The plaque hanging next to this piece at the Met reads:
Peiter Bruegel the Elder depicted proverbs in paintings and prints; this is one of his earliest depictions. Out of the mouth of a large beached fish tumble many smallers ones. A man with a helmet and an enormous knife slices open the big fish’s belly, revealing even more creatures. In the foreground, a man in a boat points out the scene to his son. The inscription at the bottom puts his gesture into words: “Look son, I have long known that the big fish eat the small.” While the print is after Bruegel’s design, it bears in the lower left corner the name of Hieronymus Bosch (Bos on the print). The print’s publisher may have thought that Bosch, who had died in 1516, was still a more famous and more salable artist than Bruegel in 1557.
TOE goes places so you don’t have to.