This study determined the effectiveness of copper sulfate (CuSO₄) to inhibit fungal growth (caused by Saprolegnia spp.) on largemouth bass (LMB) eggs spawned on/in fiber mats in very high‐alkalinity/‐hardness waters; experiments also determined the toxicity of CuSO₄ to LMB fry and juveniles. An untreated control and three CuSO₄ concentrations (10, 20, and 40 mg/L) were tested under a flow‐through scenario in the effectiveness experiment. Eggs were treated daily until hatching began. Fungal load at the time of hatch had a total area > 3.0 cm² in the untreated controls, total area 1.0 to <2.0 cm² in the 10 and 20 mg/L CuSO₄ treatments, and total area > 1.0 cm² in the 40 mg/L CuSO₄ treatments. Fungus samples were identified as Saprolegnia australis. The 24‐hr median lethal concentration (LC50) values on the LMB yolk‐sac and swim‐up fry were 32.0 and 4.6 mg/L CuSO₄, respectively; the No Observed Effect Concentrations (NOEC) were 16.0 and 0.125 mg/L CuSO₄, respectively. Juvenile LMB were extremely tolerant to CuSO₄, and their 24‐hr LC50 value was 185.5 mg/L; the NOEC was 64 mg/L. This study indicates that CuSO₄ can be an important resource for hatcheries to control egg fungus, especially in high‐alkalinity/‐hardness waters.

中文翻译：

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硫酸铜对大嘴鲈鱼卵的真菌抑制作用及其对鱼苗和幼鱼的毒性

这项研究确定了硫酸铜（CuSO ₄）抑制高碱度/高硬度水中纤维垫上/中产生的大嘴鲈鱼（LMB）卵上真菌生长（由腐烂菌引起）的有效性；实验还确定了CuSO ₄对LMB鱼苗和幼鱼的毒性。在有效性实验中，在流通情况下测试了未经处理的对照和三种CuSO ₄浓度（10、20和40 mg / L）。每天对卵进行处理，直到开始孵化。孵化时的真菌载量在未经处理的对照中总面积> 3.0 cm ²，在10和20 mg / L CuSO ₄处理中总面积1.0至<2.0 cm ²，总面积> 1.0 cm²在40毫克/升的CuSO _4分的处理。真菌样品被鉴定为南非腐腐菌（Saprolegnia australis）。LMB卵黄囊和游泳鱼苗的24小时平均致死浓度（LC50）值分别为32.0和4.6 mg / L CuSO ₄。无观察到的浓度（NOEC）分别为16.0和0.125 mg / L CuSO ₄。少年LMB极耐CuSO ₄，其24小时LC50值为185.5 mg / L。NOEC为64 mg / L。这项研究表明，CuSO ₄可能是孵化场控制蛋真菌的重要资源，特别是在高碱度/硬度的水中。