长 8.8 厘米）的有氧范围（AS），比较了所有个体（N=12）在追逐至力竭、临界游泳速度（U）测试和临界热极值（CT）测试（升温速率为 2°C h）中的表现。毛鳞鱼的 U 和 CT 值分别为 2.36±0.08 个体长/秒和 20.6±0.3°C。毛鳞鱼的 AS 在 U 测试中较高（206.4±8.5mg O kg·h），而在 CT 测试或追逐至力竭后测量的 AS 则较低（分别为 141.0±15.0 和 124.7±15.5mg O kg·h）。最大代谢率（MMR）、AS 和使用三种不同方案测量的“实际”AS（AS）之间没有显著相关性，这表明使用这些方法中的一种测量代谢能力，不能用于估计使用另一种方法得到的值。其他发现包括：1. 毛鳞鱼的代谢能力与大西洋鳕鱼相当，这表明它们并不像文献中之前所描述的那样“迟钝”；2. 它们的 CT（6°C 驯化时为 20.6°C），结合其最近确定的 IT（10°C 驯化时为 20.6°C），表明夏季在三文鱼网箱中，高海笼温度不太可能是毛鳞鱼死亡的主要原因。
