Virginia Institute of Marine Science, William & Mary, Gloucester Point, Virginia, United States of America.
PLoS One. 2020 Dec 29;15(12):e0244392. doi: 10.1371/journal.pone.0244392. eCollection 2020.
The distribution and further range expansion of non-native blue catfish Ictalurus furcatus in coastal waters throughout the United States Atlantic slope depend, in part, on the salinity tolerance of the fish. However, temperature-mediated sublethal effects of increased salinities on blue catfish biology are not yet known. We assessed the effects of salinity and temperature on growth, body condition, body composition and food consumption of juvenile blue catfish in a controlled laboratory experiment. Temperature and salinity had an interactive effect on blue catfish biology, although most fish survived 112 days in salinities up to 10 psu. At salinities ≤7 psu, mean growth rate, body condition and consumption rates were higher at 22°C than at 12°C. Mean consumption rates declined significantly with increasing salinities, yet, salinities ≤7 psu were conducive to rapid growth and high body condition, with highest growth and body condition at 4 psu. Fish at 10 psu exhibited low consumption rates, slow growth, low body condition and lower proportions of lipids. Habitats with hyperosmotic salinities (>9 psu) likely will not support the full lifecycle of blue catfish, but the fish may use salinities up to 10 psu for foraging, dispersal and even growth. Many oligohaline and mesohaline habitats in U.S. Atlantic slope drainages may thus be vulnerable to establishment of invasive blue catfish, particularly given the increasing temperatures as a result of climate warming.
非本地蓝鲶 Ictalurus furcatus 在美国大西洋沿岸水域的分布和进一步的范围扩大，部分依赖于鱼类的耐盐性。然而，高盐度对蓝鲶生物学的温度介导的亚致死效应尚不清楚。我们在受控实验室实验中评估了盐度和温度对幼年蓝鲶生长、身体状况、身体成分和食物消耗的影响。盐度和温度对蓝鲶生物学有交互作用，尽管大多数鱼在盐度高达 10 的情况下存活了 112 天。在盐度≤7 时，22°C 下的平均生长率、身体状况和消耗率高于 12°C。尽管随着盐度的增加，平均消耗率显著下降，但盐度≤7 有利于快速生长和高身体状况，在 4 psu 时生长和身体状况最高。在 10 psu 的鱼类表现出低消耗率、缓慢生长、低身体状况和较低的脂质比例。高渗透压盐度（>9 psu）的栖息地可能无法支持蓝鲶的完整生命周期，但鱼类可能会利用高达 10 psu 的盐度进行觅食、扩散甚至生长。美国大西洋沿岸流域的许多寡盐水和中盐水生境因此可能容易受到入侵蓝鲶的建立，特别是由于气候变暖导致的温度升高。
