The koi in the pond at the foot of Bok Tower were some of the largest I'd ever seen. Note the man's foot at right. One looked like it was two feet long. I'm not surprised they are this big, what with the coin-operated feeder nearby. Put in a quarter and you get a handful of fish food to toss into the pond (see it falling in the photo). The koi must have good hearing because they would come from the far corners of the pond almost immediately upon initiation of the feeding.