Chronic exposure to high biofloc total suspended solids (TSS) could affect growth, red blood cells, and generate gill alterations in fish. Red pacu, Piaractus brachypomus, fry (2.7 ± 0.5 g weight) were exposed to different biofloc TSS concentrations with low (T1: 200–300), and medium (T2: 400–600 mg/L) levels and compared to a treatment control (TC) without solids during a 45-day period in 50 L experimental units (in quadruplicate). Water quality, productive parameters, red blood cell values, and gill histopathological alteration index (HAI) were assessed. Red pacu reached higher final biomass (11.34 ± 0.73 kg/m³), better growth (DWG = 0.30 ± 0.03 g/day) and food conversion rate (1.05 ± 0.02) in TC than in biofloc treatments (p < .05). T2 had higher RBC count, and lower hemoglobin, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration (p < .05) than T1 and TC. The histological sections of TC gills showed monogenean parasites in low quantity; thus, the HAI value was similar among treatments and corresponded to low to medium gill damage. Growth, red blood cell values, and gill morphology of red pacu fingerlings were affected by moderate (400–600 mg/L) chronic exposure to TSS concentration in biofloc.

中文翻译：

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长期暴露于生物絮凝物中不同的总悬浮固体对红pacu (Piaractus brachypomus) 鱼种的生长、红细胞和鳃变化

长期接触高生物絮凝物总悬浮固体 (TSS) 会影响鱼的生长、红细胞并产生鳃改变。Red pacu、Piaractus brachypomus、鱼苗（2.7 ± 0.5 g 重量）暴露于低（T1：200-300）和中等（T2：400-600 mg/L）水平的不同生物絮团 TSS 浓度，并与处理对照进行比较(TC) 在 45 天期间在 50 L 实验单元中没有固体（一式四份）。评估了水质、生产参数、红细胞值和鳃组织病理学改变指数 (HAI)。与生物絮团处理相比，红 pacu 在 TC 中达到更高的最终生物量 (11.34 ± 0.73 kg/m ³ )、更好的生长 (DWG = 0.30 ± 0.03 g/天) 和食物转化率 (1.05 ± 0.02) ( p < .05)。与 T1 和 TC 相比，T2 的红细胞计数更高，而血红蛋白、平均红细胞血红蛋白和平均红细胞血红蛋白浓度更低 ( p  < .05)。TC鳃的组织切片显示少量的单基因寄生虫；因此，处理间的 HAI 值相似，对应于低到中等的鳃损伤。中度（400-600 mg/L）长期暴露于生物絮凝物中的 TSS 浓度会影响红pacu 鱼种的生长、红细胞值和鳃形态。