The present study was performed to examine the effects of aquatic fern (Azolla caroliniana) (AQF) on growth performance, skin mucus and serum immunities, and disease resistance of Nile tilapia reared in a biofloc system. Three hundred Nile tilapia fingerlings (average 10.48 ± 0.56 g fish-1) were distributed into 15 glass tanks (150 liters tank⁻¹) at a concentration of 20 fish tank⁻¹. A completely randomized design was used in triplicates, where the control group was fed 0 g kg⁻¹ AQF (AQF1), while AQF2, AQF3, AQF4, and AQF5 were fed 25, 50, 100, and 200 g kg⁻¹ AQF, respectively. Growth and immunological specimens were collected every 4 weeks, while disease resistance was conducted after 8 weeks post-feeding. The results showed that dietary administration of AQF significantly promoted the growth rate and feed efficiency of Nile tilapia, with the maximum level noticed in fish fed 100 g kg⁻¹ AQF. However, no significant differences were observed between the AQF1 and AQF5 diets. Similarly, incorporation of AQF resulted in significantly higher skin mucus and serum immunities than the control, except for AQF5. The highest values were observed in fish fed the AQF5 diet. The challenge test showed that in contrast to the control (26.67%), the AQF administrated diets led to significantly higher survivability by 60% (AQF2), 66.67% (AQF3), 83.33% (AQF4), and 53.33 for AQF5. The relative percent survival (RPS) was 45.45%, 54.55%, 77.27%, and 36.36% in AQF2, AQF3, AQF4, and AQF5, respectively. The highest RPS against S. agalactiae was noted in the AQF4 diet. In conclusion, dietary supplementation of 100 g kg⁻¹ AQF can be potentially used as a growth promoter and immunostimulant in Nile tilapia aquaculture.

本研究旨在检查水生蕨类植物 ( Azolla caroliniana ) (AQF) 对在生物絮团系统中饲养的尼罗罗非鱼的生长性能、皮肤粘液和血清免疫以及抗病性的影响。^{将 300 条尼罗罗非鱼鱼种（平均 10.48 ± 0.56 g fish-1）以 20 个鱼缸-1}的浓度分布到 15 个玻璃缸（150 升缸^-1 ）中。一式三份使用完全随机设计，其中对照组饲喂 0 g kg ^-1 AQF (AQF1)，而 AQF2、AQF3、AQF4 和 AQF5 饲喂 25、50、100 和 200 g kg ^-1AQF，分别。每 4 周收集一次生长和免疫学样本，而在喂食后 8 周后进行抗病性检测。结果表明，日粮施用AQF显着促进尼罗罗非鱼的生长速度和饲料效率，在喂食100 g kg ^{-1的鱼中达到最高水平}AQF。然而，在 AQF1 和 AQF5 饮食之间没有观察到显着差异。类似地，AQF 的加入导致皮肤粘液和血清免疫显着高于对照，除了 AQF5。在喂食 AQF5 饮食的鱼中观察到最高值。挑战测试表明，与对照组 (26.67%) 相比，AQF 管理的饮食导致 AQF5 的存活率显着提高 60% (AQF2)、66.67% (AQF3)、83.33% (AQF4) 和 53.33。AQF2、AQF3、AQF4 和 AQF5 的相对生存百分比 (RPS) 分别为 45.45%、54.55%、77.27% 和 36.36%。在 AQF4 饮食中注意到针对无乳链球菌的最高 RPS 。总之，膳食补充 100 g kg ^-1AQF 可潜在地用作尼罗罗非鱼水产养殖中的生长促进剂和免疫刺激剂。