The modified Costello graphics represent feeding strategy based on plotting the relationship between the percentage of weight and frequency of occurrence of food items for Butis koilomatodon in two seasons; a: dry season, n=413; b: wet season, n=347) and at six sites; c: Duyen Hai, Tra Vinh, n=126; d: Cu Lao Dung, Soc Trang, n=55; e: Tran De, Soc Trang, n=75; f: Hoa Binh, Bac Lieu, n=174; g: Dong Hai, Bac Lieu, n=115; h: Dam Doi, Ca Mau, n=215).