Determination of acute toxicity of unionized ammonia in juvenile longfin yellowtail ( <i>Seriola rivoliana</i> )

Abstract The median lethal concentration (LC 50 ) of unionized ammonia (NH 3 ‐N) in longfin yellowtail, Seriola rivoliana juveniles was assessed after 96 h exposure using a semistatic water system. Experimental fish were exposed triplicate to different concentrations: 0.55 ± 0.00; 0.94 0.02; 1.18 1.72 0.02, and 1.97 0.09 NH ‐N mg/L. Additionally, control group (0.00 0.00 mg/L) included. LC S. 0.58 Fish concentrations for displayed several lesions on gill tissues, that is, hyperplasia, epithelial lifting, fusion the secondary lamellae, some irreversible damage. Erratic behavior, such as swimming circles hyperventilation observed before died. safe this study estimated at 0.06 1.68 mg/L total nitrogen (TAN). outcomes provide valuable insights into effects better quality management semi‐intensive intensive systems culture.