It is possible that in a particular population, the number of large individuals only makes up about ten to twenty percent of the total group, with the rest being mostly medium-sized, young fish and fry.
The second point is that, whether in the wild or in man-made water bodies where large fish are introduced, once they have stayed there for a long time, they will occupy their own territory, which is their feeding ground! The more a fish has been hooked before, the smarter it becomes, and the more cautious it is when feeding!
Once large fish become familiar with their surroundings, they will exhibit certain feeding time patterns; for example, they look for food between three or four in the morning until eight or nine, and again from before sunset until eight or nine in the evening. At other times, they will retreat to the depths of their territory!