Effects of a prophylactic, intermittent, long-term formalin treatment on channel catfish, Ictalurus punctatus (Actinopterygii: Siluriformes: Ictaluridae) growth

Prophylactic chemical treatments are commonly used in fish farms to prevent and control infectious diseases, with formalin being one such chemical. The purpose of this study was to see how an eight-week trial of intermittent, prophylactic, low-dose (25 mg L-1), 1-h, and biweekly formalin baths affected channel catfish (Ictalurus punctatus) growth indices (mean weight, condition index, specific growth rate (SGR), feed conversion ratio, and feed consumption). Most growth indices were not statistically significant between the treated and control fish at the end of the trial, except for total SGR, where formalin-treated fish had a significantly higher SGR (P < 0.05) and steeper growth curve compared to control fish. In conclusion, intermittent and long-term use of formalin at low doses has no adverse effect on channel catfish growth.