The purpose of this project was to modify and improve a previously developed billfish identification kit.  The sale and/or transport of most western Atlantic billfish in the United States is prohibited. However, billfish, including sailfish, are incidentally caught and landed in commercial fisheries. The best  way of evaluating billfish stocks is by random sampling of the longline fleet. The purpose of this field test kit is to identify sailish meat landed by the longline fishery. The kit employs a monoclonal antibody that binds specifically to an epitope or site on sailfish albumin found in the blood and tissues of sailfish. The kit is constructed so that a white polystyrene paddle is dipped into a macerated sample of sailfish tissue. After the addition of three additional reagents, a blue color develops on the surface of the paddle when sailfish tissue was sampled.