reported that increasing BUN is a likely indicator of failing gill osmoregulatory function and noted that increased BUN was correlated with fish that had compromised health or were terminally ill. Among the organs evaluated through histopathology (gill, skin, heart, liver, spleen, andkidney), only gill and kidney tissue demonstrated noticeable, albeitpredominantly mild damage, and furthermore no significant dif-ferences in the extent and severity of observed lesions were notedbetween treatments. The observation of mild gill lesions is inter-esting due to the association of gill dysfunction with increased BUN