Opercular display in male betta splendens can be used as a bioindicator of disulfoton pollution

Opercular display during agonistic encounters between male Betta splendens was previously proposed to be a suitable bioindicator of organophos-phate water pollution. The experiments reported here tested the effect of disulfoton, a notorious and widely banned organophosphate, on the males aggressive opercular expansion display. Male Bettas were placed in water that had disulfoton concentration of 5 mg/l for 24 hr. The males were then paired together in an aquarium for 10 min, and the rate and duration of opercular display was recorded. Experimental males had significantly lower opercular expansion compared to controls that were placed in nonpolluted water. The findings support that use of aggressive male Bettas display to be used as bioindicator of organophosphates' water pollution.