The correct answer is 500, five hundred, 500 fishes, five hundred fishes. The chart is asking for the number of fish, and the statement "one fish = one hundred fishes" indicates that each fish represents 100 fishes. Therefore, if there are 500 fish in the chart, it means there are actually 500 x 100 = 50,000 fishes. The answer options provided all represent the same quantity of fish.