Effect of alcohol extract of a natural piscicide — Fruits of Zanthoxylum armatum DC. on Mg2+- and Na+, K+-ATPase activity in various tissues of a freshwater air-breathing fish, Heteropneustes fossilis

Effect of ethyl alcohol extract of fruits of a piscicidal plant, Zanthoxylum armatum DC., was evaluated on Mg2+- and Na+, K+-ATPase activity in different tissues of a carnivorous air-breathing catfish, Heteropneustes fossilis. Exposure of fish to various concentrations of extract, and at LC50 concentration for different time intervals revealed significant inhibition of enzyme activity in liver, brain and muscle tissues. Tissue specific inhibition was both dose and time dependent, and reversible. Activity of Mg2+-ATPase was inhibited more than that of Na+, K+-ATPase. In vitro studies on Mg2+-ATPase activity revealed that inhibition was more in tissue extract of brain than muscle and gill. Kinetic studies on Mg2+-ATPase activity suggested that piscicide is a non-competitive inhibitor. Noxious effect of extract was reversible. Hence, fruits of Z. armatum can advantageously be used as an effective piscicide in fish nursery management.