Fluoxetine (FLX) is among the top 100 pharmaceutical prescribed annually worldwide and consequently is often detected in wastewater treatment plant effluent and surface waters, in concentrations up to 2.7 and 0.33 μg/L, respectively. Despite the presence of FLX in surface waters, little is known about its chronic effects in fish. Thus, this study aimed at investigating the chronic toxicity of FLX to Danio rerio adults. Rate of weight gain, behavior (feeding and swimming activity) and tissue organization (liver and intestine) were evaluated, after 30 days exposure. A lower rate of weight gain was observed at 100 μg/L FLX. The food intake time decreased, showing a decrease in fish appetite. The preference for the upper aquarium layer was observed at 10 and 100 μg/L of FLX, indicating an inhibition of the stress level (anxiolytic effect). Mild to moderate damage of hepatic tissue and a decrease epithelium height and increase in villus height of intestine were observed in fish exposed to concentrations as low as 0.01 μg/L. Based on obtained results, chronic exposure of fish to FLX could affect swimming and feeding behavior and alter morphological structure of liver and intestine tissues at environmental levels.

氟西汀（FLX）是全球每年处方的前100名药物之一，因此经常在废水处理厂的废水和地表水中检出的浓度分别为2.7和0.33μg/ L。尽管地表水中存在FLX，但对其在鱼类中的慢性影响知之甚少。因此，本研究旨在调查FLX对Danio rerio的慢性毒性大人。暴露30天后，评估体重增加率，行为（进食和游泳活动）和组织组织（肝脏和肠）。在100μg/ L FLX下观察到较低的增重速率。食物摄取时间减少，表明鱼食欲降低。在10和100μg/ L的FLX下观察到了对上层水族箱的偏爱，表明对应力水平的抑制（抗焦虑作用）。在暴露于低至0.01μg/ L的鱼中，观察到轻度至中度的肝组织损伤以及上皮高度降低和肠绒毛高度增加。根据获得的结果，鱼类长期接触FLX可能会影响游泳和摄食行为，并在环境水平上改变肝脏和肠组织的形态结构。